3,197 results
Search Results
2. Correction to the paper: An energy dissipative spatial discretization for the regularized compressible Navier-Stokes-Cahn-Hilliard system of equations (in Math. Model. Anal., 25(1): 110-129, https://doi.org/10.3846/mma.2020.10577).
- Author
-
Balashov, Vladislav and Zlotnik, Alexander
- Subjects
- *
MATHEMATICS , *EQUATIONS , *EQUILIBRIUM , *EVIDENCE - Abstract
We correct the proof of Theorem 2 in the mentioned paper concerning finite-difference equilibrium solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
3. Quantum mechanical version of the paper by E. Schroedinger Ueber die umkehrung der naturgesetze
- Author
-
Bergmann, O
- Published
- 1988
- Full Text
- View/download PDF
4. A note on Nasr's and Wong's papers
- Author
-
Sun, Yuan Gong
- Subjects
- *
OSCILLATIONS , *DIFFERENTIAL equations , *EQUATIONS , *MATHEMATICS - Abstract
In the case of oscillatory potentials, we give sufficient conditions for the oscillation of the forced nonlinear second order differential equations with delayed argument in the form x″(t)+q(t)
γsgnx(τ(t))=f(t) in the linear (x(τ(t)) γ=1) and the superlinear (γ>1) cases. [Copyright &y& Elsevier]- Published
- 2003
- Full Text
- View/download PDF
5. Theory of Classical Fluids and the Convolution Approximation (Note on Papers by Tohru Morita)
- Author
-
Meeron, E
- Published
- 1960
- Full Text
- View/download PDF
6. Polynomial stability of transmission system for coupled Kirchhoff plates.
- Author
-
Wang, Dingkun, Hao, Jianghao, and Zhang, Yajing
- Subjects
POLYNOMIALS ,ELASTICITY ,EXPONENTS ,MATHEMATICS ,EQUATIONS - Abstract
In this paper, we study the asymptotic behavior of transmission system for coupled Kirchhoff plates, where one equation is conserved and the other has dissipative property, and the dissipation mechanism is given by fractional damping (- Δ) 2 θ v t with θ ∈ [ 1 2 , 1 ] . By using the semigroup method and the multiplier technique, we obtain the exact polynomial decay rates, and find that the polynomial decay rate of the system is determined by the inertia/elasticity ratios and the fractional damping order. Specifically, when the inertia/elasticity ratios are not equal and θ ∈ [ 1 2 , 3 4 ] , the polynomial decay rate of the system is t - 1 / (10 - 4 θ) . When the inertia/elasticity ratios are not equal and θ ∈ [ 3 4 , 1 ] , the polynomial decay rate of the system is t - 1 / (4 + 4 θ) . When the inertia/elasticity ratios are equal, the polynomial decay rate of the system is t - 1 / (4 + 4 θ) . Furthermore it has been proven that the obtained decay rates are all optimal. The obtained results extend the results of Oquendo and Suárez (Z Angew Math Phys 70(3):88, 2019) for the case of fractional damping exponent 2 θ from [0, 1] to [1, 2]. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Some sixth-order variants of Ostrowski root-finding methods
- Author
-
Chun, Changbum and Ham, YoonMee
- Subjects
- *
PAPER , *EQUATIONS , *ALGEBRA , *MATHEMATICS - Abstract
Abstract: In this paper, we present some sixth-order class of modified Ostrowski’s methods for solving nonlinear equations. Per iteration each class member requires three function and one first derivative evaluations, and is shown to be at least sixth-order convergent. Several numerical examples are given to illustrate the performance of some of the presented methods. [Copyright &y& Elsevier]
- Published
- 2007
- Full Text
- View/download PDF
8. Comments on the paper "Asymptotic behavior for a fourth-order parabolic equation involving the Hessian. Z. Angew. Math. Phys., (2018) 69: 147".
- Author
-
Ding, Hang and Zhou, Jun
- Subjects
- *
BLOWING up (Algebraic geometry) , *MATHEMATICS , *BEHAVIOR , *EQUATIONS , *PARABOLIC operators , *REVISIONS - Abstract
In this note, we make two revisions of the paper [2]. The first one is the asymptotic behavior of the energy functional as t → T (see [2, Theorem 1.6]), where T is the blow-up time. The second one is the equivalent conditions for the solutions blowing up in finite time or existing globally (see [2, Theorem 1.8]). [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
9. The parameterized accelerated iteration method for solving the matrix equation AXB=C.
- Author
-
Tian, Zhaolu, Duan, Xuefeng, Wu, Nian-Ci, and Liu, Zhongyun
- Subjects
MATHEMATICS ,EQUATIONS - Abstract
By introducing two parameters in the splittings of the matrices A and B, this paper presents a parameterized accelerated iteration (PAI) method for solving the matrix equation A X B = C . The convergence property of the PAI method and the choices of the parameters are thoroughly investigated. Additionally, based on some special splittings of the matrices A and B, several variants of the PAI method are established. Furthermore, for some certain cases, the optimal parameters can be determined, and it is demonstrated that the PAI method is more efficient than the gradient-based iteration (GBI) method (Ding et al. Appl. Math. Comput. 197, 41–50 2008). Finally, by comparing it with several existing iteration methods, the effectiveness of the PAI method is verified through four numerical examples. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Construction of multi‐bubble blow‐up solutions to the L2$L^2$‐critical half‐wave equation.
- Author
-
Cao, Daomin, Su, Yiming, and Zhang, Deng
- Subjects
- *
INTEGRALS , *MATHEMATICAL formulas , *SCHRODINGER equation , *MATHEMATICS , *EQUATIONS - Abstract
This paper concerns the bubbling phenomena for the L2$L^2$‐critical half‐wave equation in dimension one. Given arbitrarily finitely many distinct singularities, we construct blow‐up solutions concentrating exactly at these singularities. This provides the first examples of multi‐bubble solutions for the half‐wave equation. In particular, the solutions exhibit the mass quantization property. Our proof strategy draws upon the modulation method in Krieger, Lenzmann and Raphaël [Arch. Ration. Mech. Anal. 209 (2013), no. 1, 61–129] for the single‐bubble case, and explores the localization techniques in Cao, Su and Zhang [Arch. Ration. Mech. Anal. 247 (2023), no. 1, Paper No. 4] and Röckner, Su and Zhang [Trans. Amer. Math. Soc., 377 (2024), no. 1, 517–588] for bubbling solutions to non‐linear Schrödinger equations (NLS). However, unlike the single‐bubble or NLS cases, different bubbles exhibit the strongest interactions in dimension one. In order to get sharp estimates to control these interactions, as well as non‐local effects on localization functions, we utilize the Carlderón estimate and the integration representation formula of the half‐wave operator, and find that there exists a narrow room between the orders |t|2+$|t|^{2+}$ and |t|3−$|t|^{3-}$ for the remainder in the geometrical decomposition. Based on this, a novel bootstrap scheme is introduced to address the multi‐bubble non‐local structure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Note on normalized solutions to a kind of fractional Schr?odinger equation with a critical nonlinearity.
