Physical review. B./Physical review. B
Attractive multicomponent Gaudin-Yang model: Three roads to the energy gap
Marcos Mariño, Tomás Reis
Abstract
We analytically determine the energy gap at weak coupling in the attractive multicomponent Gaudin-Yang model, an integrable model which describes interacting fermions in one dimension with $\ensuremath{\kappa}$ components. We use three different methods. The first one is based on a direct analysis of the Bethe ansatz equations. The second method uses the theory of resurgence and the large order behavior of the perturbative series for the ground state energy. The third method is based on a renormalization group analysis. The three methods lead to the same answer, providing in this way a nontrivial test of the ideas of resurgence and renormalons as applied to nonrelativistic many-body systems.