Viscosity bound for anisotropic superfluids in higher derivative gravity

Abstract

In the present paper, based on the principles of gauge/gravity duality we analytically compute the shear viscosity to entropy (η/s) ratio corresponding to the super fluid phase in Einstein Gauss-Bonnet gravity. From our analysis we note that the ratio indeed receives a finite temperature correction below certain critical temperature (T < T c ). This proves the non universality of η/s ratio in higher derivative theories of gravity. We also compute the upper bound for the Gauss-Bonnet coupling (λ) corresponding to the symmetry broken phase and note that the upper bound on the coupling does not seem to change as long as we are close to the critical point of the phase diagram. However the corresponding lower bound of the η/s ratio seems to get modified due to the finite temperature effects.