Complete stability for spherically symmetric backgrounds in beyond Horndeski theory
arXiv:2404.06297
Abstract
We consider a general static, spherically symmetric background in the quadratic beyond Horndeski theory and analyse the behaviour of linear perturbations in both parity odd and parity even sectors. We derive a full set of stability conditions for an arbitrary static, spherically symmetric solution which guarantees absence of ghosts, gradient instabilities, tachyons and superluminal modes in both sectors.
16 pages, published in IJMPA ICNFP2022 Special Issue