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Cosmological correlators encode statistical properties of the initial conditions of our universe. Mathematically, they can often be written as Mellin integrals of a certain rational function associated to graphs, namely the flat space…

Algebraic Geometry · Mathematics 2025-05-27 Claudia Fevola , Guilherme L. Pimentel , Anna-Laura Sattelberger , Tom Westerdijk

We propose a morphological multi-scale analysis of large-scale structures obtained by computer simulations and by observations. Structures are obtained at different scales by applying a wavelet transform on the observed and simulated data.…

Astrophysics · Physics 2007-05-23 E. Lega , A. Bijaoui , J. -M. Alimi , H. Scholl

We compute explicitly a star product on the Minkowski space whose Poisson bracket is quadratic. This star product corresponds to a deformation of the conformal spacetime, whose big cell is the Minkowski spacetime. The description of…

High Energy Physics - Theory · Physics 2021-04-20 D. Cervantes , R. Fioresi , M. A. Lledó , F. A. Nadal

This paper deals with the computation of sectional curvature for the manifolds of $N$ landmarks (or feature points) in D dimensions, endowed with the Riemannian metric induced by the group action of diffeomorphisms. The inverse of the…

Differential Geometry · Mathematics 2012-03-19 Mario Micheli , Peter W. Michor , David Mumford

The shape of the primordial fluctuation spectrum is probed by cosmic microwave background fluctuations which measure density fluctuations at z~1000 on scales of hundreds of Mpc and from galaxy redshift surveys, which measure structure at…

Astrophysics · Physics 2014-10-13 Joseph Silk , Eric Gawiser

In this article, we introduce and study the concept of $\textit{spherical-vectors}$, which can be perceived as a natural extension of the arguments of complex numbers in the context of quaternions. We initially establish foundational…

Rings and Algebras · Mathematics 2023-05-09 Lahcen Lamgouni

We describe and study geometric properties of discrete circular and spherical means of directional derivatives of functions, as well as discrete approximations of higher order differential operators. For an arbitrary dimension we present a…

Numerical Analysis · Mathematics 2015-05-28 Alexander Belyaev , Boris Khesin , Serge Tabachnikov

Covariance functions and variograms play a fundamental role in exploratory analysis and statistical modelling of spatial and spatio-temporal datasets. In this paper, we construct a new class of spatial covariance functions using the Fourier…

Methodology · Statistics 2021-11-16 Mohammad Ghorbani , Jorge Mateu

For a large class of self-similar sets F in R^d analogues of the higher order mean curvatures of differentiable submanifolds are introduced, in particular, the fractal Gauss-type curvature. They are shown to be the densities of associated…

Metric Geometry · Mathematics 2010-10-01 Jan Rataj , Martina Zähle

We classify manifolds of small dimension that admit both, a Riemannian metric of non-negative scalar curvature, and a -- a priori different -- metric for which all wedge products of harmonic forms are harmonic. For manifolds whose first…

Differential Geometry · Mathematics 2019-10-09 D. Kotschick

A new characterization of conformal transformations is given. By use of this, the general form of conformal transformation on two-dimensional Minkowski space is given and its conformal structure is analyzed.

Differential Geometry · Mathematics 2013-11-07 Do-Hyung Kim

We present a novel method for computing the Minkowski Functionals from isodensity surfaces extracted directly from the Delaunay tessellation of a point distribution. This is an important step forward compared to the previous cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-23 Miguel A. Aragon-Calvo , Sergei F. Shandarin , Alexander Szalay

We study the morphology of convergence maps by perturbatively reconstructing their Minkowski Functionals (MFs). We present a systematics study using a set of three generalised skew-spectra as a function of source redshift and smoothing…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-01 D. Munshi , T. Namikawa , J. D. McEwen , T. D. Kitching , F. R. Bouchet

The main tools in cosmology for comparing theoretical models with the observations of the galaxy distribution are statistical. We will review the applications of spatial statistics to the description of the large-scale structure of the…

Astrophysics · Physics 2009-11-07 Vicent J. Martinez , Enn Saar

A complex system comprises multiple interacting entities whose interdependencies form a unified whole, exhibiting emergent behaviours not present in individual components. Examples include the human brain, living cells, soft matter, Earth's…

We used the mark weighted correlation functions (MCFs), $W(s)$, to study the large scale structure of the Universe. We studied five types of MCFs with the weighting scheme $\rho^\alpha$, where $\rho$ is the local density, and $\alpha$ is…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-02 Yizhao Yang , Haitao Miao , Qinglin Ma , Miaoxin Liu , Cristiano G. Sabiu , Jaime Forero-Romero , Yuanzhu Huang , Limin Lai , Qiyue Qian , Yi Zheng , Xiao-Dong Li

We construct algorithms and topological invariants that allow us to distinguish the topological type of a surface, as well as functions and vector fields for their topological equivalence. In the first part we discus the main structures…

Dynamical Systems · Mathematics 2025-01-28 Alexandr Prishlyak

Citation networks represent the flow of information between agents. They are constrained in time and so form directed acyclic graphs which have a causal structure. Here we provide novel quantitative methods to characterise that structure by…

Physics and Society · Physics 2016-10-10 James R. Clough , Tim S. Evans

Data analysis and data mining are concerned with unsupervised pattern finding and structure determination in data sets. "Structure" can be understood as symmetry and a range of symmetries are expressed by hierarchy. Such symmetries directly…

Machine Learning · Statistics 2015-03-17 Fionn Murtagh , Pedro Contreras

Some of the most outstanding questions in the field of gravitation and geometry remain unsolved as a result of our limited understanding of the global structure of the spacetime geometry and the role played by global spacetime…

General Relativity and Quantum Cosmology · Physics 2008-09-23 M. Iftime
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