A Valid Finite Bounded Expanding Carmelian Universe Without Dark Matter

The solution of Einstein’s field equations in Cosmological General Relativity (CGR), where the Galaxy is at or cosmologically near the center of a finite yet bounded spherically symmetrical isotropic gravitational field, is identical with the unbounded solution. I show that this leads to the conclusion that the Universe may be viewed as a finite expanding “white hole.” This is not the white hole solution of Einstein’s spacetime but has similarities to it. The fact that CGR has been successful in describing the distance modulus verses redshift data of the high-redshift type Ia supernovae means that the data cannot be used to distinguish between unbounded models and those with finite bounded radii of at least cτ ( ${\approx}c H_{0}^{-1}$ ). According to Carmelian theory, whether or not the Universe is finite bounded or unbounded it is spatially flat all epochs where it was matter dominated. As a consequence in a finite bounded universe no gravitational redshift in the light from distant source galaxies would be observed.     

Tensorial Perturbations in an Accelerating Universe

We study tensorial perturbations (gravitational waves) in a universe with particle production (OSC).The background of gravitational waves produces a perturbation in the redshift observed from distant sources. The modes for the perturbation in the redshift (induced redshift) are calculated in a universe with particle production.     

Thermodynamic Equilibrium in the Expanding Universe

We show that a relativistic gas may be at"global" equilibrium in the expanding universe for anyequation of state 0 < p /3, provided thatthe gas particles move under the influence of aself-interacting, efiective one-particle force in between elasticbinary collisions. In the force-free limit we recoverthe equilibrium conditions for ultrarelativistic matterwhich imply the existence of a conformal timelike Killing vector.     

Particle Creation in Anisotropically Expanding Universe

Using squeezed vacuum states formalism of quantum optics, a homogeneous and massive scalar field minimally coupled to gravity in Bianchi type-I model of the universe is examined in the frame work of semiclassical theory of gravity. Hence an approximate leading solution to the semiclassical Einstein equation is found. The next order solution for each scale factor in their respective direction show power law of expansion. It is further noted that evolution of scale factors are mutually correlated. The phenomena of nonclassical particle creation is also examined in the anisotropic background cosmology.     

Production of the Matter in the Early Universe

A gravitational analog of the nonstationary perturbation theory is developed within which the production of the scalar-field massive quanta by gravitational atoms is studied.     

Spin 2 Field Equation in Expanding Universe

The spin 2 field equations are separated in the Robertson-Walker space-time by the Newman-Penrose formalism and by using a null tetrad frame previously considered. The angular and radial separated equations are integrated by generalizing and improving results relative to the massless case. The separated time equations are governed by two coupled linear differential equations that depend on the cosmological background. They are solved and studied for some models of cosmological expansion such as the linear and exponential expansion and the matter dominated and radiative expansion of the standard cosmology.     

Self-Attracting Poisson Clouds in an Expanding Universe

 We consider the following elementary model for clustering by ballistic aggregation in an expanding universe. At the initial time, there is a doubly infinite sequence of particles lying in a one-dimensional universe that is expanding at constant rate. We suppose that each particle p attracts points at a certain rate a(p)/2 depending only on p, and when two particles, say p and q, collide by the effect of attraction, they merge as a single particle p*q. The main purpose of this work is to point at the following remarkable property of Poisson clouds in these dynamics. Under certain technical conditions, if at the initial time the system is distributed according to a spatially stationary Poisson cloud with intensity μ ₀ , then at any time t > 0, the system will again have a Poissonian distribution, now with intensity μ _t , where the family solves a generalization of Smoluchowski's coagulation equation. Received: 15 February 2002 / Accepted: 8 July 2002 Published online: 7 November 2002     

Evolution of the Early Universe

The evolution of the very early Universe from a vacuum-like state to the epoch of leptoquark decay is investigated.__________Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 33–35, March, 2005.     

Evolution of the Horizons for Dark Energy Universe

Recent observational evidences of accelerating phase of the universe strongly demand that the dominating matter in the universe is in the form of dark energy. In this work, we study the evolution of the apparent and event horizons for various dark energy models and examine their behavior across phantom barrier line.     

Letter: Density Perturbations in a Universe Dominated by the Chaplygin Gas

We study the fate of density perturbations in a Universe dominate by the Chaplygin gas, which exhibit negative pressure. In opposition to other models of perfect fluid with negative pressure, there is no instability in the small wavelength limit, due to the fact that the sound velocity for the Chaplygin gas is positive. We show that it is possible to obtain the value for the density contrast observed in large scale structure of the Universe by fixing a free parameter in the equation of state of this gas. The negative character of pressure must be significant only very recently.     

Entropy of the Universe and Hierarchical Dark Matter

We discuss the relationship between dark matter and the entropy of the universe, with the premise that dark matter exists in the form of primordial black holes (PBHs) in a hierarchy of mass tiers. The lightest tier includes all PBHs with masses below one hundred solar masses. The second-lightest tier comprises intermediate-mass PIMBHs within galaxies, including the Milky Way. Supermassive black holes at galactic centres are in the third tier. We are led to speculate that there exists a fourth tier of extremely massive PBHs, more massive than entire galaxies. We discuss future observations by the Rubin Observatory and the James Webb Space Telescope.     

大数猜想与暗物质

讨论恒星质量、核子质量、暗物质粒子质量和普朗克质量四者间通过大数A～10¹⁹联系在一起,而且强相互作用与引力间也唯象地通过大数A似乎有着某种深层的联系.     

Mixmaster Universe Models with Matter in Jordan-Brans-Dicke Theory

We discuss the dynamics of anisotropic Bianchitype IX models in Jordan-Brans-Dicke cosmological theoryrendering the evolution of a universe model with closedspace near its beginning before inflation sets in. This paper displays how, when writtenin terms of reduced variables, the field equations allowstraightforward partial integration. The mean expansionH, the scalar field, and the three scale factors aregiven in terms of the volume expansion.     

Evolution of Dark Energy in the Open Universe

In this paper we discuss the evolution of the dark energy in the open universe under the framework of the χCDM model. It is showed that the dark energy in the open universe, which drives the universe accelerating, had strange evolution behaviors: it was in the state of negative energy and positive pressure at the early stage of evolution of the dark energy, then evolved into the phase of negative energy and negative pressure during the middle period, and evolved to have the typical features of dark energy (positive energy and negative pressure) only at the later stage.