Stability of the Einstein static universe in IR modified Hořava gravity
Department of Mathematics and Institute of Origins, University College London, Gower Street, London, WC1E 6BT, UK
2 Centro de Física Teórica e Computacional, Faculdade de Ciências da Universidade de Lisboa, Avenida Professor Gama Pinto 2, 1649-003, Lisbon, Portugal
Revised: 22 October 2010
Published online: 23 November 2010
Recently, Hořava proposed a power counting renormalizable theory for (3+1)-dimensional quantum gravity, which reduces to Einstein gravity with a non-vanishing cosmological constant in IR, but possesses improved UV behaviors. In this work, we analyze the stability of the Einstein static universe by considering linear homogeneous perturbations in the context of an IR modification of Hořava gravity, which implies a ‘soft’ breaking of the ‘detailed balance’ condition. The stability regions of the Einstein static universe is parameterized by the linear equation of state parameter w=p/ρ and the parameters appearing in the Hořava theory, and it is shown that a large class of stable solutions exists in the respective parameter space.
© Springer-Verlag / Società Italiana di Fisica, 2010