English
Related papers

Related papers: Dark Radiation and Inflationary Freedom

200 papers

Current results from the Lyman alpha forest assume that the primordial power spectrum of density perturbations follows a simple power law form, with running. We present the first analysis of Lyman alpha data to study the effect of relaxing…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-16 Simeon Bird , Hiranya V. Peiris , Matteo Viel , Licia Verde

We investigate the constraints on cosmological parameters especially for EoS of dark energy, inflationary parameters, neutrino mass and curvature of universe using simulated Planck data. Firstly we determine cosmological parameters with…

Astrophysics · Physics 2014-11-18 Jun-Qing Xia , Hong Li , Gong-Bo Zhao , Xinmin Zhang

I discuss how parameters describing inflation in the very early universe may be related to primordial perturbation spectra. Precision observations of anisotropies in the cosmic microwave background (CMB) such as those provided by the WMAP…

Astrophysics · Physics 2015-06-24 David Wands

We briefly review the need to perform renormalization of inflationary perturbations to properly work out the physical power spectra. We also summarize the basis of (momentum-space) renormalization in curved spacetime and address several…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Ivan Agullo , Jose Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

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

The primordial power spectrum describes the initial perturbations in the Universe which eventually grew into the large-scale structure we observe today, and thereby provides an indirect probe of inflation or other structure-formation…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Paniez Paykari , Andrew H. Jaffe

In this paper we calculate quantum corrections to the effective potential in different models of inflationary cosmology. We show that quantum corrections lead to a modification of the initial potential uplifting its value at the minimum,…

High Energy Physics - Theory · Physics 2025-04-16 V. A. Filippov , R. M. Iakhibbaev , D. I. Kazakov , D. M. Tolkachev

Three-forms can give rise to viable cosmological scenarios of inflation and dark energy with potentially observable signatures distinct from standard single scalar field models. In this study, the background dynamics and linear…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-19 Tomi S. Koivisto , Nelson J. Nunes

We consider the effects on the primordial power spectrum of a period of radiation-dominated expansion prior to the inflationary era. If inflation lasts a total of only 60 e-folds or so, the boundary condition for quantum modes cannot be…

Astrophysics · Physics 2008-11-26 Brian A. Powell , William H. Kinney

We observationally examine cosmological models based on primordial power spectra with quantized wavevectors. Introducing a linearly quantized power spectrum with $k_0=3.225\times10^{-4}\mathrm{Mpc}^{-1}$ and spacing $\Delta k = 2.257 \times…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-18 D. J. Bartlett , W. J. Handley , A. N. Lasenby

In this paper we investigate power spectrum of a smoothed scalar field. The smoothing leads to the regularisation of the UV divergences and can be related with the internal structure of the considered field or the space itself. We apply…

High Energy Physics - Theory · Physics 2015-05-14 Jakub Mielczarek , Michal Kamionka

It is commonly believed that our Universe has experienced two different stages of accelerated expansion. The early stage is known as inflation and the current acceleration is driven by dark energy. Observing inflation and dark energy…

Astrophysics · Physics 2009-11-11 Jun-Qing Xia , Gong-Bo Zhao , Bo Feng , Xinmin Zhang

We examine the constraints cosmological observations can place on any trans-Planckian corrections to the primordial spectrum of perturbations underlying the anisotropies in the Cosmic Microwave Background. We focus on models of…

Astrophysics · Physics 2011-05-12 Richard Easther , William H Kinney , Hiranya Peiris

Loop quantum cosmology provides an efficient framework to study the evolution of the Universe beyond the classical Big Bang paradigm. Because of holonomy corrections, the singularity is replaced by a "bounce". The dynamics of the background…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Jakub Mielczarek , Thomas Cailleteau , Julien Grain , Aurelien Barrau

We study cosmological perturbations and observational aspects for mutated hilltop model of inflation. Employing mostly analytical treatment, we evaluate observable parameters during inflation as well as post-inflationary perturbations. This…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Barun Kumar Pal , Supratik Pal , B. Basu

Inflation, a period of exponential expansion in the early Universe, is considered an important part of the standard $\Lambda$CDM cosmological model, and plays a crucial role in explaining a wide range of current observations. The standard…

General Relativity and Quantum Cosmology · Physics 2023-12-08 Maria Pia Piccirilli , Gabriel Leon

The primordial power spectrum describes the initial perturbations in the Universe which eventually grew into the large-scale structure we observe today, and thereby provides an indirect probe of inflation or other structure-formation…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-02 P. Paykari , F. Lanusse , J. -L. Starck , F. Sureau , J. Bobin

We investigate the impact of a hypothesized delayed initiation of inflation, characterized by a cutoff k_min to the primordial power spectrum in the cosmic microwave background (CMB). This cutoff affects both the scalar and tensor spectra,…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-28 Jingwei Liu , Fulvio Melia

We review the currrent cosmic parameter determinations of relevance to inflation using the WMAP-1year, Boomerang, CBI, Acbar and other CMB data. The basic steps in the pipelines which determine the bandpowers from the raw data from which…

Astrophysics · Physics 2009-11-10 J. R. Bond , C. R. Contaldi , A. M. Lewis , D. Pogosyan

We consider a simple system consisting of matter, radiation and vacuum components to model the impact of thermal inflation on the evolution of primordial perturbations. The vacuum energy magnifies the primordial modes entering the horizon…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-11 Jeong-Myeong Bae , Sungwook E. Hong , Heeseung Zoe