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The Hirsch Conjecture (1957) stated that the graph of a $d$-dimensional polytope with $n$ facets cannot have (combinatorial) diameter greater than $n-d$. That is, that any two vertices of the polytope can be connected by a path of at most…

Combinatorics · Mathematics 2013-04-30 Francisco Santos

The Fuglede conjecture states that a set is spectral if and only if it tiles by translation. The conjecture was disproved by T. Tao for dimensions 5 and higher by giving a counterexample in $\mathbb{Z}_3^5$. We present a computer program…

Classical Analysis and ODEs · Mathematics 2019-02-07 Philipp Birklbauer

More than once we have heard that the Charney-Davis Conjecture makes sense only for odd-dimensional spheres. This is to point out that in fact it is also a statement about even-dimensional spheres.

Combinatorics · Mathematics 2010-10-12 Swiat R. Gal , Tadeusz Januszkiewicz

In this paper, an approach is developed to solve the three body problem involving masses which posses spherical symmetry. The problem dates back to the times of Poincare, and is undoubtedly one of the oldest of unsolved problems of…

Mathematical Physics · Physics 2007-05-23 A. B. Mehmood , U. A. Shah , G. Shabbir

In this paper we prove a conjecture about the dimension of linear systems of surfaces of degree d in P^3 through at most eight multiple points in general position.

Algebraic Geometry · Mathematics 2007-05-23 Cindy De Volder , Antonio Laface

A double disk bundle is any smooth closed manifold obtained as the union of the total spaces of two disk bundles, glued together along their common boundary. The Double Soul Conjecture asserts that a closed simply connected manifold…

Differential Geometry · Mathematics 2023-11-08 Jason DeVito

We establish Conway's thrackle conjecture in the case of spherical thrackles; that is, for drawings on the unit sphere where the edges are arcs of great circles.

Combinatorics · Mathematics 2014-12-24 Grant Cairns , Timothy J. Koussas , Yuri Nikolayevsky

In this paper, we survey recent progress on the Null Penrose Conjecture, including a proof of the conjecture for smooth null cones that are foliated by doubly convex spheres.

General Relativity and Quantum Cosmology · Physics 2017-08-04 Hubert L. Bray , Henri P. Roesch

Noncommutative geometries generalize standard smooth geometries, parametrizing the noncommutativity of dimensions with a fundamental quantity with the dimensions of area. The question arises then of whether the concept of a region smaller…

History and Philosophy of Physics · Physics 2021-06-21 Nick Huggett , Fedele Lizzi , Tushar Menon

We extend the original cylinder conjecture on point sets in affine three-dimensional space to the more general framework of divisible linear codes over $\mathbb{F}_q$ and their classification. Through a mix of linear programming,…

Combinatorics · Mathematics 2021-12-14 Sascha Kurz , Sam Mattheus

We will prove that the Pierce-Birkhoff Conjecture holds for non-singular two-dimensional affine real algebraic varieties over real closed fields, i.e., if W is such a variety, then every piecewise polynomial function on W can be written as…

Algebraic Geometry · Mathematics 2009-02-25 Sven Wagner

The Hirsch conjecture was posed in 1957 in a letter from Warren M. Hirsch to George Dantzig. It states that the graph of a d-dimensional polytope with n facets cannot have diameter greater than n - d. Despite being one of the most…

Combinatorics · Mathematics 2013-10-29 Edward D. Kim , Francisco Santos

In this paper, we prove that the statement: ``The (Generalized) Hodge Conjecture holds for codimension-two cycles on a smooth projective variety $X$" is a birationally invariant statement, that is, if the statement is true for $X$, it is…

Algebraic Geometry · Mathematics 2007-05-23 Wenchuan Hu

Circuit diameters of polyhedra are a fundamental tool for studying the complexity of circuit augmentation schemes for linear programming and for finding lower bounds on combinatorial diameters. The main open problem in this area is the…

Combinatorics · Mathematics 2024-04-10 Alexander E. Black , Steffen Borgwardt , Matthias Brugger

The Tate conjecture for squares of K3 surfaces over finite fields was recently proved by Ito-Ito-Koshikawa. We give a more geometric proof when the characteristic is at least 5. The main idea is to use twisted derived equivalences between…

Number Theory · Mathematics 2021-10-05 Ziquan Yang

In this thesis, we use normal surface theory to understand certain properties of minimal triangulations of compact orientable 3-manifolds. We describe the collapsing process of normal 2-spheres and disks. Using some geometrical…

Geometric Topology · Mathematics 2009-09-29 Alexander Barchechat

Recent developments of affine algebraic geometry, especially the theory of open algebraic surfaces, provide means to systematically explore geometric and topological properties of polynomials in two variables. Nevertheless, there is one…

Algebraic Geometry · Mathematics 2015-04-28 Masayoshi Miyanishi

Given a totally nonholonomic distribution of rank two on a three-dimensional manifold we investigate the size of the set of points that can be reached by singular horizontal paths starting from a same point. In this setting, the Sard…

Differential Geometry · Mathematics 2018-07-18 André Belotto da Silva , Ludovic Rifford

The classical Kneser-Milnor theorem says that every closed oriented connected 3-dimensional manifold admits a unique connected sum decomposition into manifolds that cannot be decomposed any further. We discuss to what degree such…

We deal with the restriction phenomenon for the Fourier transform. We prove that each of the restriction conjectures for the sphere, the paraboloid, the elliptic hyperboloid in $\mathbb{R}^n$ implies that for the cone in $\mathbb{R}^{n+1}$.…

Classical Analysis and ODEs · Mathematics 2008-04-24 Fabio Nicola