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The Cosmic Microwave Background anisotropies are difficult to measure at large angular scales. In this paper, we present a new analysis of the \Planck\ High Frequency Instrument data that brings the cosmological part and its major…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-09 J. -M. Delouis , J. -L. Puget , L. Vibert

To assess the significance and scale dependence of anomalous large scale modes in the CatWISE quasar data, we generate smoothed number density fields on the sphere and study their extreme values -- maximum, minimum, maximum antipodal…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-10 Akhil Antony , Stephen Appleby , William L Matthewson , Arman Shafieloo

We investigate the angular anisotropy of the Hubble constant using the Cosmicflows-4 catalogue, with particular emphasis on three issues often treated only implicitly in the literature: the statistical formulation of the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-16 Vincenzo Salzano , J. Beltrán Jiménez , Dario Bettoni , Philippe Brax , Aurélien Valade

Current cosmological constraints from Cosmic Microwave Background (CMB) anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination,…

Astrophysics · Physics 2009-02-23 Silvia Galli , Rachel Bean , Alessandro Melchiorri , Joseph Silk

We use recent 36 observational Hubble data (OHD) in the redshift range $0.07\leq z\leq 2.36$, latest \textgravedbl joint light curves\textacutedbl (JLA) sample, comprised of 740 type Ia supernovae (SNIa) in the redshift range $0.01\leq z…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-21 H. Amirhashchi , S. Amirhashchi

We calculate the off--center observational relations in a spherically symmetric dust universe that is inhomogeneous at small redshifts. In contrast to the usual model, in which the CMBR dipole is interpreted as a Doppler effect due to…

Astrophysics · Physics 2009-10-28 Neil Humphreys , Roy Maartens , David Matravers

An analysis of the Cosmological Constant $\Omega_\Lambda$ fitted to subsamples of the Pantheon+ Type Ia SN sample spanning 2$\pi$ sterradians for a grid of 432 pole positions covering the whole sky reveals two large scale asymmetries. One…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-04 Alejandro Clocchiatti , Ósmar Rodríguez , Ariel Órdenes Morales , Benjamín Cuevas-Tapia

Previous studies have found our velocity in the rest frame of radio galaxies at high redshift to be substantially larger than that inferred from the CMB temperature dipole anisotropy. We construct a full sky catalogue NVSUMSS, by merging…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-10 J. Colin , R. Mohayaee , M. Rameez , S. Sarkar

By using N-body hydrodynamical cosmological simulations in which the chemistry of major metals and molecules is consistently solved for, we study the interaction of metallic fine-structure lines with the CMB. Our analysis shows that the…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-10 Carlos Hernandez-Monteagudo , Umberto Maio , Benedetta Ciardi , Rashid A. Sunyaev

We have studied the angular fluctuations in the speed of light with respect to the apex of the dipole of Cosmic Microwave Background (CMB) radiation using the experimental data obtained with GRAAL facility, located at the European…

We investigate a possibility of constraining statistical anisotropies of the primordial tensor perturbations by using future observations for the Cosmic Microwave Background (CMB) B-mode polarization. By parameterizing a…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-24 Takashi Hiramatsu , Shuichiro Yokoyama , Tomohiro Fujita , Ippei Obata

We estimate the acceleration on the Local Group (LG) from the Two Micron All Sky Redshift Survey (2MRS). The sample used includes about 23,200 galaxies with extinction corrected magnitudes brighter than K_s=11.25 and it allows us to…

Recent research reveals that the Local Group is in motion towards $(l, b) = (276, 30)$ relative to the cosmic background radiation, manifesting a velocity of 600 $\frac{km}{s}$ a phenomenon recognized as the cosmic background radiation…

General Relativity and Quantum Cosmology · Physics 2025-02-18 M. Yarahmadi , A. Salehi

We study the dipole anisotropy in number counts and flux density weighted number counts {or sky brightness} in the NRAO VLA Sky Survey (NVSS) data. The dipole anisotropy is expected due to our local motion with respect to the CMBR rest…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-29 Prabhakar Tiwari , Rahul Kothari , Abhishek Naskar , Sharvari Nadkarni-Ghosh , Pankaj Jain

Recently a symmetry-based method to test for statistical isotropy of the cosmic microwave background was developed. We apply the method to template-cleaned 3-year and 5-year WMAP-$DA$ maps. We examine a wide range of angular multipoles from…

Astrophysics · Physics 2010-11-02 Pramoda Kumar Samal , Rajib Saha , Pankaj Jain , John P. Ralston

We study the anisotropy of the cosmic microwave background (CMB) in cold and mixed dark matter (CDM and MDM) models, with non scale-invariant primordial power spectra (i.e. $n \neq 1$) and a late, sudden reionization of the intergalactic…

As cosmic microwave background (CMB) photons traverse the Universe, anisotropies can be induced via Thomson scattering (proportional to the integrated electron density; optical depth) and inverse Compton scattering (proportional to the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-14 Anirban Roy , Alexander van Engelen , Vera Gluscevic , Nicholas Battaglia

The cosmological principle is one of the cornerstones in modern cosmology. It assumes that the universe is homogeneous and isotropic on cosmic scales. Both the homogeneity and the isotropy of the universe should be tested carefully. In the…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-19 Hua-Kai Deng , Hao Wei

We test anisotropic dark energy models with the 7-year WMAP temperature observations data. In the presence of imperfect sources, due to large-scale gradients or anisotropies in the dark energy field, the CMB sky will be distorted…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-08 Magnus J. Axelsson , Frode K. Hansen , Tomi Koivisto , David F. Mota

In this article we propose a novel test for statistical anisotropy of the CMB. The test is based on the fact, that the Galactic foregrounds have a remarcably strong symmetry with respect to their antipodal points and with respect to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 P. Naselsky , M. Hansen , J. Kim
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