Speaker
Jorge Noronha
(U)
Description
We argue, using the AdS/CFT correspondence, that the transient
dynamics of the shear stress tensor in a strongly coupled N = 4 SYM
plasma is not described by relaxation-type, fluid dynamical equations:
at long times the equations of motion should contain a second-order
comoving derivative of the shear stress tensor. This occurs because in
this strongly-coupled system the lowest “non-hydrodynamical”
quasinormal modes associated with shear stress possess a nonzero real
part at zero wavenumber. We use Weyl invariance to obtain the most
general equations of motion containing 2 comoving derivatives of the
shear stress tensor that are compatible with the symmetries. We show
that the asymptotic solution of this theory valid at times much larger
than the timescale associated with the “non-hydrodynamical” modes
reproduces the well-known results previously obtained directly from
the AdS/CFT correspondence. If the QGP formed in heavy ion collisions
can be at least qualitatively understood in terms of strongly-coupled
N = 4 SYM theory, the second time derivative present in the equations
of motion of the fluid may lead to an unexpected dependence on the
initial conditions for the shear stress tensor needed in numerical
hydrodynamic simulations.
Primary author
Jorge Noronha
(U)
Co-author
Gabriel Denicol
(Frankfurt University)
