430 results on '"Equivalence principle (geometric)"'
Search Results
2. Breakdown of the equivalence between gravitational mass and energy due to quantum effects
- Author
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Andrei G. Lebed
- Subjects
Physics ,0303 health sciences ,010308 nuclear & particles physics ,General relativity ,Mass–energy equivalence ,Semiclassical physics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Equivalence principle (geometric) ,General Relativity and Quantum Cosmology (gr-qc) ,01 natural sciences ,General Relativity and Quantum Cosmology ,Gravitation ,03 medical and health sciences ,Space and Planetary Science ,Quantum mechanics ,0103 physical sciences ,Quantum gravity ,Equivalence (measure theory) ,Mathematical Physics ,Energy (signal processing) ,030304 developmental biology - Abstract
We review our recent theoretical results about inequivalence between passive and active gravitational masses and energy in semiclassical variant of general relativity, where gravitational field is not quantized but matter is quantized. To this end, we consider the simplest quantum body with internal degrees of freedom - a hydrogen atom. We concentrate our attention on the following physical effects, related to electron mass. The first one is inequivalence between passive gravitational mass and energy at microscopic level. Indeed, quantum measurement of gravitational mass can give result, which is different from the expected, $m \neq m_e + \frac{E_1}{c^2}$, where electron is initially in its ground state; $m_e$ is the bare electron mass. The second effect is that the expectation values of both passive and active gravitational masses of stationary quantum states are equivalent to the expectation value of energy. The most spectacular effects are inequivalence of passive and active gravitational masses and energy at macroscopic level for ensemble of coherent superpositions of stationary quantum states. We show that, for such superpositions, the expectation values of passive and active gravitational masses are not related to the expectation value of energy by the famous Einstein's equation, $m \neq \frac{E}{c^2}$. In this review, we also improve several drawbacks of the original pioneering works., Based on talk presented at the Fifteenth Marcel Grossmann Meeting on General Relativity, Rome, July 2018. arXiv admin note: substantial text overlap with arXiv:1711.00116, arXiv:1903.03173
- Published
- 2022
3. A Study on the Measurement of Inertial Mass Using Secondary Science Experiment
- Author
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Se-Hun Kim
- Subjects
Physics ,Classical mechanics ,General Physics and Astronomy ,Equivalence principle (geometric) ,Inertial mass ,Simple harmonic motion - Published
- 2021
4. Toward an Envelope of Design Solutions for Combined/Intensified Reaction/Separation Systems
- Author
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Efstratios N. Pistikopoulos and Yuhe Tian
- Subjects
Work (thermodynamics) ,Materials science ,Continuous flow ,General Chemical Engineering ,Separation (aeronautics) ,Continuous stirred-tank reactor ,Equivalence principle (geometric) ,General Chemistry ,Mechanics ,Industrial and Manufacturing Engineering ,Envelope (waves) - Abstract
In this work, we develop an envelope of design solutions for combined intensified reaction/separation systems. The attainable region-based continuous flow stirred tank reactor equivalence principle...
- Published
- 2020
5. On the Prediction of High-Temperature Creep Processes in Metals
- Author
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G. Z. Sharafutdinov
- Subjects
Creep ,Mechanics of Materials ,Mechanical Engineering ,Diagram ,Analogy ,Equivalence principle (geometric) ,Statistical physics ,Type (model theory) ,Reduction (mathematics) ,Mathematics - Abstract
Some issues related to the development of methods for forecasting creep processes are considered. For this purpose, the temporal equivalence principle, the temperature-time analogy, the stress-time analogy, other analogies, and the modern relations between stresses and strains of the heriditary type in the form that allows describing irreversible plastic deformations are used. The expressions for multiple reduction coefficients are obtained using the time equivalence principle. A brief description is given to implementation of the method of analogies. An example of application of the concept of reduced time directly to the creep diagram is provided.
- Published
- 2020
6. Generalized Hypersonic Equivalence Principle
- Author
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Zhi-Hui Wang
- Subjects
020301 aerospace & aeronautics ,Hypersonic speed ,Angle of attack ,Mathematical analysis ,Aerospace Engineering ,Equivalence principle (geometric) ,02 engineering and technology ,01 natural sciences ,010305 fluids & plasmas ,Physics::Fluid Dynamics ,0203 mechanical engineering ,Computer Science::Systems and Control ,Inviscid flow ,Physics::Space Physics ,0103 physical sciences ,Forced convection heat transfer ,Direct simulation Monte Carlo ,Physics::Chemical Physics ,Mathematics - Abstract
The concept of the generalized hypersonic equivalence principle for viscous flows is proposed in this paper. The traditional hypersonic equivalence principle applies only to the inviscid flows and ...
- Published
- 2020
7. Study of Allowable Interlaminar Normal Stress Based on the Time–Temperature Equivalence Principle in Automated Fiber Placement Process
- Author
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Jun Xiao, Rui Xiao, and Jiaqi Shi
- Subjects
tackiness ,Molecular diffusion ,Materials science ,Polymers and Plastics ,business.industry ,Delamination ,Process (computing) ,Organic chemistry ,Equivalence principle (geometric) ,General Chemistry ,Structural engineering ,composite material ,Viscoelasticity ,Article ,Stress (mechanics) ,Reptation ,stress ,QD241-441 ,automated fiber placement ,strength ,business ,Equivalence (measure theory) - Abstract
Automatic fiber placement (AFP) is a type of labor-saving automatic technology for forming composite materials that are widely used in aviation and other fields. In this process, concave surface delamination is a common defect, as existing research on the conditions for this defect to occur is insufficient. To predict the occurrence of this defect, the concept of allowable interlaminar normal stress is proposed to define its occurrence conditions, and based on this concept, probe tests are carried out using the principle of time–temperature equivalence. Through the laying speed/allowable normal stress curve measured in the probe experiment, the physical meaning of allowable normal stress is discussed. At the same time, the measured curve is quantitatively analyzed, combined with viscoelastic theory and the molecular diffusion reptation model, and the dominating effect in the formation of a metal/prepreg layer and prepreg/prepreg layer is determined. Finally, the experimental data are used to guide the parameter selection in an automatic placement engineering case and prove its correctness.
