相关论文: Falsifying cosmological models based on a non-line…

In this work, we propose an economical model to address some open cosmological problems such as the absence of the initial cosmological singularity, an early acceleration of the Universe and the generation of matter-antimatter asymmetry.…

The NASA/IPAC Extragalactic Database (NED) is an impressive tool for finding near-exhaustive information on millions of astrophysical objects. Here, we outline a small systematic error that occurs in NED because a low-redshift approximation…

A model of a universe without big bang singularity is presented, which displaysanearly inflationary period ending just before a phase transition to a deflationary epoch. The model produces enough heavy particles so as to reheat the universe…

A continuous process of creation of particles is investigated as a possible connection between the inflationary stage with late cosmic acceleration. In this model, the inflationary era occurs due to a continuous and fast process of creation…

New Early Dark Energy (NEDE) is a component of vacuum energy at the electron volt scale, which decays in a first-order phase transition shortly before recombination [arXiv:1910.10739]. The NEDE component has the potential to resolve the…

We obtain a magnetically charged regular black hole in general relativity. The source to the Einstein field equations is nonlinear electrodynamic field in a physically reasonable model of nonlinear electrodynamics (NED). "Physically" here…

A kinematic method to access cosmic acceleration based exclusively on the Sunyaev-Zel'dovich effect (SZE) and X-ray surface brightness data from galaxy clusters is proposed. By using the SZE/X-ray data from 38 galaxy clusters [Bonament et…

We present a cosmological model arising from a gravitational theory with an infinite tower of higher-order curvature invariants that can reproduce the entire evolution of the Universe: from inflation to late-time acceleration, without…

Making observable predictions for cosmic inflation requires determining when the wavenumbers of astrophysical interest today exited the Hubble radius during the inflationary epoch. These instants are commonly evaluated using the slow-roll…

New early dark energy (NEDE) makes the cosmic microwave background consistent with a higher value of the Hubble constant inferred from supernovae observations. It is an improvement over the old early dark energy model (EDE) because it…

We present a mechanism for the emergence of cosmic acceleration within the mean-field approximation of Group Field Theory models of quantum gravity. Depending on the interaction type, the resulting cosmological dynamics can either feature a…

The late time acceleration of the Universe has challenged contemporary cosmology since its discovery. General Relativity explains this phenomenon by introducing the cosmological constant, named the standard cosmological model…

After decades of successful hot big-bang paradigm, Cosmology still lacks a framework in which the early inflationary phase of the universe smoothly matches the radiation epoch and evolves to the present `quasi' de Sitter spacetime. No less…

Despite impressive phenomenological successes, cosmological models are incomplete without an understanding of what happened at the big bang singularity. Maxwell electrodynamics, considered as a source of the classical Einstein field…

In this paper, we investigate the latetime cosmic acceleration of the Quintessence model within the framework of Hoyle Narlikar Gravity (HNG), which incorporates a creation field. Using the Hubble tension as a function of the density…

We present a consistent effective theory that violates the null energy condition (NEC) without developing any instabilities or other pathological features. The model is the ghost condensate with the global shift symmetry softly broken by a…

By-now photons are the unique universal messengers. Cosmological sources like far-away galaxies or quasars are well-known light-emitters. Here we demonstrate that the nonlinear electrodynamics (NLED) description of photon propagation…

Cosmic acceleration is widely believed to require either a source of negative pressure (i.e., dark energy), or a modification of gravity, which necessarily implies new degrees of freedom beyond those of Einstein gravity. In this paper we…

Could one start from scratch, ignore relativity theory and quantum theory, create and expand our 3-D universe with no singularities, have the mathematical model predict correctly all of the cosmological parameters, provide the origins and…

Unifying the early-universe inflationary paradigm with late-time cosmic acceleration, while resolving the initial Big Bang singularity, remains one of the most profound challenges in modern cosmology. In this paper, we propose a…