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We propose a novel representation of cosmic microwave anisotropy maps, where each multipole order l is represented by l unit vectors pointing in directions on the sky and an overall magnitude. These "multipole vectors and scalars" transform…

Astrophysics · Physics 2008-11-26 C. J. Copi , D. Huterer , G. D. Starkman

Complex systems are sometimes subject to non Gaussian alpha stable Levy fluctuations. A new method is devised to estimate this uncertain parameter and other system parameters, using observations on either mean exit time or escape…

Dynamical Systems · Mathematics 2013-06-04 Ting Gao , Jinqiao Duan

Current statistics literature on statistical inference of random fields typically assumes that the fields are stationary or focuses on models of non-stationary Gaussian fields with parametric/semiparametric covariance families, which may…

Statistics Theory · Mathematics 2024-09-04 Yunyi Zhang , Zhou Zhou

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

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

In this paper we study an anisotropic model generated from a particular Bianchi type-III metric, which is a generalization of G\"odel's metric and an exact solution of Einstein's field equations. We analyse type Ia supernova data, namely…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-02 R. S. Menezes , C. Pigozzo , S. Carneiro

Standard chance constrained control algorithms typically rely on the assumption that uncertainties in vehicle states obey Gaussian statistics. Highly nonlinear systems tend to disrupt Gaussianity, challenging standard chance-constrained…

Optimization and Control · Mathematics 2026-04-07 Ethan Burnett , Spencer Boone

Isotropic covariance structures can be unreasonable for phenomena in three-dimensional spaces such as the ocean. In the ocean, the variability of the response may vary with depth, and ocean currents may lead to spatially varying anisotropy.…

Methodology · Statistics 2023-01-13 Martin Outzen Berild , Geir-Arne Fuglstad

Cumulative sum (CUSUM) statistics are widely used in the change point inference and identification. For the problem of testing for existence of a change point in an independent sample generated from the mean-shift model, we introduce a…

Statistics Theory · Mathematics 2021-01-05 Mengjia Yu , Xiaohui Chen

We present a novel method, based on a multiscale approach, for detecting anisotropy signatures in the arrival direction distribution of the highest energy cosmic rays. This method is catalog independent, i.e. it does not depend on the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 M. De Domenico , H. Lyberis

I develop a method for assessing the ability of an instrument, coupled with an observing strategy, to measure the angular power spectrum of the cosmic microwave background (CMB). It allows for efficient calculation of expected parameter…

Astrophysics · Physics 2009-10-28 Lloyd Knox

We question the global universe isotropy by probing the alignment of local structures in the cosmic microwave background (CMB) radiation. The original method proposed relies on a steerable wavelet decomposition of the CMB signal on the…

Astrophysics · Physics 2007-05-23 Y. Wiaux , P. Vielva , E. Martinez-Gonzalez , P. Vandergheynst

This paper studies random fields on the unit sphere. Traditionally, isotropic Gaussian random fields are considered as the underlying statistical model of the cosmic microwave background (CMB) data. This paper discusses the generalized…

General Physics · Physics 2021-04-30 Phil Broadbridge , Ravindi Nanayakkara , Andriy Olenko

In spatial statistics, point processes are often assumed to be isotropic meaning that their distribution is invariant under rotations. Statistical tests for the null hypothesis of isotropy found in the literature are based either on…

Methodology · Statistics 2024-04-17 Chiara Fend , Claudia Redenbach

For a wide class of self-gravitating systems, we show that if the density is cusped like 1/r^{gamma} near the center, then the limiting value of the anisotropy parameter beta = 1 - <v_T^2>/(2<v_r^2>) at the center may not be greater than…

Astrophysics · Physics 2007-05-23 J. An , N. W. Evans

The statistical tests - done by the authors - are surveyed, which verify the null-hypothesis of the intrinsic randomness in the angular distribution of gamma-ray bursts collected at BATSE Catalog. The tests use the counts-in-cells method,…

High Energy Astrophysical Phenomena · Physics 2015-05-14 A. Meszaros , Z. Bagoly , L. G. Balazs , I. Horvath , R. Vavrek

The estimation of parameter standard errors for semi-variogram models is challenging, given the two-step process required to fit a parametric model to spatially correlated data. Motivated by an application in the social-epidemiology, we…

Methodology · Statistics 2023-07-18 Julia Dyck , Odile Sauzet

The measurements of CMB anisotropy have opened up a window for probing the global topology of the universe on length scales comparable to and beyond the Hubble radius. For compact topologies, the two main effects on the CMB are: (1) the…

Astrophysics · Physics 2011-04-15 J. Richard Bond , Dmitri Pogosyan , Tarun Souradeep

We use information entropy to test the isotropy in the nearby galaxy distribution mapped by the Two Micron All-Sky redshift survey (2MRS). We find that the galaxy distribution is highly anisotropic on small scales. The radial anisotropy…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-19 Biswajit Pandey

This paper studies polar sets of anisotropic Gaussian random fields, i.e. sets which a Gaussian random field does not hit almost surely. The main assumptions are that the eigenvalues of the covariance matrix are bounded from below and that…

Probability · Mathematics 2020-06-12 Jakob Söhl
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