Stability analysis of the $(1+1)$-dimensional Nambu-Goto action gas models
Alfred M. Grundland, Javier de Lucas, Bartosz M. Zawora
TL;DR
The paper addresses nonlinear stability of (1+1)-dimensional gas models derived from the Nambu-Goto action, focusing on Chaplygin gas and Born–Infeld equations. It develops and applies the energy-Casimir method within an infinite-dimensional Poisson framework, deriving Hamiltonian structures, identifying Casimir functionals, and formulating an explicit stability algorithm. By locating equilibria such as $p\rho=\sqrt{2\lambda}$ and $p\rho=1$ (under appropriate limits), and verifying Lyapunov stability for carefully constructed Casimirs and quadratic forms, the authors establish rigorous nonlinear stability for both models and illustrate the approach with concrete exact solutions. This work provides a geometric, variational route to stability in brane-inspired fluid models and showcases the utility of the energy-Casimir method in relativistic-like and nonlinear wave contexts.
Abstract
The aim of this paper is to perform a nonlinear stability analysis of the $(1+1)$-dimensional Nambu-Goto action gas models. The energy-Casimir method is employed to discuss in detail the Lyapunov stability of the Chaplygin and Born-Infeld models. Particular solutions are considered and their stability is studied in order to illustrate the application of our results.
