Particle horizon

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

How Smooth is the Universe on Large Scales

Abstract: We review cosmological inference from optical and radio galaxy surveys, the X-Ray Background and the Cosmic Microwave Background. We focus on three topics: (i) First results from the 2dF galaxy redshift survey; (ii) Estimation of cosmological parameters by joint analysis of redshift surveys and CMB data; and (iii) The validity of the Cosmological Principle, and constraints on the fractal dimension on large scales.

Entropy growth in the early universe, and the search for determining if gravity is classical or quantum , part II (Do physical laws/ physics parameter constants remain invariant from a prior universe, to the present universe?)

Abstract: The invariance of physical law between a prior to a present universe is brought up, as a continuation of analyzing entropy in today's universe, and the relationship of entropy to information content in a prior universe. If or not there is enough information to preserve the amount of physical law also may play a role as to if or not additional dimensions for cosmological dynamics is necessary. Introduction. author, Beckwith, is aware of how data compression, and organized information from a prior universe to a present universe is often mistakenly conflated with intelligent design. In order to avoid such specious logic, the present paper's inquiry is restricted to the essentials of finding what minimum amount of information transfer from a prior to a present universe is necessary to possibly preserve the minimum structure and character of physical law from prior to present universe. I.e. Dr. Beckwith has no interest in following in the foot steps of Dr. Tippler. Secondly, the author, Beckwith, is fully aware that photons in our present day have no mass. A speculation as to a tiny effective minimum photon mass, is presented along the line's of Honig's (1974) document before red shift values of Z=1100. Before 380 thousand years after the big bang, there was still photon related cosmological evolutions as defined by J. A. S. Lima (1996), which can be summarized, for temperature related behavior as photons having number and energy densities

Running of effective dimension and cosmological entropy in early universe

Abstract: In this paper, we suggest that the early universe starts from a high-energetic state with a two dimensional description and the state recovers to be four dimensional when the universe evolves into the radiation dominated phase. This scenario is consistent with the recent viewpoint that quantum gravity should be effectively two dimensional in the ultraviolet and recovers to be four dimensional in the infrared. A relationship has been established between the running of effective dimension and that of the entropy inside particle horizon of the universe, i.e., as the effective dimension runs from two to four, the corresponding entropy runs from the holographic entropy to the normal entropy appropriate to radiation. These results can be generalized to higher dimensional cases.

Is the Universe Finite

Abstract: (1925). Is the Universe Finite? The American Mathematical Monthly: Vol. 32, No. 5, pp. 213-223.