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In (Hansen et al. 2002) we presented a new approach for measuring non-Gaussianity of the Cosmic Microwave Background (CMB) anisotropy pattern, based on the multivariate empirical distribution function of the spherical harmonics a_lm of a…

Astrophysics · Physics 2010-11-19 Frode K. Hansen , Domenico Marinucci , Nicola Vittorio

Among systems that display generic scale invariance, those whose asymptotic properties are anisotropic in space (strong anisotropy, SA) have received a relatively smaller attention, specially in the context of kinetic roughening for…

Statistical Mechanics · Physics 2015-06-11 Edoardo Vivo , Matteo Nicoli , Rodolfo Cuerno

We use simulated maps of the cosmic microwave background anisotropy to quantify the ability of different statistical tests to discriminate between Gaussian and non-Gaussian models. Despite the central limit theorem on large angular scales,…

Astrophysics · Physics 2009-10-31 Nicholas G. Phillips , A. Kogut

In this paper, we consider isotropic and stationary real Gaussian random fields defined on $\mathbb{S}^2\times\mathbb{R}$ and we investigate the asymptotic behavior, as $T\rightarrow +\infty$, of the empirical measure (excursion area) in…

Probability · Mathematics 2020-03-12 Domenico Marinucci , Maurizia Rossi , Anna Vidotto

The two-point angular correlation function is a traditional method used to search for deviations from expectations of isotropy. In this paper we develop and explore a statistically descriptive three-point method with the intended…

Instrumentation and Methods for Astrophysics · Physics 2009-10-02 J. D. Hague , B. R. Becker , M. S. Gold , J. A. J. Matthews

This paper proposes parametric and non-parametric hypothesis testing algorithms for detecting anisotropy -- rotational variance of the covariance function in random fields. Both algorithms are based on resampling mechanisms, which enable…

Methodology · Statistics 2021-06-08 Assaf Rabinowicz , Saharon Rosset

We present results from a first test of the Gaussianity of degree-scale cosmic microwave background (CMB) anisotropy. We investigate Gaussianity of the CMB anisotropy by studying the topology of CMB anisotropy maps from the QMAP and…

Astrophysics · Physics 2009-10-07 Chan-Gyung Park , Changbom Park , Bharat Ratra , Max Tegmark

We study the sample paths properties of Operator scaling Gaussian random fields. Such fields are anisotropic generalizations of anisotropic self-similar random fields as anisotropic Fractional Brownian Motion. Some characteristic properties…

Probability · Mathematics 2013-02-05 M. Clausel , B. Vedel

The goal of this paper is to give confidence regions for the excursion set of a spatial function above a given threshold from repeated noisy observations on a fine grid of fixed locations. Given an asymptotically Gaussian estimator of the…

Methodology · Statistics 2015-01-29 Max Sommerfeld , Stephen Sain , Armin Schwartzman

We propose several pseudoentropy measures that agree well with the Wehrl entropy, but are significantly faster to compute. All of them are rotationally invariant measures of entanglement very sensitive to non-Gaussianity, anisotropy, and…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-06 Momchil Minkov , Marvin Pinkwart , Peter Schupp

Strict stationarity is a common assumption used in the time series literature in order to derive asymptotic distributional results for second-order statistics, like sample autocovariances and sample autocorrelations. Focusing on weak…

Statistics Theory · Mathematics 2023-02-28 Yunyi Zhang , Efstathios Paparoditis , Dimitris N. Politis

We consider the benefits of measuring cosmic statistical anisotropy from redshift-space correlators of the galaxy number density fluctuation and the peculiar velocity field without adopting the plane-parallel (PP) approximation. Since the…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 Maresuke Shiraishi , Teppei Okumura , Kazuyuki Akitsu

The small but measurable effect of weak gravitational lensing on the cosmic microwave background radiation provide information about the large-scale distribution of matter in the universe. We use the all sky distribution of matter, as…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-11 Priya Goyal , Pravabati Chingangbam

This article introduces a method for estimating the smoothness of a stationary, isotropic Gaussian random field from irregularly spaced data. This involves novel constructions of higher-order quadratic variations and the establishment of…

Statistics Theory · Mathematics 2015-10-30 Wei-Liem Loh

In the context of the geometrical analysis of weakly non Gaussian CMB maps, the 2D differential extrema counts as functions of the excursion set threshold is derived from the full moments expansion of the joint probability distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Dmitri Pogosyan , Christophe Pichon , Christophe Gay

Gaussian random fields are a powerful tool for modeling environmental processes. For high dimensional samples, classical approaches for estimating the covariance parameters require highly challenging and massive computations, such as the…

Statistics Theory · Mathematics 2016-10-05 Hossein Keshavarz , Clayton Scott , XuanLong Nguyen

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

This paper deals with the problem of detecting non-isotropic high-dimensional geometric structure in random graphs. Namely, we study a model of a random geometric graph in which vertices correspond to points generated randomly and…

Statistics Theory · Mathematics 2020-02-25 Ronen Eldan , Dan Mikulincer

We study how sampling geometry contributes to uncertainty in modeling spatial geophysical observations as sampled random fields characterized by stationary, isotropic, parametric covariance functions. We incorporate the signature of…

Methodology · Statistics 2026-04-03 Olivia L. Walbert , Frederik J. Simons , Arthur P. Guillaumin , Sofia C. Olhede

We present a new algorithm to sample the constrained eigenvalues of the initial shear field associated with Gaussian statistics, called the `peak/dip excursion-set-based' algorithm, at positions which correspond to peaks or dips of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Graziano Rossi