Related papers: Cosmological Constraints on Large Extra Dimensions
If there are large extra dimensions and the fundamental Planck scale is at the TeV scale, then the question arises of whether ultra-high energy cosmic rays might probe them. We study the neutrino-nucleon cross section in these models. The…
We study the consequences of the gravitino decay into dark matter. We suppose that the lightest neutralino is the main component of dark matter. In our framework gravitino is heavy enough to decay before Big Bang Nucleosynthesis starts. We…
We exactly calculate the particle number $N$ of scalar fields which are created from an initial vacuum in certain higher-dimensional cosmological models. The spacetimes in these models are the four-dimensional Chitre-Hartle or…
Axion-like particles with masses in the keV-GeV range have a profound impact on the cosmological evolution of our Universe, in particular on the abundance of light elements produced during Big Bang Nucleosynthesis. The resulting limits are…
Theories with extra dimensions of inverse TeV size (or larger) predict a multitude of signals which can be searched for at present and future colliders. In this paper, we review the different phenomenological signatures of a particular…
In a class of models designed to solve the cosmological constant problem by coupling scalar or tensor classical fields to the space-time curvature, the universal scale factor grows as a power law in the age, $a \propto t^\alpha$, regardless…
We study the consequences of the gravitino decay into dark matter. We suppose that the lightest neutralino is the main component of dark matter. In our framework gravitino is heavy enough to decay before Big Bang Nucleosynthesis starts. We…
In models with Large Extra Dimensions the smallness of neutrino masses can be naturally explained by introducing gauge singlet fermions which propagate in the bulk. The Kaluza-Klein modes of these fermions appear as towers of sterile…
We examine the virtual effects of Kaluza-Klein (KK) states on Higgs physics in universal extra dimension models. We study the partial widths $\Gamma_{h \to gg}$, $\Gamma_{h \to \gamma \gamma}$, and $\Gamma_{h \to \gamma Z}$, which are…
We derive general constraints on the relic abundances of a long-lived particle which mainly decays into a neutrino (and something else) at cosmological time scales. Such an exotic particle may show up in various particle-physics models…
In models of universal extra dimensions, gravity and all standard model fields propagate in the extra dimensions. Previous studies of such models have concentrated on the Kaluza-Klein (KK) partners of standard model particles. Here we…
We consider the production of gravitons via two photon fusion in Kaluza-Klein theories which allow TeV scale gravitational interactions. We find that the processes l+ l- to l+ l- + graviton, with l=electron or muon can put quite stringent…
We contrast the experimental signatures of low energy supersymmetry and the model of Universal Extra Dimensions and discuss various methods for their discrimination at hadron colliders. We study the discovery reach of the Tevatron and the…
We consider the Kaluza-Klein scenario in which gravity propagates in the $4+n$ dimensional bulk of spacetime and the Standard Model particles are confined to a 3-brane. We calculate the gauge boson self-energy corrections arising from the…
Electroweak symmetry can be naturally broken by observed quark and gauge fields in various extra-dimensional configurations. No new {\it fundamental} fields are required below the quantum gravitational scale ($\sim$ 10 - 100 TeV). We…
We show that higher dimensional models (brane worlds) in which the scale of quantum gravity $M_*$ is much smaller than the apparent scale $M_P \sim 10^{19}$ GeV are in conflict with bounds arising from holography and black hole entropy. The…
In the universal extra dimensions models, Kaluza Klein excitations of matter are generaly produced in pairs. However, if matter lives on a fat brane embedded in a larger space, gravity-matter interactions do not obey KK number conservation,…
Graviton production due to collapsing extra dimensions is studied. The momenta lying in the extra dimensions are taken into account. A $D$-dimensional background is matched to an effectively four-dimensional standard radiation dominated…
The Cosmic Defect theory has been confronted with four observational constraints: primordial nuclear species abundances emerging from the big bang nucleosynthesis; large scale structure formation in the universe; cosmic microwave background…
We present observational constraints on large-scale white noise (LSWN) in the cosmic density field, a phenomenon predicted to arise from non-linear mode coupling during cosmological evolution. Building on the theoretical framework of Paper…