Speaker
Description
Strong magnetic fields are expected to exist in the early stages of heavy ion
collisions and there is also an increasing evidence that the energy dependence of the
cross-sections can strongly affect the dynamics of a system even at a qualitative level.
This led us to the current study where we developed second-order non-resistive
relativistic viscous magnetohydrodynamics (MHD) derived from kinetic theory using an
extended relaxation time approximation (ERTA), where the relaxation time of the usual
relaxation time approximation (RTA) is modified to depend on the momentum of the
colliding particles. A Chapman-Enskog-like gradient expansion of the Boltzmann
equation is employed for a charge-conserved, conformal system, incorporating a
momentum-dependent relaxation time. The resulting evolution equation for the shear
stress tensor highlights significant modifications in the coupling with the dissipative
charge current and magnetic field. The results were compared with the recently
published exact analytical solutions for the scalar theory where the relaxation time
is directly proportional to momentum. Our approximated results show a very close
agreement with the exact results. This can lead us to transport coefficient calculations
for various theories for which exact results are not yet known.
