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We perform an all-sky analysis of the general relativistic galaxy power spectrum using the well-developed spherical Fourier decomposition. Spherical Fourier analysis expresses the observed galaxy fluctuation in terms of the spherical…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jaiyul Yoo , Vincent Desjacques

The paper applies a new, nonparametric, interpoint distance-based measure to confirm the inherent groups prevailing in the brightest source of light in the universe: gamma-ray bursts. Our effective metric, in association with clustering…

High Energy Astrophysical Phenomena · Physics 2026-05-07 Soumita Modak

We investigate the hemispherical power asymmetry in the cosmic microwave background on small angular scales. We find an anomalously high asymmetry in the multipole range l=601-2048, with a naive statistical significance of 6.5 sigma.…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-30 Samuel Flender , Shaun Hotchkiss

The arrival directions of multi-TeV cosmic rays show significant anisotropies at small angular scales. It has been argued that this small scale structure is reflecting the local, turbulent magnetic field in the presence of a global dipole…

High Energy Astrophysical Phenomena · Physics 2015-12-01 Philipp Mertsch , Markus Ahlers

There has been much recent interest in studying anisotropies in the astrophysical gravitational-wave (GW) background, as these could provide us with interesting new information about galaxy clustering and large-scale structure. However,…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-29 Alexander C. Jenkins , Joseph D. Romano , Mairi Sakellariadou

Gaussianity and statistical isotropy of the Universe are modern cosmology's minimal set of hypotheses. In this work we introduce a new statistical test to detect observational deviations from this minimal set. By defining the temperature…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-30 Thiago S. Pereira , L. Raul Abramo

We analyze the clustering of large scale structure in the Universe in a model independent method, accounting for anisotropic effects along and transverse to the line of sight. The Baryon Oscillation Spectroscopy Survey Data Release 11…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-01 Yong-Seon Song , Cristiano G. Sabiu , Teppei Okumura , Minji Oh , Eric V. Linder

Gravitational lensing allows to quantify the angular distribution of the convergence field around clusters of galaxies to constrain their connectivity to the cosmic web. We describe in this paper the corresponding theory in Lagrangian space…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Sandrine Codis , Raphael Gavazzi , Christophe Pichon , Celine Gouin

Clustering methods are an important tool to enumerate and describe the different coherent kinds of Gamma Ray Bursts (GRBs). But their performance can be affected by a number of factors such as the choice of clustering algorithm and inherent…

High Energy Astrophysical Phenomena · Physics 2017-06-13 Souradeep Chattopadhyay , Ranjan Maitra

We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we…

High Energy Physics - Phenomenology · Physics 2016-09-01 R. H. Brandenberger , A. T. Sornborger , M. Trodden

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

Astrophysics · Physics 2009-10-07 Max Tegmark

The normalisation of the matter power spectrum, sigma_8, is an essential ingredient to predict the phenomenology of the low redshift universe. It has been measured using several methods, such as X-ray cluster counts, weak lensing and the…

Astrophysics · Physics 2008-11-26 A. Amara , A. Refregier

We calculate the cosmic microwave background (CMB) $B$-mode power spectrum resulting from anisotropic cosmic birefringence, without relying on the thin approximation of the last scattering surface. Specifically, we consider the influence of…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-04 Toshiya Namikawa

It is often stated that gamma-ray bursts (GRBs) have typical energies of several hundred keV. Is this a real feature of GRBs or is it due to an observational bias? We consider the possibility that bursts of a given bolometric luminosity…

Astrophysics · Physics 2009-10-28 Tsvi Piran , Ramesh Narayan

In order to construct accurate point sources simulations at the frequencies relevant to 21 cm experiments, the angular correlation of radio sources must be taken into account. Using the 74 MHz VLSS survey, we measured the angular 2-point…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Angelica de Oliveira-Costa , John Capodilupo

In the past few decades, large universal structures have been found that challenge the homogeneity and isotropy expected in standard cosmological models. The largest of these, identified as the Hercules-Corona Borealis Great Wall, was found…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-02 Istvan Horvath , Zsolt Bagoly , Lajos G. Balazs , Jon Hakkila , Bendeguz Koncz , Istvan I. Racz , Peter Veres , Sandor Pinter

Because accretion and merger shocks in clusters of galaxies may accelerate particles to high energies, clusters are candidate sites for the origin of ultra-high-energy (UHE) cosmic-rays. A prediction was presented for gamma-ray emission…

Using data from the SUGAR and the AGASA experiments taken during a 10 yr period with nearly uniform exposure to the entire sky, we search for large-scale anisotropy patterns in the arrival directions of cosmic rays with energies > 10^{19.6}…

COBE has provided us with a whole-sky map of the CBR anisotropies. However, even if the noise level is negligible when the four year COBE data are available, the cosmic variance will prevent us from obtaining information about the Gaussian…

Astrophysics · Physics 2016-08-30 Xiaochun Luo

Fluctuations of the surface brightness of cosmic X-ray background (CXB) carry unique information about faint and low luminosity source populations, which is inaccessible for conventional large-scale structure (LSS) studies based on resolved…

High Energy Astrophysical Phenomena · Physics 2017-02-01 Alexander Kolodzig , Marat Gilfanov , Gert Hütsi , Rashid Sunyaev