Thermodynamics of nonstationary and transient effects in a relativistic gas

We show how a system of generalized Fourier and Navier-Stokes equations, containing relaxation terms and couplings between heat flow and viscosity, can be consistently derived from phenomenological thermodynamics and from kinetic theory. The coefficients are given explicitly for a relativistic Boltzmann gas.     

Heat flow in relativistic equilibrium thermodynamics

An attempt is made to clarify a thought experiment introduced by P. T. Landsberg concerning the relativistic heat flow between bodies in relative motion. It is shown that if the problem is analyzed within the covariant thermodynamics developed by R. Balescu, supplemented by the second law of thermodynamics as proposed here, then such heat flow considerations do not fix the transformation of temperature as Landsberg contends. Instead, the transformation of temperature is left as being purely a matter of definition.     

The laws of relativistic thermodynamics: II. The density,momentum and energy laws

The conservation laws of particle number, momentum and energy are derived from relativistic kinetic theory. The first law of relativistic thermodynamics is formulated.     

The laws of relativistic thermodynamics: I. The macroscopic quantities

The physical quantities which occur in the laws of relativistic thermodynamics are defined as statistical expressions of relativistic kinetic theory. The role of the hydrodynamic velocity field is discussed.     

Die Strahlungs-Temperatur bewegter Körper

The Radiation Temperature of Moving Bodies The comparison of the temperatures of two bodies which are in a relative motion is possible by the black-body-radiation of these bodies, unambiguously. Then, Planck's transformation law for the temperature is resulting by Einstein's theory of the transversal Doppler-effect and the aberration and by the laws of heat radiation without additional hypotheses. - Our argument is based on the transformation formulas of the specific radiation intensities which are proved by M. v. Laue (1943) in his relativistic deduction of Wien's law.     

Integrating Factors and Conservation Laws for Relativistic Mechanical System

In this paper, we present a new method to construct the conservation laws for relativistic mechanical systems by finding corresponding integrating factors. First, the Lagrange equations of relativistic mechanical systems are established, and the definition of integrating factors of the systems is given; second, the necessary conditions for the existence of conserved quantities of the relativistic mechanical systems are studied in detail, and the relation between the conservation laws and the integrating factors of the systems is obtained and the generalized Killing equations for the determination of the integrating factors are given; finally, the conservation theorem and its inverse for the systems are established, and an example is given to illustrate the application of the results.     

Entropy and anisotropy

We address the problem of defining the concept of entropy for anisotropic cosmological models. In particular, we analyze for the Bianchi I and V models the entropy which follows from postulating the validity of the laws of standard thermodynamics in cosmology. Moreover, we analyze the Cardy–Verlinde construction of entropy and show that it cannot be associated with the one following from relativistic thermodynamics.     

Locally Anisotropic Kinetic Processes and Thermodynamics in Curved Spaces

The kinetic theory is formulated with respect to anholonomic frames of reference on curved spacetimes. By using the concept of nonlinear connection we develop an approach to modelling locally anisotropic kinetic processes and, in corresponding limits, the relativistic nonequilibrium thermodynamics with local anisotropy. This leads to a unified formulation of the kinetic equations on (pseudo) Riemannian spaces and in various higher dimensional models of Kaluza–Klein type and/or generalized Lagrange and Finsler spaces. The transition rate considered for the locally anisotropic transport equations is related to the differential cross section and spacetime parameters of anisotropy. The equations of states for pressure and energy in locally anisotropic thermodynamics are derived. The obtained general expressions for heat conductivity, shear, and volume viscosity coefficients are applied to determine the transport coefficients of cosmic fluids in spacetimes with generic local anisotropy. We emphasize that such local anisotropic structures are induced also in general relativity if we are modelling physical processes with respect to frames with mixed sets of holonomic and anholonomic basis vectors which naturally admits an associated nonlinear connection structure.     

Effect of arbitrary matter-geometry coupling on thermodynamics in f(R) theories of gravity

In this paper, the thermodynamics of the Friedmann–Lemaître–Robertson–Walker universe have been explored in f(R) theories of gravity with arbitrary matter-geometry coupling. The equivalence between the modified Friedmann equations with any spatial curvature and the first law of thermodynamics is confirmed, where the assumption of the entropy plays a crucial role. Then laws of thermodynamics in our considering case are obtained. They can reduce to the ones given in Einstein’s general theory of relativity under certain conditions. Moreover, a particular model is investigated through the obtained generalized second law of thermodynamics with observational results of cosmographic parameters.     

Thermodynamics and Preferred Frame

The Lorentz covariant statistical physics and thermodynamics is formulated within the preferred frame approach. The transformation laws for geometrical and mechanical quantities such as volume and pressure as well as the Lorentz-invariant measure on the phase space are found using Lorentz transformations in absolute synchronization. Next, the probability density and partition function are investigated using the preferred frame approach, and the transformation laws for internal energy, entropy, temperature and other thermodynamical potentials are established. The Lorentz covariance of basic thermodynamical relations, including Clapeyron's equation and Maxwell's relations is shown. Finally, the relation of presented approach to the previous approaches to relativistic thermodynamics is briefly discussed.     