- Published
- 2021
- Full Text
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8. On Restricting the Impact of Self-Attacking Arguments in Gradual Semantics
- Author
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Vivien Beuselinck, Srdjan Vesic, Jérôme Delobelle, Université Fédérale Toulouse Midi-Pyrénées, Laboratoire d'Informatique Paris Descartes (LIPADE (URP_2517)), Université de Paris (UP), Centre de Recherche en Informatique de Lens (CRIL), and Université d'Artois (UA)-Centre National de la Recherche Scientifique (CNRS)
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Class (set theory) ,Self-attack ,Iterative method ,Semantics (computer science) ,Computer science ,010102 general mathematics ,Equivalence principle (geometric) ,02 engineering and technology ,Extension (predicate logic) ,16. Peace & justice ,01 natural sciences ,Argumentation theory ,[INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI] ,Subject (grammar) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,0101 mathematics ,Mathematical economics ,Abstract argumentation ,Gradual semantics - Abstract
International audience; The issue of how a semantics should deal with self-attacking arguments was always a subject of debate amongst argumentation scholars. A consensus exists for extension-based semantics because those arguments are always rejected (as soon as the semantics in question respect conflict-freeness). In case of gradual semantics, the question is more complex, since other criteria are taken into account. A way to check the impact of these arguments is to use the principles (i.e. desirable properties to be satisfied by a semantics) from the literature. Principles like Self-Contradiction and Strong Self-Contradiction prescribe how to deal with self-attacking arguments. We show that they are incompatible with the well-known Equivalence principle (which is satisfied by almost all the existing gradual semantics), as well as with some other principles (e.g. Counting). This incompatibility was not studied until now and the class of semantics satisfying Self-Contradiction is under-explored. In the present paper, we explore that class of semantics. We show links and incompatibilities between several principles. We define a semantics that satisfies (Strong) Self-Contradiction and a maximal number of compatible principles. We introduce an iterative algorithm to calculate our semantics and prove that it always converges. We also provide a characterisation of our semantics. Finally, we experimentally show that our semantics is computationally efficient.
- Published
- 2021
9. Development of Relative Humidity–Frequency Equivalence Principle for the Dielectric Properties of Asphalt Mixtures
- Author
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Li Ruan, Xiaohe Yu, Tingting Huang, Rong Luo, and Wang Jinteng
- Subjects
Materials science ,Moisture ,0211 other engineering and technologies ,Relative permittivity ,020101 civil engineering ,Equivalence principle (geometric) ,02 engineering and technology ,Building and Construction ,Dielectric ,0201 civil engineering ,Mechanics of Materials ,Asphalt ,021105 building & construction ,General Materials Science ,Relative humidity ,Development (differential geometry) ,Composite material ,Civil and Structural Engineering - Abstract
Asphalt pavement contains dynamically changing moisture, and the movement of this moisture will change the relative humidity of the pavement, thereby affecting the dielectric properties of ...
- Published
- 2021
10. IceCube constraints on Violation of Equivalence Principle
- Author
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Damiano Francesco Giuseppe Fiorillo
- Subjects
Theoretical physics ,Equivalence principle (geometric) ,Mathematics - Published
- 2021
11. Fast Analysis of Scattering from Chaff Clouds by EPA-BoR Method
- Author
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Beibei Zhang, Rushan Chen, Yamei Li, and Zi He
- Subjects
Physics ,Wavelength ,Chaff ,Electromagnetics ,Coupling effect ,Scattering ,Decomposition (computer science) ,Computational electromagnetics ,Equivalence principle (geometric) ,Computational physics - Abstract
In this paper, a domain decomposition algorithm based on equivalence principle for multiple bodies of multiple bodies of revolutions (EPA-BoR) is used to analyze the scattering characteristics of chaff clouds. It can be tested that the coupling effect of any two chaffs can be ignored when their distance is equal or greater than two wavelengths. Therefore, both memory and calculation time can be significantly reduced. Numerical results can prove the effectiveness of the proposed method.
- Published
- 2021
12. Advances of Equivalent Modeling Theory and Method in the Analysis and Design of Electromagnetic Metamaterials
- Author
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Chang Liu, Xi Zhu, and Huapeng Zhao
- Subjects
Model theory ,Theoretical physics ,Computer science ,Electromagnetic spectrum ,Physics::Optics ,Metamaterial ,Extraction methods ,Equivalence principle (geometric) ,Physics::Classical Physics ,Design methods - Abstract
Electromagnetic metamaterials (EMM) are a new kind of artificial synthetic material, and they have attracted extensive attention from academia and industry because of their special electromagnetic properties that natural substances do not possess. This paper reviews recent advances of equivalent modeling theory and method in the analysis and design of electromagnetic metamaterials. First, equivalent parameters extraction methods of electromagnetic metamaterials based on effective medium theory is briefly summarized. Second, material parameter synthesis using equivalence principle is introduced. Finally, the design method of electromagnetic metamaterials based on wave spectrum expansion theory is proposed.
- Published
- 2021
13. Isomorphisms and elementary equivalence of Chevalley groups over commutative rings
- Author
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E. I. Bunina
- Subjects
Pure mathematics ,Algebra and Number Theory ,Lie group ,Elementary equivalence ,Equivalence principle (geometric) ,Commutative ring ,Algebra over a field ,Symmetry group ,Mathematics - Abstract
It is proved that two Chevalley groups with indecomposable root systems of rank 1$?> over commutative rings (which contain in addition for the types , , , , and , and for the type ) are isomorphic or elementarily equivalent if and only if the corresponding root systems coincide, the weight lattices of the representation of the Lie algebra coincide, and the rings are isomorphic or elementarily equivalent, respectively. The isomorphisms of adjoint (elementary) Chevalley groups over the rings of the above types are also described. Bibliography: 25 titles.
- Published
- 2019
14. A New Fracability Evaluation Approach for Shale Reservoirs Based on Multivariate Analysis: A Case Study in Zhaotong Shale Gas Demonstration Zone in Sichuan, China
- Author
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Zhonghui Li, Yishan Lou, Shanyong Liu, Lin Li, and Yuan Yuan
- Subjects
Multivariate analysis ,Petroleum engineering ,Shale gas ,Geology ,Equivalence principle (geometric) ,China ,Oil shale - Published
- 2019
15. Electromagnetic scattering analysis of normal chiral, metamaterials chiral and chiral nihility materials
- Author
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Zhenkai Zhang, Zucun Zhang, Xiaoqiao Deng, Jiang Cao, and Yubo Tian
- Subjects
Physics ,Radiation ,Scattering ,High Energy Physics::Lattice ,High Energy Physics::Phenomenology ,020208 electrical & electronic engineering ,Plane wave ,Metamaterial ,020206 networking & telecommunications ,Equivalence principle (geometric) ,02 engineering and technology ,Physics::Classical Physics ,Electronic, Optical and Magnetic Materials ,Quantum mechanics ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering - Abstract
Scattering of electromagnetic plane waves from normal chiral materials, chiral metamaterials, chiral nihility materials are presented. Based on the volume equivalence principle, the integral equati...
