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Related papers: Reconstructing inflationary features on large scal…

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We analyse the post-inflationary contribution to the stochastic gravitational wave background due to a resonant feature in the scalar power spectrum, which is characterised by an oscillation in $\log(k)$, complementing our previous work…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 Jacopo Fumagalli , Sébastien Renaux-Petel , Lukas T. Witkowski

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

In this paper, we apply reconstruction techniques to recover the potential parameters for a particular class of single-field models, the $\alpha$-attractor (supergravity) models of inflation. This also allows to derive the inflaton vacuum…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-28 A. Di Marco , P. Cabella , N. Vittorio

Multi-field models of inflation typically assume that interactions between particles can be treated perturbatively. Strongly-coupled models provide an intriguing alternative and may offer novel inflationary phenomenology. We study the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-27 Oliver H. E. Philcox , Guilherme L. Pimentel , Chen Yang

We have improved further the error sensitive Richardson-Lucy deconvolution algorithm making it applicable directly on the un-binned measured angular power spectrum of Cosmic Microwave Background observations to reconstruct the form of the…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-14 Dhiraj Kumar Hazra , Arman Shafieloo , Tarun Souradeep

The residuals of the power spectra of WMAP and Planck's cosmic microwave background (CMB) anisotropies data are known to exhibit a few interesting anomalies at different scales with marginal statistical significance. Combining bottom-up and…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Matteo Braglia , Xingang Chen , Dhiraj Kumar Hazra

A plethora of inflationary models can produce interesting small-scale phenomenology, such as enhanced scalar fluctuations leading to primordial black hole (PBH) production and large scalar-induced GW. Nevertheless, good models must…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-10 Laura Iacconi , Michael Bacchi , Luiz Filipe Guimarães , Felipe T. Falciano

This paper describes a general program for deriving the action of single field inflation models with nonstandard kinetic energy terms using CMBR power spectrum data. This method assumes that an action depends on a set of undetermined…

Astrophysics · Physics 2009-06-23 Christopher S. Gauthier , Ratindranath Akhoury

We extend and improve the modeling and analysis of large-amplitude, sharp inflationary steps for second order corrections required by the precision of the Planck CMB power spectrum and for arbitrary Dirac-Born-Infeld sound speed. With two…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-18 V Miranda , Wayne Hu

We point out three correlated predictions of the axion monodromy inflation model: large amplitude of gravitational waves, suppression of power on horizon scales and on scales relevant for the formation of dwarf galaxies. While these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Quinn E. Minor , Manoj Kaplinghat

In a Quantum Field Theory with a time-dependent background, time-translational symmetry is broken. We therefore expect time-dependent loop corrections to cosmological observables after renormalization for an interacting field, with the…

General Relativity and Quantum Cosmology · Physics 2018-03-21 Laura Covi , Simone Dresti

Signatures of heavy particles during inflation are exponentially suppressed by the Boltzmann factor when the masses are far above the Hubble scale. In more realistic scenarios, however, scale-dependent features may change this conventional…

High Energy Physics - Theory · Physics 2025-05-27 Dong-Gang Wang , Bowei Zhang

All cosmological observations to date are consistent with adiabatic, Gaussian and nearly scale invariant initial conditions. These findings provide strong evidence for a particular symmetry breaking pattern in the very early universe (with…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Jens Chluba , Jan Hamann , Subodh P. Patil

We present the status of our study into the feasibility of estimating the parameters of inflation from planned satellite observations of the anisotropy of the cosmic microwave background (CMB).We describe a perturbative procedure for…

We propose a "feature-scattering" mechanism to explain the cosmic microwave background cold spot seen from WMAP and Planck maps. If there are hidden features in the potential of multi-field inflation, the inflationary trajectory can be…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-02 Yi Wang , Yin-Zhe Ma

(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

Cosmic inflation, which describes an accelerated expansion of the early Universe, yields the most successful predictions regarding temperature anisotropies in the cosmic microwave background (CMB). Nevertheless, the precise origin of the…

General Relativity and Quantum Cosmology · Physics 2020-08-14 Gabriel Leon , Maria Pia Piccirilli

Using an approximate likelihood method adapted to band--power estimates, we analyze the ensemble of first generation cosmic microwave background anisotropy experiments to deduce constraints over a six--dimensional parameter space describing…

Astrophysics · Physics 2011-05-23 M. Le Dour , M. Douspis , J. G. Bartlett , A. Blanchard

The inflationary potential and its derivatives determine the spectrum of scalar and tensor metric perturbations that arise from quantum fluctuations during inflation. The CBR anisotropy offers a promising means of determining the spectra of…

Astrophysics · Physics 2009-08-18 Michael Turner , Martin White

We revisit an inflationary scenario in which primordial inhomogeneities arise from a quantum collapse, a stochastic mechanism described in the context of quantum collapse theories in its continuous version and within semiclassical gravity.…

General Relativity and Quantum Cosmology · Physics 2026-03-04 María Pía Piccirilli , Gabriel León , Rosa-Laura Lechuga-Solis , Daniel Sudarsky