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Motivated by the idea that inflation occurs at the GUT symmetry breaking scale, in this paper we construct a new class of large field inflaton potentials where the inflaton starts with a power law potential; after initial period of relative…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 Dhiraj Kumar Hazra , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

We develop methods to calculate the curvature power spectrum in models where features in the inflaton potential nonlinearly excite modes and generate high frequency features in the spectrum. The first nontrivial effect of excitations…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 V Miranda , Wayne Hu , Chen He , Hayato Motohashi

If cosmic inflation suffered tiny time-dependent deviations from the slow-roll regime, these would induce the existence of small scale-dependent features imprinted in the primordial spectra, with their shapes and sizes revealing information…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Sander Mooij , Gonzalo A. Palma , Grigoris Panotopoulos , Alex Soto

Motivated by the prospect of testing inflation from precision cosmic microwave background observations, we present analytic results for scalar and tensor perturbations in single-field inflation models based on the application of uniform…

Astrophysics · Physics 2009-11-07 Salman Habib , Katrin Heitmann , Gerard Jungman , Carmen Molina-Paris

We present and discuss a new approach increasing by orders of magnitude the speed of performing Bayesian inference and parameter estimation within the framework of slow-roll inflation. The method relies on the determination of an effective…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-03 Christophe Ringeval

We calculate the conditions required to produce a large local trispectrum during two-field slow-roll inflation. This is done by extending and simplifying the 'heatmap' approach developed by Byrnes et al. The conditions required to generate…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-10 Joseph Elliston , Laila Alabidi , Ian Huston , David J. Mulryne , Reza Tavakol

We study higher curvature corrections to the scalar spectral index, the tensor spectral index, the tensor-to-scalar ratio, and the polarization of gravitational waves. We find that the higher curvature corrections can not be negligible in…

Astrophysics · Physics 2011-07-13 Masaki Satoh , Jiro Soda

A possible origin of the anomalous dip and bump in the primordial power spectrum, which are reconstructed from WMAP data corresponding to the multipole $\ell=100\sim 140$ by using the inversion method, is investigated as a consequence of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Kohei Kumazaki , Shuichiro Yokoyama , Naoshi Sugiyama

We present a generic inference method for inflation models from observational data by the usage of higher-order statistics of the curvature perturbation on uniform density hypersurfaces. This method is based on the calculation of the…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-25 Sebastian Dorn , Erandy Ramirez , Kerstin E. Kunze , Stefan Hofmann , Torsten A. Enßlin

Until recently our knowledge of the primordial curvature perturbation was relatively modest. Ever since COBE delivered its map of data we know the scalar spectrum of primordial perturbations is approximately flat, with the power being only…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-24 Raquel H. Ribeiro

Inflation predicts the generation of cosmological perturbations. Usually, the power spectra for the scalar and tensor modes are calculated with help of the slow roll approximation. In the case of power law inflation an exact result is…

Astrophysics · Physics 2007-05-23 Dominik J. Schwarz , Jerome Martin

We exploit a new numerical technique for evaluating the tree order contributions to the primordial scalar and tensor power spectra for scalar potential models of inflation. Among other things we use the formalism to develop a good analytic…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-06 D. J. Brooker , N. C. Tsamis , R. P. Woodard

We study the effects of a general type of features of the inflaton potential on the spectrum and bispectrum of primordial curvature perturbations. These features correspond to a discontinuity in the $n$-th order derivative of the potential…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-25 Alexander Gallego Cadavid

(Shortened abstract) While a featureless, nearly scale invariant, primordial scalar power spectrum fits the most recent CMB data rather well, certain features in the spectrum are known to lead to a better fit to the data (although, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jerome Martin , L. Sriramkumar

We investigate the ability of current CMB data to reliably constrain the form of the primordial power spectrum generated during inflation. We attempt to identify more exotic power spectra that yield equally good fits to the data as simple…

Astrophysics · Physics 2009-06-23 Brian A. Powell , William H. Kinney

We study an inflationary scenario where thermal inflation is followed by fast-roll inflation. This is a rather generic possibility based on the effective potentials of spontaneous symmetry breaking in the context of particle physics models.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jinn-Ouk Gong

We constrain slow-roll inflationary models using the recent WMAP data combined with data from the VSA, CBI, ACBAR and 2dF experiments. We find the slow-roll parameters to be $0 < \epsilon_1 < 0.032$ and $\epsilon_2 + 5.0 \epsilon_1 = 0.036…

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

A study of the slow-roll inflation for an exponential potential in the frame of the scalar-tensor theory is performed, where non-minimal kinetic coupling to curvature and non-minimal coupling of the scalar field to the Gauss-Bonnet…

High Energy Physics - Theory · Physics 2019-09-24 L. N. Granda , D. F. Jimenez

We present constraints on inflationary dynamics and features in the primordial power spectrum of scalar perturbations using the Cosmic Microwave Background temperature, polarization data from Planck 2018 data release and updated…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-28 Dhiraj Kumar Hazra , Daniela Paoletti , Ivan Debono , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

Brief periods of non-slow-roll evolution during inflation can produce interesting observable consequences, as primordial black holes, or an inflationary gravitational wave spectrum enhanced at small scales. We develop a model independent,…

High Energy Physics - Theory · Physics 2021-06-29 Gianmassimo Tasinato