English
Related papers

Related papers: Metrisability of three-dimensional projective stru…

200 papers

One dimensional metrical geometry may be developed in either an affine or projective setting over a general field using only algebraic ideas and quadratic forms. Some basic results of universal geometry are already present in this…

Metric Geometry · Mathematics 2007-05-23 N J Wildberger

The authors give a complete classification of projective threefolds admitting a holomorphic normal projective connection. Moreover, they prove a general structure theorem on complex projective manifolds admitting a holomorphic normal…

Algebraic Geometry · Mathematics 2007-05-23 Priska Jahnke , Ivo Radloff

We study the inverse spectral problem for weighted projective spaces using wave-trace methods. We show that in many cases one can "hear" the weights of a weighted projective space.

Spectral Theory · Mathematics 2008-05-08 Victor Guillemin , Alejandro Uribe , Zuoqin Wang

The twistor construction for Riemannian manifolds is extended to the case of manifolds endowed with generalized metrics (in the sense of generalized geometry \`a la Hitchin). The generalized twistor space associated to such a manifold is…

Differential Geometry · Mathematics 2018-07-03 Johann Davidov

In a space-time, a conformal structure is defined by the distribution of light-cones. Geodesics are traced by freely falling particles, and the collection of all unparameterized geodesics determines the projective structure of the…

Differential Geometry · Mathematics 2015-10-02 Vladimir S. Matveev , Andrzej Trautman

A $\sqrt{n}$ estimate in the hyperplane problem with arbitrary measures has recently been proved in \cite{K3}. In this note we present analogs of this result for sections of lower dimensions and in the complex case. We deduce these…

Metric Geometry · Mathematics 2013-09-26 Alexander Koldobsky

In 2007 H. Long-Guang and Z. Xian, [H. Long-Guang and Z. Xian, Cone Metric Spaces and Fixed Point Theorems of Contractive Mapping, J. Math. Anal. Appl., 322(2007), 1468-1476], generalized the concept of a metric space, by introducing cone…

Functional Analysis · Mathematics 2011-02-14 Mehdi Asadi , S. Mansour Vaezpour , Hossein Soleimani

We prove that any closed map between metrizable spaces can be extended to a closed map between completely metrizable spaces with the same extensional dimension.

General Topology · Mathematics 2007-05-23 H. Murat Tuncali , E. D. Tymchatin , Vesko Valov

In this Note, we will characterize the Poisson structures compatible with the canonical metric of $\reel^3$. We will also give some relvant examples of such structures. The notion of compatibility used in this Note was introduced and…

Differential Geometry · Mathematics 2007-05-23 Mohamed Boucetta

We prove a weighted Sobolev estimate of the Bergman projection on the Hartogs triangle, where the weight is some power of the distance to the singularity at the boundary. This method also applies to the $n$-dimensional generalization of the…

Complex Variables · Mathematics 2017-06-14 Liwei Chen

A combinatorial characterization of measurable filters on a countable set is found. We apply it to the problem of measurability of the intersection of nonmeasurable filters.

Logic · Mathematics 2007-05-23 Tomek Bartoszynski

C-projective structures are analogues of projective structures in the complex setting. The maximal dimension of the Lie algebra of c-projective symmetries of a complex connection on an almost complex manifold of C-dimension $n>1$ is…

Differential Geometry · Mathematics 2017-04-26 Boris Kruglikov , Vladimir Matveev , Dennis The

In this note we relate about the problem of evaluate the dimension of linear systems through fat points defined on generic $K3$ surfaces.

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

In this note we find the metric of 6-dimensional h-space of the [33] type and then determine an important projective group characteristic of this h-space.

Differential Geometry · Mathematics 2007-05-23 Z. Zakirova

This article emphasizes an extension of the study of metric and par- tition dimension to hypergraphs. We give a sharp lower bounds for the metric and partition dimension of hypergraphs in general and give exact values under specified…

Combinatorics · Mathematics 2024-06-18 Imran Javaid , Azeem Haider , Muhammad Salman , Sadaf Mehtab

The X-problem of number 3 for one dimension and related observations are discussed

Discrete Mathematics · Computer Science 2013-08-02 A. Kornyushkin

Many clustering applications in machine learning and data mining rely on solving metric-constrained optimization problems. These problems are characterized by $O(n^3)$ constraints that enforce triangle inequalities on distance variables…

Distributed, Parallel, and Cluster Computing · Computer Science 2019-01-30 Cameron Ruggles , Nate Veldt , David F. Gleich

Fundamental antenna limits of the gain-bandwidth product are derived from polarizability calculations. This electrostatic technique has significant value in many antenna evaluations. Polarizability is not available in closed form for most…

Optics · Physics 2014-02-18 Morteza Shahpari , David V. Thiel , Andrew Lewis

The coordinate projective line over a field is seen as a groupoid with a further `projection' structure. We investigate conversely to what extent such an, abstractly given, groupoid may be coordinatized by a suitable field constructed out…

Category Theory · Mathematics 2013-10-22 Anders Kock

We introduce the notion of a {\it mock tridiagonal system}. This is a generalization of a tridiagonal system in which the irreducibility assumption is replaced by a certain non-vanishing condition. We show how mock tridiagonal systems can…

Rings and Algebras · Mathematics 2008-07-29 Tatsuro Ito , Paul Terwilliger