中文
相关论文

相关论文: A flat space-time model of the Universe

200 篇论文

The aim of this paper is to show, that the 'oscillating universe' is a viable alternative to inflation. We remind that this model provides a natural solution to the flatness or entropy and to the horizon problem of standard cosmology. We…

广义相对论与量子宇宙学 · 物理学 2016-08-31 Ruth Durrer , Joachim Laukenmann

Distance measurement provide no constraints on curvature independent of assumptions about the dark energy, raising the question, how flat is our Universe if we make no such assumptions? Allowing for general evolution of the dark energy…

宇宙学与河外天体物理 · 物理学 2013-03-07 P. M. Okouma , Y. Fantaye , B. A. Bassett

We propose a mechanism for generating an inflationary phase in the early universe without resorting to any type of scalar field(s). Instead, this accelerated expansion is driven by a dynamical "cosmological constant" in the framework of…

广义相对论与量子宇宙学 · 物理学 2022-03-18 Gabriel Leon

We show that the current accelerated expansion of the Universe can be explained without resorting to dark energy. Models of generalized modified gravity, with inverse powers of the curvature can have late time accelerating attractors…

天体物理学 · 物理学 2008-11-26 Olga Mena , Jose Santiago , Jochen Weller

We consider a model in which the universe is the direct product of a (3+1)-dimensional Friedmann, Robertson-Walker (FRW) space and a compact hyperbolic manifold (CHM). Standard Model fields are confined to a point in the CHM (i.e. to a…

高能物理 - 理论 · 物理学 2008-11-26 Glenn D. Starkman , Dejan Stojkovic , Mark Trodden

In modelling galaxy structure formation, neither Cold Dark Matter (CDM) nor canonical Modified Newtonian Dynamics (MOND) (Milgrom [1]) can easily accommodate the appearance of massive galaxies at early times [2]. As a baseline We propose a…

宇宙学与河外天体物理 · 物理学 2026-03-26 James C. C. Wong , Ray J. Rivers

In the present mainstream cosmology, matter and spacetime emerged from a singularity and evolved through four distinct periods: early inflation, radiation, dark matter and late-time inflation (driven by dark energy). During the radiation…

宇宙学与河外天体物理 · 物理学 2013-10-02 E. L. D. Perico , J. A. S. Lima , Spyros Basilakos , Joan Sola

According to the standard lore, a prolonged inflation leaves a quantum field theory in a cold, low entropy state. Thus, some mechanism is needed to reheat this post-inflationary state, leaving a hot, thermal, radiation-dominated Universe.…

高能物理 - 理论 · 物理学 2023-04-26 Alex Buchel

The Standard Cosmological Model has experienced tremendous success at reproducing observational data by assuming a universe dominated by a cosmological constant and dark matter in a flat geometry. However, several studies, based on local…

宇宙学与河外天体物理 · 物理学 2022-11-29 Jailson S. Alcaniz , Jacinto P. Neto , Farinaldo S. Queiroz , Deivid R. da Silva , Raimindo Silva

It is only human nature to be reluctant to accept something new and different. This feeling is exacerbated given the success of the Big Bang model. However, there are cogent reasons for considering this new model. Some of the advantages of…

天体物理学 · 物理学 2007-05-23 J. Zzimbe

It is shown that isotropic cosmology in the Riemann-Cartan spacetime allows to solve the problem of cosmological singularity as well as the problems of invisible matter components - dark energy and dark matter. All cosmological models…

广义相对论与量子宇宙学 · 物理学 2011-02-04 A. V. Minkevich

It is shown that a subelectronvolt upper limit can be derived on the neutrino mass from the CMB data alone in the Lambda CDM model with the power-law adiabatic perturbations, without the aid of any other cosmological data. Assuming the…

天体物理学 · 物理学 2016-08-30 Kazuhide Ichikawa , Masataka Fukugita , Masahiro Kawasaki

One of the great triumphs of the inflationary model is the prediction of the flat power spectrum of the CMB fluctuation. The prediction is based on the assumption of the de-Sitter vacuum in the past infinity. However, the true past infinity…

广义相对论与量子宇宙学 · 物理学 2019-03-27 Tadashi Sasaki , Hisao Suzuki

We have studied the evolution of the Universe in the generalized Einstein action of the form $R+\beta R^2$, where $R$ is the scalar curvature and $\beta=\rm const.$. We have found exact cosmological solutions that predict the present cosmic…

高能物理 - 理论 · 物理学 2008-11-21 Arbab I. Arbab

We present a brief history of the construction of models of the universe, followed by calculations of quantitative characteristics of basic geometric and kinematic properties of the Standard Cosmological Model ($\Lambda$CDM). Using the…

广义相对论与量子宇宙学 · 物理学 2026-04-23 D. I. Nagirner , S. G. Jorstad , A. V. Dementyev

In a flat Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) geometry, we consider the expansion of the universe powered by the gravitationally induced `adiabatic' matter creation. To demonstrate how matter creation works well with the…

广义相对论与量子宇宙学 · 物理学 2016-06-07 Supriya Pan , Jaume de Haro , Andronikos Paliathanasis , Reinoud Jan Slagter

On the basis of a semi-classical analysis of vacuum energy in an expanding spacetime, we describe a non-singular cosmological model in which the vacuum density decays with time, with a concomitant production of matter. During an infinitely…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Saulo Carneiro

The recent Cosmic Microwave Background (CMB) experiments have shown that the average density of the universe is close to the critical one and the universe is asymptotically flat (Euclidean). Taking into account that the universe remains…

综合物理 · 物理学 2012-07-02 Dimitar Valev

The flat inflationary dust universe with matter creation proposed by Prigogine and coworkers is generalized and its dynamical properties are reexamined. It is shown that the starting point of these models depends critically on a…

广义相对论与量子宇宙学 · 物理学 2009-10-28 L. R. W. Abramo , J. A. S. Lima

For two decades the hot big-bang model as been referred to as the standard cosmology -- and for good reason. For just as long cosmologists have known that there are fundamental questions that are not answered by the standard cosmology and…

天体物理学 · 物理学 2007-05-23 Michael S. Turner
‹ 上一页 1 8 9 10 下一页 ›