- Published
- 2019
16. Ultimate bounds on reaction selectivity for batch reactors
- Author
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Jeffrey A. Frumkin and Michael F. Doherty
- Subjects
Process (engineering) ,Applied Mathematics ,General Chemical Engineering ,Chaotic ,Continuous stirred-tank reactor ,Process design ,Equivalence principle (geometric) ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,020401 chemical engineering ,Biochemical engineering ,Limit (mathematics) ,0204 chemical engineering ,0210 nano-technology ,Selectivity ,Design methods - Abstract
Targets and benchmarks are useful in chemical process design as they provide an objective, quantitative assessment of a proposed process flowsheet. In addition, with target bounds on reaction selectivity one can also explore the sustainability limits for a chemistry of interest. Unfortunately, targets for reaction selectivity are difficult to obtain using conventional design methods. In 2001, Feinberg and Ellison developed the Continuous Flow Stirred Tank Reactor (CFSTR) Equivalence Principle, providing a methodology to obtain ultimate bounds on steady-state productivity for a chemistry of interest entirely independent of process design. In previous articles, we showed how the CFSTR Equivalence Principle can be used to obtain bounds on reaction selectivity independent of process design for steady-state processes. In this article we prove that the CFSTR Equivalence Principle is also applicable to batch and semi-batch processes, thus providing a unifying framework to obtain an ultimate target for reaction selectivity applicable to all candidate processes for a chemistry of interest. This limit also applies to systems with periodic and chaotic operations. We demonstrate the method with an example for the production of lactic acid through the alkaline conversion of fructose.
- Published
- 2019
17. Analysis of Multilayer Structure Near- and Far-Field Radiation by the Coupled PP-PEEC and Field-Equivalence Principle Method
- Author
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Yong-Sheng Li, Wen-Yuan Cao, Er-Ping Li, Hongxing Zheng, Mengjun Wang, Zhiyi Gao, Yan Li, and Panpan Zuo
- Subjects
Physics ,Partial element equivalent circuit ,Field (physics) ,020206 networking & telecommunications ,Equivalence principle (geometric) ,Near and far field ,02 engineering and technology ,Radiation ,Condensed Matter Physics ,Topology ,Decoupling capacitor ,Capacitance ,Atomic and Molecular Physics, and Optics ,Electromagnetic interference ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering - Abstract
In this paper, the plane-pair partial element equivalent circuit method coupled with the field equivalence principle is developed and applied to calculate the radiated fields of multilayer power planes. The proposed method can be used to solve near-field and far-field radiation problems for multilayer parallel-plane structures with decoupling capacitors. The proposed method is validated by full-wave simulation and experiment. In addition, the proposed method achieves ten times higher computational efficiency than the full-wave simulation.
- Published
- 2019
18. On the s-injectivity of the x-ray transform on manifolds with hyperbolic trapped set
- Author
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Thibault Lefeuvre
- Subjects
Mathematics - Differential Geometry ,Surface (mathematics) ,Pure mathematics ,37D20, 37D40, 35R30 ,General Physics and Astronomy ,Boundary (topology) ,Dynamical Systems (math.DS) ,Riemannian geometry ,01 natural sciences ,symbols.namesake ,Mathematics - Analysis of PDEs ,FOS: Mathematics ,Mathematics - Dynamical Systems ,0101 mathematics ,Mathematical Physics ,Mathematics ,X-ray transform ,Solenoidal vector field ,Applied Mathematics ,010102 general mathematics ,Conjugate points ,Statistical and Nonlinear Physics ,Equivalence principle (geometric) ,010101 applied mathematics ,Differential Geometry (math.DG) ,symbols ,Physics::Accelerator Physics ,Convex function ,Analysis of PDEs (math.AP) - Abstract
For smooth compact connected manifolds with strictly convex boundary, no conjugate points and a hyperbolic trapped set, we prove an equivalence principle concerning the injectivity of the X-ray transform $I_m$ on symmetric solenoidal tensors and the surjectivity of an operator ${\pi_m}_*$ on the set of solenoidal tensors. This allows us to establish the injectivity of the X-ray transform on solenoidal tensors of any order in the case of a surface satisfying these assumptions., Comment: 24 pages, 2 figures. Theorem 1.2 improved thanks to a referee's suggestion: the condition "I^e_m is s-injective" is relaxed to "I_m is s-injective"
- Published
- 2019
19. Adaptive control for attitude coordination of leader-following rigid spacecraft systems with inertia parameter uncertainties
- Author
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Xiaokui Yue, Jianping Yuan, Xianghong Xue, and Haowei Wen
- Subjects
0209 industrial biotechnology ,Adaptive control ,Spacecraft ,Observer (quantum physics) ,business.industry ,Estimation theory ,Computer science ,Mechanical Engineering ,media_common.quotation_subject ,Aerospace Engineering ,TL1-4050 ,Angular velocity ,Equivalence principle (geometric) ,02 engineering and technology ,Inertia ,01 natural sciences ,010305 fluids & plasmas ,020901 industrial engineering & automation ,Control theory ,0103 physical sciences ,business ,Equivalence (measure theory) ,Motor vehicles. Aeronautics. Astronautics ,media_common - Abstract
This paper studies the leader-following attitude coordination problems of multiple spacecraft in the presence of inertia parameter uncertainties. To achieve attitude coordination in the situation that even the leader’s attitude is only applicable to a part of the following spacecraft, a non-linear attitude observer is proposed to obtain an accurate estimation of the leader’s attitude and angular velocity for all the followers. In addition, a distributed control scheme based on non-certainty equivalence principle is presented for multiple spacecraft’ attitude synchronization. With a dynamic scaling, attitude consensus can be achieved asymptotically without any information of the bounds of the uncertain inertia parameters. Furthermore, once the estimations of inertia parameters reach their ideal values, the estimation process will stop and the ideal value of inertia parameter will be held. This is a special advantage of parameter estimation method based on non-certainty equivalence. Numerical simulations are presented to demonstrate that the proposed non-certainty equivalence-based method requires smaller control toque and converges faster compared with the certainty equivalence-based method. Keywords: Adaptive control, Attitude coordination, Leader-following consensus, Non-certainty equivalence, Spacecraft formation flying
- Published
- 2019
20. Ultimate Reaction Selectivity Limits for Intensified Reactor–Separators
- Author
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Michael F. Doherty, Lorenz Fleitmann, and Jeffrey A. Frumkin
- Subjects
Optimization problem ,General Chemical Engineering ,Continuous stirred-tank reactor ,Context (language use) ,Process design ,Equivalence principle (geometric) ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Industrial and Manufacturing Engineering ,Separation process ,Nonlinear system ,020401 chemical engineering ,Applied mathematics ,0204 chemical engineering ,0210 nano-technology ,Global optimization - Abstract
The Continuous Flow Stirred Tank Reactor (CFSTR) Equivalence Principle, developed by Feinberg and Ellison, proves that any and every reaction/mixing/separation process is equivalent to a process comprising at most R+1 CFSTRs and a perfect mixer–separator, where R is the number of linearly independent chemical reactions. Frumkin and Doherty showed that the CFSTR Equivalence Principle can be used together with global optimization to find the maximum selectivity of a chemistry independent of process design. These selectivity targets are useful in the context of process intensification because they represent ultimate selectivity improvements that can be achieved by combining multiple unit operations into a single device. In this work, the model is reformulated as a mixed-integer nonlinear program to solve this nonlinear and nonconvex optimization problem. We implement a more robust, deterministic global optimization using a spatial branch-and-bound algorithm (BARON) to investigate the selectivity limits for p...
