Particle horizon

About: Particle horizon is a research topic. Over the lifetime, 2096 publications have been published within this topic receiving 69137 citations.

On a finite universe with no beginning or end

Abstract: Based on the conjecture that rather than the second law of thermodynamics inevitably be breached as matter approaches a big crunch or a black hole singularity, the order of events should reverse, a model of the universe that resolves a number of longstanding problems and paradoxes in cosmology is presented A universe that has no beginning (and no need for one), no ending, but yet is finite, is without singularities, precludes time travel, in which events are neither determined by initial or final conditions, and problems such as why the universe has a low entropy past, or conditions at the big bang appear to be so "special," require no causal explanation, is the result This model also has some profound philosophical implications

Can cosmic rotation explain an apparently periodic universe

Abstract: We demonstrate a possible explanation of the observed periodicity of the large-scale distribution of galaxies as an effect of the global rotation of the universe.

The Physics of CMBR anisotropies

Abstract: Inter University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411 007, India.(Dated: February 2, 2008)The observed structures in the universe are thought to have arisen from gravitational instability acting on smallfluctuations generated in the early universe. These spatial fluctuations are imprinted on the CMBR as angularanisotropies. The physics which connects initial fluctuati ons in the early universe to the observed anisotropies isfairly well understood, since for most part it involves linear perturbation theory. This makes CMBR anisotropiesone of the cleanest probes of the initial fluctuations, vario us cosmological parameters governing their evolutionand also the geometry of the universe. We review here in a fairly pedagogical manner the physics of the CMBRanisotropies and explain the role they play in probing cosmological parameters, especially in the light of thelatest observations from the WMAP satellite.I. INTRODUCTION

Production of fluctuations in the early universe by the quark-nucleon phase transition

Abstract: A model of the early universe is proposed which initially contains a zero-temperature quark phase. The entropy of the cosmic background radiation is generated by an irreversible transition to the usual radiation-dominated nucleon gas. At recombination time the model has density fluctuations with a characteristic mass of ${10}^{6}$ solar masses.

Inflation of universe due to nonlinear electrodynamics

Abstract: A model of nonlinear electrodynamics with a dimensional parameter $\beta$ is considered. Electromagnetic fields are the source of the gravitation field and inflation of the universe. We imply that the universe is filled by stochastic magnetic fields. It is demonstrated that after the universe inflation the universe decelerates approaching the Minkowski spacetime. We evaluate the spectral index, the tensor-to-scalar ratio, and the running of the spectral index which approximately agree with the PLANK and WMAP data.