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We introduce succinct lossless representations of query results called covers. They are subsets of the query results that correspond to minimal edge covers in the hypergraphs of these results. We first study covers whose structures are…

Databases · Computer Science 2018-01-12 Ahmet Kara , Dan Olteanu

Interest in Conformal Field Theories and Quantum Field Theory lead physicists to consider configuration spaces of marked points on the complex projective line, $Conf_{0,d}(\mathbb{P})$. In this paper, a real semi-algebraic stratification of…

Algebraic Geometry · Mathematics 2019-06-13 N. C. Combe

The emergence of trapped surfaces in solutions to the Einstein field equations is intimately tied to the well-posedness properties of the corresponding Cauchy problem in the low regularity regime. In this paper, we study the question of…

General Relativity and Quantum Cosmology · Physics 2024-06-21 Jonathan Luk , Georgios Moschidis

A ubiquitous motif in nature is the self-similar hierarchical buckling of a thin lamina near its margins. This is seen in leaves, flowers, fungi, corals, and marine invertebrates. We investigate this morphology from the perspective of…

We prove that octants are cover-decomposable, i.e., any 12-fold covering of any subset of the space with a finite number of translates of a given octant can be decomposed into two coverings. As a corollary, we obtain that any 12-fold…

Combinatorics · Mathematics 2015-03-17 Balázs Keszegh , Dömötör Pálvölgyi

The notion of graph covers is a discretization of covering spaces introduced and deeply studied in topology. In discrete mathematics and theoretical computer science, they have attained a lot of attention from both the structural and…

Discrete Mathematics · Computer Science 2023-06-13 Jan Bok , Jiří Fiala , Nikola Jedličková , Jan Kratochvíl , Michaela Seifrtová

The shellability of the boundary complex of an unbounded polyhedron is investigated. To this end, it is necessary to pass to a suitable compactification, e.g., by one point. This observation can be exploited to prove that any tropical…

Combinatorics · Mathematics 2025-06-10 George Balla , Michael Joswig , Lena Weis

Minimal surfaces are ubiquitous in nature. Here they are considered as geometric objects that bear a deformation content. By refining the resolution of the surface deformation gradient afforded by the polar decomposition theorem, we…

Differential Geometry · Mathematics 2024-08-13 André M. Sonnet , Epifanio G. Virga

Multi-layer graphs consist of several graphs (layers) over the same vertex set. They are motivated by real-world problems where entities (vertices) are associated via multiple types of relationships (edges in different layers). We chart the…

Computational Complexity · Computer Science 2019-10-23 Robert Bredereck , Christian Komusiewicz , Stefan Kratsch , Hendrik Molter , Rolf Niedermeier , Manuel Sorge

Given a closed Riemann surface $\Sigma$ equipped with a volume form $\omega$, we construct a natural probability measure on the space $\mathcal{M}_d(\Sigma)$ of degree $d$ branched coverings from $\Sigma$ to the Riemann sphere…

Algebraic Geometry · Mathematics 2020-04-07 Michele Ancona

We introduce a general notion of covering property, of which many classical definitions are particular instances. Notions of closure under various sorts of convergence, or, more generally, under taking kinds of accumulation points, are…

General Topology · Mathematics 2022-06-28 Paolo Lipparini

We survey basic properties and bounds for $q$-equivelar and $d$-covered triangulations of closed surfaces. Included in the survey is a list of the known sources for $q$-equivelar and $d$-covered triangulations. We identify all orientable…

Combinatorics · Mathematics 2010-01-19 Frank H. Lutz , Thom Sulanke , Anand K. Tiwari , Ashish K. Upadhyay

Decomposing an Eulerian graph into a minimum respectively maximum number of edge disjoint cycles is an NP-complete problem. We prove that an Eulerian graph decomposes into a unique number of cycles if and only if it does not contain two…

Combinatorics · Mathematics 2019-01-08 Irene Heinrich , Manuel Streicher

We investigate the topological structures of Galois covers of surfaces of minimal degree (i.e., degree n) in n+1 dimensional complex projective space. We prove that for n is greater than or equal to 5, the Galois covers of any surfaces of…

Algebraic Geometry · Mathematics 2023-07-13 Meirav Amram , Cheng Gong , Jia-Li Mo

We say that a pure simplicial complex ${\mathbf K}$ of dimension $d$ satisfies the removal-collapsibility condition if ${\mathbf K}$ is either empty or ${\mathbf K}$ becomes collapsible after removing $\tilde \beta_d ({\mathbf K}; {\mathbb…

Combinatorics · Mathematics 2021-02-10 Thomas Magnard , Michael Skotnica , Martin Tancer

Consider spherically symmetric initial data for a cosmology which, in the large, approximates an open $k = -1 ,\Lambda = 0$ Friedmann-Lema{\^\i}tre universe. Further assume that the data is chosen so that the trace of the extrinsic…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Uwe Brauer , Edward Malec , Niall Ó Murchadha

In this paper we present an implementation of a computer algorithm that automatically determines the topological structure of spacetime, using a branched covering space representation. This algorithm is applied to a few simple examples in…

General Relativity and Quantum Cosmology · Physics 2025-08-13 Christopher L Duston

We prove the irreducibility of the space parametrizing branched covers of a fixed Riemann surface $B$ of degree $d$, with at least 2d branch points, and with monodromy group equal to $S_d$. The result is classical for $g(B)=0$. The result…

Algebraic Geometry · Mathematics 2007-05-23 Tom Graber , Joe Harris , Jason Starr

This paper resolves the characteristic initial data problem for the three-dimensional compressible Euler equations - an open problem analogous to Christodoulou's characteristic initial value formulation for the vacuum Einstein field…

Analysis of PDEs · Mathematics 2025-08-22 Yuxuan Wang , Sifan Yu , Pin Yu

We prove that if S is a closed compact surface of negative Euler characteristic, and if R is a quasi-Fuchsian representation in PSL(2,C), then the deformation space M(k,R) of branched projective structures on S with total branching order k…

Geometric Topology · Mathematics 2014-11-11 Gabriel Calsamiglia , Bertrand Deroin , Stefano Francaviglia