- Published
- 2018
21. New test on the Einstein equivalence principle through the photon ring of black holes
- Author
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Yi-Fu Cai, Chunlong Li, HongSheng Zhao, and University of St Andrews. School of Physics and Astronomy
- Subjects
High Energy Physics - Theory ,Photon ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Quantum-electrodynamic corrections ,Physics and Astronomy (miscellaneous) ,Gravity ,T-NDAS ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,General Relativity and Quantum Cosmology ,symbols.namesake ,Theoretical physics ,NCAD ,QB Astronomy ,Einstein ,QC ,QB ,Physics ,MCC ,Ring (mathematics) ,Equivalence principle (geometric) ,Test (assessment) ,QC Physics ,High Energy Physics - Theory (hep-th) ,symbols ,Constant ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Einstein equivalence principle (EEP), as one of the foundations of general relativity, is a fundamental test of gravity theories. In this paper, we propose a new method to test the EEP of electromagnetic interactions through observations of black hole photon rings, which naturally extends the scale of Newtonian and post-Newtoian gravity where the EEP violation through a variable fine structure constant has been well constrained to that of stronger gravity. We start from a general form of Lagrangian that violates EEP, where a specific EEP violation model could be regarded as one of the cases of this Lagrangian. Within the geometrical optical approximation, we find that the dispersion relation of photons is modified: for photons moving in circular orbit, the dispersion relation simplifies, and behaves such that photons with different linear polarizations perceive different gravitational potentials. This makes the size of black hole photon ring depend on polarization. Further assuming that the EEP violation is small, we derive an approximate analytic expression for spherical black holes showing that the change in size of the photon ring is proportional to the violation parameters. We also discuss several cases of this analytic expression for specific models. Finally, we explore the effects of black hole rotation and derive a modified proportionality relation between the change in size of photon ring and the violation parameters. The numerical and analytic results show that the influence of black hole rotation on the constraints of EEP violation is relatively weak for small magnitude of EEP violation and small rotation speed of black holes., 16 pages, 6 figures
- Published
- 2021
22. Missing information in the Universe as a dark matter candidate based on the mass-energy-information equivalence principle
- Author
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E. Džaferović-Mašić
- Subjects
Physics ,History ,Mass energy ,Theoretical physics ,Dark Matter ,Information ,Equivalence Principle ,Dark matter ,Equivalence principle (geometric) ,Computer Science Applications ,Education - Abstract
There are several theoretical models proposing dark matter candidates as well as different experimental searches for dark matter, collider, and non-collider ones. One of the most intriguing dark matter candidates is missing information in the cosmos. This is based on the mass-energy-information equivalence principle presented by M Vopson [1]. This review presents the historical development of this principle from its roots in the 1960s when Landauer principle was firstly presented to the latest data on the estimated value of the mass of one bit of information as well as data on missing energy as potential dark matter. Another theoretical discussion presented here is the reformulation of the second law of thermodynamics as a possible step to great unification. In addition to this theoretical postulation with a mathematical presentation focusing on statistics, we present some of the proposed experiments in this field. Two major proposals are in the direction of using an ultra-accurate balance with measurement uncertainty low enough to be comparable with proposed theoretical limits, and originally developed sensitive interferometer similar to the one in LIGO experiment.
- Published
- 2021
23. LOCATION, ORBIT AND ENERGY OF A METEOROID IMPACTING THE MOON DURING THE LUNAR ECLIPSE OF JANUARY 21, 2019 & TESTING THE WEAK EQUIVALENCE PRINCIPLE WITH COSMOLOGICAL GAMMA RAY BURSTS
- Author
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Matipon Tangmatitham
- Subjects
Physics ,Orbit ,Meteoroid ,General relativity ,Lunar eclipse ,Astronomy ,Equivalence principle (geometric) ,Parallax ,Gamma-ray burst ,Cosmology - Published
- 2020
24. Investigation of the Surface Equivalence Principle on a Metal Surface for a Near-Field to Far-Field Transformation by the NFS3000
- Author
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Sven Lange, Dominik Schroder, Ulrich Hilleringmann, Thomas Otto, Christian Hedayat, and Christian Hangmann
- Subjects
Physics ,Transformation (function) ,Acoustics ,Electromagnetic compatibility ,Device under test ,Near and far field ,Equivalence principle (geometric) ,Near-field scanner ,Magnetic field ,Radiation pattern - Abstract
In this publication, the near-field to far-field transformation using the self-built near-field scanner NFS3000 is examined with regard to its geometry. This device allows to measure electric and magnetic fields in small distances to the DUT (Device under Test) with high geometric precision and high sensitivity. Leading to a fast examination of EMC (Electromagnetic Compatibility) problems, because the electromagnetic properties are better understandable and therefore easier to solve than e.g. measurements in a far-field chamber. In addition, it is possible to extrapolate the near-fields into the far-field and to determine the radiation pattern of antennas and emitting objects. For this purpose, this paper deals with the basis of this transformation, the so-called surface equivalence theorem. This principle is then adapted to the measurement of near-field scanners and implemented accordingly. Due to the non-ideal design of the near-field scanner, the effects on a far-field transformation are finally presented and discussed.
- Published
- 2020
25. A Generalized Transition Matrix Model for Dielectric Coated PEC Cavities
- Author
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Rui Liu, Shifeng Huang, Yuyang Hu, and Gaobiao Xiao
- Subjects
Materials science ,Current (mathematics) ,Discontinuous Galerkin method ,Scattering ,Mathematical analysis ,Reference surface ,Stochastic matrix ,Equivalence principle (geometric) ,Dielectric ,Method of moments (statistics) - Abstract
In this paper, we apply the generalized transition matrix (GTM) method to analyze the scattering characteristics of dielectric coated cavities. Discontinuous Galerkin (DG) method is applied to ensure the weak continuity of normal current at the transitional junctions. An artificial reference surface is placed to separate the target cavity into interior region and exterior region. According to equivalence principle, the electromagnetic information of the inner dielectric materials can be extracted onto the reference surface. In this case, the computational burden can be effectively simplified. Numerical examples present the accuracy and feasibility of the proposed method.
