相关论文: Adiabatic index for relativistic stars as a coeffi…

The relativistic effects in cosmological observables contain critical information about the initial conditions and gravity on large scales. Compared to the matter density fluctuation, some of these relativistic contributions scale with…

We argue that $isotropic$ scalar fluctuations in solid inflation are adiabatic in the super-horizon limit. During the solid phase this adiabatic mode has peculiar features: constant energy-density slices and comoving slices do not coincide,…

In this article, we assume that a cold charged perfect fluid is constructing a spherical relativistic star. Our purpose is the investigation of the dynamical properties of its exterior geometry, through simulating the geodesic motion of a…

We present results on the effect of the stiffness of the equation of state on the dynamical bar-mode instability in rapidly rotating polytropic models of neutron stars in full General Relativity. We determine the change in the threshold for…

We study the gravitational collapse of a spherically symmetric anisotropic relativistic star within Einstein theory of gravity making use of one of our recently developed collapsing stellar models [{\it Astrophys. Space Sci.} {\bf361} 99…

The fluctuation-response relation is a fundamental relation that is applicable to systems near equilibrium. On the other hand, when a system is driven far from equilibrium, this relation is violated in general because the detailed-balance…

In the chaotic inflation models, quantum fluctuations for axion fields lead to the overproduction of domain walls and too large isocurvature fluctuations which is inconsistent with the observations of cosmic microwave background…

The Vlasov equation embodies the smooth field approximation of the self-consistent equation of motion for charged particle beams. This framework is fundamentally altered if we include the fluctuating forces that originate from the actual…

The distinguishing feature of the evolution of close binary stars is the role played by the mass exchange between the component stars. Whether the mass transfer is dynamically stable is one of the essential questions in binary evolution. In…

The problem of the dynamical stability of anistropic systems is studied, by proposing a criterion in terms of the adiabatic local index $\gamma$. The result has general validity and can be applied to several physical situations.…

We consider a transport equation of the Boltzmann-Langevin type for non-Abelian plasmas close to equilibrium to derive the spectral functions of the underlying microscopic fluctuations from the entropy. The correlator of the stochastic…

In dissipative dynamical systems phase space volumes contract, on average. Therefore, the invariant measure on the attractor is singular with respect to the Lebesgue measure. As noted by Ruelle, a generic perturbation pushes the state out…

One of the greatest challenges in interpreting the pulsations of rapidly rotating stars is mode identification, i.e. correctly matching theoretical modes to observed pulsation frequencies. Indeed, the latest observations as well as current…

The Dark Sector is described by an additional barotropic fluid which evolves adiabatically during the universe's history and whose adiabatic exponent $\gamma$ is derived from the standard definitions of specific heats. Although in general…

We study anomalous diffusion for one-dimensional systems described by a generalized Langevin equation. We show that superdiffusion can be classified in normal superdiffusion and fast superdiffusion. For fast superdiffusion, we prove that…

In this work we present an exact model of a spherically symmetric star undergoing dissipative collapse in the form of a radial heat flux. The interior of the star is matched smoothly to the generalised Vaidya line element representing a…

The physics of stars, their workings and their evolution, is a goldmine of problems in statistical mechanics and thermodynamics. We discuss many examples that illustrate the possibility of deepening student's knowledge of statistical…

To describe the nonequilibrium states of a system we introduce a new thermodynamic parameter - the lifetime of a system. The statistical distributions which can be obtained out of the mesoscopic description characterizing the behaviour of a…

A new theory of gravitational shocking based on time-dependent perturbation theory shows that the changes in energy and angular momentum due to a slowly varying disturbance are not exponentially small for stellar dynamical systems in…

We study the role of adiabatic index in determining the critical points in the transonic low angular momentum accretion flow onto a black hole. We present the general relativistic 2D hydrodynamic simulations of axisymmetric, inviscid…