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相关论文: Probing the power spectrum bend with recent CMB da…

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We allow a more general (step-function) form of the primordial power spectrum than the usual featureless power-law Harrison--Zeldovich (with spectral index n=1) power spectrum, and fit it to the latest Cosmic Microwave Background data sets.…

天体物理学 · 物理学 2009-11-07 O. Elgaroy , M. Gramann , O. Lahav

We derive the primordial power spectrum of density fluctuations in the framework of quantum cosmology. For this purpose we perform a Born-Oppenheimer approximation to the Wheeler-DeWitt equation for an inflationary universe with a scalar…

广义相对论与量子宇宙学 · 物理学 2012-01-17 Claus Kiefer , Manuel Kraemer

The temperature fluctuations and polarization of the Cosmic Microwave Background (CMB) are now a well-known probe of the Universe at an infant age of 400,000 years. During the transit to us from the surface of last scattering, the CMB…

宇宙学与河外天体物理 · 物理学 2011-04-19 Joseph Smidt , Asantha Cooray , Alexandre Amblard , Shahab Joudaki , Dipak Munshi , Mario G. Santos , Paolo Serra

Current and future B-mode polarization data are the most powerful observables to constrain gravitational waves from the early Universe. We set conservative constraints on tensor modes when relaxing the inflationary consistency condition…

宇宙学与河外天体物理 · 物理学 2022-11-09 Daniela Paoletti , Fabio Finelli , Jussi Valiviita , Masashi Hazumi

We present the spectrum of $n_s$ constraints from current CMB data (Planck, ACT, SPT-3G) combined with DESI BAO data, and highlight the interplay of $n_s$ with the optical depth to reionization $\tau$. The spectral index $n_s$ of the…

宇宙学与河外天体物理 · 物理学 2026-02-06 Evan McDonough , Elisa G. M. Ferreira

Recent cosmic microwave background (CMB) observations put strong constraints on the spatial curvature via estimation of the parameter $\Omega_k$ assuming an almost scale invariant primordial power spectrum. We study the evolution of the…

宇宙学与河外天体物理 · 物理学 2016-10-31 Béatrice Bonga , Brajesh Gupt , Nelson Yokomizo

We propose a method to extract the projected power spectrum of density perturbations from the distortions in the cosmic microwave background (CMB). The distortions are imprinted onto the CMB by the gravitational lensing effect and can be…

天体物理学 · 物理学 2009-10-31 Uros Seljak , Matias Zaldarriaga

We constrain the spectrum of primordial curvature perturbations by using recent Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) data. Specifically, we consider CMB data from the COBE, Boomerang and Maxima experiments, the…

天体物理学 · 物理学 2009-11-06 S. Hannestad , S. H. Hansen , F. L. Villante , A. J. S. Hamilton

The absence of large-angle correlations in the temperature of the cosmic microwave background (CMB), confirmed by three independent satellite missions, creates significant tension with the standard model of cosmology. Previous work has…

宇宙学与河外天体物理 · 物理学 2024-04-15 Jingwei Liu , Fulvio Melia

We study the capability of future measurements of the galaxy clustering power spectrum to probe departures from a power-law spectrum for primordial fluctuations. On considering the information from the galaxy clustering power spectrum up to…

宇宙学与河外天体物理 · 物理学 2018-04-05 Mario Ballardini , Fabio Finelli , Cosimo Fedeli , Lauro Moscardini

Although the cosmic microwave background (CMB) is largely understood to be homogeneous and isotropic, the CMB angular power spectra present anomalies that seem to break down parity symmetry at large angular scales. We argue that the…

广义相对论与量子宇宙学 · 物理学 2024-11-12 K. Sravan Kumar , João Marto

We discuss the cosmological implications of the new constraints on the power spectrum of the Cosmic Microwave Background Anisotropy derived from a new high resolution analysis of the MAXIMA-1 measurement (Lee et al. 2001). The power…

A key prediction of cosmological theories for the origin and evolution of structure in the Universe is the existence of a `Doppler peak' in the angular power spectrum of cosmic microwave background (CMB) fluctuations. We present new results…

天体物理学 · 物理学 2020-11-25 S. Hancock , G. Rocha , A. N. Lasenby , C. M. Gutierrez

We consider the distribution of the non-Gaussian signal induced by weak lensing on the primary total intensity cosmic microwave background (CMB) anisotropies. Our study focuses on the three point statistics exploiting an harmonic analysis…

天体物理学 · 物理学 2009-11-10 Fabio Giovi , Carlo Baccigalupi , Francesca Perrotta

We propose an efficient and model independent method for reconstructing the primordial power spectrum from Cosmic Microwave Background (CMB) and large scale structure observations. The algorithm is based on a Monte Carlo principle and…

天体物理学 · 物理学 2009-11-10 Steen Hannestad

Inflationary cosmology with a preceding nonsingular bounce can lead to changes on the primordial density fluctuations. One significant prediction is that the amplitude of the power spectrum may undergo a jump at a critical scale. In this…

宇宙学与河外天体物理 · 物理学 2012-04-10 Jie Liu , Yi-Fu Cai , Hong Li

The B-mode polarization of the cosmic microwave background (CMB) provides a unique window into tensor perturbations from inflationary gravitational waves. Survey effects complicate the estimation and description of the power spectrum on the…

宇宙学与河外天体物理 · 物理学 2016-09-28 Eric R. Switzer , Duncan J. Watts

The form of the primordial power spectrum (PPS) of cosmological scalar (matter density) perturbations is not yet constrained satisfactorily in spite of the tremendous amount of information from the Cosmic Microwave Background (CMB) data.…

宇宙学与河外天体物理 · 物理学 2018-09-21 Benjamin L'Huillier , Arman Shafieloo , Dhiraj Kumar Hazra , George F. Smoot , Alexei A. Starobinsky

Combining Planck CMB temperature [1] and BICEP2 B-mode polarization data [2,3] we show qualitatively that, assuming inflationary consistency relation, the power-law form of the scalar primordial spectrum is ruled out at more than $3\sigma$…

宇宙学与河外天体物理 · 物理学 2014-07-17 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

Measuring spectral distortions (SDs) of the cosmic microwave background (CMB) will provide new constraints on previously unexplored scales of the primordial power spectrum, allowing us to extend the probed parameter space by several orders…

宇宙学与河外天体物理 · 物理学 2021-05-03 Nils Schöneberg , Matteo Lucca , Deanna C. Hooper