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Abstract We examine the thermodynamic properties of mass A ∼ 200 nuclei utilizing angular momentum (J) gated nuclear level densities (NLDs) extracted in the excitation energy range of 2–15 MeV. Interestingly, the experimental NLDs are in good agreement with the results of a microscopic approach, which is derived based on the exact pairing plus the independent-particle model at finite temperature (EP + IPM), whereas the conventional Hartree–Fock BCS (HFBCS) and Hartree–Fock–Bogoliubov plus combinatorial method (HFBC) fail to describe these data. Consequently, the thermodynamic properties of those nuclei at finite angular momentum have been extracted using the EP + IPM NLDs. While the heat capacities of 200Tl, 211Po and 212At (near spherical nuclei) follow the trend as expected in odd–odd and even–odd masses, surprisingly an S -shaped heat capacity is found in odd–odd deformed nucleus 184Re. It has been shown that this S -shaped heat capacity observed in 184Re is caused by not only the breaking of nucleon Cooper pairs but also the change of pairing induced by deformation. [ABSTRACT FROM AUTHOR]

Highlights • Lagrangian-based GPU parallelized CFD code (SOPHIA) for nuclear thermal-hydraulics and safety has been newly developed. • The novel density/continuity equation based on the normalized-density form has been developed and proposed. • The results of validation test and benchmark simulations show that the code well simulates various complicated flows with multi-phase, heat transfer, solid mechanics, and etc. Abstract Lagrangian-based meshless CFD methods have recently been developed and are being gradually applied to various research areas. In nuclear engineering, the meshless methods are gaining attention in modeling natural disasters and severe accident phenomena, such as tsunami, molten corium behaviors, etc., because of its flexible computational domain and effective treatment of non-linear deformations. This paper introduces recent progress and on-going activities in Lagrangian-based CFD code development at Seoul National University (SNU). The code, named SOPHIA, is based on the smoothed particle hydrodynamics (SPH) method, one of the best-known meshless numerical methods, based on a Lagrangian framework that can easily handle various types of physics because of its simplicity in expressing and solving mathematical equations. The SOPHIA code currently incorporates basic conservation equations and various physical models, including fluid flow, heat transfer, turbulence, multi-phase, phase change, elastic solid, diffusion and so on. To handle multi-phase, multi-component, and multi-resolution flows simultaneously, the SOPHIA code formulates density and continuity equations based on the normalized-density form, which has been recently developed and is proposed in the current study. The SOPHIA code also adapts CUDA GPU architectures for parallelization and performance improvement. Based on the benchmark calculations, the parallelized GPU code shows much higher computational speed by two orders of magnitude compared to the single CPU code for 1.0 million particles. This paper summarizes the overall features of the SOPHIA code, including governing equations, algorithms, and parallelization methods, along with some benchmark simulations. [ABSTRACT FROM AUTHOR]

Abstract Using first-principle calculations and combining with the phonon Boltzmann transport equation, we have systematically investigated the lattice thermodynamic behavior in thorium dioxide (ThO 2) and predicted the lattice thermal conductivity of thorium dioxide from 300 K up to 2000 K. According to the calculated phonon dispersion curves, phonon group velocity, relaxation time, Grüneisen parameters and weighted phase space, the contributions of acoustic and optical phonon branches to the lattice thermal conductivity are estimated. From further analyses, we know that although the phase space of three-phonon process (PW3) of acoustic phonon is large at low frequency, which is different from that of ordinary materials, the valley value appears at 3 THz, resulting in the whole thermal resistance is not too high. So acoustic phonon transports lead to the dominant contributions of the lattice thermal conductivity, while the contributions from optical components is small. Our analyses can make a significance to understand the thermodynamic behaviors of this new type of nuclear fuel dioxide at different temperatures. In addition, by means of the phonon mean-free path and nanowires width, we also studied the size dependence of the lattice thermal conductivity in ThO 2. Graphical abstract Image 1 Highlights • The phase space of three-phonon process of acoustic phonon is large at low frequency, which is different from that of ordinary material. • The phonon group velocity, relaxation time, Grüneisen parameters and weighted phase space together decided the lattice thermal conductivity. • We could reasonably design nanostructures of ThO2 to change the thermal conductivity. [ABSTRACT FROM AUTHOR]

