Particle horizon

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

Photon density and the gamma-ray flux at a point in an expanding universe

Abstract: The investigation deals with certain cosmological questions involved in the interpretation of the gamma-ray flux measurements made by the satellite Explorer XI. An expanding universe filled with similar sources of optical radiation is considered and the photon density in the neighborhood of an observer is obtained. Numerical values are given for the density of 1-eV photons when the sources are regarded as blackbodies at a temperature of 5000\ifmmode^\circ\else\textdegree\fi{}K. The necessity of specifying the bandwidth, the model of the universe, and the scale of distance before a density can be stated, is emphasized. The models of the universe considered are those of general relativity and that of the steady-state theory. It is concluded that a photon density can be specified, in the present state of astronomical knowledge, only as lying within wide limits.The gamma-ray flux observed can be interpreted theoretically by the use of general relativity models in which the density of matter is rather high. An equally satisfactory interpretation is possible by the use of the steady-state theory. It is argued that the objections to the second theory, based on the Explorer XI data, refer only to the hypothesis of the creation of antiprotons and not to the theory itself.

Falsification of the Expanding Universe Model

Abstract: This is the first of two papers on solving Stephen Weinberg’s “Central Problem of Cosmology”, that is, determining the dynamical state and metric of the universe. Weinberg considered solving this problem to be a prerequisite to understanding the universe.This paper presents the observations and the logical arguments leading to a falsification of the expanding universe model. In the second paper, the Hubble redshift is derived and the universe is shown to have a Euclidean (flat) metric based on a wave system theory of the universe.The falsification of the expanding universe model is based on the discovery that the anomalous dimming of type Ia supernovae is absent in the Hubble redshift diagrams of two sets of brightest cluster galaxies (BCG). Since the light from the supernovae and from the BCG traverses the same space, this logically shows that the anomalous dimming must be specific to supernovae. With this as a clue, it was found that the short duration of a supernova light curve and the Hubble redshift of the light resulted in a broadening of the light curve at the observer. Since this broadening spreads the total luminosity over a longer time period, the apparent luminosity is decreased. This new effect accounts quantitatively for the anomalous dimming of supernovae. Also, it is proved theoretically that BCG are not subject to anomalous dimming.Since the expanding universe model currently predicts a time‐dilation light curve broadening due to the expansion of the universe, two light curve broadening effects should occur for supernovae. However, only one light curve broadening effect was observed by Goldhaber in his study of the widths of supernovae light curves. Since Goldhaber’s result directly contradicts the prediction of two light curve broadening effects, the expanding universe model is logically falsified.Finally, because a single light curve broadening effect is consistent with the static universe model, a static universe is hypothesized. The static universe hypothesis is confirmed by Tolman surface brightness tests of the two sets of BCG.

Growth Rate and Configurational Entropy in Tsallis Holographic Dark Energy

Abstract: In this work, we analyzed the effect of different prescriptions of the IR cutoffs, namely the Hubble horizon cutoff, particle horizon cutoff, Granda and Oliveros horizon cut off, and the Ricci horizon cutoff on the growth rate of clustering for the Tsallis holographic dark energy (THDE) model in an FRW universe devoid of any interactions between the dark Universe. Furthermore, we used the concept of configurational entropy to derive constraints (qualitatively) on the model parameters for the THDE model in each IR cutoff prescription from the fact that the rate of change of configurational entropy hits a minimum at a particular scale factor $a_{DE}$ which indicate precisely the epoch of dark energy domination predicted by the relevant cosmological model as a function of the model parameter(s). By using the current observational constraints on the redshift of transition from a decelerated to an accelerated Universe, we derived constraints on the model parameters appearing in each IR cutoff definition and on the non-additivity parameter $\delta$ characterizing the THDE model and report the existence of simple linear dependency between $\delta$ and $a_{DE}$ in each IR cutoff setup.

An Inflationary Solution of Scalar Field in Finsler Universe

Abstract: Using the energy-dependent rainbow metric, we investigate the rainbow universe metric as a Finsler metric, and obtain an inflationary solution of the universe. The theoretical results are in agreement with the astronomical observations.

Time asymmetry of the universe

Abstract: The entropy of the Universe is calculated within the Einstein and Logunov concepts. It is shown that the entropies of the Universe calculated within the foregoing concepts coincide at the Beginning and at the present time.