The Self-consistent Matter Coupling of a Class of Minimally Modified Gravity Theories.
The self-consistent matter coupling has been found in a broad class of minimally modified gravity theories which was discovered recently. All constraints in the theories remain first class and thus a graviton has only 2 local degrees of freedom. The cosmological solution of one of the examples in this class, the so-called square root gravity, exhibits a null energy condition violation, given a proper time dependence of the parameters in the theory, as well a singularity freeness at high energy limit. At low energy limit, the theory smoothly connects to GR. A general feature of the theories in this class, with the self-consistent matter coupling discovered in our current work, is the non-trivial interaction among different components of matter sector.
Publisher URL: http://arxiv.org/abs/1811.02467