Related papers: Standard model with compactified spatial dimension…
In this brief review we discuss the viability of a multidimensional geometrical theory with one compactified dimension. We discuss the case of a Kaluza Klein fifth dimensional theory, addressing the problem by an overview of the…
We identify an ambiguity in the Chern-Simons formulation of three-dimensional gravity with negative cosmological constant that originates in an outer automorphism of the Lie algebra sl(2,R). It has important consequences for the stability…
We present full numerical solutions to the system of a global string embedded in a six-dimensional space time. The solutions are regular everywhere and do confine gravity in our four-dimensional world. They depend on the value of the…
We discuss the moduli stabilization in a de Sitter compactification model obtained coupling D-dimensional gravity to scalar and gauge fields. This class of models is characterized by two moduli: one related to the volume of the internal…
In theories with a low quantum gravity scale, global symmetries are expected to be violated, inducing excessive proton decay or large Majorana neutrino masses. The simplest cure is to impose discrete gauge symmetries, which in turn make…
We study some aspects of dynamical compactification scenario where stabilisation of extra dimensions occurs due to presence the Gauss-Bonnet term and non-zero spatial curvature. In the framework of the model under consideration there exists…
We investigate circularly symmetric static solutions in three-dimensional gravity with a minimally coupled massive scalar field. We integrate numerically the field equations assuming asymptotic flatness, where black holes do not exist and a…
We study neutrino physics in the context of the localized gravity model with non-factorizable metric proposed by Randall and Sundrum. Identifying the right-handed neutrino with a bulk fermion zero mode, which can be localized on the…
Studies of a class of infinite one dimensional self-gravitating systems have highlighted that, on the one hand, the spatial clustering which develops may have scale invariant (fractal) properties, and, on the other, that they display…
We consider a system of gravitating bodies in Kaluza-Klein models with toroidal compactification of extra dimensions. To simulate the astrophysical objects (e.g., our Sun and pulsars) with the energy density much greater than the pressure,…
We study circle compactifications of tensionless bosonic string theory, both at the classical and the quantum level. The physical state condition for different representations of BMS$_3$, the worldsheet residual gauge symmetry for…
All the classes of static massless scalar field models available currently in the Einstein theory of gravity necessarily contain a strong curvature naked singularity. We obtain here a family of solutions for static massless scalar fields…
We study grand unified models in the five-dimensional space-time where the extra dimension is compactified on $S^1/Z_2$. The spontaneous breaking of unified gauge symmetries is achieved via vacuum expectation values of the extra-dimensional…
We propose a deformation principle of gauge theories in three dimensions that can describe topologically stable self-dual gauge fields, i.e., vacua configurations that in spite of their masses do not deform the background geometry and are…
We find analytical vacuum stability or bounded below conditions for general scalar potentials of a few fields. After a brief review of copositivity we go beyond it. We discuss the vacuum stability conditions of the general potential of two…
We derive the equations governing static, spherically symmetric vacuum solutions to the Einstein equations, as modified by the frame-dependent effective action arising from trace dynamics. We give analytic and numerical results for the…
Models with extra dimensions have changed our understanding of the hierarchy problem. In general, these models explain the weakness of gravity by diluting gravity in a large bulk volume, or by localizing the graviton away from the standard…
The experimental data, as well as theoretical considerations allow (and, in some cases, require) the Universe at present to rest in a false vacuum, whose approximate stability imposes constraints on the model parameters. Under very general…
As a ramification of a motivational discussion for previous joint work, in which equations of motion for the finite spectral action of the Standard Model were derived, we provide a new analysis of the results of the calculations herein,…
We investigate the (noncommutative) geometry defined by the standard model, which turns out to be of Kaluza-Klein type. We find that spacetime points are replaced by extended two-dimensional objects which resemble the surface of a gyro.…