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Related papers: The Nash Conjecture for Nonprojective Threefolds

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Let $X$ be a connected compact complex manifold admitting a finite surjective map $A \to X$ from a complex torus $A.$ We prove that up to finite \'etale cover, $X$ is a product of projective spaces and a torus.

Algebraic Geometry · Mathematics 2008-02-25 Jean-Pierre Demailly , Jun-Muk Hwang , Thomas Peternell

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

Y. Benoist proved that if a closed three-manifold M admits an indecomposable convex real projective structure, then M is topologically the union along tori and Klein bottles of finitely many sub-manifolds each of which admits a complete…

Geometric Topology · Mathematics 2018-03-28 Samuel A. Ballas , Jeffrey Danciger , Gye-Seon Lee

We consider all complex projective manifolds X that satisfy at least one of the following three conditions: 1. There exists a pair $(C ,\varphi)$, where $C$ is a compact connected Riemann surface and $\varphi : C\to X$ a holomorphic map,…

Algebraic Geometry · Mathematics 2009-01-28 Indranil Biswas

We establish a conjecture of Mumford characterizing rationally connected complex projective manifolds in several cases.

Algebraic Geometry · Mathematics 2017-05-05 Vladimir Lazić , Thomas Peternell

This is the third of a series of papers studying real algebraic threefolds, but the methods are mostly independent from the previous two. Let $f:X\to S$ be a map of a smooth projective real algebraic 3-fold to a surface $S$ whose general…

Algebraic Geometry · Mathematics 2007-05-23 János Kollár

We use convex decomposition theory to (1) reprove the existence of a universally tight contact structure on every irreducible 3-manifold with nonempty boundary, and (2) prove that every toroidal 3-manifold carries infinitely many…

Geometric Topology · Mathematics 2007-05-23 Ko Honda , William H. Kazez , Gordana Matic

We prove that every continuous mapping from a separable infinite-dimensional Hilbert space $X$ into $\mathbb{R}^{m}$ can be uniformly approximated by $C^\infty$ smooth mappings {\em with no critical points}. This kind of result can be…

Differential Geometry · Mathematics 2007-05-23 Daniel Azagra , Manuel Cepedello Boiso

Any smooth projective curve embeds into $\mathbb{P}^3$. More generally, any curve embeds into a rationally connected variety of dimension at least three. We prove conversely that if every curve embeds in a threefold $X$, then $X$ is…

Algebraic Geometry · Mathematics 2024-10-15 Sixuan Lou

This is the second of a series of papers studying real algebraic threefolds using the minimal model program. The main result is the following. Let $X$ be a smooth projective real algebraic 3-fold. Assume that the set of real points is an…

alg-geom · Mathematics 2007-05-23 János Kollár

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

We show that a smooth complex projective threefold admits a holomorphic one-form without zeros if and only if the underlying real 6-manifold fibres smoothly over the circle, and we give a complete classification of all threefolds with that…

Algebraic Geometry · Mathematics 2021-03-10 Feng Hao , Stefan Schreieder

If $X$ is a closed $2n$-dimensional aspherical manifold, i.e., the universal cover of $X$ is contractible, then the Chern-Hopf-Thurston conjecture predicts that $(-1)^n\chi(X)\geq 0$. We prove this conjecture when $X$ is a complex…

Algebraic Geometry · Mathematics 2024-09-30 Ya Deng , Botong Wang

Every real algebraic variety is isomorphic to the set of totally mixed Nash equilibria of some three-person game, and also to the set of totally mixed Nash equilibria of an $N$-person game in which each player has two pure strategies. From…

Algebraic Geometry · Mathematics 2007-05-23 Ruchira S. Datta

We prove that the degree of a nonconstant morphism from a smooth projective 3-fold $X$ with N\'{e}ron-Severi group ${\bf Z}$ to a smooth 3-dimensional quadric is bounded in terms of numerical invariants of $X$. In the special case where $X$…

alg-geom · Mathematics 2008-02-03 Carmen Schuhmann

We show that the dynamics of automorphisms on all projective complex manifolds X (of dimension 3, or of any dimension but assuming the Good Minimal Model Program or Mori's Program) are canonically built up from the dynamics on just three…

Algebraic Geometry · Mathematics 2018-09-24 De-Qi Zhang

It is well known that a three dimensional (closed, connected and compact) manifold is obtained by identifying boundary faces from a polyhedron P. The study of (\partial P)/~, the boundary \partial P with the polygonal faces identified in…

General Mathematics · Mathematics 2007-05-23 Sergey Nikitin

We prove that a holomorphic projective connection on a complex projective threefold is either flat, or it is a translation invariant holomorphic projective connection on an abelian threefold. In the second case, a generic translation…

Differential Geometry · Mathematics 2023-04-25 Indranil Biswas , Sorin Dumitrescu

We prove a relative version over $\mathbb{Q}$ of Nash-Tognoli theorem, that is: Let $M$ be a compact smooth manifold with closed smooth submanifolds $M_1,\dots,M_\ell$ in general position, then there exists a nonsingular real algebraic set…

Algebraic Geometry · Mathematics 2025-12-08 Enrico Savi

We prove that if the stable foliation and the unstable foliation of an Anosov diffeomorphism on a connected compact manifold are $C^3$, then the diffeomorphism has fixed points. This is a partial positive answer to a Smale conjecture for…

Dynamical Systems · Mathematics 2011-06-14 Tomoo Yokoyama