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We introduce a versatile and spatially resolved morphological characterisation of binary fields, rooted in the opening transform of mathematical morphology. We subsequently apply it to the thresholded ionization field in simulations of…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-08 Philipp Busch , Marius B. Eide , B. Ciardi , Koki Kakiichi

The emission from neutral hydrogen (HI) clouds in the post-reionization era (z < 6), too faint to be individually detected, is present as a diffuse background in all low frequency radio observations below 1420 MHz. The angular and frequency…

Astrophysics · Physics 2009-10-29 Somnath Bharadwaj , Shiv K. Sethi , Tarun Deep Saini

The high ionization level and universal metallicity (1% solar) of the intergalactic gas at redshifts z<5 implies that nonlinear structure had started to form in the universe at earlier times than we currently probe. In Cold Dark Matter…

Astrophysics · Physics 2009-10-28 Zoltan Haiman , Abraham Loeb

Recently, attempts have been made to understand the apparent near coincidence of the present dark energy and matter energy in terms of a dynamical attractor-like solution for the evolution of a scalar field. In these models the field…

Astrophysics · Physics 2009-11-06 M. Yahiro , G. J. Mathews , K. Ichiki , T. Kajino , M. Orito

Recently, few cosmological models with additional non-Riemannian volume form(s) have been proposed. In this article we use Supernovae type Ia experimental data to test one of these models which provides a unified description of both dark…

General Relativity and Quantum Cosmology · Physics 2018-10-05 Denitsa Staicova , Michail Stoilov

Current observations suggest that the universe was reionized sometime before z~6. One way to observe this epoch of the universe is through the Near Infrared Background (NIRB), which contains information about galaxies which may be too faint…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-18 Elizabeth R. Fernandez , Ilian T. Iliev , Eiichiro Komatsu , Paul R. Shapiro

We perform fits to DESI, CMB and supernova data to understand the physical origin of the DESI hint for dynamical dark energy. We find that the linear parametrization of the equation of state $w$ may guide to misleading interpretations, such…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-27 Ioannis D. Gialamas , Gert Hütsi , Kristjan Kannike , Antonio Racioppi , Martti Raidal , Martin Vasar , Hardi Veermäe

A disconcerting mismatch of thermal pressures for two media in contact with each other, (1) the warm, Circum-heliospheric Interstellar Medium (CHISM) and (2) the very hot material within a much larger region called the Local Bubble (LB),…

Astrophysics · Physics 2011-05-30 Edward B. Jenkins

The negative pressure accompanying gravitationally-induced particle creation can lead to a cold dark matter (CDM) dominated, accelerating Universe (Lima et al. 1996) without requiring the presence of dark energy or a cosmological constant.…

Astrophysics · Physics 2009-07-22 G. Steigman , R. C. Santos , J. A. S. Lima

Using the First Light And Reionisation Epoch Simulations (\textsc{Flares}) we explore the dust driven properties of massive high-redshift galaxies at $z\in[5,10]$. By post-processing the galaxy sample using the radiative transfer code…

We model the transmission of the Lyman-alpha line through the circum- and intergalactic media around dark matter haloes expected to host Lyman-alpha emitters (LAEs) at z > 5.7, using the high-dynamic-range Sherwood simulations. We find very…

Astrophysics of Galaxies · Physics 2018-06-27 Lewis H. Weinberger , Girish Kulkarni , Martin G. Haehnelt , Tirthankar Roy Choudhury , Ewald Puchwein

Density inhomogeneity in the intergalactic medium (IGM) can boost the recombination rate of ionized gas substantially, affecting the growth of HII regions during reionization. Previous attempts to quantify this effect typically failed to…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-09 Hyunbae Park , Paul R. Shapiro , Jun-hwan Choi , Naoki Yoshida , Shingo Hirano , Kyungjin Ahn

We highlight the general scenario of dark matter freeze-out whilst the energy density of the universe is dominated by a decoupled non-relativistic species. Decoupling during matter domination changes the freeze-out dynamics, since the…

High Energy Physics - Phenomenology · Physics 2025-11-06 Saleh Hamdan , James Unwin

Though half of cosmic starlight is absorbed by dust and reradiated at long wavelengths (3$\mu$m-3mm), constraints on the infrared through millimeter galaxy luminosity function (the `IRLF') are poor in comparison to the rest-frame…

The large cross-section of the Lyman alpha (Lya) line makes it a sensitive probe of the ionization state of the intergalactic medium (IGM). Here we present the most complete study to date of the IGM Lya opacity, and its application to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Andrei Mesinger , Aycin Aykutalp , Eros Vanzella , Laura Pentericci , Andrea Ferrara , Mark Dijkstra

A number of recent works in astronomy and cosmology have relied upon theoretical He I emissivities, but we know of no effort to quantify the uncertainties in the atomic data. We analyze and assign uncertainties to all relevant atomic data,…

Astrophysics · Physics 2009-11-13 R. L. Porter , G. J. Ferland , K. B. MacAdam , P. J. Storey

We use lookback time versus redshift data from galaxy clusters (Capozziello et al., 2004) and passively evolving galaxies (Simon et al., 2005), and apply a bayesian prior on the total age of the Universe based on WMAP measurements, to…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Lado Samushia , Abha Dev , Deepak Jain , Bharat Ratra

We present a semi-analytic model for the thermal and ionization history of the universe at 1000 >~ z >~ 3. This model incorporates much of the essential physics included in full-scale hydrodynamical simulations, such as (1) gravitational…

Astrophysics · Physics 2009-10-31 Weihsueh A. Chiu , Jeremiah P. Ostriker

We revisit the possibility of constraining the properties of dark matter (DM) by studying the epoch of cosmic reionization. Previous studies have shown that DM annihilation was unlikely to have provided a large fraction of the photons that…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Alexander A. Kaurov , Dan Hooper , Nickolay Y. Gnedin

It is well known that annihilations in the homogeneous fluid of dark matter (DM) can leave imprints in the cosmic microwave background (CMB) anisotropy power spectrum. However, the relevance of DM annihilations in halos for cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-20 Vivian Poulin , Pasquale D. Serpico , Julien Lesgourgues