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We consider an inhomogeneous model and independently an anisotropic model of primordial power spectrum in order to describe the observed hemispherical anisotropy in Cosmic Microwave Background Radiation. This anisotropy can be parametrized…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-31 Rahul Kothari , Shamik Ghosh , Pranati K. Rath , Gopal Kashyap , Pankaj Jain

We show that cosmological quantum relaxation predicts an anisotropic primordial power spectrum with a specific dependence on wavenumber k. We explore some of the consequences for precision measurements of the cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-12 Antony Valentini

The so-called shift parameter is related to the position of the first acoustic peak in the power spectrum anisotropies of the cosmic microwave background (CMB) anisotropies. It is an often used quantity in simple tests of dark energy…

Astrophysics · Physics 2009-11-13 Oystein Elgaroy , Tuomas Multamaki

This work is an analytical study of the main differences between classical inflationary effects of a fast-roll regime and imprints of hybrid Loop Quantum Cosmology (LQC) on the primordial power spectrum. Effective LQC solutions of…

General Relativity and Quantum Cosmology · Physics 2021-10-01 Beatriz Elizaga Navascués , Guillermo A. Mena Marugán

Quantum reduced loop gravity is designed to consistently study symmetry reduced systems within the loop quantum gravity framework. In particular, it bridges the gap between the effective cosmological models of loop quantum cosmology and the…

General Relativity and Quantum Cosmology · Physics 2018-12-05 Emanuele Alesci , Aurélien Barrau , Gioele Botta , Killian Martineau , Gabriele Stagno

We investigate the ability to constrain oscillatory features in the primordial power spectrum using current and future cosmic microwave background observations. In particular, we study the observability of an oscillation arising from…

Astrophysics · Physics 2011-05-12 Takemi Okamoto , Eugene A. Lim

We have made a likelihood statistical analysis of the angular correlations in the {\it COBE}-DMR two-year sky maps by Monte Carlo simulation of the temperature fluctuations. We assume an open universe and consider as primordial power…

Astrophysics · Physics 2015-06-24 L. Cayon , E. Martinez-Gonzalez , J. L. Sanz , N. Sugiyama , S. Torres

We calculate a general effective stress-energy tensor induced by cosmological inhomogeneity in effective theories of gravity where the action is Taylor-expandable in the Riemann tensor and covariant derivatives of the Riemann tensor. This…

General Relativity and Quantum Cosmology · Physics 2016-08-19 Anthony W. H. Preston

The possibility that quantum geometry effects may alleviate the apparent tensions existing at large angular scales in the observations of the Cosmic Microwave Background explains the increasing interest in considering primordial…

General Relativity and Quantum Cosmology · Physics 2024-07-26 Guillermo A. Mena Marugán , Antonio Vicente-Becerril , Jesús Yébana Carrilero

In order to constrain and possibly detect unusual physics during inflation, we allow the power spectrum of primordial matter density fluctuations, P_{in}(k), to be an arbitrary function in the estimation of cosmological parameters from…

Astrophysics · Physics 2016-08-30 Pia Mukherjee , Yun Wang

We report the most complete analysis to date of observations of the Cosmic Microwave Background (CMB) obtained during the 1998 flight of BOOMERANG. We use two quite different methods to determine the angular power spectrum of the CMB in 20…

Loop quantum cosmology has recently been applied in order to extend the analysis of primordial perturbations to the Planck era and discuss the possible effects of quantum geometry on the cosmic microwave background. Two approaches to loop…

General Relativity and Quantum Cosmology · Physics 2018-02-28 Beatriz Elizaga Navascués , Daniel Martín de Blas , Guillermo A. Mena Marugán

The cosmic microwave background (CMB) has provided a precise template for features in the linear power spectrum: the matter-radiation turnover, sound horizon drop, and acoustic oscillations. In a two dimensional power spectrum in redshift…

Astrophysics · Physics 2008-11-26 Wayne Hu , Zoltan Haiman

We study the physical limitations placed on CMB temperature and polarization measurements of the initial power spectrum by geometric projection, acoustic physics, gravitational lensing and the joint fitting of cosmological parameters.…

Astrophysics · Physics 2009-11-10 Wayne Hu , Takemi Okamoto

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 first derive the primordial power spectra, spectral indices and runnings of both scalar and tensor perturbations of a flat inflationary universe to the second-order approximations of the slow-roll parameters, in the framework of loop…

General Relativity and Quantum Cosmology · Physics 2016-03-25 Tao Zhu , Anzhong Wang , Klaus Kirsten , Gerald Cleaver , Qin Sheng , Qiang Wu

We forecast and optimize the cosmological power of various weak-lensing aperture mass ($M_{\rm ap}$) map statistics for future cosmic shear surveys, including peaks, voids, and the full distribution of pixels (1D $M_{\rm ap}$). These…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-10 Nicolas Martinet , Joachim Harnois-Déraps , Eric Jullo , Peter Schneider

We use cosmological perturbation theory to study the backreaction effects of a self-consistent and well-defined cosmological averaging on the dynamics and the evolution of the Universe. Working with a perturbed…

General Relativity and Quantum Cosmology · Physics 2013-10-30 Iain A. Brown , Alan A. Coley , D. Leigh Herman , Joey Latta

We estimate the impact of weak lensing by strongly nonlinear cosmological structures on the cosmic microwave background. Accurate calculation of large $\ell$ multipoles requires N-body simulations and ray-tracing schemes with both high…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. J. Fullana , J. V. Arnau , R. J. Thacker , H. M. P. Couchman , D. Sáez

We investigate strong gravitational lensing by a charged loop quantum gravity (LQG) black hole obtained through the polymerisation scheme of Borges \textit{et al.} \cite{Borges:2023fog}. These effective geometries replace the…

General Relativity and Quantum Cosmology · Physics 2025-11-25 Arun Kumar , Qiang Wu , Tao Zhu , Sushant G. Ghosh