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We study the signal of cosmic string wakes present before the time of reionization in the cross-correlation signal of 21-cm redshift and B-mode CMB polarization maps. The specific non-Gaussian signal of strings in the position space…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-14 Matteo Blamart , Hannah Fronenberg , Robert Brandenberger

Since the public release of Planck data, several attempts have been made to explain the observed small tensions with other data-sets, most of them involving an extension of the {\Lambda}CDM Model. We try here an alternative approach to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Benjamin Audren

In this paper, we use a set of observational $H(z)$ data (OHD) to constrain the $\Lambda$CDM cosmology. This data set can be derived from the differential ages of the passively evolving galaxies. Meanwhile, the $\mathcal {A}$-parameter,…

Astrophysics · Physics 2014-11-18 Hui Lin , Cheng Hao , Xiao Wang , Qiang Yuan , Ze-Long Yi , Tong-Jie Zhang , Bao-Quan Wang

The implications of string theory for understanding the dimension of uncompactified spacetime are investigated. Using recent ideas in string cosmology, a new model is proposed to explain why three spatial dimensions grew large. Unlike the…

High Energy Physics - Theory · Physics 2010-11-01 Gerald B. Cleaver , Philip J. Rosenthal

A class of well-motivated models of inflation end by producing cosmic strings. The current status of efforts to calculate and observe the signals from such models are outlined, with a particular emphasis on cosmic strings, and on the Cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Mark Hindmarsh

An implicit, fully characteristic, numerical scheme for solving the field equations of a cosmic string coupled to gravity is described. The inclusion of null infinity as part of the numerical grid allows us to apply suitable boundary…

General Relativity and Quantum Cosmology · Physics 2009-10-31 U. Sperhake , K. R. P. Sjodin , J. A. Vickers

Effects invoked by the passage of the cosmic string through the Earth are investigated. The cosmic string induces global oscillations of the Earth whose amplitude and acceleration both linearly depend on the string line density. For the…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-11 Hayato Motohashi , Teruaki Suyama

We investigate deviations from $\Lambda$CDM by independently parameterizing modifications in the background evolution and the growth of structures. The background is characterized by two parameters, $A$ and $B$, which reduce to…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-08 Shibendu Gupta Choudhury , Purba Mukherjee , Anjan Ananda Sen

We perform the numerical field evolution for the collision of two Abelian type I cosmic strings. We present evidence that, for collisions at small but characteristic relative velocities and angles, these cosmic strings do not exchange ends…

High Energy Physics - Phenomenology · Physics 2009-10-30 Luis M. A. Bettencourt , Pablo Laguna , Richard A. Matzner

Because cosmic superstrings generically form junctions and gauge theoretic strings typically do not, junctions may provide a signature to distinguish between cosmic superstrings and gauge theoretic cosmic strings. In cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Rebecca J. Danos , Robert H. Brandenberger

After reviewing the cosmological constant problem - why is Lambda not huge? - I outline the two basic approaches that had emerged by the late 1980s, and note that each made a clear prediction. Precision cosmological experiments now indicate…

High Energy Physics - Theory · Physics 2007-05-23 Raphael Bousso

We explore the use of random forest and gradient boosting, two powerful tree-based machine learning algorithms, for the detection of cosmic strings in maps of the cosmic microwave background (CMB), through their unique Gott-Kaiser-Stebbins…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-12 A. Vafaei Sadr , M. Farhang , S. M. S. Movahed , B. Bassett , M. Kunz

We compute the power spectra in the cosmic microwave background and cold dark matter (CDM) fluctuations seeded by strings, using the largest string simulations performed so far to evaluate the two-point functions of their stress energy…

Astrophysics · Physics 2009-10-30 Carlo Contaldi , Mark Hindmarsh , Joao Magueijo

We perform a detailed confrontation of various oscillating dark-energy parame-trizations with the latest sets of observational data. In particular, we use data from Joint Light Curve analysis (JLA) sample from Supernoave Type Ia, Baryon…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Supriya Pan , Emmanuel N. Saridakis , Weiqiang Yang

We have studied the cosmological evolution of domain wall networks in two, three and four spatial dimensions using high-resolution field theory simulations. The dynamical range and number of our simulations is larger than in previous works,…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. C. R. E. Oliveira , C. J. A. P. Martins , P. P. Avelino

We present cosmic microwave background (CMB) power spectra from recent numerical simulations of cosmic strings in the Abelian Higgs model and compare them to CMB power spectra measured by Planck. We obtain revised constraints on the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-28 Joanes Lizarraga , Jon Urrestilla , David Daverio , Mark Hindmarsh , Martin Kunz

We develop a model of string dynamics with back-reaction from both scaling and non-scaling loops taken into account. The evolution of a string network is described by the distribution functions of coherence segments and kinks. We derive two…

High Energy Physics - Theory · Physics 2010-11-19 Vitaly Vanchurin

Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the…

High Energy Physics - Phenomenology · Physics 2015-06-23 Andrew J. Long , Tanmay Vachaspati

We examine the validity of the $\Lambda$CDM model, and probe for the dynamics of dark energy using latest astronomical observations. Using the $Om(z)$ diagnosis, we find that different kinds of observational data are in tension within the…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-14 Yuecheng Zhang , Hanyu Zhang , Dandan Wang , Yanghan Qi , Yuting Wang , Gong-Bo Zhao

We review the properties and evolution of strings networks containing both a spectrum of string tensions as well as Y-junctions, namely a point at which three different strings meet. Such a situation is expected in cosmic superstring…

High Energy Physics - Theory · Physics 2015-06-17 D. A. Steer