arXiv subjects

S. G. Rubin

Publications and source records attributed to S. G. Rubin.

49 records · Page 3Linked to original sources

arXiv2002

Fine tuning of parameters of the universe

The mechanism of production of a large number of universes is considered. It is shown that universes with parameters suitable for creation of life are necessarily produced as a result of quantum fluctuations. Fractal structures are formed provided fluctuations take place near a maximum of the potential. Several ways of formation of similar fractal structures within our universe are discussed. Theoretical predictions are compared with observational data.

astro-ph↗

arXiv2002

Strong Primordial Inhomogeneities and Galaxy Formation

The new element of theory of galaxy formation, strong primordial inhomogeneities, is shown to be a reflection of unstable large scale structures of topological defects, created in second order phase transitions in the inflationary Universe. In addition to {\it archioles-like} large scale correlation of the primordial inhomogeneity of energy density of coherent scalar field oscillations, the same mechanism, based on the second order phase transitions on the inflational stage and the domain wall formation upon the end of inflation, leads to the formation of massive black hole clusters that can serve as nuclei for the future galaxies. The number of black holes with $M \sim 100M_{\odot}$ and above is comparable with the number of galaxies within the modern cosmological horizon. The primordial fractal structure of galaxies can find natural grounds in the framework of model we developed . The proposed approach offers the physical basis for new scenarios of galaxy formation in the Big Bang Universe.

astro-ph↗

arXiv2001

Effect of massive fields on inflation

Effects caused by an additional massive scalar field interacting with an inflaton field are analyzed. Inflation is shown to have two stages, the first of which is dominant and characterized by ultraslow dynamics of the inflaton field. Constraints on the model parameters are obtained.

hep-ph↗

arXiv2001

Quantum Instantons and Quantum Chaos

Based on a closed form expression for the path integral of quantum transition amplitudes, we suggest rigorous definitions of both, quantum instantons and quantum chaos. As an example we compute the quantum instanton of the double well potential.

quant-ph↗

arXiv2000

Expansion of True Vacuum Bubbles at the End of Inflation

The dynamics of false vacuum decay at the end of inflation is studied. It is shown that the creation of a new phase is mainly stimulated by temperature fluctuations. Moving walls of O(3)-symmetric bubbles weakly interact with their surroundings at the inflation stage. Large field fluctuations might arise as a result of wall collisions.

hep-ph↗

arXiv2000

Primordial Black Holes from Non-Equilibrium Second Order Phase Transition

The collapse of sufficiently large closed domain wall produced during second order phase transition in the vacuum state of a scalar field can lead to the formation of black hole. The origin of domain walls with appropriate size and energy density could be a result of evolution of an effectively massless scalar field at the inflational epoch. We demonstrate that in this case the situation is valued when there are compact domains of less favorable vacuum surrounded by a sea of another vacuum. Each domain has a surface composed of vacuum wall that stores a significant amount of energy, and can collapse into the black hole. This offers the way of massive primordial black holes formation in the early Universe.

hep-ph↗

arXiv2000

Possible Signature of Low Scale Gravity in Ultra High Enegry Cosmic Rays

We show that the existence of low scale gravity at TeV scale could lead to a direct production of photons with energies above 10^22 eV due to annihilation of ultra high energy neutrinos on relic massive neutrinos of the galactic halo. Air showers initialized in the terrestrial atmosphere by these ultra energetic photons could be collected in near future by the new generation of cosmic ray experiments.

astro-ph↗

arXiv2000

Closed Path Integrals and Renormalisation in Quantum Mechanics

We suggest a closed form expression for the path integral of quantum transition amplitudes. We introduce a quantum action with renormalized parameters. We present numerical results for the $V \sim x^{4}$ potential. The renormalized action is relevant for quantum chaos and quantum instantons.

hep-th↗

arXiv1999

First Order Phase Transitions as a Source of Black Holes in the Early Universe

A new mechanism of black hole formation in a first order phase transition is proposed. In vacuum bubble collisions the interaction of bubble walls leads to the formation of nontrivial vacuum configuration. The consequent collapse of this vacuum configuration induces the black hole formation with high probability. The primordial black holes that have been created by this way at the end of first order inflation could give essential contribution into the total density of the early Universe. The possibilities to establish some nontrivial restrictions on the inflation models with first order phase transition are discussed.

hep-ph↗

arXiv1999

Band structure of local pairs. Mathematical tools

A system of strongly interacting fermions in a solid state is discussed. A structure of singlet and triplet coupled 2-particle states and their excitation spectra are investigated. It is shown that an account of intersite fermion interaction leads to new boson modes. A problem of interaction of pairs with external fields are discussed. The same analysis can be performed for another sorts of pairings like d-wave.

cond-mat↗

arXiv1999

AMS-Shuttle test for antimatter stars in our Galaxy

The AMS--Shuttle experiment is shown to be sensitive to test the hypothesis on the existence of antimatter globular cluster in our Galaxy. The hypothesis follows from the analysis of possible tests for the mechanisms of baryosynthesis and uses antimatter domains in the matter dominated Universe as the probe for the physics underlying the origin of the matter. The total mass for the antimatter objects in our Galaxy is fixed from the below by the condition of antimatter domain survival in the matter dominated Universe and from above by the observed gamma ray flux. For this mass interval the expected fluxes of antinuclei can lead to up to ten antihelium events in the AMS-Shuttle experiment.

astro-ph↗

arXiv1998

Physical Origin, Evolution and Observational Signature of Diffused Antiworld

The existence of macroscopic regions with antibaryon excess in the baryon asymmetric Universe with general baryon excess is the possible consequence of practically all models of baryosynthesis. Diffusion of matter and antimatter to the border of antimatter domains defines the minimal scale of the antimatter domains surviving to the present time. A model of diffused antiworld is considered, in which the density within the surviving antimatter domains is too low to form gravitationally bound objects. The possibility to test this model by measurements of cosmic gamma ray fluxes is discussed. The expected gamma ray flux is found to be acceptable for modern cosmic gamma ray detectors and for those planned for the near future.

astro-ph↗

arXiv1998

Formation of Black Holes in First Order Phase Transitions

A new mechanism of black hole formation in a first order phase transition is proposed. In vacuum bubble collisions the interaction of bubble walls leads to the formation of nontrivial vacuum configuration. The consequent collapse of this vacuum configuration induces the black hole formation with high probability. Observational constraints on the spectrum of primordial black holes allow to obtain new nontrivial restrictions on parameters of inflation models with first order phase transitions.

hep-ph↗