Related papers: Helicity Decomposition of Ghost-free Massive Gravi…
We find the explicit forms of the anti-de Sitter plane, anti-de Sitter spherical, and pp waves that solve both the linearized and exact field equations of the most general higher derivative gravity theory in three dimensions. As a…
The triviality Higgs mass bound is studied {\it without} lattice regulator in the spontaneously broken phase of the four dimensional O(4) symmetric scalar field theory with quartic self-interaction. A higher derivative term is introduced in…
We study the number of degrees of freedom (DOFs) in quadratic scalar-nonmetricity (QSN) theory, whose Lagrangian is the linear combination of five quadratic nonmetricity invariants with coefficients depending on a dynamical scalar field.…
Many theories of modified gravity with higher order derivatives are usually ignored because of serious problems that appear due to an additional ghost degree of freedom. Most dangerously, it causes an immediate decay of the vacuum. However,…
Exact, degenerate two-forms on time-extended space R X M which are invariant under the unsteady, incompressible fluid motion on 3D region M are introduced. The equivalence class up to exact one-forms of each potential one-form is splitted…
In this paper, we investigate the Higgs Triplet Model with hypercharge $Y_{\Delta}=0$ (HTM0), an extension of the Standard model, caracterised by a more involved scalar spectrum consisting of two CP even Higgs $h^0, H^0$ and two charged…
Four-dimensional gravitational theories derived from an infinite sum of Lovelock curvature invariants, combined with a conformal rescaling of the metric, are equivalent to a subclass of shift-symmetric Horndeski theories that possess a…
We revisit the problem of the helicity-0 ghost mode of massive graviton in the de Sitter background. In general, the presence of a ghost particle, which has negative energy, drives the vacuum to be unstable through pair production of ghost…
Perturbation theory of a large class of scalar field theories in $d<4$ can be shown to be Borel resummable using arguments based on Lefschetz thimbles. As an example we study in detail the $\lambda \phi^4$ theory in two dimensions in the…
Motivated by the ideas of Jacob Bekenstein concerning gravity-assisted symmetry breaking, we consider a non-canonical model of f(R)=R+R^2 extended gravity coupled to neutral scalar "inflaton", as well as to SU(2)xU(1) multiplet of fields…
In gravitational Higgs mechanism graviton components acquire mass in the process of spontaneous breaking of diffeomorphisms (via scalar vacuum expectation values). Recently, gravitational Higgs mechanism was discussed in the context of…
We introduce conformal traceless decomposition in Lagrange Multiplier modified RFDiff invariant Horava-Lifshitz gravity. We perform Hamiltonian analysis of given action and determine the action for the physical degrees of freedom.
Pure massive gravity is strongly coupled at a certain low scale, known as Lambda_3. I show that the theory can be embedded into another one, with new light degrees of freedom, to increase the strong scale to a significantly larger value.…
A number of approaches to gravitation have much in common with the gauge theories of the standard model of particle physics. In this paper, we develop the Hamiltonian formulation of a class of gravitational theories that may be regarded as…
We present a general model of interacting metric fields with the sum of massless non-interacting spin 2 fields as the linear limit. In the non-interacting limit the model is reduced to a sum of general relativity actions, with the usual…
We present the Hamiltonian formalism for $f(T)$ gravity, and prove that the theory has $\frac{n(n-3)}{2}+1$ degrees of freedom (d.o.f.) in $n$ dimensions. We start from a scalar-tensor action for the theory, which represents a scalar field…
A general paradigm for describing classical (and semiclassical) gravity is presented. This approach brings to the centre-stage a holographic relationship between the bulk and surface terms in a general class of action functionals and…
Freely decaying relativistic force-free turbulence is studied for the first time. We initiate the magnetic field at a short wavelength and simulate its relaxation toward equilibrium on two and three dimensional periodic domains, in both…
In this work we shall address the ghost issue of $F\left( R,\mathcal{G} \right)$ gravity, which is known to be plagued with ghost degrees of freedom. These ghosts occur due to the presence of higher than two derivatives in the field…
The (m^2,\Lambda) plane of spin s>1 massive fields in (A)dS backgrounds is shown to consist of separate phases, divided by lines of novel ``partially massless'' gauge theories that successively remove helicities, starting from the lowest, 0…