Two-dimensional gravity with a dynamical aether

Abstract

We investigate the two-dimensional behavior of gravity coupled to a dynamical unit timelike vector field, i.e. "Einstein-aether theory". The classical solutions of this theory in two dimensions depend on one coupling constant. When this coupling is positive the only solutions are (i) flat spacetime with constant aether, (ii) de Sitter or anti-de Sitter spacetimes with a uniformly accelerated unit vector invariant under a two-dimensional subgroup of SO(2,1) generated by a boost and a null rotation, and (iii) a non-constant curvature spacetime that has no Killing symmetries and contains singularities. In this case the sign of the curvature is determined by whether the coupling is less or greater than one. When instead the coupling is negative only solutions (i) and (iii) are present. This classical study of the behavior of Einstein-aether theory in 1+1 dimensions may provide a starting point for further investigations into semiclassical and fully quantum toy models of quantum gravity with a dynamical preferred frame.

11 pages, 4 figures

Cited by in corpus (6)

• Einstein-aether gravity: a status report
• Vector field theories in cosmology
• Superluminal dispersion relations and the Unruh effect
• A momentum-space representation of Green's functions with modified dispersion on ultra-static space-time
• A momentum-space representation of Green's functions with modified dispersion relations on general backgrounds
• Superluminal Travel Made Possible (in two dimensions)