- Published
- 2020
26. Herpin Equivalence Principle
- Author
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Andrew Sarangan
- Subjects
Pure mathematics ,Equivalence principle (geometric) ,Mathematics - Published
- 2020
27. A Higher Structure Identity Principle
- Author
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Dimitris Tsementzis, Benedikt Ahrens, Michael Shulman, and Paige Randall North
- Subjects
FOS: Computer and information sciences ,Computer Science - Logic in Computer Science ,Class (set theory) ,Pure mathematics ,010102 general mathematics ,Structure (category theory) ,Mathematics - Category Theory ,Equivalence principle (geometric) ,Mathematics - Logic ,0102 computer and information sciences ,16. Peace & justice ,01 natural sciences ,Logic in Computer Science (cs.LO) ,Type theory ,010201 computation theory & mathematics ,FOS: Mathematics ,Homotopy type theory ,Category Theory (math.CT) ,Isomorphism ,0101 mathematics ,Invariant (mathematics) ,Logic (math.LO) ,Univalent foundations ,Mathematics - Abstract
The ordinary Structure Identity Principle states that any property of set-level structures (e.g., posets, groups, rings, fields) definable in Univalent Foundations is invariant under isomorphism: more specifically, identifications of structures coincide with isomorphisms. We prove a version of this principle for a wide range of higher-categorical structures, adapting FOLDS-signatures to specify a general class of structures, and using two-level type theory to treat all categorical dimensions uniformly. As in the previously known case of 1-categories (which is an instance of our theory), the structures themselves must satisfy a local univalence principle, stating that identifications coincide with "isomorphisms" between elements of the structure. Our main technical achievement is a definition of such isomorphisms, which we call "indiscernibilities", using only the dependency structure rather than any notion of composition., Comment: Long version of publication in LICS 2020 (DOI: 10.1145/3373718.3394755); v2: added sections "Axioms and Theories" and "Version History", other minor changes; v3: added examples
- Published
- 2020
28. Resource Exploitation in a Stochastic Horizon under Two Parametric Interpretations
- Author
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José Daniel López-Barrientos, Ekaterina Gromova, and Ekaterina Sergeevna Miroshnichenko
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Logarithm ,Computer science ,General Mathematics ,chen distribution ,0211 other engineering and technologies ,differential games ,02 engineering and technology ,Notation ,random time horizon ,020901 industrial engineering & automation ,Computer Science (miscellaneous) ,Engineering (miscellaneous) ,weibull distribution ,Parametric statistics ,time until failure ,021103 operations research ,Conjecture ,lcsh:Mathematics ,Stochastic game ,Equivalence principle (geometric) ,discounted equilibrium ,lcsh:QA1-939 ,Dynamic programming ,equivalence principle ,Terminal (electronics) - Abstract
This work presents a two-player extraction game where the random terminal times follow (different) heavy-tailed distributions which are not necessarily compactly supported. Besides, we delve into the implications of working with logarithmic utility/terminal payoff functions. To this end, we use standard actuarial results and notation, and state a connection between the so-called actuarial equivalence principle, and the feedback controllers found by means of the Dynamic Programming technique. Our conclusions include a conjecture on the form of the optimal premia for insuring the extraction tasks, and a comparison for the intensities of the extraction for each player under different phases of the lifetimes of their respective machineries.
- Published
- 2020
29. Breakdown of the Einstein's Equivalence Principle for a quantum body
- Author
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Andrei G. Lebed
- Subjects
Physics ,Nuclear and High Energy Physics ,Quantum field theory in curved spacetime ,FOS: Physical sciences ,General Physics and Astronomy ,Mass–energy equivalence ,Astronomy and Astrophysics ,Equivalence principle (geometric) ,General Relativity and Quantum Cosmology (gr-qc) ,General Relativity and Quantum Cosmology ,Gravitation ,Theoretical physics ,symbols.namesake ,symbols ,Quantum gravity ,Einstein ,Quantum ,Energy (signal processing) - Abstract
We review our recent theoretical results about inequivalence between passive gravitational mass and energy for a composite quantum body at a macroscopic level. In particular, we consider macroscopic ensembles of the simplest composite quantum bodies - hydrogen atoms. Our results are as follows. For the most ensembles, the Einstein's Equivalence Principle is valid. On the other hand, we discuss that for some special quantum ensembles - ensembles of the coherent superpositions of the stationary quantum states in the hydrogen atoms (which we call Gravitational demons) - the Equivalence Principle between passive gravitational mass and energy is broken. We show that, for such superpositions, the expectation values of passive gravitational masses are not related to the expectation values of energies by the famous Einstein's equation, i.e, $m_g \neq \frac{E}{c^2}$. Possible experiments at the Earth's laboratories are briefly discussed, in contrast to the numerous attempts and projects to discover the possible breakdown of the Einstein's Equivalence Principle during the space missions., Brief review
- Published
- 2020
30. On the origin of the weak equivalence principle in a theory of emergent quantum mechanics
- Author
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Ricardo Gallego Torromé
- Subjects
Physics ,High Energy Physics - Theory ,Quantum Physics ,Physics and Astronomy (miscellaneous) ,010308 nuclear & particles physics ,Concentration of measure ,FOS: Physical sciences ,Equivalence principle (geometric) ,General Relativity and Quantum Cosmology (gr-qc) ,Mathematical Physics (math-ph) ,01 natural sciences ,Weak equivalence ,General Relativity and Quantum Cosmology ,High Energy Physics - Theory (hep-th) ,Quantum mechanics ,0103 physical sciences ,Quantum Physics (quant-ph) ,010306 general physics ,Mathematical Physics - Abstract
We argue that in a framework for emergent quantum mechanics, the weak equivalence principle is a consequence of concentration of measure in large dimensional spaces of $1$-Lipshitz functions. Furthermore, as a consequence of the emergent framework and the properties that we assume for the fundamental dynamics, it is argued that gravity must be a classical, emergent interaction., 25 pages; no figures. Accepted for publication in International Journal of Geometric Methods in Modern Physics. arXiv admin note: substantial text overlap with arXiv:1402.5070
- Published
- 2020
31. Quantum Weak Equivalence Principle and the Gravitational Casimir Effect in Superconductors
- Author
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Richard A. Norte, Mir Faizal, James Q. Quach, and Sebastian Bahamonde
- Subjects
FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,01 natural sciences ,Weak equivalence ,General Relativity and Quantum Cosmology ,High Energy Physics - Experiment ,Gravitation ,Superconductivity (cond-mat.supr-con) ,symbols.namesake ,Theoretical physics ,High Energy Physics - Experiment (hep-ex) ,0103 physical sciences ,010306 general physics ,Fisher information ,Quantum ,Mathematical Physics ,Physics ,Superconductivity ,Quantum Physics ,010308 nuclear & particles physics ,Gravitational wave ,Condensed Matter - Superconductivity ,Astronomy and Astrophysics ,Equivalence principle (geometric) ,Casimir effect ,Space and Planetary Science ,symbols ,Quantum Physics (quant-ph) - Abstract
We will use Fisher information to properly analyze the quantum weak equivalence principle. We argue that gravitational waves will be partially reflected by superconductors. This will occur as the violation of the weak equivalence principle in Cooper pairs is larger than the surrounding ionic lattice. Such reflections of virtual gravitational waves by superconductors can produce a gravitational Casimir effect, which may be detected using currently available technology., Essay received an honorable mention in the Gravity Research Foundation Essay Competition 2020. 9 pages, 3 figures. Matches published version in IJMPD
- Published
- 2020
32. Construction and classification of point-group symmetry-protected topological phases in two-dimensional interacting fermionic systems
- Author
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Yang Qi, Zheng-Cheng Gu, Shuo Yang, Qing-Rui Wang, and Jian-Hao Zhang
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Superconductivity ,High Energy Physics::Lattice ,Equivalence principle (geometric) ,Astrophysics::Cosmology and Extragalactic Astrophysics ,02 engineering and technology ,Fermion ,Construct (python library) ,021001 nanoscience & nanotechnology ,Topology ,01 natural sciences ,Scheme (mathematics) ,0103 physical sciences ,Molecular symmetry ,010306 general physics ,0210 nano-technology ,Realization (systems) - Abstract
The construction and classification of symmetry-protected topological (SPT) phases in interacting bosonic and fermionic systems have been intensively studied in the past few years. Very recently, a complete classification and construction of space-group SPT phases were also proposed for interacting bosonic systems. In this Rapid Communication, we attempt to generalize this classification and construction scheme systematically into interacting fermion systems. In particular, we construct and classify point-group SPT phases for two-dimensional (2D) interacting fermion systems via lower-dimensional block-state decorations. We discover several intriguing fermionic SPT states that can only be realized in interacting fermion systems (i.e., not in free-fermion or bosonic SPT systems). Moreover, we also verify the recently conjectured crystalline equivalence principle for 2D interacting fermion systems. Finally, the potential experimental realization of these different classes of point-group SPT phases in 2D correlated superconductors is addressed.
