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Related papers: Star configurations in $\mathbb P^n$

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One way to characterize configurations of points up to congruence is by considering the distribution of all mutual distances between points. This paper deals with the question if point configurations are uniquely determined by this…

Commutative Algebra · Mathematics 2007-05-23 Mireille Boutin , Gregor Kemper

We investigate the formation of clusters of galaxies in an expanding universe using a new code that regrids at a region of high density. In particular we investigate two models for the initial conditions, both with the standard CDM power…

Astrophysics · Physics 2015-06-24 Suvendra N. Dutta

Let $\mathcal{W}^{n}$ be the class of $C^{\infty }$ complete simply connected $n-$dimensional manifolds without conjugate points. The hyperbolic space as well as Euclidean space are good examples of such manifolds. Let $% W\in…

Differential Geometry · Mathematics 2019-12-05 Sameh Shenawy

We study the connection between probability distributions satisfying certain conditional independence (CI) constraints, and point and line arrangements in incidence geometry. To a family of CI statements, we associate a polynomial ideal…

Commutative Algebra · Mathematics 2021-04-01 Oliver Clarke , Fatemeh Mohammadi , Harshit J. Motwani

We study initial degrees of symbolic powers of ideals of arbitrary finite sets of points in the projective plane over an algebraically closed field of characteristic zero. We show, how bounds on the growth of these degrees determine the…

Algebraic Geometry · Mathematics 2012-05-29 Marcin Dumnicki , Tomasz Szemberg , Halszka Tutaj-Gasinska

The triangulations of point configurations which decompose as a free sum are classified in terms of the triangulations of the summands. The methods employ two new kinds of partially ordered sets to be associated with any triangulation of a…

Combinatorics · Mathematics 2018-10-30 Benjamin Assarf , Michael Joswig , Julian Pfeifle

Let $I_n$ be the ideal of all algebraic relations on the slopes of the $\binom{n}{2}$ lines formed by placing $n$ points in a plane and connecting each pair of points with a line. Under each of two natural term orders, the initial ideal of…

Combinatorics · Mathematics 2011-10-05 Jeremy L. Martin , Jennifer D. Wagner

Young massive star clusters spanning $\sim 10^4 - 10^8 M_\odot$ in mass have been observed to have similar surface brightness profiles. Recent hydrodynamical simulations of star cluster formation have also produced star clusters with this…

A topological hyperplane is a subspace of R^n (or a homeomorph of it) that is topologically equivalent to an ordinary straight hyperplane. An arrangement of topological hyperplanes in R^n is a finite set H such that k topological…

Combinatorics · Mathematics 2010-01-24 David Forge , Thomas Zaslavsky

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

An elegant procedure which characterizes a decomposition of some class of binomial configurations into two other, resembling a definition of Pascal's Triangle, was given in \cite{gevay}. In essence, this construction was already presented…

Combinatorics · Mathematics 2019-07-23 Krzysztof Prażmowski

We compute small rational models for configuration spaces of points on oriented surfaces, as right modules over the framed little disks operad. We do this by splitting these surfaces in unions of several handles. We first describe rational…

Quantum Algebra · Mathematics 2026-02-05 Ricardo Campos , Najib Idrissi , Thomas Willwacher

Effective star formation rates in tabular form are computed which yield a prescription for the star formation activity in model galaxies as a function of ambient density, metallicity, and stellar feedback. The effects of supernova…

Astrophysics · Physics 2009-10-30 Marco Spaans , Marcella Carollo

The understanding and modeling of the structure and evolution of stars is based on statistical physics as well as on hydrodynamics. Today, a precise identification and proper description of the physical processes at work in stellar…

Astrophysics · Physics 2018-10-31 Y. Lebreton

Given distinct points $p_1,\cdots,p_r$ of the projective plane $P^2$ and a positive integer $m$, the homogeneous ideal defining the fat point subscheme $Z=m(p_1+\cdots+p_r)$ is the symbolic power $I^{(m)}$ of the homogeneous ideal $I$…

alg-geom · Mathematics 2011-11-09 Brian Harbourne

We show that the space of sections of any line bundle on the augmented wonderful variety of a hyperplane arrangement has the structure of a coalgebra. These coalgebras correspond to the hyperplane arrangement power ideals of Ardila and…

Algebraic Geometry · Mathematics 2026-04-09 Colin Crowley , Matt Larson

A class of general relativistic solutions in isotropic spherical polar coordinates are discussed which describe compact stars in hydrostatic equilibrium. The stellar models obtained here are characterized by four parameters, namely,…

Solar and Stellar Astrophysics · Physics 2015-06-17 Rumi Deb , Bikash Chandra Paul , Ramesh Tikekar

We answer the question whether, when forming constellations in the night sky, people in astronomical cultures around the world and through time consistently imagined and assigned the same symbolism to the same (type of) star group. Evidence…

Physics and Society · Physics 2024-04-22 Doina Bucur

In this paper, we introduce the notions of Star-$\sigma\mathcal{K}$ and absolutely Star-$\sigma\mathcal{K}$ spaces which allow us to unify results among several properties in the theory of star selection principles on small spaces. In…

General Topology · Mathematics 2021-05-17 Javier Casas-de la Rosa , Sergio A. Garcia-Balan

Let R be a commutative ring and I an ideal of R. A sub-ideal J of I is a reduction of I if JI^n = I^n+1 for some positive integer n. The ring R has the (finite) basic ideal property if (finitely generated) ideals of R do not have proper…

Commutative Algebra · Mathematics 2016-02-24 E. Houston , S. Kabbaj , A. Miomouni