- Author
-
Xizheng Sun and Zhiqing Han
- Subjects
NONLINEAR Schrodinger equation ,MATHEMATICS ,EQUATIONS - Abstract
In this paper, we study normalized solutions of the fractional Schrödinger equation with a critical nonlinearity... we prove the existence of a second normalized solution under some conditions on a, p, s, and N. This is a continuation of our previous work (Z. Angew. Math. Phys., 73 (2022) 149) where only one solution is obtained. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. A new class of hybrid contractions with higher-order iterative Kirk's method for reckoning fixed points.
- Author
-
Nisar, Kottakkaran Sooppy, Hammad, Hasanen A., and Elmursi, Mohamed
- Subjects
CONCEPT mapping ,POINT set theory ,MATHEMATICS ,ALGORITHMS ,EQUATIONS - Abstract
The concept of contraction mappings plays a significant role in mathematics, particularly in the study of fixed points and the existence of solutions for various equations. In this study, we described two types of enriched contractions: enriched F-contraction and enriched F'-contraction associated with u-fold averaged mapping, which are involved with Kirk's iterative technique with order u. The contractions extracted from this paper generalized and unified many previously common super contractions. Furthermore, u-fold averaged mappings can be seen as a more general form of both averaged mappings and double averaged mappings. Moreover, we demonstrated that the ufold averaged mapping with enriched contractions has a unique fixed point. Our work examined the necessary conditions for the u-fold averaged mapping and weak enriched contractions to have equal sets of fixed points. Additionally, we illustrated that an appropriate Kirk's iterative algorithm can effectively approximate a fixed point of a u-fold averaged mapping as well as the two enriched contractions. Also, we delved into the well-posedness, limit shadowing property, and Ulam-Hyers stability of the u-fold averaged mapping. Furthermore, we established necessary conditions that guaranteed the periodic point property for each of the illustrated strengthened contractions. To underscore the generality of our findings, we presented several examples that aligned with comparable results found in the existing literature. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Strichartz Estimates for Schrödinger Equations with Non-degenerate Coefficients*.
- Author
-
Yu Miao
- Subjects
ESTIMATES ,ESTIMATION theory ,PAPER ,EQUATIONS ,MATHEMATICS - Abstract
In the present paper, the full range Strichartz estimates for homogeneous Schrödinger equations with non-degenerate and non-smooth coefficients are proved. For inhomogeneous equation, the non-endpoint Strichartz estimates are also obtained. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
14. Least energy solutions for affine p-Laplace equations involving subcritical and critical nonlinearities.
- Author
-
Leite, Edir Júnior Ferreira and Montenegro, Marcos
- Subjects
CONVEX geometry ,EQUATIONS ,MATHEMATICS - Abstract
The paper is concerned with Lane–Emden and Brezis–Nirenberg problems involving the affine p-Laplace nonlocal operator Δ p 풜 , which has been introduced in [J. Haddad, C. H. Jiménez and M. Montenegro, From affine Poincaré inequalities to affine spectral inequalities, Adv. Math. 386 2021, Article ID 107808] driven by the affine L p energy ℰ p , Ω from convex geometry due to [E. Lutwak, D. Yang and G. Zhang, Sharp affine L p Sobolev inequalities, J. Differential Geom. 62 2002, 1, 17–38]. We are particularly interested in the existence and nonexistence of positive C 1 solutions of least energy type. Part of the main difficulties are caused by the absence of convexity of ℰ p , Ω and by the comparison ℰ p , Ω (u) ≤ ∥ u ∥ W 0 1 , p (Ω) generally strict. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. A singular Adams' inequality with logarithmic weights and applications.
- Author
-
Zhang, Shiqi
- Subjects
MATHEMATICS ,EQUATIONS - Abstract
In this paper, we consider a singular Adams' inequality with logarithmic weights in the unit ball of $ \mathbb {R}^4 $ R 4 . Our results extend the results of Zhu and Wang [Adams' inequality with logarithmic weights in $ \mathbb {R}^4 $ R 4 . Proc Amer Math Soc. 2021;149(8):3463–3472] on Adams' inequality with logarithmic weights to singular case. Then, we study the existence of solutions for some weighted mean field equations, relying on variational methods and the singular Adams' inequality with logarithmic weights we previously established. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. A note correcting the proof of a lemma in a recent paper
- Author
-
Peng, Mingshu
- Subjects
- *
OSCILLATION theory of differential equations , *LINEAR differential equations , *LINEAR systems , *EQUATIONS , *MATHEMATICS - Abstract
A nonoscillation criterion for a second-order linear difference equation is established correcting a result in [1]. [Copyright &y& Elsevier]
- Published
- 2003
- Full Text
- View/download PDF
17. EXPOSITORY RESEARCH PAPERS.
- Author
-
Ipsen, Ilse
- Subjects
- *
ELLIPTIC operators , *PARTIAL differential operators , *EQUATIONS , *MATHEMATICS , *MATRICES (Mathematics) - Abstract
The article discusses research featured in the Expository Research Papers section including one by Laurent Demanet and Lexing Ying on the efficient representations for functions of elliptic operators and another by Jeffrey Blanchard, Coralia Cartis and Jared Tanner on restricted isometry property.
- Published
- 2011
- Full Text
- View/download PDF
18. Using Math in Physics: Overview.
- Author
-
Redish, Edward F.