- Published
- 2020
33. Efficient Self-Rotation Perception
- Author
-
Andrew Duggins
- Subjects
Lorentz transformation ,media_common.quotation_subject ,Equivalence principle (geometric) ,Time perception ,Special relativity (alternative formulations) ,symbols.namesake ,Classical mechanics ,biophysics ,Perception ,symbols ,Efficient coding hypothesis ,Vestibulo–ocular reflex ,Rotation (mathematics) ,Mathematics ,media_common - Abstract
An event occurring within a stationary environment, in the direction toward which an observer self-rotates, is perceived to precede a simultaneous event, in the direction away from which she moves. When self-rotation results from angular acceleration in the dark, perception of space is also distorted, such that the subjective straight-ahead shifts in the opposite direction to motion and temporal event promotion. A reference frameshift theory, based on the special theory of relativity, is proposed to explain these findings. Here, a hyperbolic tangent transformation of objective angular velocity constrains subjective self-rotation velocity within finite bounds, consistent with it being a limited perceptual resource. Identifying this subjective variable with vestibular nystagmus slow-phase angular velocity, the asymptotic perceived self-rotation velocity is estimated at ~200 °⁄s. When included in the Lorentz transformations of the new formalism, this value predicts experimental simultaneity distortion. Hypothetically, the hyperbolic tangent objective-to-subjective transfer function would maximize the differential entropy of the percept, and thereby also the stimulus/percept mutual information, if angular velocities of body rotation encountered in naturalistic environmental interaction have a logistic probability density distribution of scale 100 °⁄s, a proposed experimental test of the scheme.
- Published
- 2020
34. Reliability-Equivalent Field Reference Usage and Stress Level When Both are Random for Product with Weibull Life Distribution
- Author
-
Fengbin Sun
- Subjects
021103 operations research ,Distribution (number theory) ,0211 other engineering and technologies ,Equivalence principle (geometric) ,02 engineering and technology ,01 natural sciences ,Shape parameter ,Field (computer science) ,Stress level ,010104 statistics & probability ,Product (mathematics) ,Applied mathematics ,0101 mathematics ,Reliability (statistics) ,Mathematics ,Weibull distribution - Abstract
This paper derives, based on reliability equivalence principle, the analytic expression of the equivalent singlevalued usage and stress level when the underlying life distribution is Weibull with a known shape parameter (slope). Numerical example is provided to illustrate the advantage of the method for reliability life test design over the traditional practice, especially for a high-reliability product.
- Published
- 2020
35. Generalized potential for apparent forces: The Coriolis effect
- Author
-
Ettore Laserra, Ivana Bochicchio, Elmo Benedetto, Fabiano Feleppa, and Christian Corda
- Subjects
Physics ,Physics::General Physics ,generalized potential ,05 social sciences ,050301 education ,General Physics and Astronomy ,FOS: Physical sciences ,accelerated observers ,Equivalence principle (geometric) ,01 natural sciences ,Frame of reference ,Motion (physics) ,equivalence principle ,Physics - General Physics ,Classical mechanics ,General Physics (physics.gen-ph) ,0103 physical sciences ,010306 general physics ,0503 education - Abstract
It is well known, from Newtonian physics, that apparent forces appear when the motion of masses is described by using a non-inertial frame of reference. The generalized potential of such forces is rigorously analyzed focusing on their mathematical aspects., Comment: 8 pages, accepted for publication in Eur. J. Phys
- Published
- 2020
36. Relativistic generalization of the Schrodinger-Newton model for the wavefunction reduction
- Author
-
Nina V. Markova and Vladimir V. Kassandrov
- Subjects
High Energy Physics - Theory ,Nuclear and High Energy Physics ,Generalization ,FOS: Physical sciences ,General Relativity and Quantum Cosmology (gr-qc) ,Pattern Formation and Solitons (nlin.PS) ,01 natural sciences ,General Relativity and Quantum Cosmology ,Reduction (complexity) ,symbols.namesake ,Measurement theory ,0103 physical sciences ,010306 general physics ,Wave function ,Mathematical physics ,Physics ,Quantum Physics ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Equivalence principle (geometric) ,Nonlinear Sciences - Pattern Formation and Solitons ,Atomic and Molecular Physics, and Optics ,High Energy Physics - Theory (hep-th) ,symbols ,Poisson's equation ,Quantum Physics (quant-ph) ,Schrödinger's cat - Abstract
We consider the model of the self-gravity driven spontaneous wavefunction reduction proposed by L. Diosi, R. Penrose et al. and based on a self-consistent system of the Schrodinger and Poisson equations. An analogous system of coupled Dirac and Maxwell-like equations is proposed as a relativization. Regular solutions to the latter form a discrete spectrum in which all the "active" gravitational masses are always positive, and approximately equal to inertial masses and to the mass $m$ of the quanta of Dirac field up to the corrections of order $\alpha^2$. Here $\alpha=(m/M_{pl})^2$ is the gravitational analogue of the fine structure constant negligibly small for nucleons. In the limit $\alpha \to 0$ the model reduces back to the nonrelativistic Schrodinger-Newton one. The equivalence principle is fulfilled with an extremely high precision. The above solutions correspond to various states of the same (free) particle rather than to different particles. These states possess a negligibly small difference in characteristics but essentially differ in the widths of the wavefunctions. For the ground state the latter is $\alpha$ times larger the Compton length, so that a nucleon cannot be sufficiently localized to model the reduction process, Comment: 5 pages. Talk presented at the 10-th Friedmann Seminar (Saint-Petersburg, Russia, 2019)
- Published
- 2020
- Full Text
- View/download PDF
37. Higher Order Method of Moments Analysis of Metallic Waveguides Loaded With Composite Metallic and Dielectric Structures
- Author
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Xunwang Zhao, Yu Zhang, Hongwei Liu, and Zhongchao Lin
- Subjects
Physics ,Discretization ,020208 electrical & electronic engineering ,Mathematical analysis ,020206 networking & telecommunications ,Basis function ,Equivalence principle (geometric) ,02 engineering and technology ,Method of moments (statistics) ,Eigenfunction ,Integral equation ,law.invention ,law ,0202 electrical engineering, electronic engineering, information engineering ,Boundary value problem ,Electrical and Electronic Engineering ,Waveguide - Abstract
A set of coupled integral equations is presented based on Love’s and Schelkunoff’s field equivalence principles. According to Love’s equivalence principle and the boundary conditions, a general form of the Poggio–Miller–Chang–Harrington–Wu formulation is applied for modeling the waveguide cavities containing composite structures. The structures are discretized using the higher order polynomial basis functions, whose orders are adaptively adjusted for accurately modeling current distributions in this kind of strong near-field coupling and resonance problems. Moreover, the integral equations for the apertures involving the waveguide ports, each of which is terminated by a semi-infinite waveguide, are established according to Schelkunoff’s equivalence principle and the boundary conditions. Because the free-space Green’s function as well as the spatial discretization-based basis functions cannot be applied to semi-infinite waveguides, we employ waveguide eigenfunctions as the basis functions for the outer surface of an aperture. These coupled integral equations are then solved numerically using the method of moments accelerated by the parallel computing techniques. Comparisons with two well-developed software products demonstrate the accuracy and efficiency of the proposed method.
