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Recent estimates of cosmological parameters derived from Cosmic Microwave Background (CMB) anisotropies are based on the assumption that we know the precise amount of energy density in relativistic particles in the universe, $\omega_{rel}$,…

Astrophysics · Physics 2008-11-26 R. Bowen , S. H. Hansen , A. Melchiorri , J. Silk , R. Trotta

The Microwave Anisotropy Probe and Planck missions will provide low noise maps of the temperature of the cosmic microwave background (CMB). These maps will allow measurement of the power spectrum of the CMB with measurement noise below…

We point out that if quantum field renormalization is taken into account, and the counterterms are evaluated at the Hubble-radius crossing time or few e-foldings after it, the predictions of slow-roll inflation for both the scalar and…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-14 Ivan Agullo , Jose Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

Cosmic microwave background (CMB) anisotropy is our richest source of cosmological information; the standard cosmological model was largely established thanks to study of the temperature anisotropies. By the end of the decade, the Planck…

Astrophysics · Physics 2009-11-11 James G. Bartlett

We carry out numerical investigations of the dynamics and perturbations in the Nflation model of Dimopoulos et al. (2005). This model features large numbers of scalar fields with different masses, which can cooperate to drive inflation…

Astrophysics · Physics 2009-11-11 Soo A Kim , Andrew R Liddle

As a test of the standard inflationary cosmology, which generically predicts nearly scale-invariant spectrum of primordial curvature fluctuations, we perform Markov-Chain Monte-Carlo analysis to search for possible modulations in the power…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-12 Kiyotomo Ichiki , Ryo Nagata , Jun'ichi Yokoyama

The Planck experiment will soon provide a very accurate measurement of Cosmic Microwave Background anisotropies. This will let cosmologists determine most of the cosmological parameters with unprecedented accuracy. Future experiments will…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-24 Silvia Galli , Matteo Martinelli , Alessandro Melchiorri , Luca Pagano , Blake D. Sherwin , David N. Spergel

We consider a more general initial condition satisfying the minimal uncertainty relationship. We calculate the power spectrum of a simple model in inflationary cosmology. The results depend on perturbations generated below a fundamental…

High Energy Physics - Theory · Physics 2009-11-10 Ke Ke

We evaluate new observational constraints on the two-parameter scale-dependent spectral index predicted by the running-mass inflation model by combining the latest Cosmic Microwave Background (CMB) anisotropy measurements with the recent…

High Energy Physics - Phenomenology · Physics 2014-11-17 Laura Covi , David H. Lyth , Alessandro Melchiorri

Recently, the Planck 2013 results showed possible evidence for a dipolar power modulation of the CMB temperature fluctuations at low--(\ell) multipoles. This anomaly might imply certain deviations from statistical isotropy. To incorporate…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-24 Zhe Chang , Sai Wang

In light of the recent Planck 2015 results for the measurement of the CMB anisotropy, we study simple inflationary models in the context of the Gauss-Bonnet brane-world cosmology. The brane-world cosmological effect modifies the power…

High Energy Physics - Phenomenology · Physics 2017-03-15 Nobuchika Okada , Satomi Okada

We investigate the anisotropy in cosmic microwave background Planck maps due to the coupling between its beam asymmetry and uneven scanning strategy. Introducing a pixel space estimator based on the temperature gradients, we find a highly…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-17 Ben Rathaus , Ely D. Kovetz

We calculate the impact of quantum gravity-motivated ultraviolet cutoffs on inflationary predictions for the cosmic microwave background spectrum. We model the ultraviolet cutoffs fully covariantly to avoid possible artifacts of covariance…

General Relativity and Quantum Cosmology · Physics 2017-10-31 Aidan Chatwin-Davies , Achim Kempf , Robert T. W. Martin

The cosmic microwave background (CMB) contains perturbations that are close to Gaussian and isotropic. This means that its information content, in the sense of the ability to constrain cosmological models, is closely related to the number…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-06 Douglas Scott , Dagoberto Contreras , Ali Narimani , Yin-Zhe Ma

The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history,…

The Planck satellite is expected to improve the measurement of most cosmological parameters by several factors with respect to current WMAP results. The actual performance may depend upon various aspects of the data analysis. In this paper…

Astrophysics · Physics 2010-11-02 L. P. L. Colombo , E. Pierpaoli , J. R. Pritchard

Spectra of density perturbations produced during chaotic inflation are calculated, taking both adiabatic and isocurvature modes into account in a class of scalar-tensor theories of gravity in which the dilaton is metrically coupled.…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Takeshi Chiba , Naoshi Sugiyama , Jun'ichi Yokoyama

A rigorous constraint analysis on cosmic inflation entails several probes which collectively survey an extensive range of energy scales. We complement the cosmic microwave background data with an updated compilation of the cosmic abundance…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-23 Jurgen Mifsud , Carsten van de Bruck

The cosmic microwave background (CMB) temperature and polarization anisotropies, as observed by independent astronomical missions such as WMAP, Planck, and most recently the Atacama Cosmology Telescope and the South Pole Telescope have…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-13 William Giarè , Supriya Pan , Eleonora Di Valentino , Weiqiang Yang , Jaume de Haro , Alessandro Melchiorri

We determine the power spectrum for inflation models covering all regimes from cold (isentropic) to warm (nonisentropic) inflation. We work in the context of the stochastic inflation approach, which can nicely describe both types of…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-27 Rudnei O. Ramos , L. A. da Silva