- Subjects
MATHEMATICS ,PHYSICS ,EQUATIONS ,ABILITY ,MATHEMATICAL ability - Abstract
The key difference between math as math and math in science is that in science we blend our physical knowledge with our knowledge of math. This blending changes the way we put meaning to math and even the way we interpret mathematical equations. Learning to think about physics with math instead of just calculating involves a number of general scientific thinking skills that are often taken for granted (and rarely taught) in physics classes. In this paper, I give an overview of my analysis of these additional skills. I propose specific tools for helping students develop these skills in subsequent papers. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
19. An iterative method for the solution of Laplace-like equations in high and very high space dimensions.
- Author
-
Yserentant, Harry
- Subjects
INTEGRABLE functions ,EQUATIONS ,LINEAR operators ,STRUCTURAL frames ,MATHEMATICS ,MEAN value theorems ,FOURIER transforms - Abstract
This paper deals with the equation - Δ u + μ u = f on high-dimensional spaces R m , where the right-hand side f (x) = F (T x) is composed of a separable function F with an integrable Fourier transform on a space of a dimension n > m and a linear mapping given by a matrix T of full rank and μ ≥ 0 is a constant. For example, the right-hand side can explicitly depend on differences x i - x j of components of x. Following our publication (Yserentant in Numer Math 146:219–238, 2020), we show that the solution of this equation can be expanded into sums of functions of the same structure and develop in this framework an equally simple and fast iterative method for its computation. The method is based on the observation that in almost all cases and for large problem classes the expression ‖ T t y ‖ 2 deviates on the unit sphere ‖ y ‖ = 1 the less from its mean value the higher the dimension m is, a concentration of measure effect. The higher the dimension m, the faster the iteration converges. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Digitization of Handwritten Equations.
- Author
-
Khan, Hamid Saeed and Hussain, Syed Safdar
- Subjects
EQUATIONS ,COMPUTERS ,DIGITIZATION ,COMPUTER systems ,MATHEMATICS - Abstract
While doing any mathematical derivation or writing some mathematical equations, a pen and a paper is an obvious choice and todays world is of computer age. It clearly indicates a need for a system, which can understand the handwritten equations and convert it into digital format. This project performs the digitization of handwritten equations, which takes the image of handwritten equations as input and convert it into computer generated text form. [ABSTRACT FROM AUTHOR]
- Published
- 2019
21. Quantum dynamics calculations using symmetrized, orthogonal Weyl-Heisenberg wavelets with a phase space truncation scheme. III. Representations and calculations.
- Author
-
Poirier, Bill and Salam, A.
- Subjects
QUANTUM theory ,EQUATIONS ,LINEAR algebra ,MATRICES (Mathematics) ,MATHEMATICS ,PHYSICS - Abstract
In a previous paper [J. Theo. Comput. Chem. 2, 65 (2003)], one of the authors (B.P.) presented a method for solving the multidimensional Schrödinger equation, using modified Wilson-Daubechies wavelets, and a simple phase space truncation scheme. Unprecedented numerical efficiency was achieved, enabling a ten-dimensional calculation of nearly 600 eigenvalues to be performed using direct matrix diagonalization techniques. In a second paper [J. Chem. Phys. 121, 1690 (2004)], and in this paper, we extend and elaborate upon the previous work in several important ways. The second paper focuses on construction and optimization of the wavelength functions, from theoretical and numerical viewpoints, and also examines their localization. This paper deals with their use in representations and eigenproblem calculations, which are extended to 15-dimensional systems. Even higher dimensionalities are possible using more sophisticated linear algebra techniques. This approach is ideally suited to rovibrational spectroscopy applications, but can be used in any context where differential equations are involved. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
22. Well-Posedness of a Class of Radial Inhomogeneous Hartree Equations.
- Author
-
Almuthaybiri, Saleh, Ghanmi, Radhia, and Saanouni, Tarek
- Subjects
SOBOLEV spaces ,EQUATIONS ,NONLINEAR equations ,MATHEMATICS - Abstract
The present paper investigates the following inhomogeneous generalized Hartree equation i u ˙ + Δ u = ± | u | p − 2 | x | b (I α ∗ | u | p | · | b) u , where the wave function is u : = u (t , x) : R × R N → C , with N ≥ 2 . In addition, the exponent b > 0 gives an unbounded inhomogeneous term | x | b and I α ≈ | · | − (N − α) denotes the Riesz-potential for certain 0 < α < N . In this work, our aim is to establish the local existence of solutions in some radial Sobolev spaces, as well as the global existence for small data and the decay of energy sub-critical defocusing global solutions. Our results complement the recent work (Sharp threshold of global well-posedness versus finite time blow-up for a class of inhomogeneous Choquard equations, J. Math. Phys. 60 (2019), 081514). The main challenge in this work is to overcome the singularity of the unbounded inhomogeneous term | x | b for certain b > 0 . [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
23. A NEW PERSPECTIVE FOR STABILITY ANALYSIS OF STRUCTURES.
- Author
-
Ranjbaran, Abdolrasoul, Ranjbaran, Mohammad, Ranjbaran, Fatema, Rousta, Ali Mohammad, and Hashemi, Shamsodin
- Subjects
MATHEMATICS ,THERMODYNAMIC state variables ,REASONING ,PARAMETERS (Statistics) ,EQUATIONS - Abstract
The classical methods for stability analysis of structures contain some levels of epistemic uncertainty. This paper presents an alternative method for the analysis of system stability phenomena. The analysis is conducted by using a new method which is called the change of state philosophy. The phenomenon is considered as the change in the state of the system in this method. The basic principle in the formulation is the use of an equation in which the product of the key parameter of the system and its inverse is set equal to 1. Logical reasoning and mathematics principles are used to explicitly derive the basic theory. The results are presented as the Persian curve which is a super function of the state functions. The accuracy of the proposed method has been verified by using several examples related to the ultimate strength analysis of structural systems. The state functions are defined as explicit functions of the state variable. The state variable is an identification parameter of the system. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. Using Math in Physics: 3. Anchor equations.
- Author
-
Redish, Edward F.
