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相关论文: Cosmic strings and their induced non-Gaussianities…

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Primordial magnetic fields lead to non-Gaussian signals in the Cosmic Microwave Background (CMB) even at the lowest order, as magnetic stresses, and the temperature anisotropy they induce, depend quadratically on the magnetic field. In…

宇宙学与河外天体物理 · 物理学 2009-09-03 T. R. Seshadri , Kandaswamy Subramanian

Cusps of cosmic strings emit strong beams of high-frequency gravitational waves (GW). As a consequence of these beams, the stochastic ensemble of gravitational waves generated by a cosmological network of oscillating loops is strongly non…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Thibault Damour , Alexander Vilenkin

Anisotropies in the cosmic microwave background radiation due to gravity waves are investigated. An initial spectrum of gravity waves may have been induced during an epoch of inflation. We study the propagation of such a spectrum in a…

天体物理学 · 物理学 2008-02-03 Ruth Durrer , Tina Kahniashvili

We study the problem of searching for cosmic string signal patterns in the present high resolution and high sensitivity observations of the Cosmic Microwave Background (CMB). This article discusses a technique capable of recognizing…

宇宙学与河外天体物理 · 物理学 2014-11-20 E. Jeong , Carlo Baccigalupi , G. F. Smoot

We present theoretical and observational studies of non-Gaussian fluctuations in CMB, by using the angular bispectrum and trispectrum. We predict the primary angular bispectrum from inflation, and forecast how well we can measure the…

天体物理学 · 物理学 2007-05-23 Eiichiro Komatsu

We report on a current investigation of the anisotropy pattern induced by cosmic strings on the cosmic microwave background radiation (MBR). We have numerically evolved a network of cosmic strings from a redshift of $Z = 100$ to the present…

天体物理学 · 物理学 2007-05-23 B. Allen , R. R. Caldwell , E. P. S. Shellard , A. Stebbins , S. Veeraraghavan

The presence of non--Gaussian features in the Cosmic Microwave Background (CMB) radiation maps represents one of the most long--awaited clues in the search for the actual structure of the primordial radiation, still needing confirmation.…

天体物理学 · 物理学 2009-10-22 Alejandro Gangui

In the framework of inflationary models with non-vacuum initial states for cosmological perturbations, we study non-Gaussian signatures on the cosmic microwave background radiation produced by a broken-scale-invariant model which…

天体物理学 · 物理学 2019-04-03 Alejandro Gangui

We investigate the anisotropies of the stochastic gravitational-wave background (SGWB) produced by cosmic strings associated with the spontaneous U(1) symmetry breaking of Grand Unified Theory, which happens at the onset of inflation. The…

宇宙学与河外天体物理 · 物理学 2021-12-21 Rong-Gen Cai , Zong-Kuan Guo , Jing Liu

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

Anisotropies in distortions to the frequency spectrum of the cosmic microwave background (CMB) can be created through spatially varying heating processes in the early Universe. For instance, the dissipation of small-scale acoustic modes…

宇宙学与河外天体物理 · 物理学 2017-01-25 Jens Chluba , Emanuela Dimastrogiovanni , Mustafa A. Amin , Marc Kamionkowski

The presence of axion strings in the Universe after recombination can leave an imprint on the polarization pattern of the cosmic microwave background radiation through the phenomenon of axion-string-induced birefringence via the hyperlight…

宇宙学与河外天体物理 · 物理学 2023-09-19 Ray Hagimoto , Andrew J. Long

Non-Gaussianity in the inflationary perturbations can couple observable scales to modes of much longer wavelength (even superhorizon), leaving as a signature a large-angle modulation of the observed cosmic microwave background (CMB) power…

宇宙学与河外天体物理 · 物理学 2013-05-30 Fabian Schmidt , Lam Hui

We present the first ever calculation of cosmic microwave background CMB anisotropy power spectra from semilocal cosmic strings, obtained via simulations of a classical field theory. Semilocal strings are a type of non-topological defect…

天体物理学 · 物理学 2009-06-23 Jon Urrestilla , Neil Bevis , Mark Hindmarsh , Martin Kunz , Andrew R. Liddle

We develop a powerful analytical formalism for calculating the energy density of the stochastic gravitational wave background, including a full description of its anisotropies. This is completely general, and can be applied to any…

宇宙学与河外天体物理 · 物理学 2018-09-19 Alexander C. Jenkins , Mairi Sakellariadou

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…

宇宙学与河外天体物理 · 物理学 2014-11-20 Rebecca J. Danos , Robert H. Brandenberger

A metastable cosmic-string network is a generic consequence of many grand unified theories (GUTs) when combined with cosmic inflation. Metastable cosmic strings are not topologically stable, but decay on cosmic time scales due to pair…

高能物理 - 唯象学 · 物理学 2021-12-15 Wilfried Buchmuller , Valerie Domcke , Kai Schmitz

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

Cosmic strings are linear concentrations of energy that may be formed at phase transitions in the very early universe. At one time they were thought to provide a possible origin for the density inhomogeneities from which galaxies eventually…

高能物理 - 理论 · 物理学 2009-11-11 A. -C. Davis , T. W. B. Kibble

Although cosmological observations suggest that the fluctuations of seed fields are almost Gaussian, the possibility of a small deviation of their fields from Gaussianity is widely discussed. Theoretically, there exist numerous inflationary…

宇宙学与河外天体物理 · 物理学 2022-09-21 Maresuke Shiraishi