We present a conjecture for the massless sector of perturbative 4D N = 1 heterotic ( 0 , 2 ) string vacua, including U ( 1 ) n gauge symmetries, one of them possibly anomalous (like in standard heterotic compactifications). Mathematically it states that the positive hull generated by the charges of the massless chiral multiplets spans a sublattice of the full charge lattice. We have tested this conjecture in many heterotic N = 1 compactifications in 4D. Our motivation for this conjecture is that it allows to understand a very old puzzle in ( 0 , 2 ) N = 1 heterotic compactification with an anomalous U ( 1 ) . The conjecture guarantees that there is always a D-flat direction cancelling the FI-term and restoring N = 1 SUSY in a nearby vacuum. This is something that has being verified in the past in a large number of cases, but whose origin has remained obscure for decades. We argue that the existence of a lattice generated by massless states guarantees the instability of heterotic non-BPS extremal blackholes, as required by Weak Gravity Conjecture arguments. Thus the pervasive existence of these nearby FI-cancelling vacua would be connected with WGC arguments. [ABSTRACT FROM AUTHOR]

Many-body nuclear theory utilizing microscopic or chiral potentials has developed to the point that collectivity might be studied within a microscopic or ab initio framework without the use of effective charges; for example with the proper evolution of the E 2 operator, or alternatively, through the use of an appropriate and manageable subset of particle–hole excitations. We present a precise determination of E 2 strength in 22 Mg and its mirror 22 Ne by Coulomb excitation, allowing for rigorous comparisons with theory. No-core symplectic shell-model calculations were performed and agree with the new B ( E 2 ) values while in-medium similarity-renormalization-group calculations consistently underpredict the absolute strength, with the missing strength found to have both isoscalar and isovector components. The discrepancy between two microscopic models demonstrates the sensitivity of E 2 strength to the choice of many-body approximation employed. [ABSTRACT FROM AUTHOR]

Based on the modification to area-law due to thermal fluctuation at small horizon radius, we investigate the thermodynamics of charged quasitopological and charged rotating quasitopological black holes. In particular, we derive the leading-order corrections to the Gibbs free energy, charge and total mass densities. In order to analyze the behavior of the thermal fluctuations on the thermodynamics of small black holes, we draw a comparative analysis between the first-order corrected and original thermodynamical quantities. We also examine the stability and bound points of such black holes under effect of leading-order corrections. [ABSTRACT FROM AUTHOR]

To study and optimize negative ion production, the SPIDER (Source for Production of Deuterium Extracted from RF plasma) prototype (beam energy 100 keV, current 48 A) is under construction in Padova, Italy. The instrumented calorimeter STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment) has been designed with the main purpose of characterizing the SPIDER negative ion beam in terms of beam uniformity and divergence during short pulse operations. STRIKE is made of 16 1D Carbon Fibre Composite (CFC) tiles, intercepting the whole beam and observed on the rear side by infrared (IR) cameras. As the front observation is not convenient, it is necessary to solve an inverse non-linear problem to determine the energy flux profile impinging on the calorimeter, starting from the 2D temperature pattern measured on the rear side of the tiles. The aim of the paper is to give an overview about the transfer function technique which may be used to retrieve the flux profile, dealing with non-linearity and non-stationariness. [ABSTRACT FROM AUTHOR]

Exergetic and thermoeconomic analyses of a coal-fired power plant with 160 MW capacity where located in Turkey were performed. Specific Exergy Costing (SPECO) and Modified Productive Structure Analysis (MOPSA) methods were separately applied to the system to determine the unit exergy cost of electricity generated by the coal-fired plant. The differences of these methods were discussed. As a result, the exergy efficiency of coal-fired power plant is found to be 39.89%. The equipment having the highest improvement potential is determined as boiler. The unit specific exergy cost of electricity generated by the system obtained for SPECO and MOPSA thermoeconomic analysis methods are 12.14 US$/GJ and 14.06 US$/GJ, respectively. The unit specific exergy cost of electricity obtained by using MOPSA thermoeconomic method is the same as the one obtained by the overall cost-balance equation for the coal-fired power plant. [ABSTRACT FROM AUTHOR]

