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Related papers: Extracting New Physics from the CMB

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The space of parameters characterizing an inflationary primordial power spectrum with small superimposed oscillations is explored using Monte Carlo methods. The most interesting region corresponding to high frequency oscillations is…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jerome Martin , Christophe Ringeval

The effect of the initial condition of inflation on the power spectra of scalar and tensor perturbations is estimated assuming a slow-roll inflation model. By defining a more general initial state in inflation particular properties of the…

Astrophysics · Physics 2007-10-15 Shiro Hirai , Tomoyuki Takami

We investigate if the hemispherical asymmetry in the CMB is produced from "asymmetric" excited initial condition. We show that in the limit where the deviations from the Bunch-Davies vacuum is large and the scale of new physics is maximally…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Amjad Ashoorioon , Tomi Koivisto

We explore the possibility of a single field quasi-de Sitter inflationary model with general initial state for primordial fluctuations. In this paper, first we compute the power spectrum and the bispectrum of scalar perturbations with…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-02 Sandipan Kundu

Although the cosmic microwave background (CMB) is largely understood to be homogeneous and isotropic, the CMB angular power spectra present anomalies that seem to break down parity symmetry at large angular scales. We argue that the…

General Relativity and Quantum Cosmology · Physics 2024-11-12 K. Sravan Kumar , João Marto

We perform a cosmological analysis in which we allow the primordial power spectrum of scalar perturbations to assume a shape that is different with respect to the usual power-law, arising from the simplest models of cosmological inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Stefano Gariazzo

In low-energy effective string theory and modified gravity theories, the propagating speed $c_T$ of primordial gravitational waves may deviate from unity. We find that the step-like variation of $c_T$ during slow-roll inflation may result…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Yong Cai , Yu-Tong Wang , Yun-Song Piao

We study the asymmetric primordial fluctuations in a model of inflation in which translational invariance is broken by a domain wall. We calculate the corrections to the power spectrum of curvature perturbations; they are anisotropic and…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-02 Sadra Jazayeri , Yashar Akrami , Hassan Firouzjahi , Adam R. Solomon , Yi Wang

There exist several models of inflation that produce primordial bispectra that contain a large number of oscillations. In this paper we discuss these models, and aim at finding a method of detecting such bispectra in the data. We explain…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 P. Daniel Meerburg

We perform a Bayesian analysis to study possible features in the primordial inflationary power spectrum of scalar perturbations. In particular, we analyse the possibility of detecting the imprint of these primordial features in the…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Micol Benetti , Jailson S. Alcaniz

The damping of primordial perturbations at small scales gives rise to distortions of the cosmic microwave background (CMB). Here, the dependence of the distortion on the different types of cosmological initial conditions is explored,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-18 Jens Chluba , Daniel Grin

According to inflationary cosmology, the CMB anisotropy gives an opportunity to test predictions of new physics hypotheses. The initial state of quantum fluctuations is one of the important options at high energy scale, as it can affect…

High Energy Physics - Theory · Physics 2016-04-01 A. Sojasi , M. Mohsenzadeh , E. Yusofi

The hemispherical power asymmetry in the cosmic microwave background may be explained by the modulation of some primordial cosmological parameter, such as the sound speed of the inflaton. This modulation can be achieved by the perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-20 Yi-Fu Cai , Wen Zhao , Yang Zhang

CMB polarization provides a unique window into cosmological inflation; the amplitude of the B-mode polarization from last scattering is uniquely sensitive to the energetics of inflation. However, numerous systematic effects arising from…

Astrophysics · Physics 2009-09-29 Meir Shimon , Brian Keating , Nicolas Ponthieu , Eric Hivon

The prediction of a nearly scale-invariant spectrum of curvature and tensor fluctuations is among the main features of cosmic inflation. The current measurements of the primordial fluctuations in the cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-30 Marcos A. G. Garcia , Aline Pereyra-Flores

We study the production, spectrum and detectability of gravitational waves in models of the early Universe where first order phase transitions occur during inflation. We consider all relevant sources. The self-consistency of the scenario…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-16 Diego Chialva

The impact of particle production during inflation on the primordial curvature perturbation spectrum is investigated both analytically and numerically. We obtain an oscillatory behavior on small scales, while on large scales the spectrum is…

General Relativity and Quantum Cosmology · Physics 2009-02-23 Antonio Enea Romano , Misao Sasaki

We review the relevant 10+ parameters associated with inflation and matter content; the relation between LSS and primary and secondary CMB anisotropy probes; COBE constraints on energy injection; current anisotropy band-powers which…

Astrophysics · Physics 2009-10-30 J. Richard Bond , Andrew H. Jaffe

We discuss cosmic microwave background anisotropies in models with an unconventional primordial power spectrum. In particular, we consider an initial power spectrum with some ``spiky'' corrections. Interestingly, such a primordial power…

Astrophysics · Physics 2010-04-05 Masahiro Kawasaki , Fuminobu Takahashi , Tomo Takahashi

The observed power spectrum of the cosmic microwave background (CMB) is consistent with inflationary cosmology, which predicts a nearly scale-invariant power spectrum of quantum fluctuations of the inflaton field as they exit the Hubble…

High Energy Physics - Theory · Physics 2007-05-23 Leonard Parker