相关论文: Graviton Cosmology in Universal Extra Dimensions

We consider the scale at which gravity becomes strong in linearized General Relativity coupled to the gauge-Higgs unified(GHU) model. We also discuss the unitarity of S-matrix in the same framework. The Kaluza-Klein(KK) gauge bosons, KK…

We construct a model of higher dimensional cosmology in which extra dimensions are frozen by virtue of the cubic-order Lovelock gravity throughout the cosmic history from inflation to the present with radiation and matter-dominated regimes…

Universal Extra Dimensions (UEDs) with compactification radius near the TeV scale provide interesting phenomenology at future colliders. The collider signals of the first Kaluza-Klein (KK) level are very similar to those of a supersymmetric…

We discuss the production and evolution of cosmological gravitons showing how the cosmological background affects their dynamics. Besides, the detection of cosmological gravitons could constitute an extremely important signature to…

In Kaluza-Klein theories of low-scale quantum gravity, gravitons and isosinglet neutrinos may propagate in a higher-dimensional space with large compact dimensions, whereas all particles of the Standard Model are confined on a…

The gravitational production of superheavy dark matter, in the Peebles-Vilenkin quintessential inflation model, is studied in two different scenarios: When the particles, whose decay products reheat the universe after the end of the…

In theories with large extra dimensions, constraints from cosmology lead to non-trivial lower bounds on the fundamental scale M_F, corresponding to upper bounds on the radii of the compact extra dimensions. These constraints are especially…

Gravitino dark matter, together with thermal leptogenesis, implies an upper bound on the masses of superparticles. In the case of broken R-parity the constraints from primordial nucleosynthesis are naturally satisfied and decaying…

Gravitational particle production in the context of braneworlds is considered from a phenomenological point of view. The production of KK modes for bulk fields is discussed and their abundances computed. The results have been applied to…

We construct models with a Kaluza-Klein (KK) parity in a five- dimensional warped geometry, in an attempt to address the little hierarchy problem present in setups with bulk Standard Model fields. The lightest KK particle (LKP) is stable…

The production and the final abundance of gravitino dark matter appear to depend crucially on the restoration of the global U(1) $R$-symmetry of GMSB sectors in a threefold way. An $R$-symmetric phase effectively suppresses the production…

The gravitino in models with a small violation of R-parity is a well-motivated decaying dark matter candidate that leads to a cosmological scenario that is consistent with big bang nucleosynthesis and thermal leptogenesis. The gravitino…

We consider the possibility of charged stable Kaluza-Klein leptons in orbifold models in which all the Standard Model fields propagate (UED models). At tree level the masses of the 1st mode states are nearly identical and kinematics can…

The constraint on the ADD model of extra dimensions coming from photon annihilation into Kaluza-Klein graviton in supernova cores is revisited. In the two photon process for a conservative choice of the core parameters, we obtain the bound…

Recent theoretical scenarios propose that quantum gravity effects may manifest at LEP energies by means of gravitons that couple to Standard Model particles and propagate into extra space dimensions. These predictions are checked against…

In the framework of quantum gravity propagating in large extra dimensions, we analyze the inclusive radiative emission of Kaluza-Klein spin-2 gravitons in the two-fermions decays of massive gauge bosons, heavy quarks, Higgs bosons, and in…

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…

We set up a vacuum theory of gravity with an extra dimension of vanishing proper length. The most general solution to the field equations are presented. This formulation is free of Kaluza-Klein modes and does not allow the propagation of…

We discuss extra timelike dimensions and their effects on the gravitational stability of spherical massive bodies. Here we specifically report our results for the case of one extra timelike dimension where we have made analytically rigorous…

We present the results on non-perturbative quantum gravity effects related to extra dimensions which can be comparable, in some cases, with the SM contributions, e.g. in lepton-lepton or lepton-nucleon scattering. The case of cosmic…