- Subjects
EQUATIONS ,MATHEMATICS ,PHYSICAL constants ,PHYSICS - Abstract
An important step in learning to use math in science is learning to see symbolic equations not just as calculational tools, but as ways of expressing fundamental relationships among physical quantities, of coding conceptual information, and of organizing physics knowledge structures. In this paper, I propose "anchor equations" as a construct to support teaching and learning in introductory physics. I define anchor equation, provide examples, and suggest ways anchor equations can be used in instruction to support the development of students' mathematical sense-making. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
25. Dynamics for a class of energy beam models with rotational forces.
- Author
-
Gomes Tavares, Eduardo H., Li, Yanan, Narciso, Vando, and Sun, Yue
- Subjects
- *
MOMENTS of inertia , *BEAM dynamics , *AIR forces , *MATHEMATICS , *EQUATIONS - Abstract
This paper is concerned with the well-posedness and long-time dynamics of a class of beam/plate equations with rotational inertia and nonlinear energy damping. The model is derived from nonlocal dissipative energy models for flight structures, as proposed by Balakrishnan-Taylor (Proceedings Damping 89, Flight Dynamics Lab and Air Force Wright Aeronautical Labs, WPAFB, 1989). Our main results address the existence of compact global attractors. The work complements the degenerate coefficient case left open by Sun and Yang (J. Math. Anal. Appl., Volume 512, Issue 2, 2022). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Existence results for the generalized Riemann–Liouville type fractional Fisher‐like equation on the half‐line.
- Author
-
Nyamoradi, Nemat and Ahmad, Bashir
- Subjects
- *
FRACTIONAL calculus , *BOUNDARY value problems , *MATHEMATICS , *EQUATIONS , *MULTIPLICITY (Mathematics) - Abstract
In this paper, we discuss the existence of multiplicity of positive solutions to a new generalized Riemann–Liouville type fractional Fisher‐like equation on a semi‐infinite interval equipped with nonlocal multipoint boundary conditions involving Riemann–Liouville fractional derivative and integral operators. The existence of at least two positive solutions for the given problem is established by using the concept of complete continuity and iterative positive solutions. We show the existence of at least three positive solutions to the problem at hand by applying the generalized Leggett–Williams fixed‐point theorem due to Bai and Ge [Z. Bai, B. Ge, Existence of three positive solutions for some second‐order boundary value problems, Comput. Math. Appl. 48 (2014) 699‐70]. Illustrative examples are constructed to demonstrate the effectiveness of the main results. It has also been indicated in Section 5 that some new results appear as special cases by choosing the parameters involved in the given problem appropriately. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. On the stability of a double porous elastic system with visco-porous damping.
- Author
-
Nemsi, Aicha, Keddi, Ahmed, and Fareh, Abdelfeteh
- Subjects
- *
THERMOELASTICITY , *POROSITY , *MATHEMATICS , *BULLS , *EQUATIONS - Abstract
In this paper, we focused on a one-dimensional elastic system with a double porosity structure and frictional damping acting on both porous equations. We introduce two stability numbers χ 0 {\chi_{0}} and χ 1 {\chi_{1}} and prove that the solution of the system decays exponentially provided that χ 0 = 0 {\chi_{0}=0} and χ 1 ≠ 0 {\chi_{1}\neq 0} . Otherwise, we prove the absence of exponential decay. Our results improve the results of [N. Bazarra, J. R. Fernández, M. C. Leseduarte, A. Magaña and R. Quintanilla, On the thermoelasticity with two porosities: Asymptotic behaviour, Math. Mech. Solids 24 2019, 9, 2713–2725] and [A. Nemsi and A. Fareh, Exponential decay of the solution of a double porous elastic system, Politehn. Univ. Bucharest Sci. Bull. Ser. A Appl. Math. Phys. 83 2021, 1, 41–50]. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. New lower bounds on the radius of spatial analyticity for the higher order nonlinear dispersive equation on the real line.
- Author
-
Zhang, Zaiyun, Deng, Youjun, and Li, Xinping
- Subjects
- *
NONLINEAR equations , *CONSERVATION laws (Physics) , *MATHEMATICS , *EQUATIONS , *TILLAGE - Abstract
In this paper, benefited some ideas of Wang [J. Geom. Anal. 33, 18 (2023)] and Dufera et al. [J. Math. Anal. Appl. 509, 126001 (2022)], we investigate persistence of spatial analyticity for solution of the higher order nonlinear dispersive equation with the initial data in modified Gevrey space. More precisely, using the contraction mapping principle, the bilinear estimate as well as approximate conservation law, we establish the persistence of the radius of spatial analyticity till some time δ. Then, given initial data that is analytic with fixed radius σ0, we obtain asymptotic lower bound σ (t) ≥ c | t | − 1 2 , for large time t ≥ δ. This result improves earlier ones in the literatures, such as Zhang et al. [Discrete Contin. Dyn. Syst. B 29, 937–970 (2024)], Huang–Wang [J. Differ. Equations 266, 5278–5317 (2019)], Liu–Wang [Nonlinear Differ. Equations Appl. 29, 57 (2022)], Wang [J. Geom. Anal. 33, 18 (2023)] and Selberg–Tesfahun [Ann. Henri Poincaré 18, 3553–3564 (2017)]. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. A method based on the meshless approach for the numerical solution of the singularly perturbed differential-difference equation arising in the modeling of neuronal variability.
- Author
-
Ghassabzade, Fahimeh Akhavan, Saberi-Nadjafi, Jafar, and Soheili, Ali Reza
- Subjects
NUMERICAL solutions for linear algebra ,RADIAL basis functions ,MATHEMATICS ,EQUATIONS ,COLLOCATION methods - Abstract
In this paper, an efficient procedure based on the multiquadric radial basis functions (RBFs) collocation method is applied for the numerical solution of the singularly perturbed differentialdifference (SPDDE) equation. The method is coupled with the Residual subsampling algorithm for support adaptivity. The problem considered in this paper shows turning point behavior which is added to the complexity in the construction of numerical approximation to the solution of the problem. The proposed algorithm is very simple to perform. Some numerical examples are given to validate the computational efficacy of the suggested numerical scheme. [ABSTRACT FROM AUTHOR]