- Published
- 2018
38. Mean field stochastic linear quadratic games for continuum-parameterized multi-agent systems
- Author
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Zhipeng Li, Huanshui Zhang, Minyue Fu, and Zongze Wu
- Subjects
0209 industrial biotechnology ,Series (mathematics) ,Computer Networks and Communications ,Continuum (topology) ,Applied Mathematics ,010102 general mathematics ,Parameterized complexity ,Equivalence principle (geometric) ,02 engineering and technology ,State (functional analysis) ,01 natural sciences ,Decentralised system ,Multiplicative noise ,020901 industrial engineering & automation ,Mean field theory ,Control and Systems Engineering ,Signal Processing ,Applied mathematics ,0101 mathematics ,Mathematics - Abstract
In this paper, we consider a stochastic linear quadratic mean field game for the continuum-parameterized multi-agent systems with multiplicative noise. Based on the Nash certain equivalence principle, we obtain a series of decentralized control laws. Then, Dynkin’s formula and comparison principle are employed to prove the boundedness of the state of the closed loop system in the mean square sense. Finally, we show that the set of decentralized controls has an ϵ-Nash equilibrium property.
- Published
- 2018
39. Experimental Research on Dynamic Stability of Asphalt Mixture Based on Time-Temperature Equivalence Principle
- Author
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Fei Chen, Sheng Jun Yu, and Jiang Li
- Subjects
Road engineering ,Materials science ,Mechanical Engineering ,Stability (learning theory) ,Equivalence principle (geometric) ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Experimental research ,0104 chemical sciences ,Mechanics of Materials ,Asphalt ,Applied mathematics ,General Materials Science ,0210 nano-technology - Abstract
Asphalt mixture is a kind of a viscoelastic material with viscoelastic characteristic of time-temperature equivalence. This paper, from the engineering practical consideration, and the perspective of time-temperature equivalence principle, based on the Rutting Test of Asphalt Mixture,has obtained equivalence relations of the effect of wheel speed and temperature on asphalt mixture rut index by different wheel speed and different temperatures rutting test, so as to provide the data support for the research of anti-rutting mechanism of asphalt pavement.
- Published
- 2018
40. OMSI (Optically Masked Size Increase): Einstein’s Fourth 1907 Miracle, Exposed
- Author
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Rossler Oe and Kuske F
- Subjects
Physics ,symbols.namesake ,Miracle ,media_common.quotation_subject ,symbols ,Equivalence principle (geometric) ,General Medicine ,Einstein ,Size increase ,Hawking radiation ,Mathematical physics ,media_common ,Gravitational redshift - Abstract
The Einstein equivalence principle of 1907 applies to the interior of a constantly accelerating long Rocketship in free outer space...
- Published
- 2019
41. The Limits of Physical Equivalence in Algebraic Quantum Field Theory
- Author
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Tracy Lupher
- Subjects
History ,Function field of an algebraic variety ,Thermal quantum field theory ,05 social sciences ,Equivalence principle (geometric) ,06 humanities and the arts ,0603 philosophy, ethics and religion ,Relationship between string theory and quantum field theory ,050105 experimental psychology ,Philosophy ,Theoretical physics ,History and Philosophy of Science ,Quantum mechanics ,060302 philosophy ,Real algebraic geometry ,Quantum gravity ,Beta function (physics) ,0501 psychology and cognitive sciences ,Quantum field theory ,Mathematics - Abstract
Some physicists and philosophers argue that unitarily inequivalent representations (UIRs) in quantum field theory (QFT) are mathematical surplus structure. Support for that view, sometimes ...
- Published
- 2018
42. Los principios de la relatividad: una introducci´on pedag´ogica
- Author
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Y. Bonder and Elias Okon
- Subjects
Theoretical physics ,Theory of relativity ,General relativity ,General Physics and Astronomy ,Quantum gravity ,Equivalence principle (geometric) ,Special relativity (alternative formulations) ,Education ,Mathematics - Abstract
The principles underlying the theory of relativity, special and general, are presented. An easy to follow and pedagogical language is used and, based on physical examples, the motivation and some consequences of such principles are discussed. In addition, some roles of these principles when looking for a quantum gravity theory are mentioned
- Published
- 2018
43. MoM analysis of cavity‐backed annular conical antennas
- Author
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Vanine Sabino and Odilon M. C. Pereira-Filho
- Subjects
Physics ,Commercial software ,Acoustics ,05 social sciences ,050301 education ,020206 networking & telecommunications ,Equivalence principle (geometric) ,02 engineering and technology ,Conical surface ,Input impedance ,Method of moments (statistics) ,Radiation ,0202 electrical engineering, electronic engineering, information engineering ,Physics::Accelerator Physics ,Electrical and Electronic Engineering ,Coaxial ,Galerkin method ,0503 education - Abstract
This study presents theoretical formulation and results for cavity-backed annular conical antennas. The formulation is based on equivalence principle and method of moments (MoM), in both point-matching and Galerkin forms. Results are presented for radiation diagram, and input impedance, and compared to those obtained using commercial software. The effects of dielectric thickness and of cavity dimensions on input impedance are presented. In addition, the feeding using two coaxial cables for radiation maximum at cone axis is also presented.
