Related papers: Entropy production, viscosity bounds and bumpy bla…
We present the first ab initio determination of the shear viscosity eta of the Unitary Fermi Gas, based on finite temperature quantum Monte Carlo calculations and the Kubo linear-response formalism. We determine the temperature dependence…
We evaluate the transport properties such as shear viscosity ($\eta$), bulk viscosity ($\zeta$) and their ratios over entropy density ($s$) for hadronic matter using relativistic non-extensive Boltzmann transport equation (NBTE) in…
Entropy production quantifies the amount of irreversibility of a physical process, leading to fundamental bounds for thermodynamic quantities. It captures the inability to run a physical system forward and then backward, bringing it to the…
We argue that the phenomenologically inferred ratio of shear viscosity to entropy density of the quark-gluon plasma, $\eta/\s < 0.5$ near the deconfinement temperature $T_c$, can be understood from perturbative QCD. To rebut the widespread,…
We study the temperature dependence of the ratio of the shear viscosity to entropy density for the LQCD-contrasted hadron resonance gas of different finite system-sizes, which may represent the final state hadronic matter, formed in systems…
Entropy production is a fundamental concept that plays a crucial role in the second law of thermodynamics and the measure of irreversibility. It imposes rigorous constraints on the kinds of transformations allowed in thermodynamic…
There is a debate as to what is the value of the the entropy $S$ of extremal black holes. There are approaches that yield zero entropy $S=0$, while there are others that yield the Bekenstein-Hawking entropy $S=A_+/4$, in Planck units. There…
For an isolated assembly that comprises a system and its surrounding reservoirs, the total entropy ($S_{a}$) always monotonically increases as time elapses. This phenomenon is known as the second law of thermodynamics ($S_{a}\geq0$). Here…
Linear irreversible thermodynamics asserts that the instantaneous local spontaneous entropy production is always nonnegative. However for a viscoelastic fluid this is not always the case. Given the fundamental status of the Second Law, this…
Controversy exists regarding the possible existence of a transition between the liquid and glassy states of water. Here we use experimental measurements of the entropy, specific heat, and enthalpy of both liquid and glassy water to…
We report on a numerical experiment performed to analyze fluctuations of the entropy production in turbulent thermal convection, a physical configuration that represents here a prototypical case of an out-of-equilibrium dissipative system.…
We have evaluated the shear viscosity of pion gas taking into account its scattering with the low mass resonances, $\sigma$ and $\rho$ during propagation in the medium. The thermal width (or collisional rate) of the pions is calculated from…
The relation of the shear viscosity coefficient to the recently introduced transport rate is derived within relativistic kinetic theory. We calculate the shear viscosity over entropy ratio \eta/s for a gluon gas, which involves elastic gg->…
We investigate the entropy production within dissipative hydrodynamics in the Israel-Stewart (IS) and Navier-Stokes theory (NS) for relativistic heavy ion physics applications. In particular we focus on the initial condition in a 0+1D…
We derive the statistical entropy of the Schwarzschild black hole by considering the asymptotic symmetry algebra near the $\cal{I^{-}}$ boundary of the spacetime at past null infinity. Using a two-dimensional description and the Weyl…
Through the consideration of spherically symmetric gravitating systems consisting of perfect fluids with linear equation of state constrained to be in a finite volume, an account is given of the properties of entropy at conditions in which…
Time evolution of shear viscosity $\eta$, entropy density $s$, and their ratio $\eta / s$ in the central area of central gold-gold collisions at NICA energy range is studied within the UrQMD transport model. The extracted values of energy…
We reexamine the possibility of employing the viscosity over entropy density ratio as a diagnostic tool to identify a phase transition in hadron physics to the strongly coupled quark-gluon plasma and other circumstances where direct…
We study the ratio of the shear viscosity to the entropy density for various holographic superfluids. For the s-wave case, the ratio has the universal value 1/(4pi) as in various holographic models. For the p-wave case, there are two shear…
We review the modern view of fluid dynamics as an effective low energy, long wavelength theory of many body systems at finite temperature. We introduce the concept of a nearly perfect fluid, defined by a ratio $\eta/s$ of shear viscosity to…