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The cosmological relic density of the lightest supersymmetric particle of the minimal supersymmetric standard model is calculated under the assumption of gauge and Yukawa coupling unification. We employ radiative electroweak breaking with…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. E. Gomez , G. Lazarides , C. Pallis

Some Lyman continuum photons are likely to escape from most galaxies, and these can play an important role in ionizing gas around and between galaxies, including gas that gives rise to Lyman alpha absorption. Thus the gas surrounding…

We study structure formation in cosmological void regions using high-resolution hydrodynamical simulations. Despite being significantly underdense, voids are populated abundantly with small dark matter halos which should appear as dwarf…

Astrophysics · Physics 2009-11-10 Matthias Hoeft , Gustavo Yepes , Stefan Gottloeber , Volker Springel

We derive new bounds on hidden sector gauge bosons which could produce new energy loss mechanisms in supernovae, enlarging the excluded region in mass-coupling space by a significant factor compared to earlier estimates. Both considerations…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-16 James B. Dent , Francesc Ferrer , Lawrence M. Krauss

The concentrations of the cuspy dark matter halos predicted by simulations of cold dark matter are related to the cosmology in which the halos form. Observational constraints on halo concentration therefore map into constraints on…

Astrophysics · Physics 2009-11-07 S. McGaugh , M. Barker , E. de Blok

We demonstrate that ionization of $\text{H}_2$ by dark matter in dense molecular clouds can provide strong constraints on the scattering strength of dark matter with electrons. Molecular clouds have high UV-optical attenuation, shielding…

High Energy Physics - Phenomenology · Physics 2023-08-28 Anirudh Prabhu , Carlos Blanco

In warm dark matter scenarios structure formation is suppressed on small scales with respect to the cold dark matter case, reducing the number of low-mass halos and the fraction of ionized gas at high redshifts and thus, delaying…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-24 Laura Lopez-Honorez , Olga Mena , Sergio Palomares-Ruiz , Pablo Villanueva Domingo

Cosmic voids are underdense regions filling up most of the volume in the Universe. They are expected to emerge in regions comprising negative initial density fluctuations, and subsequently expand as the matter around them collapses and…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-07 David Vallés-Pérez , Vicent Quilis , Susana Planelles

Identifying the population of galaxies that was responsible for the reionization of the universe is a long-standing quest in astronomy. We present a possible local analog that has an escape fraction of ionizing flux of 21%. Our detection…

Astrophysics of Galaxies · Physics 2014-10-15 Sanchayeeta Borthakur , Timothy M. Heckman , Claus Leitherer , Roderik A. Overzier

Cosmic voids, the less dense patches of the Universe, are promising laboratories to extract cosmological information. Thanks to their unique low density character, voids are extremely sensitive to diffuse components such as neutrinos and…

We study the relationship between dark-matter haloes and matter in the MIP $N$-body simulation ensemble, which allows precision measurements of this relationship, even deeply into voids. What enables this is a lack of discreteness,…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-06 Mark C. Neyrinck , Miguel A. Aragon-Calvo , Donghui Jeong , Xin Wang

The ionization parameter U is potentially useful for measuring radiation pressure feedback from massive star clusters, as it reflects the radiation-to-gas-pressure ratio and is readily derived from mid-infrared line ratios. We consider…

Astrophysics of Galaxies · Physics 2013-10-30 Sherry C. C. Yeh , Christopher D. Matzner

Supervoids are regions in the local Universe which do not contain rich clusters of galaxies. We have studied the closest example, the Northern Local Void, situated between the Local, Coma, and the Hercules superclusters. We find that this…

Astrophysics · Physics 2016-08-30 Ulrich Lindner , Jaan Einasto , Maret Einasto , Wolfram Freudling , Klaus Fricke , Erik Tago

We derive apparent and absolute ultraviolet (UV) magnitudes, and luminosities in the infrared (IR) range of a large sample of low-redshift (0<z<1) compact star-forming galaxies (CSFGs) selected from the Data Release 12 of the Sloan Digital…

Astrophysics of Galaxies · Physics 2023-05-03 Y. I. Izotov , N. G. Guseva , K. J. Fricke , C. Henkel , D. Schaerer

We use a three-dimensional radiation transfer code to calculate the steady-state escape fraction of ionizing photons from disk galaxies as a function of redshift and galaxy mass. The gaseous disks are assumed to be isothermal (with a sound…

Astrophysics · Physics 2009-10-31 Kenneth Wood , Abraham Loeb

According to the discussion on Birkhoff's theorem by Peebles (1993), a void with a negative perturbation \delta may evolve as a separate homogeneous universe with a local expansion parameter H_V\simeq H_0(1-\delta/3). This slightly low…

Astrophysics · Physics 2007-05-23 C. V. Manning

Recent observations have successfully detected UV or infrared flux from galaxies at the epoch of reionization. However, the origin of their radiative properties has not been fully understood yet. Combining cosmological hydrodynamic…

Astrophysics of Galaxies · Physics 2020-06-10 Shohei Arata , Hidenobu Yajima , Kentaro Nagamine , Yuexing Li , Sadegh Khochfar

Cosmic rays are the only agent able to penetrate into the interior of dense molecular clouds. Depositing (part of) their energy through ionisation, cosmic rays play an essential role in determining the physical and chemical evolution of…

High Energy Astrophysical Phenomena · Physics 2023-06-21 Vo Hong Minh Phan , Sarah Recchia , Philipp Mertsch , Stefano Gabici

Within the Halo Model of large scale structure, all matter is contained in dark matter halos. This simple yet powerful framework has been broadly applied to multiple data sets and enriched our comprehension of how matter is distributed in…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-25 Rodrigo Voivodic , Henrique Rubira , Marcos Lima

We derive analytic lower bounds on the cosmic baryon density by requiring that the high-redshift IGM contain enough neutral hydrogen to produce the observed \lya absorption in quasar spectra. The key theoretical assumption is that absorbing…

Astrophysics · Physics 2009-10-30 David H. Weinberg , Jordi Miralda-Escude , Lars Hernquist , Neal Katz