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We present an extensive comparison of models of structure formation with observations, based on linear and quasi-linear theory. We assume a critical matter density, and study both cold dark matter models and cold plus hot dark matter…

Astrophysics · Physics 2015-06-24 Andrew R Liddle , David H Lyth , R K Schaefer , Q Shafi , Pedro T P Viana

We constrain the shape of the primordial power spectrum using recent measurements of the cosmic microwave background (CMB) from the Wilkinson Microwave Anisotropy Probe (WMAP) 7-year data and other high-resolution CMB experiments. We also…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-27 J. Alberto Vazquez , A. N. Lasenby , M. Bridges , M. P. Hobson

With the Planck 2015 Cosmic Microwave Background (CMB) temperature and polarization data, we search for possible features in the primordial power spectrum (PPS). We revisit the Wiggly Whipped Inflation (WWI) framework and demonstrate how…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-14 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

We have developed a precise dictionary between the spectrum of primordial density fluctuations and the parameters of the effective field theory (EFT) of inflation that determine the primordial power spectrum (PPS). At lowest order the EFT…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-15 Amel Durakovic

The purpose of this work is to use a renormalized quantum scalar field to investigate very early cosmology, in the Planck era immediately following the big bang. Renormalization effects make the field potential dependent on length scale,…

General Relativity and Quantum Cosmology · Physics 2012-07-16 Kerson Huang , Hwee-Boon Low , Roh-Suan Tung

Inflationary models with power-law potentials are starting to be severely constrained by the recent measurements of Cosmic Microwave Background anisotropies provided by the Planck Satellite and by the BICEP2 telescope. In particular, models…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-03 Mehdi Shokri , Fabrizio Renzi , Alessandro Melchiorri

For most initial conditions, cosmologically relevant physical modes were trans-planckian at the bounce time, often by many magnitude orders. We improve the usual loop quantum cosmology calculation of the primordial power spectra -- in the…

General Relativity and Quantum Cosmology · Physics 2018-05-23 Killian Martineau , Aurélien Barrau , Julien Grain

In this work, we analyze a power-law inflationary potential enhanced with a step that can introduce features in the primordial power spectrum. We focus on the computation of the Spectral Distortions (SD) induced by these features obtained…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-27 Jorge Mastache , Wilson Barrera , Raúl Henríquez-Ortiz

The angular power spectra of the cosmic microwave background (CMB) temperature anisotropies reconstructed from Planck data seem to present too much gravitational lensing distortion. This is quantified by the control parameter $A_L$ that…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 F. Couchot , S. Henrot-Versillé , O. Perdereau , S. Plaszczynski , B. Rouillé d'Orfeuil , M. Spinelli , M. Tristram

An inflationary gravitational wave background consistent with BICEP2 is difficult to reconcile with a simple power-law spectrum of primordial scalar perturbations. Tensor modes contribute to the temperature anisotropies at multipoles with…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-28 Kevork N. Abazajian , Grigor Aslanyan , Richard Easther , Layne C. Price

The BICEP2 collaboration reports a detection of primordial cosmic microwave background (CMB) B-mode with a tensor-scalar ratio $r=0.20^{+0.07}_{-0.05}$ (68% C.L.). However, this result is in tension with the recent Planck limit, $r<0.11$…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-30 Jun-Qing Xia , Yi-Fu Cai , Hong Li , Xinmin Zhang

Amongst the multitude of inflationary models currently available, models that lead to features in the primordial scalar spectrum are drawing increasing attention, since certain features have been found to provide a better fit to the CMB…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-30 Moumita Aich , Dhiraj Kumar Hazra , L. Sriramkumar , Tarun Souradeep

The best-fit values of the density parameter and the amplitude of the linear density power spectrum obtained from the Cosmic Microwave Background (CMB) temperature field scanned by the Planck satellite are found to notably disagree with…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Jounghun Lee

We forecast the ability of future CMB and galaxy lensing surveys to constrain variations of the fine structure constant. We found that lensing data, as those expected from satellite experiments as Euclid could improve the constraint from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Matteo Martinelli , Eloisa Menegoni , Alessandro Melchiorri

The {\em Planck} DR3 measurements of the temperature and polarization anisotropies power spectra of the cosmic microwave background (CMB) show an excess of smoothing of the acoustic peaks with respect to $\Lambda$CDM, often quantified by a…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 Mario Ballardini , Fabio Finelli

We constrain the primordial fluctuation spectrum P(k) by using the new data on the Cosmic Microwave Background (CMB) from the Boomerang and MAXIMA experiments. Our study is based on slow-roll inflationary models, and we consider the…

Astrophysics · Physics 2009-10-31 S. Hannestad , S. H. Hansen , F. L. Villante

We revisit the degeneracy between the Hubble constant, $H_0$, and matter density, $\Omega_m$, for current cosmic microwave background (CMB) observations within the standard $\Lambda CDM$ model. We show that Planck, Wilkinson Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-26 Joshua A. Kable , Graeme E. Addison , Charles L. Bennett

Inflation is the leading theory to describe elegantly the initial conditions that led to structure formation in our universe. In this paper, we present a novel phenomenological fit to the Planck, WMAP polarisation (WP) and the BICEP2…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 Laura Barranco , Lotfi Boubekeur , Olga Mena

In conventional model independent approaches, the power spectrum of primordial perturbations is characterized by such free parameters as spectral index, its running, the running of running, and the tensor-to-scalar ratio. In this work we,…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Moslem Zarei

We determine the best-fit values and confidence limits for dynamical dark energy parameters together with other cosmological parameters on the basis of different datasets which include WMAP9 or Planck-2013 results on CMB anisotropy, BAO…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 B. Novosyadlyj , O. Sergijenko , R. Durrer , V. Pelykh