Particle horizon

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

The CMB Axis of Evil

Abstract: The cosmic microwave background (CMB) is the thermal radiation due to the time of recombination. The temperature variations on very large angular scales observed by WMAP and Planck are both larger than expected (there appears the CMB axis of evil) and, contrary to smaller-scale fluctuations, aligned with each other. The initial inflation in the big- bang model suggests that both deviations cannot be realized by Nature. The CMB axis of evil, if it exists, leads to the distinguished frame of reference in the Universe and is a sign of new cosmological phenomena. There are many ideas to explain the deviations in CMB. If we neglect the trivial explanation that the applied statistics is incomplete then there are two important ideas: that CMB is a local variation of an infinite universe or some characteristic features of finite/"small" universe. It was shown in 2003 (A. de Oliveira-Costa, M. Tegmark, M. Zaldarriaga, A. Hamilton) that "the simplest small universe model where the universe has toroidal topology with one small dimension of order half the horizon scale, in the direction towards Virgo, could explain three independent anomalies involving the quadrupole and octopole but the applied S-statistic and the circle test on the WMAP data show that we should rule out this model". Here we present a solution that follows from the Scale-Symmetric Theory. Due to the phase transitions of inflation field (i.e. of the Higgs field), the expansion of the Universe (the "soft" big bang) was separated in time from the inflation (the big bang). The dark matter had initially toroidal topology with internal helicity and inside such 3- dimensional torus with central condensate there were two very thin (in cosmic scale) baryonic loops (the loops had left-handed internal helicity and antiparallel unitary spins). It leads to the CMB axis of evil. We solved a few other cosmological problems as well.

Emptiness of the Universe as a Cause of Inflation and Dark Energy (Graviton Dominated Eras of Universe's Evolution)

Abstract: The empty space (with no matter fields) is not really empty because of natural metric fluctuations, quantum and classical. We show that gravitons as well as classical gravitational waves of super-horizon wavelengths are able to form the de Sitter state of the empty homogeneous isotropic Universe. This state is the exact solution to the self-consistent equations of one-loop quantum gravity for gravitons in the empty FLRW space. It also is the exact solution to the self-consistent equations of back reaction for classical gravitational waves. Technically, to get this de Sitter solution in both quantum and classical cases, it is necessary to make the transition to imaginary time and then come back to real time which is possible because this de Sitter state is invariant with respect to Wick rotation. Such a procedure means that the time was used as a complex variable, and this fact has a deep but still not understood meaning. De Sitter accelerated expansion of the empty Universe naturally explains the origin of dark energy and inflation because the Universe is empty at the start and by the end of its evolution. This theory is consistent with the existing observational data. The CMB anisotropy of the order of 10^-5 is produced by fluctuations in the number of gravitons. The existence of a threshold and unique coincidence of topologically impenetrable barriers for tunneling takes place for the matter-dominated epoch and De Sitter State only. These facts provide a solution to the coincidence problem. The theoretical prediction that the equation-of-state parameter should be w>-1 for inflation and w<-1 for dark energy is consistent with observational data. To provide the reader with a complete picture, this paper gather together new and some published results of the graviton theory of the origin of inflation and dark energy

The universe is expanding by entirely moving at some very high speed and not by flying away of the galaxies from each other

Abstract: Expansion of the universe has already been confirmed by the Hubble discovered nebular red-shift. But, is it expanding in the simple Newtonian way that the distance between any observed distant star and the observer is continuously increasing? The argument against this is: If so, then the apparent brightness and size of that distant star will continuously decrease and thus the stars at the outer edge of the visible universe will disappear in no time. To understand the way in which the universe is expanding it is important, in accordance with the special theory of relativity, to bear in mind the fundamental difference between the way electromagnetic waves spread and the way Newtonian point particles move. Accordingly, the Hubble discovered nebular red-shift is explained here as due to relative motion between the Newtonian point particle observer, which is moving along with the entire universe, and the space-time fixed origins (Events) of the received pulses of light. But, as the source is also moving with the entire universe, these space-time fixed origins are continuously repeated on the continuous world line of the star and hence the recession is continuously repeated while the star remains at the same fixed distance from the observer.

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.

Inflation, Microwave Background Anisotropy, and Open Universe Models

Abstract: The inflationary scenario for the very early universe has proven very attractive, because it can simultaneously solve a number of cosmological puzzles, such as the homogeneity of the Universe on scales exceeding the particle horizon at early times, the flatness or entropy problem, and the origin of density fluctuations for large-scale structure [1]. In this scenario, the observed Universe (roughly, the present Hubble volume) represents part of a homogeneous inflated region embedded in an inhomogeneous space-time. On scales beyond the size of this homogeneous patch, the initially inhomogeneous distribution of energy-momentum that existed prior to inflation is preserved, the scale of the inhomogeneities merely being stretched by the expansion.