Functional renormalization group (FRG) methods applied to calculations of isospin-symmetric and asymmetric nuclear matter as well as neutron matter are reviewed. The approach is based on a chiral Lagrangian expressed in terms of nucleon and meson degrees of freedom as appropriate for the hadronic phase of QCD with spontaneously broken chiral symmetry. Fluctuations beyond mean-field approximation are treated solving Wetterich’s FRG flow equations. Nuclear thermodynamics and the nuclear liquid–gas phase transition are investigated in detail, both in symmetric matter and as a function of the proton fraction in asymmetric matter. The equations of state at zero temperature of symmetric nuclear matter and pure neutron matter are found to be in good agreement with advanced ab-initio many-body computations. Contacts with perturbative many-body approaches (in-medium chiral perturbation theory) are discussed. As an interesting test case, the density dependence of the pion mass in the medium is investigated. The question of chiral symmetry restoration in nuclear and neutron matter is addressed. A stabilization of the phase with spontaneously broken chiral symmetry is found to persist up to high baryon densities once fluctuations beyond mean-field are included. Neutron star matter including beta equilibrium is discussed under the aspect of the constraints imposed by the existence of two-solar-mass neutron stars. [ABSTRACT FROM AUTHOR]

We analyze four- and six-derivative couplings in the low energy effective action of D = 3 string vacua with half-maximal supersymmetry. In analogy with an earlier proposal for the ( ∇ Φ ) 4 coupling, we propose that the ∇ 2 ( ∇ Φ ) 4 coupling is given exactly by a manifestly U-duality invariant genus-two modular integral. In the limit where a circle in the internal torus decompactifies, the ∇ 2 ( ∇ Φ ) 4 coupling reduces to the ∇ 2 F 4 and R 2 F 2 couplings in D = 4 , along with an infinite series of corrections of order e − R , from four-dimensional 1/4-BPS dyons whose worldline winds around the circle. Each of these contributions is weighted by a Fourier coefficient of a meromorphic Siegel modular form, explaining and extending standard results for the BPS index of 1/4-BPS dyons. [ABSTRACT FROM AUTHOR]

The volume of a black hole under noncommutative spacetime background is found to be infinite, in contradiction with the surface area of a black hole, or its Bekenstein–Hawking (BH) entropy, which is well-known to be finite. Our result rules out the possibility of interpreting the entropy of a black hole by counting the number of modes wrapped inside its surface if the final evaporation stage can be properly treated. It implies the statistical interpretation for the BH entropy can be independent of the volume, provided spacetime is noncommutative. The effect of radiation back reaction is found to be small and doesn't influence the above conclusion. [ABSTRACT FROM AUTHOR]

The spectral shape of reactor antineutrinos measured in recent experiments shows anomalies in comparison to neutrino reference spectra. New precision measurements of the reactor neutrino spectra as well as more complete input in nuclear data bases are needed to resolve the observed discrepancies between models and experimental results. This article proposes the combination of experiments at reactors which are highly enriched in U 235 with commercial reactors with typically lower enrichment to gain new insights into the origin of the anomalous neutrino spectrum. The presented method clarifies, if the spectral anomaly is either solely or not at all related to the predicted U 235 spectrum. Considering the current improvements of the energy scale uncertainty of present-day experiments, a significance of three sigma and above can be reached. As an example, we discuss the option of a direct comparison of the measured shape in the currently running Double Chooz near detector and the upcoming Stereo experiment. A quantitative feasibility study emphasizes that a precise understanding of the energy scale systematics is a crucial prerequisite in recent and next generation experiments investigating the spectral anomaly. [ABSTRACT FROM AUTHOR]