- Published
- 2021
30. Are physicists afraid of mathematics?
- Author
-
Jonathan E Kollmer, Thorsten Pöschel, and Jason A C Gallas
- Subjects
MATHEMATICS ,CITATION analysis ,REPORT writing ,EQUATIONS ,MATHEMATICAL formulas ,PHYSICISTS ,BIOLOGISTS ,PSYCHOLOGY ,ATTITUDE (Psychology) - Abstract
A recent study claimed that heavy use of equations impedes communication among biologists, as measured by the ability to attract citations from peers. It was suggested that to increase the probability of being cited one should reduce the density of equations in papers, that equations should be moved to appendices, and that math training among biologists should be improved. Here, we report a detailed study of the citation habits among physicists, a community that has traditionally strong training and dependence on mathematical formulations. Is it possible to correlate statistical citation patterns and fear of mathematics in a community whose work strongly depends on equations? By performing a systematic analysis of the citation counts of papers published in one of the leading journals in physics covering all its disciplines, we find striking similarities with distribution of citations recorded in biological sciences. However, based on the standard deviations in citation data of both communities, biologists and physicists, we argue that trends in statistical indicators are not reliable to unambiguously blame mathematics for the existence or lack of citations. We digress briefly about other statistical trends that apparently would also enhance citation success. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
31. On Weak Generalized Stability of Random Variables via Functional Equations.
- Author
-
Jarczyk, Witold, Járai, Antal, Matkowski, Janusz, and Misiewicz, Jolanta
- Subjects
FUNCTIONAL equations ,CHARACTERISTIC functions ,FUNCTIONAL analysis ,MATHEMATICS ,EQUATIONS - Abstract
In this paper we characterize random variables which are stable but not strictly stable in the sense of generalized convolution. We generalize the results obtained in Jarczyk and Misiewicz (J Theoret Probab 22:482-505, 2009), Misiewicz and Mazurkiewicz (J Theoret Probab 18:837-852, 2005), Oleszkiewicz (in Milman VD and Schechtman Lecture Notes in Math. 1807, Geometric Aspects of Functional Analysis (2003), Israel Seminar 2001–2002, Springer-Verlag, Berlin). The main problem was to find the solution of the following functional equation for symmetric generalized characteristic functions φ , ψ : ∀ a , b ≥ 0 ∃ c (a , b) ≥ 0 ∃ d (a , b) ≥ 0 ∀ t ≥ 0 φ (a t) φ (b t) = φ (c (a , b) t) ψ (d (a , b) t) , (A) where both functions c and d are continuous, symmetric, homogeneous but unknown. We give the solution of equation (A) assuming that for fixed ψ , c , d there exist at least two different solutions of (A). To solve (A) we also determine the functions that satisfy the equation (f (t (x + y)) - f (t x)) (f (x + y) - f (y)) = (f (t (x + y)) - f (t y)) (f (x + y) - f (x)) , (B) x , y , t > 0 , for a function f : (0 , ∞) → R . As an additional result we infer that each Lebesgue measurable or Baire measurable function f satisfying equation (B) is infinitely differentiable. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Steps Towards a Minimalist Account of Numbers.
- Author
-
Schindler, Thomas
- Subjects
MATHEMATICAL equivalence ,SENTENCES (Logic) ,MATHEMATICS ,EQUATIONS ,EQUIVALENCE relations (Set theory) - Abstract
This paper outlines an account of numbers based on the numerical equivalence schema (NES), which consists of all sentences of the form ' # x. F x = n if and only if ∃ n x F x ', where # is the number-of operator and ∃ n is defined in standard Russellian fashion. In the first part of the paper, I point out some analogies between the NES and the T-schema for truth. In light of these analogies, I formulate a minimalist account of numbers, based on the NES, which strongly parallels the minimalist (deflationary) account of truth. One may be tempted to develop the minimalist account in a fictionalist direction, according to which arithmetic is useful but untrue, if taken at face value. In the second part, I argue that this suggestion is not as attractive as it may first appear. The NES suffers from a similar problem to the T-schema: it is deductively weak and does not enable the derivation of any non-trivial generalizations. In the third part of the paper, I explore some strategies to deal with the generalization problem, again drawing inspiration from the literature on truth. In closing this paper, I briefly compare the minimalist to some other accounts of numbers. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
33. Response to "Comment on 'Classification of Lie point symmetries for quadratic Liénard type equation ẍ + f(x)ẋ2 + g(x) = 0'" [J. Math. Phys. 61, 044101 (2020)].
- Author
-
Chandrasekar, V. K., Tiwari, A. K., Pandey, S. N., Senthilvelan, M., and Lakshmanan, M.
- Subjects
QUADRATIC equations ,HARMONIC oscillators ,MATHEMATICS ,EQUATIONS ,SYMMETRY ,CLASSIFICATION - Abstract
We respond to the comment on 'Classification of Lie point symmetries for quadratic Liénard type equation ẍ + f(x)ẋ
2 + g(x) = 0' [J. Math. Phys. 61, 044101 (2013)] by Iacono regarding linearizability and isochronicity. We assert here that the condition for linearization of the equation ẍ + f(x)ẋ2 + g(x) = 0 given by us in our paper is correct with the condition g 1 = ω 0 2 > 0. We present the explicit form of local and nonlocal transformations that transform the quadratic Liénard equation x ̈ + F + 1 1 − x x ̇ 2 + x (1 − x) (1 + D x) = 0 into the harmonic oscillator equation for the four cases mentioned in the comment and confirm the statements given in our paper are all valid. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