Thermodynamic potentials and thermodynamic relations in nonextensive thermodynamics

The generalized Gibbs free energy and enthalpy are derived in the framework of nonextensive thermodynamics by using the concept of the physical temperature and the physical pressure. Some relations of the thermodynamical potentials are changed due to the difference between the physical temperature and the inverse of Lagrange multiplier. We derive the thermodynamical relation between the heat capacities at a constant volume and at a constant pressure using the generalized thermodynamical potential. We find that it has a different form from the traditional one in Gibbs thermodynamics. But, the expressions of the heat capacities in this framework using the generalized thermodynamical potentials are still the same as the traditional one.     

On the nature of the so-called generic instabilities in dissipative relativistic hydrodynamics

It is shown that the so-called generic instabilities that appear in the framework of relativistic linear irreversible thermodynamics (LIT), describing the fluctuations of a simple fluid close to equilibrium, arise due to the coupling of heat with hydrodynamic acceleration which appears in Eckart’s formalism of relativistic irreversible thermodynamics. Further, we emphasize that such behavior should be interpreted as a contradiction to the postulates of LIT, namely a violation of Onsager’s hypothesis on the regression of fluctuations, and not as fluid instabilities. Such contradictions can be avoided within a relativistic linear framework if a Meixner-like approach to the phenomenological equations is employed.     

Nonlinear heat equations

The modified Smoluchowski equation, coupled to a temperature field, leads to a pair of nonlinear heat equations obeying the first and second laws of thermodynamics. We obtain a solution representing a particle under gravity, moving in a slab and maintained in stasis away from the Gibbs state by a temperature gradient. A two-state atom in a potential in isothermal conditions is described by coupled equations satisfying detailed balance. It is shown that the free energy is a monotonic decreasing function of time.     

相对论热力学向量理论对Schwarzschild场中物质系统特性的研究

应用相对论热力学向量理论，讨论了Ｓｃｈｗａｒｚｓｃｈｉｌｄ场中球对称静态理想流体恒星结构，得到了Ｔｏｌｍａｎ-Ｏｐｐｅｎｈｅｉｍｅｒ-Ｖｏｌｋｏｆ方程，并且就该引力场中粒子系统的不同运动状况做了讨论，由此得到了与经典极限相符合的结果．     

Relativistic thermodynamics of fluids. I

In 1953, Stueckelberg and Wanders derived the basic laws of relativistic linear nonequilibrium thermodynamics for chemically reacting fluids from the relativistic local conservation laws for energy-momentum and the local laws of production of substances and of non-negative entropy production by the requirement that the corresponding currents (assumed to depend linearly on the first derivatives of the state variables) should not be independent. Generalizing their method, we determine the most general allowed form of the energy-momentum tensor T^αβ and of the corresponding rate of entropy production under the same restriction on the currents. The problem of expressing this rate in terms of thermodynamic forces and fluxes is discussed in detail; it is shown that the number of independent forces is not uniquely determined by the theory, and several possibilities are explored. A number of possible new cross effects are found, all of which persist in the Newtonian (low-velocity) limit. The treatment of chemical reactions is incorporated into the formalism in a consistent manner, resulting in a derivation of the law for rate of production, and in relating this law to transport processes differently than suggested previously. The Newtonian limit is discussed in detail to establish the physical interpretation of the various terms of T^αβ. In this limit, the interpretation hinges on that of the velocity field characterizing the fluid. If it is identified with the average matter velocity following from a consideration of the number densities, the usual local conservation laws of Newtonian nonequilibrium thermodynamics are obtained, including that of mass. However, a slightly different identification allows conversion of mass into energy even in this limit, and thus a macroscopic treatment of nuclear or elementary particle reactions. The relation of our results to previous work is discussed in some detail.     

Relativistic thermodynamics of gases

Relativistic thermodynamics of degenerate gases is presented here as a field theory of the 14 fields of

• particle density—particle flux, and
• stress—energy—momentum.

The field equations are based on the conservation laws of particle numbers, and energy-momentum and on a balance of fluxes. The necessary constitutive equations are strongly restricted by the

• principle of relativity,
• entropy principle,
• requirement of hyperbolicity.

It turns out that the resulting field equations contain only viscosity, bulk viscosity and heat conductivity as unknown functions. All other constitutive coefficients may be calculated from the equilibrium equations of state that are known from statistical arguments.The paper offers a more systematic version of relativistic thermodynamics of gases than the earlier papers by Müller and Israel. At the same time the present version contains less unknown functions than those earlier papers. All speeds of propagation are finite.The relation between the present theory and the classical one formulated by Eckart is described.     

One-dimensional non-relativistic and relativistic Brownian motions: a microscopic collision model

We study a simple microscopic model for the one-dimensional stochastic motion of a (non-)relativistic Brownian particle, embedded into a heat bath consisting of (non-)relativistic particles. The stationary momentum distributions are identified self-consistently (for both Brownian and heat bath particles) by means of two coupled integral criteria. The latter follow directly from the kinematic conservation laws for the microscopic collision processes, provided one additionally assumes probabilistic independence of the initial momenta. It is shown that, in the non-relativistic case, the integral criteria do correctly identify the Maxwellian momentum distributions as stationary (invariant) solutions. Subsequently, we apply the same criteria to the relativistic case. Surprisingly, we find here that the stationary momentum distributions differ slightly from the standard Jüttner distribution by an additional prefactor proportional to the inverse relativistic kinetic energy.