The thermodynamics and phase transitions of charged RN–AdS and rotating Kerr–AdS black holes in a generalized Randall–Sundrum braneworld are investigated in the framework of thermodynamic geometry. A detailed analysis of the thermodynamics, stability and phase structures in the canonical and the grand canonical ensembles for these AdS braneworld black holes are described. The thermodynamic curvatures for both these AdS braneworld black holes are computed and studied as a function of the thermodynamic variables. Through this analysis we illustrate an interesting dependence of the phase structures on the braneworld parameter for these black holes. [ABSTRACT FROM AUTHOR]

The new Skyrme parameter set is determined by requiring that Variational Monte Carlo (VMC) calculations reproduce empirical values for properties of nuclear matter, such as binding energy per particle and saturation density. We found the new Landau parameter set by using the new Skyrme parameter set, the saturation density, and energy obtained from the new Skyrme parameter set for symmetric nuclear matter (SNM). Incompressibility of symmetric nuclear matter is also calculated by the described Skyrme-Landau Parameterization. [ABSTRACT FROM AUTHOR]

Fusion breeding blanket as one of the key in-vessel components performs the functions of breeding the tritium, removing the nuclear heat and heat flux from plasma chamber as well as acting as part of shielding system. The radial build design which determines the arrangement of function zones and material properties on the radial direction is the basis of the detailed design of fusion breeding blanket. For facilitating the radial build design, this study aims for developing a pre-design code to optimize the radial build of blanket with considering the performance of nuclear and thermal-hydraulic simultaneously. Two main features of this code are: (1) Coupling of the neutronics analysis with the thermal-hydraulic analysis to speed up the analysis progress; (2) preliminary optimization algorithm using one or multiple specified objectives subject to the design criteria in the form of constrains imposed on design variables and performance parameters within the possible engineering ranges. This pre-design code has been applied to the conceptual design of water-cooled ceramic breeding blanket in project of China fusion engineering testing reactor (CFETR). [ABSTRACT FROM AUTHOR]

pH-potentiometry and mathematical modeling were used to study interactions in the system $$ {\text{Ni}}^{2 +}{-}{\text{MoO}}_{4}^{2 -}{-}{\text{H}}^{ + } {-}{\text{H}}_{ 2} {\text{O}} $$ acidified to mole ratio $$ Z = \nu ({\text{H}}^{ + } )/\nu \left( {{\text{MoO}}_{4}^{2 - } } \right) = 1.00 $$ , within the acidity interval Z = 0.6-2.5 at 298 ± 0.1 K, with background electrolyte NaNO ( I = 0.1-0.5 mol·dm). Previously unknown thermodynamic constants and Gibbs energies for the formation reactions of Anderson type heteropoly anions H[Ni(OH)MO] (M = Mo, W) from $$ {\text{MoO}}_{4}^{2 - } $$ and H, as well as their standard Gibbs energies of formation $$ \Delta G_{\text{f}}^{0} $$ , were calculated. For the first time, the speciation schemes of the ions in Ni- $$ {\text{MoO}}_{4}^{2 - } $$ -H-HO (M = Mo, W) solutions are proposed. [ABSTRACT FROM AUTHOR]

Finite volume techniques with staggered mesh are used to develop a new numerical solver for the one-dimensional two-phase two-fluid model using a high-resolution, Total Variation Diminishing (TVD) scheme. The solver is implemented to analyze numerical benchmark problems for verification and testing its abilities to handle discontinuities and fast transients with phase change. Convergence rates are investigated by comparing numerical results to analytical solutions available in literature for the case of the faucet flow problem. The solver based on a new TVD scheme is shown to exhibit higher-order of accuracy compared to other numerical schemes. Mass errors are also examined when phase change occurs for the shock tube problem, and compared to those of the 1st-order upwind scheme implemented in the nuclear thermal-hydraulics code TRACE. The solver is shown to exhibit numerical stability when applied to problems with discontinuous solutions and results of the new solver are free of spurious oscillations. [ABSTRACT FROM AUTHOR]

