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Related papers: Cosmic reionization in a dynamic quintessence cosm…

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We explore a time-dependent energy dissipation of the energetic electrons in the inhomogeneous intergalactic medium (IGM) during the epoch of cosmic reionization. In addition to the atomic processes we take into account the Inverse Compton…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Alexander A. Kaurov

We use high-redshift type Ia supernova and compact radio source data in order to test the infrared (IR) fixed point model of the late Universe which was proposed recently. It describes a cosmology with a time dependent cosmological constant…

Astrophysics · Physics 2009-11-07 E. Bentivegna , A. Bonanno , M. Reuter

We present a complete numerical study of cosmological models with a time dependent coupling between the dark energy component driving the present accelerated expansion of the Universe and the Cold Dark Matter (CDM) fluid. Depending on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Marco Baldi

We present cosmological, radiation-hydrodynamics simulations of galaxy formation during the epoch of reionization in an effort towards modelling the interstellar medium (ISM) and interpreting ALMA observations. Simulations with and without…

Astrophysics of Galaxies · Physics 2018-05-02 Harley Katz , Taysun Kimm , Debora Sijacki , Martin Haehnelt

In this paper we study the cosmological evolution of the holographic dark energy in a cyclic universe, generalizing the model of holographic dark energy proposed by Li. The holographic dark energy with $c<1$ can realize a quintom behavior;…

High Energy Physics - Theory · Physics 2008-11-26 Jingfei Zhang , Xin Zhang , Hongya Liu

We use data from observational cosmology to put constraints on higher-dimensional extensions of general relativity in which the effective four-dimensional dark-energy density (or cosmological "constant") decays with time. In particular we…

Astrophysics · Physics 2009-11-13 J. M. Overduin , P. S. Wesson , B. Mashhoon

At the epoch of reionization, when the high-redshift inter-galactic medium (IGM) is being enriched with metals, the 63.2 micron fine structure line of OI is pumped by the ~ 1300 AA soft UV background and introduces a spectral distortion in…

Astrophysics · Physics 2009-11-13 Carlos Hernandez-Monteagudo , Zoltan Haiman , Licia Verde , Raul Jimenez

We study some cosmological constraints on the two phenomenological models of oscillating dark energy. In these scenarios, the equation of state of dark energy varies periodically and may provide a way to unify the early acceleration…

Astrophysics · Physics 2009-06-23 Deepak Jain , Abha Dev , J. S. Alcaniz

The source responsible for reionizing the universe at z > 6 remains uncertain. While an energetically adequate population of star-forming galaxies may be in place, it is unknown whether a large enough fraction of their ionizing radiation…

We show the universe was reionized twice, first at z~15-16 and second at z~6. Such an outcome appears inevitable, when normalizing to two well determined observational measurements, namely, the epoch of the final cosmological reionization…

Astrophysics · Physics 2009-06-15 Renyue Cen

We use new studies of the cosmic evolution of star-forming galaxies to estimate the production rate of ionizing photons from hot, massive stars at low and intermediate redshifts. The luminosity function of blue galaxies in the Canada-France…

Astrophysics · Physics 2015-06-24 E. Giallongo , A. Fontana , P. Madau

We report that the neutral hydrogen (HI) mass density of the Universe ($\rho_{HI}$) increases with cosmic time since $z \sim 5$, peaks at $z \sim 3$, and then decreases toward $z \sim 0$. This is the first result of Qz5, our spectroscopic…

This research addresses the influence of Primordial Black Holes (PBHs) on cosmic reionization, using a robust semi-analytical model. This model encapsulates cosmological theory, PBH physics, and radiative transfer, with a lognormal PBH mass…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-07 Krish Jhurani , Pranav Gunhal

In this manuscript, we investigate late-time cosmology and the evolution of cosmic structures using an interacting dark fluid model in which dark matter (DM) and dark energy (DE) interact through a diffusive mechanism. To provide a…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Shambel Sahlu , Upala Mukhopadhyay , Remudin R. Mekuria , Amare Abebe

The evolution of large-scale structure, galaxies and the intergalactic medium (IGM) during the Epoch of Reionization (EoR) can be probed by upcoming Line Intensity Mapping (LIM) experiments, which sample in redshift and direction without…

The effects of reionization, occurring after standard recombination in cold dark matter-dominated models, on CMB anisotropies are investigated. Late-time reionization reduces the CMB anisotropies, in particular, on degree scales. It is…

Astrophysics · Physics 2009-10-22 Naoshi Sugiyama , Joseph Silk , Nicola Vittorio

We consider the angular power spectrum in a finite universe with different boundary conditions and perform a fit to the CMB, LSS and supernova data. A finite universe could be the consequence of a holographic constraint, giving rise to an…

Astrophysics · Physics 2010-12-09 Kari Enqvist , Steen Hannestad , Martin S. Sloth

Primordial black holes (PBHs) of stellar mass or heavier would accrete baryonic gas, which becomes denser and hotter, injecting energetic photons in the cosmological medium soon after cosmic recombination, in the so-called dark ages. The…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-19 Pasquale Dario Serpico

We investigate the ionization of the diffuse interstellar medium by cosmic rays by modeling their propagation along the wandering magnetic fields using a Monte Carlo method. We study how low-energy cosmic rays propagate in turbulent,…

High Energy Astrophysical Phenomena · Physics 2022-12-05 Riccardo Franceschi , Steven Neil Shore

We examine the impact of helium reionization on the structure of the intergalactic medium (IGM). We model the reionization using a radiative transfer (RT) code coupled to the combined gravity hydrodynamics code Enzo. Neutral hydrogen and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. Meiksin , E. R. Tittley
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