- Published
- 2018
44. Properties of Elementary Embeddability in Model Theory
- Author
-
M. I. Bekenov
- Subjects
Statistics and Probability ,Model theory ,Pure mathematics ,Class (set theory) ,Mathematical model ,Applied Mathematics ,General Mathematics ,Mathematics::General Topology ,Equivalence principle (geometric) ,Elementary equivalence ,First order ,Mathematics::Logic ,Countable set ,Isomorphism ,Mathematics - Abstract
In the class of models of some theory in a countable first order language, we consider relationships between isomorphism, elementary embeddability, and elementary equivalence.
- Published
- 2018
45. Application of Tone’s and embedded self-shielding methods to pressurized water reactor assemblies
- Author
-
Alain Hébert
- Subjects
Materials science ,020209 energy ,Nuclear engineering ,Pressurized water reactor ,Equivalence principle (geometric) ,02 engineering and technology ,Self shielding ,Dilution ,law.invention ,Tone (musical instrument) ,Nuclear Energy and Engineering ,Homogeneous ,law ,0202 electrical engineering, electronic engineering, information engineering ,Energy (signal processing) - Abstract
The Tone’s and embedded self shielding methods are based on a heterogeneous-homogeneous equivalence principle. They both provide a formula for an equivalent dilution parameter that can be used to interpolate pretabulated effective cross sections for the infinite homogeneous medium. These two methods have been traditionally applied to fast reactor analysis with fine or ultrafine group energy mesh. We are investigating the accuracy of these two methods for the generation of self-shielded cross sections for typical pressurized water reactor assemblies.
- Published
- 2018
46. Volume integral equation equivalence principle algorithm domain decomposition with body of revolution equivalence surface
- Author
-
Rushan Chen, Mengmeng Li, and Tao Zhuang
- Subjects
Surface (mathematics) ,Numerical analysis ,Mathematical analysis ,020206 networking & telecommunications ,Domain decomposition methods ,Equivalence principle (geometric) ,Basis function ,02 engineering and technology ,Matrix equivalence ,01 natural sciences ,Integral equation ,010101 applied mathematics ,0202 electrical engineering, electronic engineering, information engineering ,0101 mathematics ,Electrical and Electronic Engineering ,Algorithm ,Equivalence (measure theory) ,Mathematics - Abstract
A novel equivalence principle algorithm (EPA) domain decomposition method previously for the surface integral equation is explored for volume integral equation in this work. The whole object is decomposed into several subdomains, the equivalence spheres are automatically produced to enclose each subdomain. The Rao–Wilton–Glisson (RWG) and body of revolution (BoR) basis functions are defined on the equivalence sphere surface. The equivalence currents defined on the RWG basis functions are evaluated with multilevel fast multipole algorithm, and then the currents defined on the RWGs can be projected onto the BoR basis functions. Compared with surface integral equation EPA-BoR algorithm, the ratio of the number of average original unknowns in each subdomain with respect to the equivalence unknowns is relatively larger, which leads to significant reduction of computations. Numerical simulations validate the accuracy and efficiency of the proposed method.
- Published
- 2018
47. Application of the radiation equivalence principle to estimation of levels of radiological protection of the population: risk-oriented approach
- Author
-
P.V. Kashcheeva, М.А. Maksioutov, K.A. Tumanov, A.N. Menyajlo, A.V. Lopatkin, V.K. Ivanov, S.Yu. Chekin, E.O. Adamov, and S.S. Lovachev
- Subjects
Estimation ,Nuclear and High Energy Physics ,Mathematical optimization ,Radiation ,Computer science ,Radiological weapon ,Public Health, Environmental and Occupational Health ,Radiology, Nuclear Medicine and imaging ,Equivalence principle (geometric) ,Population Risk - Published
- 2018
48. Surface equivalence principle and Surface Integral Equation (SIE) revisited for bioelectromagnetics application
- Author
-
Dragan Poljak and Mario Cvetković
- Subjects
Surface (mathematics) ,Physics ,Computational Mathematics ,Applied Mathematics ,Modeling and Simulation ,Mathematical analysis ,Computational Mechanics ,Surface integral equation ,Computational electromagnetics ,Equivalence principle (geometric) ,Equivalence principle ,Human exposure to electromagnetic fields ,Bioelectromagnetics ,Computer Science Applications - Abstract
The paper revisits the use of a surface equivalence theorem in deriving the surface integral equation (SIE) based formulation for a homogeneous bio- electromagnetics problem. The vector analog of Green’s 2nd identity is used to obtain the expression for the electric field representing the mathematical foundation of the equivalence theorem. The particular emphasis is put on the treatment of boundary integral when the observation and source points, respectively, coincide. The boundary conditions at infinity are taken into account via the Sommerfeld radiation conditions. The derived coupled SIE set can be used in problems involving biological body exposed to electro- magnetic field radiation.
- Published
- 2018
49. Unified elastoplastic model based on a strain energy equivalence principle
- Author
-
Li-xun Cai and Hui Chen
- Subjects
Strain (chemistry) ,business.industry ,Applied Mathematics ,Mathematical analysis ,Equivalence principle (geometric) ,02 engineering and technology ,Unified Model ,Structural engineering ,021001 nanoscience & nanotechnology ,Finite element method ,Strain energy ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Modeling and Simulation ,von Mises yield criterion ,0210 nano-technology ,business ,Displacement (fluid) ,Energy (signal processing) ,Mathematics - Abstract
A unified elastoplastic model was proposed to describe the relation among load, displacement, and uniaxial constitutive parameters of ductile materials according to the von Mises energy equivalence principle at a special location or energy center in the deformed region of a structural component (SC). Two pairs of parameters were considered in the model: one was related to the volume of deformed region and the other to the Mises equivalent strain at the energy center. In addition, they are easily determined by finite element analysis (FEA). For eight kinds of SCs under proportional loading, the load–displacement behaviors of various materials predicted by the unified model were highly consistent with the results of FEA.
- Published
- 2017
50. Improved Timoshenko beam-based micropolar peridynamic method incorporating particle geometry
- Author
-
Li Guo, Xiaofeng Yan, and Wanjin Li
- Subjects
Timoshenko beam theory ,Physics ,Mechanical Engineering ,Stiffness ,Equivalence principle (geometric) ,Fracture mechanics ,Mechanics ,Finite element method ,Physics::Geophysics ,Shear (sheet metal) ,Brittleness ,Mechanics of Materials ,medicine ,General Materials Science ,medicine.symptom ,Numerical stability - Abstract
Shear effect is a crucial factor in determining crack propagation of mode II and mixed-mode fractures for brittle and quasi-brittle materials. Based on Timoshenko beam theory, shear effect is introduced into micropolar peridynamic model. The peridynamic parameters for two-dimensional and three-dimensional cases are derived with energy equivalence principle. Particle geometry is originally considered in the derived formulations to obtain independent rotational stiffness. An implicit algorithm in finite element framework is adopted to calculate elastic deformation and to simulate quasi-static crack propagation. Several numerical examples are conducted to verify the accuracy and efficiency of the developed model. The results show that the proposed model possesses high accuracy and numerical stability in simulating crack propagation of mode I, mode II and mixed-mode fractures.
- Published
- 2021
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