34. Lorentz–Morrey global bounds for singular quasilinear elliptic equations with measure data.
- Author
-
Tran, Minh-Phuong and Nguyen, Thanh-Nhan
- Subjects
ELLIPTIC equations ,LORENTZ spaces ,RICCATI equation ,DUALITY theory (Mathematics) ,RADON transforms ,MATHEMATICS ,RADON ,EQUATIONS - Abstract
The aim of this paper is to present the global estimate for gradient of renormalized solutions to the following quasilinear elliptic problem: − div (A (x , ∇ u)) = μ in Ω , u = 0 on ∂ Ω , in Lorentz–Morrey spaces, where Ω ⊂ ℝ n (n ≥ 2), μ is a finite Radon measure, A is a monotone Carathéodory vector-valued function defined on W 0 1 , p (Ω) and the p -capacity uniform thickness condition is imposed on the complement of our domain Ω. It is remarkable that the local gradient estimates have been proved first by Mingione in [Gradient estimates below the duality exponent, Math. Ann.346 (2010) 571–627] at least for the case 2 ≤ p ≤ n , where the idea for extending such result to global ones was also proposed in the same paper. Later, the global Lorentz–Morrey and Morrey regularities were obtained by Phuc in [Morrey global bounds and quasilinear Riccati type equations below the natural exponent, J. Math. Pures Appl.102 (2014) 99–123] for regular case p > 2 − 1 n . Here in this study, we particularly restrict ourselves to the singular case 3 n − 2 2 n − 1 < p ≤ 2 − 1 n . The results are central to generalize our technique of good- λ type bounds in the previous work [M.-P. Tran, Good- λ type bounds of quasilinear elliptic equations for the singular case, Nonlinear Anal.178 (2019) 266–281], where the local gradient estimates of solution to this type of equation were obtained in the Lorentz spaces. Moreover, the proofs of most results in this paper are formulated globally up to the boundary results. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
35. Context Variation and Syntax Nuances of the Equal Sign in Elementary School Mathematics.
- Author
-
Voutsina, Chronoula
- Subjects
ELEMENTARY schools ,MATHEMATICS ,DIFFERENCE equations ,MATHEMATICAL equivalence ,TEXTBOOKS - Abstract
Copyright of Canadian Journal of Science, Mathematics & Technology Education is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
36. Hahn series and Mahler equations: Algorithmic aspects.
- Author
-
Faverjon, C. and Roques, J.
- Subjects
- *
EQUATIONS , *LINEAR equations , *MATHEMATICS , *EXPONENTS - Abstract
Many articles have recently been devoted to Mahler equations, partly because of their links with other branches of mathematics such as automata theory. Hahn series (a generalization of the Puiseux series allowing arbitrary exponents of the indeterminate as long as the set that supports them is well ordered) play a central role in the theory of Mahler equations. In this paper, we address the following fundamental question: is there an algorithm to calculate the Hahn series solutions of a given linear Mahler equation? What makes this question interesting is the fact that the Hahn series appearing in this context can have complicated supports with infinitely many accumulation points. Our (positive) answer to the above question involves among other things the construction of a computable well‐ordered receptacle for the supports of the potential Hahn series solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. Maximum norm error bounds for the full discretization of nonautonomous wave equations.
- Author
-
Dörich, Benjamin, Leibold, Jan, and Maier, Bernhard
- Subjects
DIFFERENTIAL operators ,EULER method ,MATHEMATICS ,EQUATIONS - Abstract
In the present paper, we consider a specific class of nonautonomous wave equations on a smooth, bounded domain and their discretization in space by isoparametric finite elements and in time by the implicit Euler method. Building upon the work of Baker and Dougalis (1980, On the |${L}^{\infty }$| -convergence of Galerkin approximations for second-order hyperbolic equations. Math. Comp. , 34 , 401–424), we prove optimal error bounds in the |$W^{1,\infty } \times L^\infty $| -norm for the semidiscretization in space and the full discretization. The key tool is the gain of integrability coming from the inverse of the discretized differential operator. For this, we have to pay with (discrete) time derivatives on the error in the |$H^{1} \times L^2$| -norm, which are reduced to estimates of the differentiated initial errors. To confirm our theoretical findings, we also present numerical experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. A shift‐splitting Jacobi‐gradient iterative algorithm for solving the matrix equation A풱−풱‾B=C.
- Author
-
Bayoumi, Ahmed M. E.
- Subjects
ALGORITHMS ,EQUATIONS ,MATRICES (Mathematics) ,MATHEMATICS - Abstract
To improve the convergence of the gradient iterative (GI) algorithm and the Jacobi‐gradient iterative (JGI) algorithm [Bayoumi, Appl Math Inf Sci, 2021], a shift‐splitting Jacobi‐gradient iterative (SSJGI) algorithm for solving the matrix equation A풱−풱‾B=C is presented in this paper, which is based on the splitting of the coefficient matrices. The proposed algorithm converges to the exact solution for any initial value with some conditions. To demonstrate the effectiveness of the SSJGI algorithm and to compare it to the GI algorithm and the JGI algorithm [Bayoumi, Appl Math Inf Sci, 2021], numerical examples are provided. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Comparison results for solutions of Poisson equations with Robin boundary on complete Riemannian manifolds.
- Author
-
Chen, Daguang, Li, Haizhong, and Wei, Yilun
- Subjects
RIEMANNIAN manifolds ,ISOPERIMETRIC inequalities ,EQUATIONS ,MATHEMATICS - Abstract
In this paper, by using Schwarz rearrangement and isoperimetric inequalities, we prove comparison results for the solutions of Poisson equations on complete Riemannian manifolds with Ric ≥ (n − 1) κ , κ = 0 or 1 , which extends the results in [A. Alvino, C. Nitsch and C. Trombetti, A Talenti comparison result for solutions to elliptic problems with Robin boundary conditions, Comm. Pure Appl. Math. 76(3) (2023) 585–603]. Furthermore, as applications of our comparison results, we obtain the Saint-Venant inequality and Bossel–Daners inequality for Robin Laplacian. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. Generalized Set-valued Nonlinear Variational-like Inequalities and Fixed Point Problems: Existence and Approximation Solvability Results.
- Author
-
Balooee, Javad, Chang, Shih-sen, and Yao, Jen-Chih
- Subjects
NONEXPANSIVE mappings ,BANACH spaces ,POINT set theory ,MATHEMATICS ,EQUATIONS - Abstract
The paper is devoted to the introduction of a new class of generalized set-valued nonlinear variational-like inequality problems in the setting of Banach spaces. By means of the notion of P- η -proximal mapping, we prove its equivalence with a class of generalized implicit Wiener–Hopf equations and employ the obtained equivalence relationship and Nadler's technique to suggest a new iterative algorithm for finding an approximate solution of the considered problem. The existence of solution and the strong convergence of the sequences generated by our proposed iterative algorithm to the solution of our considered problem are verified. The problem of finding a common element of the set of solutions of a generalized nonlinear variational-like inequality problem and the set of fixed points of a total asymptotically nonexpansive mapping is also investigated. The final section deals with the investigation and analysis of the main results appeared in Kazmi and Bhat (Appl Math Comput 166:164–180, 2005) and some comments relating to them are given. The results presented in this article extend and improve some known results in the literature. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. On the equation x2+dy6=zp for square-free 1≤d≤20.
