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[Abridged] A sharp cut-off in the primordial scalar power spectrum on large scales has been known to improve the fit to the cosmic microwave background (CMB) data when compared to the more standard, nearly scale invariant power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-11 H. V. Ragavendra , Debika Chowdhury , L. Sriramkumar

We apply boson expansion methods to an extended Lipkin-Meshkov-Glick model including anharmonicities in analogy with previous microscopic calculations. We study the effects of different approximations present in these calculations, among…

Nuclear Theory · Physics 2009-10-31 C. Volpe , Ph. Chomaz , M. V. Andres , F. Catara , E. G. Lanza

We present an analysis of anisotropic baryon acoustic oscillations and elucidate how a mis-estimation of the cosmology, which leads to incorrect values of the angular diameter distance, d_A, and Hubble parameter, H, manifest themselves in…

Astrophysics · Physics 2008-11-26 Nikhil Padmanabhan , Martin White

Certain modified gravity theories predict the existence of an additional, non-conformally coupled scalar field. A disformal coupling of the field to the Cosmic Microwave Background (CMB) is shown to affect the evolution of the energy…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Carsten van de Bruck , Jack Morrice , Susan Vu

Large galaxy surveys demand fast and scalable estimators for anisotropic clustering statistics beyond the monopole. We present a suite of efficient FFT-based estimators for power-spectrum and bispectrum multipoles, built upon exact…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-07 Yunchen Xie , Ruiyang Zhao , Gan Gu , Xiaoma Wang , Xiaoyong Mu , Yuting Wang , Gong-Bo Zhao , Florian Beutler , John A. Peacock

We consider Cosmic Microwave Background constraints on inflation models for which the primordial power spectrum is a mixture of perturbations generated by inflaton fluctuations and fluctuations in a curvaton field. If future experiments do…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-10 William H. Kinney , Azadeh Moradinezhad Dizgah , Antonio Riotto

The fully general calculation of the cosmic error on N-point correlation functions and related quantities is presented. More precisely, the variance caused by the finite volume, discreteness, and edge effects is determined for {\em any}…

Astrophysics · Physics 2016-11-23 I. Szapudi

We simulate Planck observations by adopting a detailed model of the microwave sky including monopole, dipole, anisotropies of the cosmic microwave background (CMB) and galactic and extragalactic foregrounds. We estimate the impact of main…

We present a determination of the bispectrum of the flux in the Lyman-alpha forest of QSO absorption spectra obtained from LUQAS which consists of spectra observed with the high resolution Echelle spectrograph UVES. Typical errors on the…

Astrophysics · Physics 2009-11-10 M. Viel , S. Matarrese , A. Heavens , M. G. Haehnelt , T. -S. Kim , V. Springel , L. Hernquist

Forthcoming missions probing the absolute intensity of the CMB are expected to be able to measure spectral distortions, which are deviations from its blackbody distribution. As cosmic inflation can induce spectral distortions, these…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-22 Alexander Baur , Marcos A. G. Garcia , Raul Henriquez-Ortiz , Mauricio Hernandez-Neri , Saul Ramos-Sanchez

We consider a non-inflationary early Universe scenario in which relevant scalar perturbations get frozen out at some point, but then are defrosted and follow a long nearly Minkowskian evolution before the hot era. This intermediate stage…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-22 S. A. Mironov , S. R. Ramazanov , V. A. Rubakov

The hemispherical power asymmetry, observed in the CMBR data, has generally been interpreted in terms of the dipole modulation model for the temperature fluctuations. Here we point out that this model leads to several predictions, which can…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-31 Pranati K. Rath , Pankaj Jain

We investigate the role of the electron correlation effects in the calculations of the electric dipole polarizabilities (\alpha) of elements belonging to three different groups of periodic table. To understand the propagation of the…

Atomic Physics · Physics 2014-05-21 Yashpal Singh , B. K. Sahoo

WMAP observations have accurately determined the position of the first two peaks and dips in the CMB temperature power spectrum. These encode information on the ratio of the distance to the last scattering surface to the sound horizon at…

Astrophysics · Physics 2008-11-26 Pier Stefano Corasaniti , Alessandro Melchiorri

We consider the distribution of the non-Gaussian signal induced by weak lensing on the primary total intensity cosmic microwave background (CMB) anisotropies. Our study focuses on the three point statistics exploiting an harmonic analysis…

Astrophysics · Physics 2009-11-10 Fabio Giovi , Carlo Baccigalupi , Francesca Perrotta

The significant increase in precision that will be achieved by Stage IV cosmic shear surveys means that several currently used theoretical approximations may cease to be valid. An additional layer of complexity arises from the fact that…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-28 Anurag C. Deshpande , Thomas D. Kitching

A linear modulation of the primordial perturbations is proposed as an explanation for the observed asymmetry between the northern and southern hemispheres of the Wilkinson Microwave Anisotropy Probe (WMAP) data. A cut sky, reduced…

Astrophysics · Physics 2008-11-26 Christopher Gordon

We develop a methodology for estimating parity-odd bispectra in the cosmic microwave background (CMB). This is achieved through the extension of the original separable modal methodology to parity-odd bispectrum domains ($\ell_1 + \ell_2 +…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-12 Maresuke Shiraishi , Michele Liguori , James R. Fergusson

We investigate the effect of non-linear dispersion relations on the bispectrum. In particular, we study the case were the modified relations do not violate the WKB condition at early times, focusing on a particular example which is exactly…

High Energy Physics - Theory · Physics 2015-03-19 Amjad Ashoorioon , Diego Chialva , Ulf Danielsson

We compute the spectral distortions of the Cosmic Microwave Background (CMB) polarization induced by non-linear effects in the Compton interactions between CMB photons and cold intergalactic electrons. This signal is of the $y$-type and is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Sebastien Renaux-Petel , Christian Fidler , Cyril Pitrou , Guido W. Pettinari