4 research outputs found
Massive Gravity with N=1 local Supersymmetry
A consistent theory of massive gravity, where the graviton acquires mass by
spontaneously breaking diffeomorphism invariance, is now well established. We
supersymmetrize this construction using N =1 fields. Coupling to N = 1
supergravity is done by applying the rules of tensor calculus to construct an
action invariant under local N = 1 supersymmetry. The supersymmetric action is
shown, at the quadratic level, to be free of ghosts and have as its spectrum a
massive graviton, two gravitinos with different masses, and a massive vector.Comment: change in wording, references adde
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
Scalar Curvature in Discrete Gravity
We focus on studying, numerically, the scalar curvature tensor in a
two-dimensional discrete space. The continuous metric of a two-sphere is
transformed into that of a lattice using two possible slicings. In the first,
we use two integers, while in the second we consider the case where one of the
coordinates is ignorable. The numerical results of both cases are then compared
with the expected values in the continuous limit as the number of cells of the
lattice becomes very large