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We use a compilation of cosmic microwave anisotropy data (including the recent VSA, CBI and Archeops results), supplemented with an additional constraint on the expansion rate, to directly constrain the parameters of slow-roll inflation…

Astrophysics · Physics 2009-11-07 Samuel M Leach , Andrew R Liddle

Distortions of the Cosmic Microwave Background energy spectrum of the $\mu$ type are sensitive to the primordial power spectrum through the dissipation of curvature perturbations on scales $k\simeq 50$ - $10^4\,\mathrm{Mpc}^{-1}$. Their…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Giovanni Cabass , Enrico Pajer , Drian van der Woude

We place observational constraints on slow-variation single-field inflationary models by carrying out the cosmological Monte Carlo simulation with the recent data of Planck combined with the WMAP large-angle polarization, baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-12 Shinji Tsujikawa , Junko Ohashi , Sachiko Kuroyanagi , Antonio De Felice

We use the flow equations to determine the different hierarchy Hubble parameters as a function of the number of e-folds for intermediate models in single-field inflation. The obtained expressions allow us to determine at second order in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-10 Sergio del Campo

The recent data from the Boomerang and MAXIMA-1 balloon flights have marked the beginning of the precision era of Cosmic Microwave Background anisotropy (CMB) measurements. We investigate the observational constraints from the current CMB…

Astrophysics · Physics 2009-10-31 William H. Kinney , Alessandro Melchiorri , Antonio Riotto

We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of…

$k$-inflation represents the most general single-field inflation, in which the perturbations usually obey an equation of motion with a time-dependent sound speed. In this paper, we study the observational predictions of the $k$-inflation by…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-19 Tao Zhu , Anzhong Wang , Gerald Cleaver , Klaus Kirsten , Qin Sheng

A new inflationary scenario whose exponential potential $V(\Phi)$ has a quadratic dependence on the field $\Phi$ in addition to the standard linear term is confronted with the tree-year observations of the Wilkinson-Microwave Anisotropy…

Astrophysics · Physics 2009-06-23 F. C. Carvalho , J. S. Alcaniz , J. A. S. Lima , R. Silva

We identify examples of single field inflationary trajectories beyond the slow-roll regime which improve the fit to Planck 2018 data compared to baseline $\Lambda$CDM model with power law form of primordial spectrum and at the same time…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-05 Akhil Antony , Fabio Finelli , Dhiraj Kumar Hazra , Arman Shafieloo

We revisit the constraints on inflation models by using the current cosmological observations involving the latest local measurement of the Hubble constant ($H_{0} = 73.00\pm 1.75$ km s $^{-1}$ Mpc$^{-1}$). We constrain the primordial power…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-20 Rui-Yun Guo , Xin Zhang

We derive new constraints on the Hubble function H(phi) and subsequently on the inflationary potential V(phi) from WMAP 3-year data combined with the Sloan Luminous Red Galaxy survey (SDSS-LRG), using a new methodology which appears to be…

Astrophysics · Physics 2009-06-23 Julien Lesgourgues , Alexei A. Starobinsky , Wessel Valkenburg

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…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-31 Béatrice Bonga , Brajesh Gupt , Nelson Yokomizo

We present the constraints on inflationary parameters in a flat $\Lambda$CDM universe obtained by WMAP three year data release, plus smaller scale CMB and two LSS data sets, 2dF and SDSS (treated separately). We use a Markov Chain Monte…

Astrophysics · Physics 2009-11-11 F. Finelli , M. Rianna , N. Mandolesi

In this paper, inflationary cosmology is reviewed, paying particular attention to its observational signatures associated with large-scale density perturbations generated from quantum fluctuations. In the most general scalar-tensor theories…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-13 Shinji Tsujikawa

We extend an alternative, phenomenological approach to inflation by means of an equation of state and a sound speed, both of them functions of the number of $e$-folds and four phenomenological parameters. This approach captures a number of…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Hector Ramirez , Lotfi Boubekeur

Inflationary cosmology predicts that the particle horizon should be generically much bigger than the present-day Hubble radius, $1/H_0$. This implies a special regime of super-Hubble scale energy density fluctuations imprinted on the cosmic…

Astrophysics · Physics 2009-10-30 Arjun Berera , Li-Zhi Fang , Gary Hinshaw

Inflation as the leading paradigm depicting the very early universe physics could leave imprints on the cosmic microwave background (CMB) radiation. Using currently available CMB observations, we give the tightest constraints on inflation…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-30 Deng Wang

We update constraints on the Hubble function H(phi) during inflation, using the most recent cosmic microwave background (CMB) and large scale structure (LSS) data. Our main focus is on a comparison between various commonly used methods of…

Astrophysics · Physics 2009-06-23 Jan Hamann , Julien Lesgourgues , Wessel Valkenburg

Inflation produces nearly Harrison-Zel'dovich scalar and tensor perturbation spectra which lead to anisotropy in the cosmic microwave background (CMB). The amplitudes and shapes of these spectra can be parametrized by $Q_S^2$, $r\equiv…

Astrophysics · Physics 2009-10-28 Lloyd Knox

Observations of the temperature anisotropies in the Cosmic Microwave Background (CMB) radiation show that the models of inflation with the monomial potentials are inconsistent with the allowed $n_s-r$ bounds. However certain monomial…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-17 Richa Arya , Raghavan Rangarajan