Related papers: Gravitional coupling constant in higher dimensions
A mechanism for suppressing the cosmological constant is developed, based on an analogy with a superconducting phaseshift in which free fermions coupled perturbatively to a weak gravitational field are in an unstable false vacuum state. The…
A classical two dimensional theory of gravity which has a number of interesting features (including a Newtonian limit, black holes and gravitational collapse) is quantized using conformal field theoretic techniques. The critical dimension…
We study a Newtonian cosmological model in the context of a noncommutative space. It is shown that the trajectories of a test particle undergo modifications such that it no longer satisfies the cosmological principle. For the case of a…
In the Horndeski's most general scalar-tensor theories the equations of scalar density perturbations are derived in the presence of non-relativistic matter minimally coupled to gravity. Under a quasi-static approximation on sub-horizon…
Spatial correlation characteristics of the anomalous density matrix $\kappa$ in a slab of nuclear matter with the Paris and Argonne v18 forces are calculated. A detailed comparison with predictions of the effective Gogny force is made. It…
The main goal of this paper is the manifestly covariant derivation of the classical relation between the gauge-fixed Grassmann variables of the NSR string and the Type II GS superstring. To this end we analyze the superembedding equation…
A covariant scheme for matter coupling with a GL(3,R) gauge formulation of gravity is studied. We revisit a known Yang-Mills type construction, where quadratical power of cosmological constant have to be considered in consistence with…
The quantum gravitational contribution to the renormalization group behavior of the electric charge in Einstein-Maxwell theory with a cosmological constant is considered. Quantum gravity is shown to lead to a contribution to the running…
In the framework of the theory of scale relativity, we suggest a solution to the cosmological problem of the formation and evolution of gravitational structures on many scales. This approach is based on the giving up of the hypothesis of…
We study evolution of a flat Friedmann-Robertson Walker universe filled with a bulk viscous cosmological fluid in a higher derivative theory of gravity in the presence of time varying gravitational and cosmological constant. Cosmological…
We consider the evolution of a flat Friedmann-Roberstson-Walker Universe in a higher derivative theories, including $\alpha R^{2}$ terms to the Einstein-Hilbert action in the presence of a variable gravitational and cosmological constants.…
We construct a cosmological model from the inception of the Friedmann-Lem\^aitre-Robertson-Walker metric into the field equations of the f(R,L_m) gravity theory, with R being the Ricci scalar and L_m being the matter lagrangian density. The…
We study cosmological models derived from higher-order Gauss-Bonnet gravity $F(R,G)$ by using the Lagrange multiplier approach without assuming the presence of additional fields with the exception of standard perfect fluid matter. The…
We investigate the correspondence between modified gravity theories and general entropic cosmology theory. Such a theory is proposed by an analogy with Jacobson's work, where the Einstein equation was derived from the Bekenstein-Hawking…
We study linearized graviton in the presence of a four-dimensional cosmological constant in two brane models with a warped extra dimension. In explicit models including bulk scalar fields, we calculate the masses of Kaluza-Klein modes of…
We calculate the contribution of graviton exchange to the running of gauge couplings at lowest non-trivial order in perturbation theory. Including this contribution in a theory that features coupling constant unification does not upset this…
In this paper on the basis of the generalized $f(R)$ gravity model with arbitrary coupling between geometry and matter, four classes of $f(R)$ gravity models with non minimal coupling between geometry and matter will be studied. By means of…
Gravitational contributions to the running of gauge couplings are calculated by using different regularization schemes. As the $\beta$ function concerns counter-terms of dimension four, only quadratic divergences from the gravitational…
We consider a multiplicatively renormalizable higher-derivative scalar theory which is used as an effective theory for quantum gravity at large distances (infrared phase of quantum gravity). The asymptotic regimes (in particular, the…
We study a general Scalar-Tensor Theory with an arbitrary coupling funtion $\omega (\phi )$ but also an arbitrary dependence of the ``gravitational constant'' $G(\phi )$ in the cases in which either one of them, or both, do not admit an…