There exists, in general, no unique definition of the size (volume, area, etc., depending on dimension) of a soliton. Here we demonstrate that the geometric volume (area etc.) of a soliton is singled out in the sense that it exactly coincides with the thermodynamical or continuum-mechanical volume. In addition, this volume may be defined uniquely for rather arbitrary solitons in arbitrary dimensions. [ABSTRACT FROM AUTHOR]

The results of the numerical simulation of the behavior of a system consisting a spherical bubble filled with gaseous argon and surrounded by water under the impact of an external periodic pressure are presented. It is shown that, under typical conditions for the experimental investigation of single-bubble sonoluminescence in such a system, conditions are created for its thermal ionization near the time instant of the maximum compression in the gas. This proves one of the main provisions of the polarization model of sonoluminescence. [ABSTRACT FROM AUTHOR]

In this paper, the intrinsic point defects in ZnO crystal have been studied by the approach that integrates first-principles, thermodynamic calculations and the contributions of vibrational entropy. With temperature increasing and oxygen partial pressure decreasing, the formation energies of oxygen vacancy , zinc interstitial and zinc anti-site are decreasing, while it increases for zinc vacancy , oxygen interstitial and oxygen anti-site . They are more sensitive to temperature than oxygen partial pressure. There are two interesting phenomena. First, or have the lowest formation energies for whole Fermi level at special environment condition (such as at , about or , about ) and intrinsic -type doping of ZnO is possible by at these special conditions. Second, as donors have lowest formation energy for all Fermi level at high temperature and low oxygen partial pressure , . According to our analysis, the could produce -type doping in ZnO at these special conditions and change -type ZnO to -type ZnO at condition from low temperature and high oxygen partial pressure to high temperature and low oxygen partial pressure. [ABSTRACT FROM AUTHOR]

The dynamics of partons and hadrons in relativistic nucleus-nucleus collisions is analyzed within the Parton-HadronString Dynamics (PHSD) transport approach which is based on a dynamical quasiparticle model for the partonic phase (DQPM) including a dynamical hadronization scheme with covariant transition rates. The PHSD approach is applied to nucleus-nucleus collisions from FAIR/NICA to LHC energies. The traces of partonic interactions are found in particular in the directed and elliptic flow of hadrons and in their transverse mass spectra. Whereas at RHIC and LHC energies the dynamics is dominated by partonic degrees-of-freedom in the hot QGP, we find at FAIR/NICA energies a moderately hot but dense matter where chiral symmetry restoration and hadronic potentials appear to play a major role. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

The system of intermediate fissility 132Ce has been studied experimentally and theoretically to investigate the dissipation properties of nuclear matter. Cross sections of fusion-fission and evaporation-residue channels together with light charged particle multiplicities in both channels, their spectra, light charged particle-evaporation residue angular correlations, and mass-energy distribution of fission fragments have been measured. Theoretical analysis has been performed using a multidimensional stochastic approach coupled with a Hauser-Feshbach treatment of particle evaporation. The main conclusions are that the full one-body shape-dependent dissipation mechanism allows the reproduction of the full set of experimental data and that after a time τd=5×10-21 s from the equilibrium configuration of the compound nucleus, fission decay can occur in a time that can span several orders of magnitude. [ABSTRACT FROM AUTHOR]

It has been customary to use data from the Oklo natural nuclear reactor to place bounds on the change that has occurred in the electromagnetic fine structure constant α over the last 2 billion years. Alternatively, an analysis could be based on a recently proposed expression for shifts in resonance energies which relates them to changes in both α and the average m of the u and d current quark masses, and which makes explicit the dependence on mass number A and atomic number Z. (Recent model independent results on hadronic $${\sigma}$$ -terms suggest sensitivity to the strange quark mass is negligible.) The most sophisticated analysis, to date, of the quark mass term invokes a calculation of the nuclear mean-field within the Walecka model of quantum hadrodynamics. We comment on this study and consider an alternative in which the link to low-energy quantum chromodynamics and its pattern of chiral symmetry-breaking is more readily discernible. Specifically, we investigate the sensitivity to changes in the pion mass $${M_\pi}$$ of a single nucleon potential determined by an in-medium chiral perturbation theory ( $${\chi}$$ PT) calculation which includes virtual $${{\Delta}}$$ -excitations. Subject to some reasonable assumptions about low-energy constants, we confirm that the m-contribution to resonance shifts is enhanced by a factor of 10 or so relative to the $${\alpha}$$ -term and deduce that the Oklo data for Sm imply that $${|m_q({\rm Oklo})- m_q({\rm now})| \lesssim 10^{-9}m_q({\rm now})}$$ . [ABSTRACT FROM AUTHOR]

