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相关论文: Relics of spatial curvature in the primordial non-…

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Cosmic inflation, a period of accelerated expansion in the early universe, can give rise to large amplitude ultra-large scale inhomogeneities on distance scales comparable to or larger than the observable universe. The cosmic microwave…

宇宙学与河外天体物理 · 物理学 2017-08-09 Jonathan Braden , Matthew C. Johnson , Hiranya V. Peiris , Anthony Aguirre

We forecast the ability of cosmic microwave background (CMB) temperature and polarization datasets to constrain theories of eternal inflation using cosmic bubble collisions. Using the Fisher matrix formalism, we determine both the overall…

宇宙学与河外天体物理 · 物理学 2015-10-21 Stephen M. Feeney , Franz Elsner , Matthew C. Johnson , Hiranya V. Peiris

Two different predictions for the primordial curvature fluctuation bispectrum are compared through their effects on the Cosmic Microwave Background temperature fluctuations. The first has a local form described by a single parameter f_{NL}.…

天体物理学 · 物理学 2009-06-23 Ian G Moss , Chris M Graham

In this article, we do a thorough investigation of the competency of the forthcoming Cosmic Microwave Background (CMB) and Galaxy surveys in probing the features in the primordial power spectrum. Primordial features are specific…

宇宙学与河外天体物理 · 物理学 2022-11-01 Debabrata Chandra , Supratik Pal

Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings…

宇宙学与河外天体物理 · 物理学 2016-03-09 Christophe Ringeval , Daisuke Yamauchi , Jun'ichi Yokoyama , Francois R. Bouchet

We consider the primordial gravitational wave (GW) background in a class of spatially-flat inflationary cosmological models with cold dark matter (CDM), a cosmological constant, and a broken-scale-invariant (BSI) steplike primordial…

天体物理学 · 物理学 2009-10-30 J. Lesgourgues , D. Polarski , A. A. Starobinsky

If the spatial sections of the Universe are positively curved, extrapolating the inflationary stage backward in time inevitably leads to a classical bounce. This simple scenario, non-singular and free of exotic physics, deserves to be…

广义相对论与量子宇宙学 · 物理学 2022-09-21 Cyril Renevey , Aurélien Barrau , Killian Martineau

We describe a new numerical algorithm to obtain high-resolution simulated maps of the Cosmic Microwave Background (CMB), for a broad class of non-Gaussian models. The kind of non-Gaussianity we account for is based on the simple idea that…

天体物理学 · 物理学 2009-11-07 Michele Liguori , Sabino Matarrese , Lauro Moscardini

We discuss the polarization signature of primordial gravitational waves imprinted in cosmic microwave background (CMB) anisotropies. The high-energy physics motivated by superstring theory or M-theory generically yield parity violating…

天体物理学 · 物理学 2009-06-23 Shun Saito , Kiyotomo Ichiki , Atsushi Taruya

We propose a fast and efficient bispectrum statistic for Cosmic Microwave Background (CMB) temperature anisotropies to constrain the amplitude of the primordial non-Gaussian signal measured in terms of the non-linear coupling parameter…

天体物理学 · 物理学 2009-11-11 P. Cabella , F. K. Hansen , M. Liguori , D. Marinucci , S. Matarrese , L. Moscardini , N. Vittorio

One of the most powerful tools to probe the existence of cosmic defects in the early universe is through the Cosmic Microwave Background (CMB) radiation. It is well known that computations with causal sources are more involved than the…

天体物理学 · 物理学 2007-05-23 Alejandro Gangui

Under the existence of chiral non-Gaussian sources during inflation, the trispectrum of primordial curvature perturbations can break parity. We examine signatures of the induced trispectrum of the cosmic microwave background (CMB)…

宇宙学与河外天体物理 · 物理学 2016-10-06 Maresuke Shiraishi

We study temperature and polarization anisotropies of the cosmic microwave background (CMB) radiation sourced from primordial cross-bispectra between metric perturbations and vector fields, which are generated from the inflation model where…

宇宙学与河外天体物理 · 物理学 2012-12-18 Maresuke Shiraishi , Shohei Saga , Shuichiro Yokoyama

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

We analyze the spectrum of cosmic microwave background (CMB) anisotropies in the timescape cosmology: a potentially viable alternative to homogeneous isotropic cosmologies without dark energy. We exploit the fact that the timescape…

宇宙学与河外天体物理 · 物理学 2015-03-18 M. Ahsan Nazer , David L. Wiltshire

Perturbations from inflation evolve into large scale structure of the late universe, and encode abundant cosmic structure formation physics. We allow freedom in the primordial power spectrum, rather than assuming a power law scale…

宇宙学与河外天体物理 · 物理学 2020-05-12 Guilherme Brando , Eric V. Linder

This work presents a detailed analysis of Cosmic Microwave Background (CMB) radiation intensity observations. The CMB is a relic of the Big Bang and its study greatly enhances our knowledge of cosmology. This work has led to new values for…

天体物理学 · 物理学 2007-05-23 Henrik P. Nordberg , George F. Smoot

The current suite of results from Cosmic Microwave Background anisotropy experiments is fulfilling the promise of providing extraordinary levels of discrimination between cosmological models. We calculate a binned anisotropy power spectrum,…

天体物理学 · 物理学 2007-05-23 Elena Pierpaoli , Douglas Scott , Martin White

We outline the expected constraints on non-Gaussianity from the cosmic microwave background (CMB) with current and future experiments, focusing on both the third (f_{NL}) and fourth-order (g_{NL} and \tau_{NL}) amplitudes of the local…

宇宙学与河外天体物理 · 物理学 2010-07-27 Joseph Smidt , Alexandre Amblard , Christian T. Byrnes , Asantha Cooray , Alan Heavens , Dipak Munshi

Cosmic microwave background (CMB) anisotropy may result from both scalar and tensor perturbations. For a sufficiently narrow range of angular scales, CMB perturbations can be characterized by four parameters. Results from the Cosmic…

天体物理学 · 物理学 2009-10-22 Scott Dodelson , Lloyd Knox , Edward W. Kolb