V. Sreekanth

Relativistic viscous hydrodynamics for heavy-ion collisions: A comparison between the Chapman-Enskog and Grad methods

Derivations of relativistic second-order dissipative hydrodynamic equations have relied almost exclusively on the use of Grads 14-moment approximation to write

Thermal photons in QGP and non-ideal effects

f(x,p)

Particle production in relativistic heavy-ion collisions: A consistent hydrodynamic approach

, the nonequilibrium distribution function in the phase space. Here we consider an alternative Chapman-Enskog-like method, which, unlike Grads, involves a small expansion parameter. We derive an expression for

Shear viscosity, cavitation and hydrodynamics at LHC

f(x,p)

Cavitation and thermal dilepton production in QGP

to second order in this parameter. We show analytically that while Grads method leads to the violation of the experimentally observed

Bulk viscosity in hyperonic star and r-mode instability

1/\sqrt{m_T}

PHOTON EMISSION FROM OUT OF EQUILIBRIUM DISSIPATIVE PARTON PLASMA

scaling of the longitudinal femtoscopic radii, the alternative method does not exhibit such an unphysical behavior. We compare numerical results for hadron transverse-momentum spectra and femtoscopic radii obtained in these two methods, within the one-dimensional scaling expansion scenario. Moreover, we demonstrate a rapid convergence of the Chapman-Enskog-like expansion up to second order. This leads to an expression for

Quark and gluon distribution functions in a viscous quark-gluon plasma medium and dilepton production via q(q)over-bar annihilation

\delta f(x,p)

Attributes of a rotating neutron star with a hyperon core

which provides a better alternative to Grads approximation for hydrodynamic modeling of relativistic heavy-ion collisions.

Impact of momentum anisotropy and turbulent chromo-fields on thermal particle production in quark-gluon-plasma medium

We investigate the thermal photon production-rates using one dimensional boost-invariant second order relativistic hydrodynamics to find proper time evolution of the energy density and the temperature. The effect of bulk-viscosity and non-ideal equation of state are taken into account in a manner consistent with recent lattice QCD estimates. It is shown that the non-ideal gas equation of state i.e ε − 3 P ≠ 0 behaviour of the expanding plasma, which is important near the phase-transition point, can significantly slow down the hydrodynamic expansion and thereby increase the photon production-rates. Inclusion of the bulk viscosity may also have similar effect on the hydrodynamic evolution. However the effect of bulk viscosity is shown to be significantly lower than the non-ideal gas equation of state. We also analyze the interesting phenomenon of bulk viscosity induced cavitation making the hydrodynamical description invalid. It is shown that ignoring the cavitation phenomenon can lead to erroneous estimation of the photon flux.