Thermodynamic quantities of 46 Ti have been calculated in the framework of the BCS model with inclusion of modified nuclear pairing gap (MPBCS) that was proposed in our previous publication. Using modified paring gap results in an S-shaped heat capacity curve at critical temperature with a smooth behavior instead of singular behavior of the same curve in the BCS calculations. In addition the thermal quantities have been extracted within the framework of a canonical ensemble according to the new experimental data on nuclear level densities measured by the Oslo group. Comparison shows a good agreement between our calculations in MPBCS and the extracted quantities in the canonical ensemble framework. [ABSTRACT FROM AUTHOR]

By linking to the thermodynamic and atomic mobility databases in Al alloys well established in our research group, the microstructure evolution in industrial A2214 alloy (Al-4.5Cu-0.5Mg-1.0Si, in wt pct) during solidification process was studied by means of two-dimensional phase-field simulation via MICRostructure Evolution Simulation Software in the framework of the multi-phase-field formalism. The thermophysical parameters including interfacial energies and interfacial mobilities were carefully chosen for reproducing the experimental features. The solidification sequence due to the present phase-field simulation conforms to both equilibrium calculation and Scheil simulation. The predicted microstructure reproduces the experimental data very well. These facts indicate that a quantitative phase-field simulation was achieved in the present work. Moreover, the mechanisms of characteristic patterns and microstructure formation were revealed with the aid of the phase-field simulation. In addition, the effect of cooling rate on the secondary dendrite arm spacing and microsegregation was also investigated through comprehensive comparison with the experimental data. [ABSTRACT FROM AUTHOR]

The usual formulation of thermodynamics is based on the additivity of macroscopic systems. However, there are numerous examples of macroscopic systems that are not additive, due to the long-range character of the interaction among the constituents. We present here an approach in which nonadditive systems can be described within a purely thermodynamics formalism. The basic concept is to consider a large ensemble of replicas of the system where the standard formulation of thermodynamics can be naturally applied and the properties of a single system can be consequently inferred. After presenting the approach, we show its implementation in systems where the interaction decays as 1/ra in the interparticle distance r, with α smaller than the embedding dimension d, and in the Thirring model for gravitational systems. [ABSTRACT FROM AUTHOR]

Effects of an external magnetic field on various properties of quantum chromodynamics (QCD) matter under extreme conditions of temperature and density (chemical potential) have been analyzed. To this end, we use SU(3) Polyakov linear-o-model and assume that the external magnetic field (ell) adds some restrictions to the quarks" energy due to the existence of free charges in the plasma phase. In doing this, we apply the Landau theory of quantization, which assumes that the cyclotron orbits of charged particles in a magnetic field should be quantized. This requires an additional temperature to drive the system through the chiral phase transition. Accordingly, the dependence of the critical temperature of chiral and confinement phase transitions on the magnetic field is characterized. Based on this, we have studied the thermal evolution of thermodynamic quantities (energy density and trace anomaly) and the first four higher-order moment of particle multiplicity. Having all these calculations, we have studied the effects of the magnetic field on the chiral phase transition. We found that both critical temperature l\ and critical chemical potential increase with increasing magnetic field, ell Last but not least, the magnetic effects of the thermal evolution of four scalar and four pseudoscalar meson states are studied. We concluded that the meson masses decrease as the temperature increases up to Tc. Then, the vacuum effect becomes dominant and rapidly increases with the temperature T. At low T. the scalar meson masses normalized to the lowest Matsubara frequency rapidly decrease as T increases. Then, starting from Tc, we find that the thermal dependence almost vanishes. Furthermore, the meson masses increase with increasing magnetic field. This gives a characteristic phase diagram of T vs external magnetic field eB. At high/, we find that the masses of almost all meson states become temperature independent. It is worthwhile to highlight that the various meson states likely have different critical temperatures. [ABSTRACT FROM AUTHOR]

