Resurgence in Extended Hydrodynamics

Understand

It has recently been understood that the hydrodynamic series generated by the M\"uller-Israel-Stewart theory is divergent, and that this large order behaviour is consistent with the theory of resurgence.

• Furthermore, it was observed, that the physical origin of this is the presence of a purely damped nonhydrodynamic mode.
• It is very interesting to ask whether this picture persists in cases where the spectrum of nonhydrodynamic modes is richer.
• We take the first step in this direction by considering the simplest hydrodynamic theory which, instead of the purely damped mode, contains a pair of nonhydrodynamic modes of complex conjugate frequencies.