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Related papers: A Three-Point Cosmic Ray Anisotropy Method

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A thorough search for large scale anisotropies in the distribution of arrival directions of cosmic rays detected above $10^{18}$ eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and…

High Energy Astrophysical Phenomena · Physics 2012-12-05 Pierre Auger Collaboration

Different options can be used in order to measure the shear from observations in the context of weak lensing. Here we introduce new methods where the isotropy assumption for the distribution of the source galaxies is implemented directly on…

Astrophysics · Physics 2008-02-03 Marco Lombardi , Giuseppe Bertin

We present a comparative study of the accuracy and precision of correlation function methods and full-field inference in cosmological data analysis. To do so, we examine a Bayesian hierarchical model that predicts log-normal fields and…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-07 Florent Leclercq , Alan Heavens

During the past two decades, experiments in both the northern and southern hemispheres have observed a small but measurable energy-dependent sidereal anisotropy in the arrival direction distribution of Galactic cosmic rays with relative…

High Energy Astrophysical Phenomena · Physics 2017-08-11 The HAWC Collaboration , The IceCube Collaboration

The direction and magnitude of the dipole anisotropy of ultra-high-energy cosmic rays with energies above 8 EeV observed by the Pierre Auger Observatory indicate their extragalactic origin. The observed dipole on Earth does not necessarily…

High Energy Astrophysical Phenomena · Physics 2024-02-13 Alena Bakalová , Jakub Vícha , Petr Trávníček

Any isotropy violating phenomena on cosmic microwave background (CMB) induces off-diagonal correlations in the two-point function. These correlations themselves can be used to estimate the underlying anisotropic signals. Masking due to…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-09 Pavan K. Aluri , Nidhi Pant , Aditya Rotti , Tarun Souradeep

This paper proposes and discusses a test of the chemical composition of ultra-high energy cosmic rays that relies on the anisotropy patterns measured as a function of energy. In particular, we show that if one records an anisotropy signal…

High Energy Astrophysical Phenomena · Physics 2009-11-13 Martin Lemoine , Eli Waxman

The impact of local space anisotropy on the transverse Doppler effect is examined. Two types of laboratory experiments aimed at seeking and measuring the local space anisotropy are proposed. In terms of the conventional special relativity…

General Relativity and Quantum Cosmology · Physics 2007-06-19 George Bogoslovsky

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 present a new method of constraining the mass and velocity anisotropy profiles of galaxy clusters from kinematic data. The method is based on a model of the phase space density which allows the anisotropy to vary with radius between two…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Radoslaw Wojtak , Ewa L. Lokas , Gary A. Mamon , Stefan Gottloeber

Searches for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above $\simeq 10 $PeV at the Pierre Auger Observatory are presented. Although no significant deviation from isotropy is revealed at…

High Energy Astrophysical Phenomena · Physics 2018-08-20 Olivier Deligny

The arrival directions of Galactic cosmic rays (CRs) are highly isotropic. This is expected from the presence of turbulent magnetic fields in our Galactic environment that repeatedly scatter charged CRs during propagation. However, various…

High Energy Astrophysical Phenomena · Physics 2017-04-05 Markus Ahlers , Philipp Mertsch

We study the optimal use of third order statistics in the analysis of weak lensing by large-scale structure. These higher order statistics have long been advocated as a powerful tool to break measured degeneracies between cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-15 S. Vafaei , T. Lu , L. van Waerbeke , E. Semboloni , C. Heymans , U. L. Pen

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 calculate the CMB anisotropy in compact hyperbolic universe models using the regularized method of images described in paper-I, including the 'line-of-sight `integrated Sachs-Wolfe' effect, as well as the last-scattering surface terms.…

Astrophysics · Physics 2009-10-31 J. Richard Bond , Dmitry Pogosyan , Tarun Souradeep

Several hypothesis testing methods have been proposed to validate the assumption of isotropy in spatial point patterns. A majority of these methods are characterised by an unknown distribution of the test statistic under the null hypothesis…

Methodology · Statistics 2025-04-09 Jakub J. Pypkowski , Adam M. Sykulski , James S. Martin

Important informations on the origin and the propagation mechanisms of cosmic rays may be provided by the measurement of the anisotropies of their arrival direction. In this paper the observation of anisotropy regions at different angular…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Roberto Iuppa

Extensive, accurate imaging of the Cosmic Background Radiation temperature anisotropy at sub--degree angular resolution is widely recognized as one of the most crucial goals for cosmology and astroparticle physics in the next decade. We…

Astrophysics · Physics 2016-08-30 L. Danese , L. Toffolatti , A. Franceschini , M. Bersanelli , N. Mandolesi

Recent detections of cosmic microwave background (CMB) anisotropy at half-degree angular scales show considerable scatter in the reported amplitude even at similar angular resolution. We use Monte Carlo techniques to simulate the current…

Astrophysics · Physics 2007-05-23 A. Kogut , G. Hinshaw

The cosmological principle asserts that the Universe is homogeneous and isotropic on large enough scales. However, alternative cosmological models can bring about anisotropies through local inhomogeneities, anisotropic evolution, or exotic…