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We present a detailed analytical study of ultra-relativistic neutrinos in cosmological perturbation theory and of the observable signatures of inhomogeneities in the cosmic neutrino background. We note that a modification of perturbation…

Astrophysics · Physics 2008-11-26 Sergei Bashinsky , Uros Seljak

It is well known that our motion with respect to the cosmic microwave background (CMB) rest frame introduces a large dipolar CMB anisotropy, with an amplitude ~beta=v/c~10^{-3}. In addition it should lead to a small breaking of statistical…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 J. Chluba

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

[Abridged] An observable signature of a detectable nontrivial spatial topology of the Universe is the circles-in-the-sky in the CMB sky. In the most general search, pairs of circles with deviation from antipodality $0^\circ \leq \theta \leq…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-10 G. I. Gomero , B. Mota , M. J. Reboucas

Current cosmological tensions show that it is crucial to test the predictions from the canonical $\Lambda$CDM paradigm at different cosmic times. One very appealing test of structure formation in the universe is the growth rate of structure…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-27 Deng Wang , Olga Mena

We compute the Bayesian Evidence for models considered in the main analysis of Planck cosmic microwave background data. By utilising carefully-defined nearest-neighbour distances in parameter space, we reuse the Monte Carlo Markov Chains…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-13 Alan Heavens , Yabebal Fantaye , Elena Sellentin , Hans Eggers , Zafiirah Hosenie , Steve Kroon , Arrykrishna Mootoovaloo

In this work we investigate observational signatures of a primordial power spectrum with exponential infrared suppression, motivated by the choice of a non-oscillatory vacuum in a bouncing and inflationary geometry within Loop Quantum…

General Relativity and Quantum Cosmology · Physics 2024-10-21 Mercedes Martín-Benito , Rita B. Neves , Javier Olmedo

Using the fact that the comoving angular diameter distance to the last scattering surface is strictly constrained almost model independently, we show that, for any model agreeing with the standard $\Lambda$CDM model on its background…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Ozgur Akarsu , Eoin O. Colgain , Emre Ozulker , Somyadip Thakur , Lu Yin

It is possible to reduce the discrepancy between the local measurement of the cosmological parameter $H_0$ and the value derived from the $Planck$ measurements of the Cosmic Microwave Background (CMB) by considering contamination of the CMB…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-27 V. N. Yershov , A. A. Raikov , N. Yu. Lovyagin , N. P. M. Kuin , E. A. Popova

Cosmological simulations suggest that most of the matter in the Universe is distributed along filaments connecting galaxies. Illuminated by the cosmic UV background (UVB), these structures are expected to glow in fluorescent Lyman alpha…

Galaxy redshift surveys, such as 2dF, SDSS, 6df, GAMA and VIPERS, have shown that the spatial distribution of matter forms a rich web, known as the cosmic web. The majority of galaxy survey analyses measure the amplitude of galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-29 Siyu He , Shadab Alam , Simone Ferraro , Yen-Chi Chen , Shirley Ho

In the standard cosmological model, the dimming of distant Type Ia supernovae is explained by invoking the existence of repulsive `dark energy' which is causing the Hubble expansion to accelerate. However this may be an artifact of…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-22 Seshadri Nadathur , Subir Sarkar

We present stellar mass measurements for a sample of 36 Luminous Compact Blue Galaxies (LCBGs) at redshifts z = 0.4-1.2 in the Flanking Fields around the Hubble Deep Field North. The technique is based on fitting a two-component galaxy…

Astrophysics · Physics 2009-11-07 R. Guzman , G. Ostlin , D. Kunth , M. Bershady , D. Koo , M. Pahre

Based on the Lema\^itre-Tolman-Bondi (LTB) metric we consider two flat inhomogeneous big-bang models. We aim at clarifying, as far as possible analytically, basic features of the dynamics of the simplest inhomogeneous models and to point…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Eddy G. Chirinos Isidro , Cristofher Zuñiga Vargas , Winfried Zimdahl

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

Recent tentative findings of non-Gaussian structure in the COBE-DMR dataset have triggered renewed attention to candidate models from which such intrinsic signature could arise. In the framework of slow roll inflation with built-in non…

Astrophysics · Physics 2009-10-31 Alejandro Gangui , Jerome Martin

We investigate early dark energy models in the context of the lensing anomaly by considering two different Cosmic Microwave Background (CMB) datasets: a complete Planck, and a second one primarily based on SPTPol and Planck temperature…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-20 Balakrishna S. Haridasu , Hasti Khoraminezhad , Matteo Viel

We present an estimate of the bulk flow in a volume of radii $150-200h^{-1}$Mpc using the minimum variance (MV) method with data from the CosmicFlows-4 (CF4) catalog. The addition of new data in the CF4 has resulted in an increase in the…

We consider a cosmological model in which the tensor mode becomes massive during inflation, and study the Cosmic Microwave Background (CMB) temperature and polarization bispectra arising from the mixing between the scalar mode and the…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-24 Guillem Domènech , Takashi Hiramatsu , Chunshan Lin , Misao Sasaki , Maresuke Shiraishi , Yi Wang

Cosmological scenarios wherein the cumulative number of spontaneously formed, cognitively impaired, disembodied transient observers is vastly larger than the corresponding number of atypical `ordinary observers' (OOs) formed in the…

General Physics · Physics 2025-12-22 Meir Shimon