相关论文: Loop-Generated Bounds on Changes to the Graviton D…
In braneworld models coming from string theory one generally encounters massless scalar degrees of freedom -moduli- parameterizing the volume of small compact extra-dimensions. Here we discuss the effects of such moduli on Newton's law for…
Planck scale inspired theories which are also often accompanied with maximum energy and/or momentum scale predict deformed dispersion relations compared to ordinary special relativity and quantum mechanics. In this paper we resort to the…
Recently there has been a lot of interest in models in which gravity becomes strong at the TeV scale. The observed weakness of gravitational interactions is then explained by the existence of extra compact dimensions of space, which are…
The vacuum energy density arising from the broken supersymmetry of the (standard-model) fields living on a brane cannot be fully "off-loaded" to the bulk: even assuming the existence of an effective "self-tuning" mechanism, a small fraction…
In this paper we explore some general aspects of the embeddings associated with brane-localized gravity. In particular we show that the consistency of such embeddings can require (or impose) very specific relations between all the involved…
Generic arguments lead to the idea that quantum gravity has a minimal length scale. A possible observational signal of such a minimal length scale is that photons should exhibit dispersion. In 2009 the observation of a short gamma ray burst…
In this work we study the gravitational radiation produced by a keplerian binary system within the context of Very Special Linear Gravity (VSLG), a novel theory of linearized gravity in the framework of Very Special Relativity (VSR)…
The brane-worlds model was inspired partly by Kaluza-Klein's theory, where the gravitation and the gauge fields are obtained of a geometry of higher dimension (bulk). Such a model has been showing positive in the sense of we find…
Massive spin-1/2 fields are studied in the framework of loop quantum gravity by considering a state approximating, at a length scale $\cal L$ much greater than Planck length $\ell_P=1.2\times 10^{-33}$cm, a spin-1/2 field in flat spacetime.…
Recently much work has been done in lowering the Planck threshold of quantum gravitational effects (sub-millimeter dimension(s), Horava-Witten fifth dimension, strings or branes low energy effects, etc.). Working in the framework of 4-dim…
The gravitational interactions of the four-dimensional effective theory describing a general $N$-brane model in five dimensions without radion stabilization are analyzed. Both uncompactified and orbifolded models are considered. The…
Within loop quantum gravity we construct a coarse-grained approximation for the Einstein-Maxwell theory that yields effective Maxwell equations in flat spacetime comprising Planck scale corrections. The corresponding Hamiltonian is defined…
It is shown that the consideration of the braneworld consistency conditions within the framework of bulk modified gravities allows for the existence of thick branes in the five- dimensional case with compact extra dimension. In studing the…
The search for extra dimensions is a challenging endeavor to probe physics beyond the Standard Model. The joint detection of gravitational waves (GW) and electromagnetic (EM) signals from the merging of a binary system of compact objects…
It has been recently speculated that global symmetries are broken by gravity. We propose a scenario for the generation of the baryon asymmetry in the early Universe in which the domain walls predicted by theories with discrete symmetries…
Many theories of modified gravity, including the well studied Horndeski models, are characterized by a screening mechanism that ensures that standard gravity is recovered near astrophysical bodies. In a recently introduced class of…
In this paper a model in a space-time with compact extra dimension is presented, describing five-dimensional fermion fields interacting with an electromagnetic field localized on a brane. This model can be considered as a toy model for…
We study whether modification of gravity at large distances is possible in warped backgrounds with two branes and a brane-induced term localized on one of the branes. We find that there are three large regions in the parameter space where…
It has been proposed recently that the scale of strong gravity can be very close to the weak scale. Dimensions of sizes anywhere from $\sim $mm to $\sim $TeV$^{-1}$ can be populated by bulk gravitons, vector bosons and fermions. In this…
Lowering the string scale in the TeV region provides a theoretical framework for solving the mass hierarchy problem and unifying all interactions. The apparent weakness of gravity can then be accounted by the existence of large internal…