A simple model for open quantum systems is analyzed with random matrix theory. The system is coupled to the continuum in a minimal way. In this paper the effect on the level statistics of opening the system is seen. In particular the Δ3(L) statistic, the width distribution and the level spacing are examined as a function of the strength of this coupling. The emergence of a super-radiant transition is observed. The level spacing and Δ3(L) statistics exhibit the signatures of missed levels or intruder levels as the super-radiant state is formed. [ABSTRACT FROM AUTHOR]

We investigate the extended thermodynamic properties of higher-dimensional Taub–NUT/Bolt–AdS spaces where a cosmological constant is treated as a pressure. We find a general form for thermodynamic volumes of Taub–NUT/Bolt–AdS black holes for arbitrary dimensions. Interestingly, it is found that the Taub–NUT–AdS metric has a thermodynamically stable range when the total number of dimensions is a multiple of 4 (4, 8, 12, …). We also explore their phase structure and find the first order phase transition holds for higher-dimensional cases. [ABSTRACT FROM AUTHOR]

In the present work we discuss a third alternative to explain the latest observational data concerning the accelerating Universe and its different stages. The particle creation mechanism in the framework of non-equilibrium thermodynamics is considered as a basic cosmic mechanism acting on the flat FRW geometry. By assuming that the gravitationally induced particle production occurs under “adiabatic” conditions, the deceleration parameter is expressed in terms of the particle creation rate which is chosen as a truncated power series of the Hubble parameter. The model shows the evolution of the Universe starting from inflation to the present late time acceleration and it also predicts future decelerating stage. [ABSTRACT FROM AUTHOR]

In this paper we analyze the thermodynamic properties of a photon gas under the influence of a background electromagnetic field in the context of any nonlinear electrodynamics. Neglecting the self-interaction of photons, we obtain a general expression for the grand canonical potential. Particularizing for the case when the background field is uniform, we determine the pressure and the energy density for the photon gas. Although the pressure and the energy density change when compared with the standard case, the relationship between them remains unaltered, namely ρ = 3 p . Finally, we apply the developed formulation to the cases of Heisenberg–Euler and Born–Infeld nonlinear electrodynamics. For the Heisenberg–Euler case, we show that our formalism recovers the results obtained with the 2-loop thermal effective action approach. [ABSTRACT FROM AUTHOR]

We calculate the heat transfer passing through two horizons of charged dilaton-axion black hole and the quasi-localized energy in the patch M between two horizons. The result EEinstein|M= EMɸller|M - ΣδM TS is a Legendre transformation. So that the quasi-localized energy EEinstein and EMɸller in the patch M could be considered as thermodynamic potentials. [ABSTRACT FROM AUTHOR]

We investigate the thermodynamic equation of state of isospin-symmetric nuclear matter with microscopic nuclear forces derived within the framework of chiral effective field theory. Two- and three-body nuclear interactions constructed at low-resolution scales form the basis for a perturbative calculation of the finitetemperature equation of state. The nuclear force models and many-body methods are benchmarked against bulk properties of isospin-symmetric nuclear matter at zero temperature, which are found to be well reproduced when chiral nuclear interactions constructed at the lowest resolution scales are employed. The calculations are then extended to finite temperatures, where we focus on the liquid-gas phase transition and the associated critical point. The Maxwell construction is applied to construct the physical equation of state, and the value of the critical temperature is determined to be Tc = 17.2-19.1 MeV, in good agreement with the value extracted from multifragmentation reactions of heavy ions. [ABSTRACT FROM AUTHOR]