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Related papers: Reionization from cosmic string loops

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Cosmic strings are a common prediction in many grand unified theories and a promising source of stochastic gravitational waves (GWs) from the early Universe. In this paper, we point out that the GW signal from cosmic strings produced at a…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-24 Kai Schmitz , Tobias Schröder

Axions that couple to electromagnetism are produced in the early Universe by, among other channels, freeze-in via the Primakoff process. For sufficiently large axion masses, the same coupling causes the axions to decay into two photons,…

High Energy Physics - Phenomenology · Physics 2025-10-24 Ziwen Yin , Hanyu Cheng , Eleonora Di Valentino , Naomi Gendler , David J. E. Marsh , Luca Visinelli

Reducing the power on small scales relative to the `standard' LCDM model alleviates a number of possible discrepancies with observations, and is favored by the recent analysis of WMAP plus galaxy and Lyman-alpha forest data. Here, we…

Astrophysics · Physics 2008-11-26 Rachel S. Somerville , James S. Bullock , Mario Livio

Reionizing the Universe with galaxies appears to require significant star formation in low-mass halos at early times, while local dwarf galaxy counts tell us that star formation has been minimal in small halos around us today. Using simple…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-08 Michael Boylan-Kolchin , James S. Bullock , Shea Garrison-Kimmel

I calculate a hybrid cross-power spectrum estimator from the WMAP 5-year CMB temperature maps, discuss the goodness of fit, and then constrain cosmological parameters. The spectrum and results are generally consistent with previous results,…

Astrophysics · Physics 2017-08-07 Antony Lewis

Cosmic superstrings of string theory differ from conventional cosmic strings of field theory. We review how the physical and cosmological properties of the macroscopic string loops influence experimental searches for these relics from the…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-16 David F. Chernoff , S. -H. Henry Tye

Using the formalism developed in a previous paper we analyze the cosmological implications of our conclusions concerning the scaling behaviour of a network of cosmic strings, in particular the idea that once gravitational back-reaction…

High Energy Physics - Phenomenology · Physics 2010-01-06 Daren Austin , E. J. Copeland , T. W. B. Kibble

We present the properties of a cosmic superstring network in the scenario of flux compactification. An infinite family of strings, the (p,q)-strings, are allowed to exist. The flux compactification leads to a string tension that is periodic…

Astrophysics · Physics 2008-11-26 Louis Leblond , Mark Wyman

Large-scale magnetic fields are observed today to be coherent on galactic scales. While there exists an explanation for their amplification and their specific configuration in spiral galaxies -- the dynamo mechanism -- a satisfying…

High Energy Physics - Theory · Physics 2009-12-04 Rhiannon Gwyn , Stephon Alexander , Robert H. Brandenberger , Keshav Dasgupta

A general formulation for describing odd-harmonic cosmic strings is developed and used to determine the self-intersection properties of high-harmonic loops. This is important because loop formation mechanisms produce high-harmonic…

High Energy Physics - Phenomenology · Physics 2010-12-09 Xavier A. Siemens , T. W. B. Kibble

We discuss the signature of a cosmic string wake in 21cm redshift surveys. Since 21cm surveys probe higher redshifts than optical large-scale structure surveys, the signatures of cosmic strings are more manifest in 21cm maps than they are…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Robert H. Brandenberger , Rebecca J. Danos , Oscar F Hernandez , Gilbert P. Holder

We demonstrate that cosmic string loops may provide a joint resolution of two mysteries surrounding recently observed black holes. For a string tension in an appropriate range, large radius string loops have the potential to provide the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Robert Brandenberger , Bryce Cyr , Hao Jiao

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 generalize the calculation of cosmic superstring reconnection probability to non-trivial backgrounds. This is done by modeling cosmic strings as wound tachyon modes in the 0B theory, and the spacetime effective action is then used to…

High Energy Physics - Theory · Physics 2014-11-18 Mark G. Jackson

We show that the existence of cosmic strings can be strongly constrained by the next generation of gravitational lensing surveys at radio frequencies. We focus on cosmic string loops, which simulations suggest would be far more numerous…

Astrophysics · Physics 2008-11-26 Katherine J. Mack , Daniel H. Wesley , Lindsay J. King

We investigate cosmic strings arising from a hierarchical gauge symmetry breaking sequence, $\mathrm{SU}(2) \times \mathrm{U}(1) \rightarrow \mathrm{U}(1) \times \mathrm{U}(1) \rightarrow \mathrm{U}(1)' \rightarrow \text{Nothing}$. This…

High Energy Physics - Phenomenology · Physics 2025-06-19 Akifumi Chitose , Masahiro Ibe , Satoshi Shirai , Yaxuan Wen

We use cosmological simulations to explore the large-scale effects of reionization. Since reionization is a process that involves a large dynamic range - from galaxies to rare bright quasars - we need to be able to cover a significant…

Astrophysics · Physics 2008-11-26 Katharina Kohler , Nickolay Y. Gnedin , Andrew J. S. Hamilton

We compute the gravitational waveform produced by cosmic superstring reconnections. This is done by first constructing the superstring reconnection trajectory, which closely resembles that of classical, instantaneous reconnection but with…

High Energy Physics - Theory · Physics 2009-07-22 Mark G. Jackson , Xavier Siemens

Large-scale reionization simulations are described which combine the results of cosmological N-body simulations that model the evolving density and velocity fields and identify the galactic halo sources, with ray-tracing radiative transfer…

We examine the reionization history of present-day galaxies by explicitly tracing the building blocks of halos from the Cosmic Reionization On Computers project. We track dark matter particles that belong to $z=0$ halos to trace the neutral…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-02 Hanjue Zhu , Camille Avestruz , Nickolay Y. Gnedin