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相关论文: Probing polarization states of primordial gravitat…

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Since the temperature fluctuations in cosmic microwave background (CMB) on large-angular scales probe length scales that were super-horizon sized at photon decoupling and hence insensitive to microphysical processes, the low-multipole CMB…

宇宙学与河外天体物理 · 物理学 2015-12-30 Cheng Cheng , Qing-Guo Huang

Multi-field inflation models and non-Bunch-Davies vacuum initial conditions both predict sizeable non-Gaussian primordial perturbations and anisotropic $\mu$-type spectral distortions of the cosmic microwave background (CMB) blackbody.…

宇宙学与河外天体物理 · 物理学 2022-02-23 Mathieu Remazeilles , Andrea Ravenni , Jens Chluba

Since the very first observations, the Cosmic Microwave Background (CMB) has revealed on large-scales unexpected features known as anomalies, which challenge the standard $\Lambda$ cold dark matter ($\Lambda$CDM) cosmological model. One…

宇宙学与河外天体物理 · 物理学 2023-10-24 Giacomo Galloni , Mario Ballardini , Nicola Bartolo , Alessandro Gruppuso , Luca Pagano , Angelo Ricciardone

Precision measurements of the polarization of the cosmic microwave background (CMB) radiation, especially experiments seeking to detect the odd-parity "B-modes", have far-reaching implications for cosmology. To detect the B-modes generated…

宇宙学与河外天体物理 · 物理学 2012-12-27 Brian Keating , Meir Shimon , Amit Yadav

The cosmic microwave background (CMB) is affected by the total radiation density around the time of decoupling. At that epoch, neutrinos comprised a significant fraction of the radiative energy, but there could also be a contribution from…

宇宙学与河外天体物理 · 物理学 2013-05-30 Irene Sendra , Tristan L. Smith

The Cosmic Gravitational Wave Background (CGWB) is an irreducible background of gravitational waves generated by particle exchange in the early Universe plasma. Standard Model particles contribute to such a stochastic background with a peak…

高能物理 - 唯象学 · 物理学 2023-09-12 Francesco Muia , Fernando Quevedo , Andreas Schachner , Gonzalo Villa

The non-thermal nature of the cosmological gravitational wave background (CGWB) makes it difficult to define the initial condition for the graviton distribution, which determines the initial contribution to the CGWB anisotropies.…

宇宙学与河外天体物理 · 物理学 2026-02-19 Lorenzo Valbusa Dall'Armi , Alina Mierna , Sabino Matarrese , Angelo Ricciardone

We present a new and especially powerful signature of cosmic strings and other topological or non-topological defects in the polarization of the cosmic microwave background (CMB). We show that even if defects contribute 1% or less in the…

宇宙学与河外天体物理 · 物理学 2011-01-27 Juan Garcia-Bellido , Ruth Durrer , Elisa Fenu , Daniel G. Figueroa , Martin Kunz

String models can produce successful inflationary scenarios in the context of brane collisions and in many of these models cosmic strings may also be produced. In scenarios such as KKLMMT the string contribution is naturally predicted to be…

天体物理学 · 物理学 2009-11-11 Uros Seljak , Anze Slosar

The study of cosmic microwave background (CMB) polarization is still in a pioneering stage, but promises to bring a huge advancement in cosmology in the near future, just as high-accuracy observations of the anisotropies in the total…

天体物理学 · 物理学 2007-05-23 Amedeo Balbi , Paolo Natoli , Nicola Vittorio

We review in a pedagogical way the present status of the impact of non-Gaussianity (NG) on the Cosmic Microwave Background (CMB) anisotropies. We first show how to set the initial conditions at second-order for the (gauge invariant) CMB…

宇宙学与河外天体物理 · 物理学 2015-05-18 N. Bartolo , S. Matarrese , A. Riotto

We discuss fluctuations in the cosmic microwave background (CMB) polarization due to scattering from reionized gas at low redshifts. Polarization is produced by re-scattering of the primordial temperature anisotropy quadrupole and of the…

天体物理学 · 物理学 2016-08-30 Daniel Baumann , Asantha Cooray , Marc Kamionkowski

We study the large scale power spectrum of gravitational wave perturbations of the microwave background in the context of single-bubble open inflation models. We compute the ratio of tensor to scalar contributions to the CMB anisotropies as…

天体物理学 · 物理学 2016-08-25 Juan Garcia-Bellido

Inflation provides a unified paradigm for understanding the isotropy of the cosmic microwave background (CMB), the flatness problem, and the origin of large-scale structure. Although the physics responsible for inflation is not yet well…

天体物理学 · 物理学 2015-06-24 Marc Kamionkowski

The polarization of the Cosmic Microwave Background (CMB)is a powerful observational tool at hand for modern cosmology. It allows to break the degeneracy of fundamental cosmological parameters one cannot obtain using only anisotropy data…

天体物理学 · 物理学 2009-11-07 M. V. Sazhin , G. Sironi , O. S. Khovanskaya

We present a Gaussianity test of the cosmic microwave background (CMB) polarization by analyzing the statistics of unpolarized points in the sky, classified into three distinct types: saddles, comets, and beaks. This classification of…

宇宙学与河外天体物理 · 物理学 2025-12-01 K. O. Parfenov , D. I. Novikov , A. O. Mihalchenko

Measurements of the cosmic microwave background (CMB) radiation provide a unique opportunity for a direct study of the primordial cosmic plasma at redshift z ~1000. The angular power spectra of temperature and polarisation fluctuations are…

天体物理学 · 物理学 2009-11-10 Marco Bersanelli , Davide Maino , Aniello Mennella

The polarization of the CMB offers a potentially valuable probe of the physics of the early universe, specifically of the velocity of the photon-baryon fluid on the last scattering surface. Here we discuss qualitatively the correlations…

天体物理学 · 物理学 2007-05-23 Robert Crittenden

Current bounds from the polarization of the CMB predict the scale-invariant gravitational wave (GW) background of inflation to be out of reach for upcoming GW interferometers. This prospect dramatically changes if the inflaton is a…

宇宙学与河外天体物理 · 物理学 2018-10-10 Valerie Domcke , Mauro Pieroni , Pierre Binétruy

The recent evidence for a stochastic gravitational wave background (GWB) in the nanohertz band, announced by pulsar timing array (PTA) collaborations around the world, has been posited to be sourced by either a population of supermassive…

广义相对论与量子宇宙学 · 物理学 2024-09-25 David Wright , John T. Giblin , Jeffrey Hazboun