arXiv subjects

A. V. Grobov

Publications and source records attributed to A. V. Grobov.

6 recordsLinked to original sources

arXiv2017

Inhomogeneous compact extra dimensions

We show that an inhomogeneous compact extra space possesses two necessary features --- their existence does not contradict the observable value of the cosmological constant $Λ_4$ in pure $f(R)$ theory, and the extra dimensions are stable relative to the "radion mode" of perturbations, the only mode considered. For a two-dimensional extra space, both analytical and numerical solutions for the metric are found, able to provide a zero or arbitrarily small $Λ_4$. A no-go theorem has also been proved, that maximally symmetric compact extra spaces are inconsistent with 4D Minkowski space in the framework of pure $f(R)$ gravity.

gr-qc↗

arXiv2016

Cosmological implications of Higgs field fluctuations during inflation

Cosmological implications of Higgs field fluctuations during inflation are considered. This study is based on the Standard Model and the standard quadratic model of chaotic inflation where the Higgs field is minimally coupled to gravity and has no direct coupling to the inflaton. In the Standard model the renormalisation group improved effective potential develops an instability (an additional minimum and maximum) at large field values. It is shown that such a new maximum should take place at an energy scale above $10^{14} \;\text{GeV},$ otherwise a universe like ours is extremely unlikely. The extension to the case of the Higgs field interacting with the inflaton field is discussed.

astro-ph.CO↗

arXiv2015

Formation and Search of Large Scale Antimatter Regions

In the present paper we discuss a generation of large antimatter regions with sizes exceeding the critical surviving size. In the modern epoch domains with high antimatter density evolve to single galaxies with a peculiar content of anti-helium and anti-deuterium.

astro-ph.CO↗

arXiv2014

Signatures of primordial black hole dark matter

The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro world and mechanisms of its symmetry breaking. In the early Universe heavy metastable particles can dominate, leaving primordial black holes (PBHs) after their decay, as well as the structure of particle symmetry breaking gives rise to cosmological phase transitions, from which massive black holes and/or their clusters can originate. PBHs can be formed in such transitions within a narrow interval of masses about $10^{17}$g and, avoiding severe observational constraints on PBHs, can be a candidate for the dominant form of dark matter. PBHs in this range of mass can give solution of the problem of reionization in the Universe at the redshift $z\sim 5... 10$. Clusters of massive PBHs can serve as a nonlinear seeds for galaxy formation, while PBHs evaporating in such clusters can provide an interesting interpretation for the observations of point-like gamma-ray sources. Analysis of possible PBH signatures represents a universal probe for super-high energy physics in the early Universe in studies of indirect effects of the dark matter.

astro-ph.CO↗

arXiv2013

Baryon number of the Universe as a result of extra space dynamics

Origin of baryon asymmetry is studied in the framework of extra dimensional approach. Baryon excess production and the symmetrization of extra-space are performed simultaneously. Baryon number is conserved long after the inflationary stage when the U(1) symmetry is achieved.

gr-qc↗

arXiv2013

Higgs-Like Field and Extra Dimensions

We study the origin of the Higgs field in the framework of the universal extra dimensions. It is shown that a Higgs-like Lagrangian can be extracted from a metric of an extra space. The way to distinguish our model and the Standard Model is discussed.

gr-qc↗