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Related papers: Mixing Bispectrum Multipoles Under Geometric Disto…

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We have studied the cosmic microwave background (CMB) map looking for features beyond cosmological isotropy. We began by tiling the CMB variance map (which are produced by different smoothing scales) with stripes of different sizes along…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-12 MohammadHossein Jamshidi , Abdolali Banihashemi , Nima Khosravi

Inflationary models predicting abundant primordial black holes (PBHs) and large amplitude of scalar-induced gravitational waves (SIGWs) often rely on amplified fluctuations over limited scales, typically driven by phase transitions,…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-15 Mohammad Hossein Namjoo , Bahar Nikbakht

Observations by the Wilkinson Microwave Anisotropy Probe and the Planck mission suggest a hemispherical power amplitude asymmetry in the cosmic microwave background, with a correlation length on the order of the size of the observable…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-05 Qiaoli Yang , Hongbiao Yu , Haoran Di

We study the information content of the angle-averaged (monopole) redshift space galaxy bispectrum. The main novelty of our approach is the use of a systematic tree-level perturbation theory model that includes galaxy bias, IR resummation,…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-23 Mikhail M. Ivanov , Oliver H. E. Philcox , Takahiro Nishimichi , Marko Simonović , Masahiro Takada , Matias Zaldarriaga

Several analyses of the microwave sky maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have drawn attention to alignments amongst the low-order multipoles. Amongst the various possible explanations, an effect of cosmic topology has…

Astrophysics · Physics 2009-11-13 James G. Cresswell , Andrew R. Liddle , Pia Mukherjee , Alain Riazuelo

We derive uniform approximations for contributions to Gutzwiller's periodic-orbit sum for the spectral density which are valid close to bifurcations of periodic orbits in systems with mixed phase space. There, orbits lie close together and…

chao-dyn · Physics 2008-02-03 Henning Schomerus , Martin Sieber

This article constructs flat-sky approximations in a controlled way in the context of the cosmic microwave background observations for the computation of both spectra and bispectra. For angular spectra, it is explicitly shown that there…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Francis Bernardeau , Cyril Pitrou , Jean-Philippe Uzan

Future lensing surveys will be nearly full-sky and reach an unprecedented depth, probing scales closer and closer to the Hubble radius. This motivates the study of the cosmic shear beyond the small-angle approximation and including general…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-09 Francis Bernardeau , Camille Bonvin , Nicolas Van de Rijt , Filippo Vernizzi

Our peculiar motion with respect to the CMB rest frame represents a preferred direction in the observed CMB sky since it induces an apparent deflection of the observed CMB photons (aberration) and a shift in their frequency (Doppler). Both…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Alessio Notari , Miguel Quartin , Riccardo Catena

We make a detailed assessment of which form of the dipole operator to use in calculating high order harmonic generation within the framework of the strong field approximation, and look specifically at the role the form plays in the…

Atomic Physics · Physics 2015-05-19 B. B. Augstein , C. Figueira de Morisson Faria

Methods are studied to compute the boosting effects produced by the observer motion that modifies and transfers to higher l the isotropic monopole frequency spectrum of the cosmic background. Explicit analytical solutions for spherical…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-11 Tiziana Trombetti , Carlo Burigana , Marco Tucci , Luigi Toffolatti

Ab initio computation of two-dimensional electronic spectra is an expanding field, whose goal is improving upon simple, few-dimensional models often employed to explain experiments. Here, we propose an accurate and computationally…

Chemical Physics · Physics 2024-09-26 Tomislav Begušić , Jiří Vaníček

The present spatial distribution of galaxies in the Universe is non-Gaussian, with 40% skewness in 50 Mpc/h spheres, and remarkably little is known about the information encoded in it about cosmological parameters beyond the power spectrum.…

Astrophysics · Physics 2008-11-26 Emiliano Sefusatti , Martin Crocce , Sebastian Pueblas , Roman Scoccimarro

A number of studies of WMAP and Planck claimed the low multipole (specially quadrupole) power deficiency in CMB power spectrum. Anomaly in the orientations of the low multipoles have also been claimed. There is a possibility that the power…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-11 Santanu Das , Tarun Souradeep

Cross-correlating the lensing signals of galaxies and comic microwave background (CMB) fluctuations is expected to provide valuable cosmological information. In particular it may help tighten constraints on parameters describing the…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-14 Philipp M. Merkel , Bjoern Malte Schaefer

A new and promising avenue was recently developed for analyzing large-scale structure data with a model-independent approach, in which the linear power spectrum shape is parametrized with a large number of freely varying wavebands rather…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-24 Luca Amendola , Marco Marinucci , Massimo Pietroni , Miguel Quartin

We study the bispectrum in Lagrangian perturbation theory. Extending past results for the power spectrum, we describe a method to efficiently compute the bispectrum in LPT, focusing on the Zeldovich approximation, in which contributions due…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-07 Shi-Fan Chen , Zvonimir Vlah , Martin White

We examine the effects of the linear and the cosmological redshift-space distortions on the power spectrum of cosmological objects on a light cone. We develop theoretical formulae for the power spectrum in linear theory of density…

Astrophysics · Physics 2009-10-31 Hiroaki Nishioka , Kazuhiro Yamamoto

Scale transformations have played an extremely successful role in studies of cosmological large-scale structure by relating the non-linear spectrum of cosmological density fluctuations to the linear primordial power at longer wavelengths.…

Astrophysics · Physics 2009-11-13 Jun Pan , Peter Coles , Istvan Szapudi