Unification of Gauge and Gravity Chern-Simons Theories in 3-D Space time

Chamseddine and Mukhanov showed that gravity and gauge theories could be unified in one geometric construction provided that a metricity condition is imposed on the vielbein. In this paper we are going to show that by enlarging the gauge group we are able to unify Chern-Simons gauge theory and Chern-Simons gravity in 3-D space-time. Such unification leads to the quantization of the coefficients for both Chern-Simons terms for compact groups but not for non-compact groups. Moreover, it leads to a topological invariant quantity of the 3 dimensional space-time manifold on which they are defined

Mimetic Horava Gravity and Surface terms

We consider mimetic Horava gravity, where the scalar field of mimetic gravity was used in the construction of diffeomorphism invariant models reducing to Horava gravity in the synchronous gauge. It will be shown that the surface terms resulting from the variation of the action constructed will cancel out; therefore, there is no need for the addition of Gibbons-Hawking-York boundary term. The resulting surface terms contain higher order space derivatives and no higher order time derivativesComment: 9 page