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Related papers: Deviation From \Lambda CDM With Cosmic Strings Net…

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Cosmic strings, a hot subject in the 1980's and early 1990's, lost its appeal when it was found that it leads to inconsistencies in the power spectrum of the measured cosmic microwave background temperature anisotropies. However,…

High Energy Physics - Theory · Physics 2008-11-26 Mairi Sakellariadou

Cosmic string loops contain cusps which decay by emitting bursts of particles. A significant fraction of the released energy is in the form of photons. These photons are injected non-thermally and can hence cause spectral distortions of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-23 Madeleine Anthonisen , Robert Brandenberger , Alex Laguë , Ian A. Morrison , Daixi Xia

In this paper, we present results for large-angle CMB anisotropies generated from high resolution simulations of cosmic string networks in a range of flat FRW universes with a cosmological constant. Using an ensemble of all-sky maps, we…

Astrophysics · Physics 2008-11-26 M. Landriau , E. P. S. Shellard

The concordance (LambdaCDM) model reproduces the main current cosmological observations assuming the validity of general relativity at all scales and epochs, the presence of cold dark matter, and of a cosmological constant, equivalent to a…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-08 Guido Risaliti , Elisabeta Lusso

Cosmic strings are a well-motivated extension to the standard cosmological model and could induce a subdominant component in the anisotropies of the cosmic microwave background (CMB), in addition to the standard inflationary component. The…

Instrumentation and Methods for Astrophysics · Physics 2017-09-18 J. D. McEwen , S. M. Feeney , H. V. Peiris , Y. Wiaux , C. Ringeval , F. R. Bouchet

We propose a novel approach using neural networks (NNs) to differentiate between cosmological models, and implemented LIME as an interpretability approach to identify the key features influencing our model's decisions. We show the potential…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-03 Indira Ocampo , George Alestas , Savvas Nesseris , Domenico Sapone

Cosmic string networks are expected to form in early Universe phase transitions via the Kibble mechanism and are unavoidable in several Beyond the Standard Model theories. While most predictions of observational signals of string networks…

High Energy Physics - Phenomenology · Physics 2024-06-07 J. R. C. C. C. Correia , C. J. A. P. Martins , F. C. N. Q. Pimenta

One of the most interesting predictions of string-inspired cosmological models is the presence of a stochastic background of relic gravitational waves in the frequency band accessible to Earth-based detectors. Here we consider a ``minimal''…

General Relativity and Quantum Cosmology · Physics 2009-10-31 C. Ungarelli , A. Vecchio

We compute the power spectrum of the stochastic gravitational wave background generated by cosmic string networks described by the Velocity-Dependent One-Scale (VOS) model, for a wide range of macroscopic and microscopic parameters. The VOS…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-09 L. Sousa , P. P. Avelino

Multiple $\Lambda$CDM cosmology is studied in a way that is formally a classical analog of the Casimir effect. Such cosmology corresponds to a time-dependent dark fluid model or, alternatively, to its scalar field presentation, and it…

General Relativity and Quantum Cosmology · Physics 2015-06-05 E. Elizalde , A. N. Makarenko , S. Nojiri , V. V. Obukhov , S. D. Odintsov

Recent observations of Type 1a supernovae indicating an accelerating universe have once more drawn attention to the possible existence, at the present epoch, of a small positive Lambda-term (cosmological constant). In this paper we review…

Astrophysics · Physics 2009-10-31 Varun Sahni , Alexei Starobinsky

Cosmic strings are predicted in various extensions of the Standard Model, including grand unified theories. Depending on the symmetry-breaking pattern, they can be either topologically stable or metastable. Intriguingly, metastable strings…

High Energy Physics - Phenomenology · Physics 2025-07-17 Akifumi Chitose , Masahiro Ibe , Shunsuke Neda , Satoshi Shirai

We assess dataset agreement and late-time predictive adequacy in $\Lambda$CDM and its sign-switching extension, $\Lambda_{\rm s}$CDM, using a suite of Gaussian and exact non-Gaussian consistency diagnostics. Both models are constrained with…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-11 Sehjal Khandelwal , Abraão J. S. Capistrano , Suresh Kumar

We investigate in detail some popular cosmological models in light of the latest observational data, including the Union2.1 supernovae compilation, the baryon acoustic oscillation measurements from the WiggleZ Dark Energy Survey, the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ke Shi , Yongfeng Huang , Tan Lu

The success of present and future cosmological studies is tied to the ability to detect discrepancies in complex data sets within the framework of a cosmological model. Tensions caused by the presence of unknown systematic effects need to…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-13 Marco Raveri , Wayne Hu

At early stages the dynamics of cosmic string networks is expected to be influenced by an excessive production of small loops at the scales of initial conditions l_{min}. To understand the late time behavior we propose a very simple…

High Energy Physics - Theory · Physics 2014-11-21 Vitaly Vanchurin

There has been increasing interest by cosmologists in applying Bayesian techniques, such as Bayesian Evidence, for model selection. A typical example is in assessing whether observational data favour a cosmological constant over evolving…

Astrophysics · Physics 2009-11-13 G. Efstathiou

Cosmic superstrings are produced towards the end of the brane inflation. If the string tension is low enough, loops tend to be relatively long-lived. The resultant string network is expected to contain many loops which are smaller than…

Astrophysics · Physics 2007-09-10 David F. Chernoff , S. -H. Henry Tye

We study the reconstructed deceleration parameter splitting the data in different redshift bins, fitting both a cosmographic luminosity distance and also assuming a flat $\Lambda$CDM model, using the Pantheon+ sample of type Ia supernova…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-20 Erick Pastén , Victor Cárdenas

We study the formation of cosmic strings by confining a stochastic magnetic field into flux tubes in a numerical simulation. We use overdamped evolution in a potential that is minimized when the flux through each face in the simulation…

High Energy Physics - Theory · Physics 2008-11-26 Jose J. Blanco-Pillado , Ken D. Olum , Alexander Vilenkin
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