# Shear quasinormal modes of Gauss-Bonnet black brane: the first post-hydrodynamic order

## TL;DR

This paper computes the dispersion relation of shear quasinormal modes in Gauss-Bonnet black branes, extending previous results by treating the Gauss-Bonnet parameter nonperturbatively and developing a general formula for higher-order terms.

## Contribution

It introduces a refined method to calculate shear quasinormal mode dispersion relations, including nonperturbative treatment of the Gauss-Bonnet parameter and deriving a general formula for higher-order coefficients.

## Key findings

- Confirmed previous results for first and second-order coefficients.
- Developed a general formula for higher-order dispersion coefficients.
- Paved the way for more comprehensive analyses of quasinormal modes in Gauss-Bonnet gravity.

## Abstract

Assuming $\omega=\sum_n C^{(n)}q^{2n}$ in the low-frequency limit, we apply the refined recipe to compute the dispersion relation of shear quasinormal modes of the Gauss-Bonnet black brane. Treating the Gauss-Bonnet parameter $\lagb$ nonperturbatively and the momentum $q$ perturbatively, we work out $C^{(1)}$, $C^{(2)}$, confirm previous results in the literature and pave the way to a general formula for $C^{(n)}$.