- Author
-
Madriaga, Franco Golfieri, Pacetti, Ariel, and Torcomian, Lucas Villagra
- Subjects
DIOPHANTINE equations ,EQUATIONS ,MATHEMATICS ,MODULAR forms - Abstract
The purpose of this paper is to show how the modular method together with different techniques can be used to prove non-existence of primitive non-trivial solutions of the equation x 2 + d y 6 = z p for square-free values 1 ≤ d ≤ 2 0. The key ingredients are: the approach presented in [A. Pacetti and L. V. Torcomian, ℚ -curves, Hecke characters and some Diophantine equations, Math. Comp. 91(338) (2022) 2817–2865] (in particular its recipe for the space of modular forms to be computed) together with the use of the symplectic method (as developed in [E. Halberstadt and A. Kraus, Courbes de Fermat: Résultats et problèmes, J. Reine Angew. Math. 548 (2002) 167–234], although we give a variant over ramified extensions needed in our applications) to discard solutions and the use of a second Frey curve, aiming to prove large image of residual Galois representations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. Dubrovin–Frobenius manifolds associated with Bn and the constrained KP hierarchy.
- Author
-
Ma, Shilin and Zuo, Dafeng
- Subjects
COXETER groups ,ORBITS (Astronomy) ,MATHEMATICS ,EQUATIONS - Abstract
In this paper, we will show that the Dubrovin–Frobenius prepotentials on the orbit space of the Coxeter group B n constructed by Arsie et al. [Sel. Math. New Ser. 29, 1 (2023)] coincide with the solutions of Witten-Dijkgraaf-Verlinde-Verlinde (WDVV) equations associated with the constrained KP hierarchy. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. Extinction of solutions in parabolic equations with different diffusion operators.
- Author
-
Liu, Bingchen, Wang, Yuxi, and Wang, Lu
- Subjects
HEAT equation ,MATHEMATICS ,PARABOLIC operators ,EQUATIONS - Abstract
In this paper, we study the evolution p, q-Laplacian equations u t = d i v (| ∇ u | p − 2 ∇ u) + u α ∫ Ω v m d x and v t = d i v (| ∇ v | q − 2 ∇ v) + v β ∫ Ω u n d x with 1
(p − 1 − α) (q − 1 − β) , there exist suitable initial data such that vanishing solutions exist. If m n < (p − 1 − α) (q − 1 − β) , we find the explicit scopes of initial data such that the solutions could not vanish, which complete the corresponding classifications of solutions in Math. Methods Appl. Sci. 39 (2016) 1325–1335 and Appl. Math. Comp. 259 (2015) 587–595, respectively. For the critical case m n = (p − 1 − α) (q − 1 − β) , the solutions vanish in finite time with small initial data. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. Asymptotic behaviour on the linear self-interacting diffusion driven by α-stable motion.
- Author
-
Sun, Xichao and Yan, Litan
- Subjects
LIMIT theorems ,DISTRIBUTION (Probability theory) ,INFINITY (Mathematics) ,MATHEMATICS ,EQUATIONS - Abstract
In this paper, as an attempt we consider the linear self-interacting diffusion driven by an α-stable motion, which is the solution to the equation X t α = M t α − θ ∫ 0 t ∫ 0 s (X s α − X r α) d r d s + ν t , where θ ≠ 0 , ν ∈ R and M α is an α-stable motion on R ( 0 < α ≤ 2). The process is an analogue of the self-attracting diffusion (see Durrett-Rogers, Prob. Theory Related Fields92 (1992), 337–349, and Cranston-Le Jan, Math. Ann.303 (1995), 87–93.). The main object of this paper is to prove some limit theorems associated with the solution process X α for 1 2 < α ≤ 2. When θ > 0 we show that ψ α (t) (X t α − X ∞ α) converges to an α-stable random variable in distribution, as t tends to infinity, where ψ α (t) = t 1 / α for 1 ≤ α ≤ 2 and ψ α (t) = t 2 − 1 α for 1 2 < α < 1. When θ < 0 , for all 1 2 < α ≤ 2 we show that, as t → ∞ , J t α (θ , ν , 0) := t e 1 2 θ t 2 X t α converges to ξ ∞ α − ν θ and J t α (θ , ν , n) : = − θ t 2 (J t α (θ , ν , n − 1) − (2 n − 3) ! ! (ξ ∞ α − ν θ)) → (2 n − 1) ! ! (ξ ∞ α − ν θ) a.s. for all n ≥ 1 , where (− 1) ! ! = 1 and ξ ∞ α = ∫ 0 ∞ s e 1 2 θ s 2 d M s α . [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. KOLMOGOROV'S EQUATIONS FOR JUMP MARKOV PROCESSES AND THEIR APPLICATIONS TO CONTROL PROBLEMS.
- Author
-
FEINBERG, E. A. and SHIRYAEV, A. N.
- Subjects
JUMP processes ,STOCHASTIC systems ,EQUATIONS ,MARKOV processes ,MATHEMATICS - Abstract
This paper describes the structure of solutions to Kolmogorov's equations for nonhomogeneous jump Markov processes and applications of these results to control of jump stochastic systems. These equations were studied by Feller [Trans. Amer. Math. Soc., 48 (1940), pp. 488--515], who clarified in 1945 in the errata to that paper that some of its results covered only nonexplosive Markov processes. In this work, which is largely of a survey nature, the case of explosive processes is also considered. This paper is based on the invited talk presented by the authors at the conference "P. L. Chebyshev -- 200," and it describes the results of their joint studies with Manasa Mandava (1984--2019). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
46. The dynamics of an elastic structure coupled with a rocking wall.
- Author
-
Makris, Nicos and Aghagholizadeh, Mehrdad
- Subjects
DYNAMICS ,EQUATIONS ,MATHEMATICS ,ALGEBRA ,DEGREES of freedom - Abstract
This paper investigates the dynamic response of an elastic single-degree-of-freedom oscillator coupled with a rocking wall. Both configurations of a stepping rocking wall and a pinned rocking wall that have been reported in the literature are examined. The full nonlinear equations of motions are derived, and the paper shows through a comprehensive parametric analysis that the coupling with a rocking wall has mixed results on suppressing the dynamic response of the elastic oscillator. The stepping rocking wall is most effective in suppressing displacements of relative flexible structures with a heavier wall being most effective. In contrast, the pinned wall amplifies the displacements along a wide range of the spectrum with a heavier wall being most detrimental. This happens partly because in a pinned wall the moment from its weight works against stability. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
