English
Related papers

Related papers: A Fake Projective Plane with an order 7 automorphi…

200 papers

The purpose of this article is to give an interpretation of real projective structures and associated cohomology classes in terms of connections, sections, etc. satisfying elliptic partial differential equations in the spirit of Hodge…

Differential Geometry · Mathematics 2007-05-23 F. Labourie

In this paper we present the results from a program developed by the author that finds the unitals of the known 193 projective planes of order 25.. There are several planes for which we have not found any unital. One or more than one…

Combinatorics · Mathematics 2012-11-06 Stoicho D. Stoichev

This report gives an overview of the history of finite projective planes and their properties before going on to outline the proof that no projective plane of order 10 exists. The report also investigates the search carried out by…

History and Overview · Mathematics 2016-03-18 Xander Perrott

It is known for a long time that a nonsingular real algebraic curve of degree 2k in the projective plane cannot have more than 7/2*k^2-9/4*k+3/2$ even ovals. We show here that this upper bound is asymptotically sharp, that is to say we…

Algebraic Geometry · Mathematics 2007-05-23 Erwan brugalle

We deal with seven dimensional compact Riemannian manifolds of positive curvature which admit a cohomogeneity one action by a compact Lie group G. We prove that the manifold is diffeomorphic to a sphere if the dimension of the semisimple…

dg-ga · Mathematics 2007-05-23 Fabio Podesta , Luigi Verdiani

A pseudo-edge graph of a convex polyhedron K is a 3-connected embedded graph in K whose vertices coincide with those of K, whose edges are distance minimizing geodesics, and whose faces are convex. We construct a convex polyhedron K in…

Metric Geometry · Mathematics 2019-03-01 Nicholas Barvinok , Mohammad Ghomi

An outerplanar graph is a planar graph that has a planar drawing with all vertices on the unbounded face. The matching complex of a graph is the simplicial complex whose faces are subsets of disjoint edges of the graph. In this paper we…

Combinatorics · Mathematics 2024-11-08 Margaret Bayer , Marija Jelić Milutinović , Julianne Vega

Every $\mathbb{A}^{1}-$bundle over the complex affine plane punctured at the origin, is trivial in the differentiable category but there are infinitely many distinct isomorphy classes of algebraic bundles. Isomorphy types of total spaces of…

Algebraic Geometry · Mathematics 2011-06-16 Adrien Dubouloz , David R. Finston

The complex projective structures considered is this article are compact curves locally modeled on $\mathbb{CP}^1$. To such a geometric object, modulo marked isomorphism, the monodromy map associates an algebraic one: a representation of…

Differential Geometry · Mathematics 2025-08-28 Titouan Sérandour

Quasi-vertex-transitive maps are the homogeneous maps on the plane with finitely many vertex orbits under the action of their automorphism groups. We show that there exist quasi-vertex-transitive maps of types $[p^3, 3]$ for $p \equiv 1$…

Geometric Topology · Mathematics 2020-03-26 Arun Maiti

We exhibit a smooth complex rational affine surface with uncountably many nonisomorphic real forms.

Algebraic Geometry · Mathematics 2023-08-10 Anna Bot

We show that Shavel type surfaces are fake quadrics of even type which are not Mori dream surfaces, yet there are infinitely many primes $p$ such that the reduction modulo $p$ is a Mori dream surface. We investigate fake quadrics, first…

Algebraic Geometry · Mathematics 2025-09-24 Paolo Cascini , Fabrizio Catanese , Yifan Chen , Jong Hae Keum

In a previous paper, the authors proved that the Prym variety of any non-cyclic etale triple cover of a smooth curve of genus 2 is a Jacobian variety of dimension 2. This gives a map from the moduli space of such covers to the moduli space…

Algebraic Geometry · Mathematics 2013-01-04 Herbert Lange , Angela Ortega

This article describes an example of a real projective K3 surface admitting a real automorphism $f$ satisfying $h_{top}(f, X(\mathbb{C})) < 2 h_{top}(f, X(\mathbb{R}))$. The example presented is a $(2,2,2)$-surface in $\mathbb{P}^1 \times…

Dynamical Systems · Mathematics 2025-06-05 Ethan Cohen

We discuss the isomorphism problem of projective schemes; given two projective schemes, can we algorithmically decide whether they are isomorphic? We give affirmative answers in the case of one-dimensional projective schemes, the case of…

Algebraic Geometry · Mathematics 2024-02-27 Takehiko Yasuda

We study the Prym map for degree-7 etale cyclic coverings over a curve of genus 2. We extend this map to a proper map on a partial compactification of the moduli space of such coverings, and prove that the Prym map is generically finite…

Algebraic Geometry · Mathematics 2016-07-13 Herbert Lange , Angela Ortega

We analyze the moduli space of non-flat homogeneous affine connections on surfaces. For Type $\mathcal{A}$ surfaces, we write down complete sets of invariants that determine the local isomorphism type depending on the rank of the Ricci…

Differential Geometry · Mathematics 2016-04-25 Miguel Brozos-Vázquez , Eduardo García-Río , P. Gilkey

In this paper, we investigate automorphisms of compact K\"ahler manifolds with different levels of topological triviality. In particular, we provide several examples of smooth complex projective surfaces X whose groups of…

Algebraic Geometry · Mathematics 2021-04-16 Fabrizio Catanese , Wenfei Liu

The geometric and algebraic properties of smooth projective varieties with 1-regular structure sheaf are well understood, and the complete classification of these varieties is a classical result. The aim of this paper is to study the next…

Algebraic Geometry · Mathematics 2018-03-06 Sijong Kwak , Jinhyung Park

For any given natural $d\ge 1$ we provide examples of rational self-maps of complex projective plane $\pp^2$ of degree $d$ without (holomorphic) fixed points. This makes a contrast with the situation in one dimension. We also prove that the…

Complex Variables · Mathematics 2010-03-01 Sergey Ivashkovich