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Related papers: Reionization from cosmic string loops

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This work studies the connection between the first galaxies and their hosting dark matter halos in the early Universe when Reionization is concluding. Our numerical models (already presented in an earlier study) trace the star formation…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-23 Luz Ángela García

Observations of the 21-centimetre line of atomic hydrogen in the early Universe directly probe the history of the reionization of the gas between galaxies. The observations are challenging, though, because of the low expected signal…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Judd D. Bowman , Alan E. E. Rogers

We have modelled the process of reionization of the IGM by photoionization by galaxies, in order to predict the epoch of reionization. We use a sophisticated semi-analytic model to track the formation of galaxies. Our study represents a…

Astrophysics · Physics 2009-11-11 A. J. Benson , Naoshi Sugiyama , Adi Nusser , C. G. Lacey

A new candidate source of gravitational radiation is described: the nearly-perfect harmonic series from individual loops of cosmic string. It is argued that theories with light cosmic strings give rise to a population of numerous long-lived…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-02 Matthew R DePies , Craig J Hogan

The Pulsar timing data from NANOGrav Collaboration has regenerated interest in the possibility of observing stochastic gravitational wave background arising from cosmic strings. In the standard theory, the cosmic string network forms during…

General Relativity and Quantum Cosmology · Physics 2024-05-08 Ajit M. Srivastava

The fraction of cosmic string loops which collapse to form black holes is estimated using a set of realistic loops generated by loop fragmentation. The smallest radius sphere into which each cosmic string loop may fit is obtained by…

General Relativity and Quantum Cosmology · Physics 2009-10-28 R. R. Caldwell , Paul Casper

Cosmic strings are predicted in many models beyond the Standard Model of particle physics. In models which admit strings, a network of strings will inevitably be formed in a phase transition in the early universe and will persist to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Robert H. Brandenberger

Cosmic strings and primordial black holes (PBHs) commonly and naturally form in many scenarios describing the early universe. Here we show that if both cosmic strings and PBHs are present, their interaction leads to a range of interesting…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-14 Alexander Vilenkin , Yuri Levin , Andrei Gruzinov

Cosmic strings are topological defects which can be formed as a result of phase transitions with a spontaneous symmetry breaking in the early Universe. The possibility of the generation of a magnetic field around a cosmic string on the…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-02 L. V. Zadorozhna , B. I. Hnatyk , Yu. A. Sitenko

The reionization of the Universe is expected to leave a signal in the form of a sharp step in the spectrum of the sky. If reionization occurs at 5 < z < 20, a feature should appear in the radio sky at 70 - 240 MHz due to redshifted HI 21-cm…

Astrophysics · Physics 2007-05-23 P. A. Shaver , R. A. Windhorst , P. Madau , A. G. de Bruyn

The existence of a scaling evolution for cosmic string loops in an expanding universe is demonstrated for the first time by means of numerical simulations. In contrast with what is usually assumed, this result does not rely on any…

Astrophysics · Physics 2009-11-13 Christophe Ringeval , Mairi Sakellariadou , Francois Bouchet

We calculate the contribution of cosmic strings arising from a phase transition in the early universe, or cosmic superstrings arising from brane inflation, to the cosmic 21 cm power spectrum at redshifts z > 30. Future experiments can…

Astrophysics · Physics 2011-07-19 Rishi Khatri , Benjamin D. Wandelt

Cosmic strings are linear concentrations of energy that form whenever phase transitions in the early universe break axial symmetries as originally shown by Kibble. They are the result of frustrated order in the quantum fields responsible…

Astrophysics · Physics 2008-11-11 A. Achucarro , C. J. A. P. Martins

The early reionization of the intergalactic medium, which is favored from the WMAP temperature-polarization cross-correlations, contests the validity of the standard scenario of structure formation in the cold dark matter cosmogony. It is…

Astrophysics · Physics 2009-11-11 Hiroyuki Tashiro , Naoshi Sugiyama

We examine the spectrum of gravitational radiation emitted by a network of cosmic strings, with emphasis on the observational constraints and the opportunities for detection. The analysis improves over past work, as we use a…

Astrophysics · Physics 2009-12-30 R. R. Caldwell , R. A. Battye , E. P. S. Shellard

Cosmic strings provide a radically different paradigm for the formation of structure to the prevailing inflationary one. They afford some extra technical complications: for example, the calculation of the power spectrum of matter and…

Astrophysics · Physics 2007-05-23 Mark Hindmarsh , Mairi Sakellariadou , Graham R. Vincent

The universe was reionized by redshift z ~ 6 by a small fraction of the baryons in the universe, which released energy following their condensation out of a cold, dark, and neutral IGM into the earliest galaxies. The theory of this…

Astrophysics · Physics 2009-11-06 Paul R. Shapiro

The gravitational wave (GW) signals emitted by a network of cosmic strings are reexamined in view of the possible formation of a network of cosmic superstrings at the end of brane inflation. The reconnection probability $p$ of intersecting…

High Energy Physics - Theory · Physics 2009-11-10 Thibault Damour , Alexander Vilenkin

We present observation of large, expanding string loops forming around a heated wire tip embedded in a nematic liquid crystal sample. Loops expand due to convective stretching. This observation leads to a new insight into phenomena which…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ajit M. Srivastava

The fragmentation of horizon crossing superstrings creates loops that accrete and bind to collapsing matter perturbations if the string tension is less than a critical value and if the loops are large-scale. For typical model parameters…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-01 David F. Chernoff