47. A blow‐up result for the travelling waves of the pseudo‐relativistic Hartree equation with small velocity.
- Author
-
Wang, Qingxuan
- Subjects
VELOCITY ,EQUATIONS ,MATHEMATICS ,LIPSCHITZ continuity ,BLOWING up (Algebraic geometry) - Abstract
In this paper, we consider the pseudo‐relativistic Hartree equation i∂tψ=−△+m2ψ−1|x|∗|ψ|2ψonℝ3and study travelling solitary waves of the form ψ(t, x) = eitμφ(x − v t) , where v∈ℝ3 denotes travelling velocity. Fröhlich, Jonsson and Lenzmann in [Comm. Math. Phys. 2007, 274:1‐30] proved that for |v|<1 there exists a critical constant Nc(v), such that the travelling waves exist if and only if 0 < N < Nc(v), where N denotes particle number. In this paper, we consider v=(β,0,0) with 0 < β < 1, and let Nc(β)=Nc(v)|v=(β,0,0). We find that Nc(β) is Lipschitz continuity with respect to β. Based on this fact, we then prove that the boosted ground states φβ with ‖φβ‖L22=(1−β)Nc(β) satisfy limβ→0+‖φβ‖H1/2→+∞. The explicit blow‐up profile and rate will be computed. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
48. Global existence and blow-up for a mixed pseudo-parabolic p-Laplacian type equation with logarithmic nonlinearity-II.
- Author
-
Ding, Hang and Zhou, Jun
- Subjects
BLOWING up (Algebraic geometry) ,EQUATIONS ,MATHEMATICS - Abstract
This paper deals with the following mixed pseudo-parabolic p-Laplacian type equation with logarithmic nonlinearity u t − Δ u t − d i v (| ∇ u | p − 2 ∇ u) = | u | q − 2 u log | u | in a bounded domain with zero Dirichlet boundary condition, which was studied in our previous paper [J Math Anal Appl. 2019;478(2):393-420]. In view the results of [J Math Anal Appl. 2019;478(2):393-420], for the case (1) 1 < p ≤ q ≤ 2 , i f n ≤ p , ≤ 2 , i f 2 n n + 2 < p < n , < n p n − p , i f p ≤ 2 n n + 2 , the global existence and blow-up results were got when J (u 0) ≤ d , where d denotes the mountain-pass level. But for the case (2) 1 < p ≤ q a n d 2 < q < ∞ , i f n ≤ p , n p n − p , i f 2 n n + 2 < p < n , the blow-up results were got when J (u 0) ≤ M , where M ≤ d is a constant. In this paper, we extend and complete the results of [J Math Anal Appl. 2019;478(2):393-420] on the following three aspects: First, the blow-up results are got when J (u 0) ≤ d and (2) are satisfied. Second, the upper and lower bounds of blow-up time are estimated. Third, the global existence and blow-up results are got when J (u 0) > d. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
49. Rank 3 quadratic generators of Veronese embeddings.
- Author
-
Han, Kangjin, Lee, Wanseok, Moon, Hyunsuk, and Park, Euisung
- Subjects
CHAR ,CHAR fish ,MATHEMATICS ,EQUATIONS ,CURVES - Abstract
Let $L$ be a very ample line bundle on a projective scheme $X$ defined over an algebraically closed field $\Bbbk$ with ${\rm char}\,\Bbbk \neq 2$. We say that $(X,L)$ satisfies property $\mathsf {QR}(k)$ if the homogeneous ideal of the linearly normal embedding $X \subset {\mathbb {P}} H^{0} (X,L)$ can be generated by quadrics of rank less than or equal to $k$. Many classical varieties, such as Segre–Veronese embeddings, rational normal scrolls and curves of high degree, satisfy property $\mathsf {QR}(4)$. In this paper, we first prove that if ${\rm char}\,\Bbbk \neq 3$ then $({\mathbb {P}}^{n} , \mathcal {O}_{{\mathbb {P}}^{n}} (d))$ satisfies property $\mathsf {QR}(3)$ for all $n \geqslant 1$ and $d \geqslant 2$. We also investigate the asymptotic behavior of property $\mathsf {QR}(3)$ for any projective scheme. Specifically, we prove that (i) if $X \subset {\mathbb {P}} H^{0} (X,L)$ is $m$ -regular then $(X,L^{d})$ satisfies property $\mathsf {QR}(3)$ for all $d \geqslant m$ , and (ii) if $A$ is an ample line bundle on $X$ then $(X,A^{d})$ satisfies property $\mathsf {QR}(3)$ for all sufficiently large even numbers $d$. These results provide affirmative evidence for the expectation that property $\mathsf {QR}(3)$ holds for all sufficiently ample line bundles on $X$ , as in the cases of Green and Lazarsfeld's condition $\mathrm {N}_p$ and the Eisenbud–Koh–Stillman determininantal presentation in Eisenbud et al. [Determinantal equations for curves of high degree, Amer. J. Math. 110 (1988), 513–539]. Finally, when ${\rm char}\,\Bbbk = 3$ we prove that $({\mathbb {P}}^{n} , \mathcal {O}_{{\mathbb {P}}^{n}} (2))$ fails to satisfy property $\mathsf {QR}(3)$ for all $n \geqslant 3$. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
50. A GENERALIZATION OF S-NEKRASOV MATRICES.
- Author
-
ZHEN-HUA LYU, LIXIN ZHOU, and JIANZHOU LIU
- Subjects
MATRICES (Mathematics) ,MATHEMATICS ,MATHEMATICAL ability ,MATHEMATICAL programming ,EQUATIONS - Abstract
The class of H -matrices plays an important role in various scientific disciplines. In this paper, we introduce a new subclass of H -matrices, called generalized S -Nekrasov matrices. We prove that this class contains the class of S -Nekrasov matrices. We also present a sufficient condition for a weak Nekrasov matrix to be an H -matrix. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.