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In cosmology, emulators play a crucial role by providing fast and accurate predictions of complex physical models, enabling efficient exploration of high-dimensional parameter spaces that would be computationally prohibitive with direct…

宇宙学与河外天体物理 · 物理学 2026-04-10 Deaglan J. Bartlett , Shivam Pandey

Precise estimation of cosmological parameters from the cosmic microwave background (CMB) remains a central goal of modern cosmology and a key test of inflationary physics. However, this task is fundamentally limited by strong foreground…

宇宙学与河外天体物理 · 物理学 2026-04-03 Larissa Santos , Camila P. Novaes , Elisa G. M. Ferreira , Carlo Baccigalupi

Line discontinuities in cosmic microwave background anisotropy maps are a distinctive prediction of models with cosmic strings. These signatures are visible in anisotropy maps with good angular resolution and should be identifiable using…

天体物理学 · 物理学 2009-06-23 Stephen Amsel , Joshua Berger , Robert H. Brandenberger

Cosmological emulators of observables such as the Cosmic Microwave Background (CMB) spectra and matter power spectra commonly use training data sampled from a Latin hypercube. This method often incurs high computational costs by covering…

宇宙学与河外天体物理 · 物理学 2024-05-03 Andreas Nygaard , Emil Brinch Holm , Steen Hannestad , Thomas Tram

We showed that the part of strings could be detected by optical method is only 20% from the total available amount of such objects, therefore the gravitational lensing method has to be "completed" by CMB one. We found the general structure…

天体物理学 · 物理学 2009-11-13 O. S. Sazhina , M. V. Sazhin , V. N. Sementsov , M. Capaccioli , G. Longo , G. Riccio , G. D'Angelo

We study how the presence of world-sheet currents affects the evolution of cosmic string networks, and their impact on predictions for the cosmic microwave background (CMB) anisotropies generated by these networks. We provide a general…

宇宙学与河外天体物理 · 物理学 2020-10-21 I. Yu. Rybak , A. Avgoustidis , C. J. A. P. Martins

We present updated constraints on cosmic string and superstring parameters derived from Cosmic Microwave Background (CMB) anisotropies. The constraints are obtained via Markov Chain Monte Carlo (MCMC) analyses of the full \textit{Planck}…

宇宙学与河外天体物理 · 物理学 2026-03-23 Juhan Raidal , Anastasios Avgoustidis , Edmund Copeland , Adam Moss

The number of cosmic strings in the observable universe is relevant in determining the probability of detecting such cosmic defects through their gravitational signatures. In particular, we refer to the observation of gravitational lensing…

宇宙学与河外天体物理 · 物理学 2017-03-15 Rosa Consiglio , Olga Sazhina , Giuseppe Longo , Mikhail Sazhin , Franco Pezzella

Cosmological probes pose an inverse problem where the measurement result is obtained through observations, and the objective is to infer values of model parameters which characterize the underlying physical system -- our Universe. Modern…

天体物理仪器与方法 · 物理学 2019-05-21 Timur Takhtaganov , Zarija Lukic , Juliane Mueller , Dmitriy Morozov

Motivated by the morphological measures in assessing the geometrical and topological properties of a generic cosmological stochastic field, we propose an extension of the weighted morphological measures, specifically the $n$th conditional…

宇宙学与河外天体物理 · 物理学 2025-08-19 Adeela Afzal , M. Alakhras , M. H. Jalali Kanafi , S. M. S. Movahed

The topic of cosmic strings provides a bridge between the physics of the very small and the very large. They are predicted by some unified theories of particle interactions. If they exist, they may help to explain some of the largest-scale…

高能物理 - 唯象学 · 物理学 2010-11-01 M. B. Hindmarsh , T. W. B. Kibble

Motivated by the fact that cosmological perturbations of inflationary quantum origin were born Gaussian, the search for non-Gaussianities in the cosmic microwave background (CMB) anisotropies is considered as the privileged probe of…

宇宙学与河外天体物理 · 物理学 2015-03-17 Christophe Ringeval

Observations of the Cosmic Microwave Background (CMB) provide increasingly accurate information about the structure of the Universe at the recombination epoch. Most of this information is encoded in the angular power spectrum of the CMB.…

天体物理学 · 物理学 2011-08-01 G. Faÿ , F. Guilloux , M. Betoule , J. -F. Cardoso , J. Delabrouille , M. Le Jeune

Machine learning can accelerate cosmological inferences that involve many sequential evaluations of computationally expensive data vectors. Previous works in this series have examined how machine learning architectures impact emulator…

Upcoming ground-based cosmic microwave background experiments will provide CMB maps with high sensitivity and resolution that can be used for high fidelity lensing reconstruction. However, the sky coverage will be incomplete and the noise…

宇宙学与河外天体物理 · 物理学 2019-12-11 Mark Mirmelstein , Julien Carron , Antony Lewis

In the first part of this work, I review the theoretical framework of cosmological perturbation theory necessary to understand the generation and evolution of cosmic microwave background (CMB) anisotropies. Using analytical and numerical…

天体物理学 · 物理学 2009-09-29 Roberto Trotta

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,…

高能物理 - 理论 · 物理学 2008-11-26 Mairi Sakellariadou

We use wavelet and curvelet transforms to extract signals of cosmic strings from cosmic microwave background (CMB) temperature anisotropy maps, and to study the limits on the cosmic string tension which various ongoing CMB temperature…

宇宙学与河外天体物理 · 物理学 2017-06-21 Lukas Hergt , Adam Amara , Robert Brandenberger , Tomasz Kacprzak , Alexandre Refregier

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…

宇宙学与河外天体物理 · 物理学 2018-10-12 A. Vafaei Sadr , M. Farhang , S. M. S. Movahed , B. Bassett , M. Kunz

The predictions of the inflationary LCDM paradigm match today's high-precision measurements of the cosmic microwave background anisotropy extremely well. The same data put tight limits on other sources of anisotropy. Cosmic strings are a…

宇宙学与河外天体物理 · 物理学 2013-05-29 Cora Dvorkin , Mark Wyman , Wayne Hu