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Particle horizon
About: Particle horizon is a research topic. Over the lifetime, 2096 publications have been published within this topic receiving 69137 citations.
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TL;DR: In this paper, observations on the large-scale structure of the universe and the anisotropy of the cosmic background radiation are used to derive constraints on the parameters of an inflationary model for the early universe (Λ inflation).
Abstract: Observational data on the large-scale structure of the Universe and the anisotropy of the cosmic background radiation are used to derive constraints on the parameters of an inflationary model for the early Universe (Λ inflation).
3 citations
TL;DR: In this article, it was shown that random fluctuations of the density field at the same instant of equality and with comoving wavelength shorter than the causal horizon at that time can naturally account for the observed scale invariance of the anisotropies over cosmologically large comoving volumes.
Abstract: We revise the statistical properties of the primordial cosmological density anisotropies that, at the time of matter-radiation equality, seeded the gravitational development of large scale structures in the otherwise homogeneous and isotropic Friedmann-Robertson-Walker flat universe. Our analysis shows that random fluctuations of the density field at the same instant of equality and with comoving wavelength shorter than the causal horizon at that time can naturally account, when globally constrained to conserve the total mass (energy) of the system, for the observed scale invariance of the anisotropies over cosmologically large comoving volumes. Statistical systems with similar features are generically known as glasslike or latticelike. Obviously, these conclusions conflict with the widely accepted understanding of the primordial structures reported in the literature, which requires an epoch of inflationary cosmology to precede the standard expansion of the universe. The origin of the conflict must be found in the widespread, but unjustified, claim that scale invariant mass (energy) anisotropies at the instant of equality over comoving volumes of cosmological size, larger than the causal horizon at the time, must be generated by fluctuations in the density field with comparably large comoving wavelength.
3 citations
TL;DR: In this article, it is shown that gravitating systems with mass density rising with time evolve to a singular state with infinite curvature scalar, and the universe evolution during the radiation-dominated epoch is studied in the R2-extended gravity theory.
Abstract: Astronomical data in favor of cosmological acceleration and possible explanations of accelerated expansion of the universe are discussed. Main attention is paid to gravity modifications at small curvature which could induce accelerated cosmological expansion. It is shown that gravitating systems with mass density rising with time evolve to a singular state with infinite curvature scalar. The universe evolution during the radiation-dominated epoch is studied in the R2-extended gravity theory. Particle production rate by the oscillating curvature and the back reaction of particle production on the evolution of R are calculated in one-loop approximation. Possible implications of the model for cosmological creation of non-thermal dark matter are discussed.
3 citations
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TL;DR: In this paper, the Scale Law is used to explore several cosmological issues such as the age of the universe, the universe mass density, the radius of the present particle horizon and the Friedmann's equation.
Abstract: Based on the Scale Law this paper explores several cosmological issues such as the age of the Universe, the Universe mass density, the radius of the present particle horizon and the Friedmann’s equation. The Scale Law is the first Model Meta law we, humans, have discovered. The significance of this investigation is the formula for the age of the Universe. This formula is in excellent agreement with the experimental data from the Planck spacecraft- 2013 and suggests that one of more of the constants it contains is a function of time.
3 citations
TL;DR: In the early moments of time, when the expansion was far more rapid, producing in this brief instant a radial increase 25 orders of magnitude greater than that which would otherwise have occurred, it could account for some features of our observable universe hitherto unexplained by the standard theory of the Big Bang as mentioned in this paper.
Abstract: Ever since the Big Bang, the universe has been growing at a rate proportional to a fractional power of time—or has it been? Could there have been an instant, in the earliest moments of time, when the expansion was far more rapid, producing in this brief instant a radial increase 25 orders of magnitude greater than that which would otherwise have occurred? If such an inflationary period did occur, it could account for some features of our observable universe hitherto unexplained by the standard theory of the Big Bang. These features include the remarkable homogeneity of the universe, its sparse population of magnetic monopoles (if there are any at all) and the pinpoint balance it maintains between an infinitely expanding and an eventually collapsing condition. In short, inflation may be far better news for cosmology than it is for the economy.
3 citations