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Related papers: Extracting New Physics from the CMB

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A formula for the power spectrum of curvature perturbations having any initial conditions in inflation is obtained. Based on the physical conditions before inflation, the possibility exists that the initial state of scalar perturbations is…

High Energy Physics - Theory · Physics 2017-08-23 Shiro Hirai

We give a new interpretation of the effect of initial state entanglement on the spectrum of vacuum fluctuations. We consider an initially entangled state between two free massive scalar fields in de Sitter space. We construct the initial…

High Energy Physics - Theory · Physics 2016-12-30 Sugumi Kanno

An estimate of the one-loop correction to the power spectrum of the primordial curvature perturbation is given, assuming it is generated during a phase of single-field, slow-roll inflation. The loop correction splits into two parts, which…

Astrophysics · Physics 2010-02-09 David Seery

The presence of CMB Hemispherical Asymmetry (HPA) challenges the current understanding of inflationary cosmology which does not generically predict the parity violation in the primordial correlations. In this paper, we shall review the…

High Energy Physics - Theory · Physics 2023-05-11 K. Sravan Kumar , João Marto

We investigate an inflationary model of the universe based on the assumption that space-time is noncommutative in the very early universe. We analyze the effects of space-time noncommutativity on the quantum fluctuations of an inflaton…

High Energy Physics - Theory · Physics 2010-04-05 Masafumi Fukuma , Yuji Kono , Akitsugu Miwa

In this Letter we study the effects of the Modified Uncertainty Principle as proposed in [8] on the inflationary dynamics of the early universe in both standard and Randall-Sundrum type II scenarios. We find that the quantum gravitational…

High Energy Physics - Phenomenology · Physics 2012-02-27 Barun Majumder

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 study the observable implications of an incomplete first order phase transition during inflation. In such a phase transition, the nucleated bubbles do not percolate and instead are continuously produced until the onset of reheating. The…

High Energy Physics - Phenomenology · Physics 2023-12-20 Joel Barir , Michael Geller , Chen Sun , Tomer Volansky

In this work we study the imprints of bubble nucleation on primordial inflationary perturbations. We assume that the bubble is formed via the tunneling of a spectator field from the false vacuum of its potential to its true vacuum. We…

General Relativity and Quantum Cosmology · Physics 2017-12-27 Hassan Firouzjahi , Sadra Jazayeri , Asieh Karami , Tahereh Rostami

We describe an attempt to reconstruct the initial conditions for the formation of cosmological large-scale structure. The power spectrum of the primordial fluctuations is affected by bias, nonlinear evolution and redshift-space distortions,…

Astrophysics · Physics 2015-06-24 J. A. Peacock , S. J. Dodds

The fluctuations of the cosmic microwave background (CMB) are investigated for a small open universe, i.e., one which is periodically composed of a small fundamental cell. The evolution of initial metric perturbations is computed using the…

Astrophysics · Physics 2009-10-31 Ralf Aurich

The aim of this paper is to probe the features of the bouncing cosmology with the current observational data. Basing on bounce inflation model, with high derivative term, we propose a general parametrization of primordial power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-07 Shulei Ni , Hong Li , Taotao Qiu , Wei Zheng , Xin Zhang

We use a numerical code to compute the density perturbations generated during an inflationary epoch which includes a spontaneous symmetry breaking phase transition. A sharp step in the inflaton potential generates $k$ dependent oscillations…

Astrophysics · Physics 2009-11-06 Jennifer Adams , Bevan Cresswell , Richard Easther

Perturbations from inflation evolve into large scale structure of the late universe, and encode abundant cosmic structure formation physics. We allow freedom in the primordial power spectrum, rather than assuming a power law scale…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-12 Guilherme Brando , Eric V. Linder

Primordial magnetic fields could provide an explanation for the galactic magnetic fields observed today, in which case they may also leave interesting signals in the CMB and the small-scale matter power spectrum. We discuss how to…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-26 J. Richard Shaw , Antony Lewis

The latest analysis of the cosmic microwave background by the Planck team finds more smoothing of the acoustic peaks in the temperature power spectrum than predicted by $\Lambda$CDM. Here we investigate whether this additional smoothing can…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-18 Guillem Domènech , Marc Kamionkowski

Primordial magnetic fields lead to non-Gaussian signals in the Cosmic Microwave Background (CMB) even at the lowest order, as magnetic stresses, and the temperature anisotropy they induce, depend quadratically on the magnetic field. In…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-03 T. R. Seshadri , Kandaswamy Subramanian

The delensing of cosmic microwave background (CMB) maps will be increasingly valuable for extracting as much information as possible from future CMB surveys. Delensing provides many general benefits, including sharpening of the acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-20 Cynthia Trendafilova , Selim C. Hotinli , Joel Meyers

The computation of the primordial power spectrum in multi-field inflation models requires us to correctly account for all relevant interactions between adiabatic and non-adiabatic modes around and after horizon crossing. One specific…

High Energy Physics - Phenomenology · Physics 2015-03-17 Ana Achúcarro , Jinn-Ouk Gong , Sjoerd Hardeman , Gonzalo A. Palma , Subodh P. Patil

Quantum mechanical metric fluctuations during an early inflationary phase of the universe leave a characteristic imprint in the polarization of the cosmic microwave background (CMB). The amplitude of this signal depends on the energy scale…