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Related papers: Newton polyhedra and good compactification theorem

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Topologically, compact toric varieties can be constructed as identification spaces: they are quotients of the product of a compact torus and the order complex of the fan. We give a detailed proof of this fact, extend it to the non-compact…

Algebraic Topology · Mathematics 2010-10-25 Matthias Franz

In this paper, we prove that the Todd genus of a compact complex manifold $X$ of complex dimension $n$ with vanishing odd degree cohomology is one if the automorphism group of $X$ contains a compact $n$-dimensional torus $\Tn$ as a…

Algebraic Topology · Mathematics 2014-10-01 Hiroaki Ishida , Mikiya Masuda

We prove that the Newton product of efficient polynomial projectors is still efficient. Various polynomial approximation theorems are established involving Newton product projectors on spaces of holomorphic functions on a neighborhood of a…

Complex Variables · Mathematics 2021-03-24 François Bertrand , Jean-Paul Calvi

We present a simple proof of a precise version of the localization theorem in equivariant cohomology. As an application, we describe the cohomology algebra of any compact symplectic variety with a multiplicity-free action of a compact Lie…

dg-ga · Mathematics 2007-05-23 Michel Brion , Michèle Vergne

A generalized topology in a set $X$ is a collection $\text{Cov}_X$ of families of subsets of $X$ such that the triple $(X,\bigcup \text{Cov}_X,\text{Cov}_X)$ is a generalized topological space in the sense of Delfs and Knebusch. In this…

General Topology · Mathematics 2020-09-09 Artur Piȩkosz , Eliza Wajch

Given a pure, full-dimensional, locally strongly connected polyhedral complex C with convex support, we characterize, by a local codimension-2 condition, polyhedral complexes that coarsen C. The proof of the characterization draws upon a…

Combinatorics · Mathematics 2026-05-15 Nathan Reading

Let $\mathrm G$ be an isotrivial reductive group over a scheme $S$. We construct a smooth projective $S$-scheme containing $\mathrm G$ as a fiberwise-dense open subscheme equipped with left and right actions of $\mathrm G$ which extend the…

Algebraic Geometry · Mathematics 2026-02-18 Ayan Nath

For a complex variety with a torus action we propose a new method of computing Chern-Schwartz-MacPherson classes. The method does not apply resolution of singularities. It is based on Localization Theorem in equivariant cohomology.

Algebraic Geometry · Mathematics 2012-06-07 Andrzej Weber

This paper surveys the theory of compactness of the d-bar-Neumann problem. It also contains several results which improve upon what was previously known.

Complex Variables · Mathematics 2007-05-23 Siqi Fu , Emil J. Straube

We prove a combinatorial version of Thom's Isotopy Lemma for projection maps applied to any complex or real toric variety. Our results are constructive and give rise to a method for associating the Whitney strata of the projection to the…

Algebraic Geometry · Mathematics 2024-08-20 Boulos El Hilany , Martin Helmer , Elias Tsigaridas

We describe a canonical compactification of a polyhedral complex in Euclidean space. When the recession cones of the polyhedral complex form a fan, the compactified polyhedral complex is a subspace of a tropical toric variety. In this case,…

Algebraic Geometry · Mathematics 2020-12-23 Lars Kastner , Kristin Shaw , Anna-Lena Winz

We point out that the remarkable Knutson and Tao Saturation Theorem and polynomial time algorithms for LP have together an important and immediate consequence in Geometric Complexity Theory. The problem of deciding positivity of…

Computational Complexity · Computer Science 2007-05-23 Ketan D. Mulmuley , Milind Sohoni

We associate to any convenient nondegenerate Laurent polynomial on the complex torus (C^*)^n a canonical Frobenius-Saito structure on the base space of its universal unfolding. According to the method of K. Saito (primitive forms) and of M.…

Algebraic Geometry · Mathematics 2011-01-04 Antoine Douai , Claude Sabbah

The paper concerns a compactification of the isospectral varieties of nilpotent Toda lattices for real split simple Lie algebras. The compactification is obtained by taking the closure of unipotent group orbits in the flag manifolds. The…

Algebraic Geometry · Mathematics 2007-05-23 Luis Casian , Yuji Kodama

Let $f:\mathbb{C}^2 \to \mathbb{C}$ be a polynomial map. Let $\mathbb{C}^2 \subset X$ be a compactification of $\mathbb{C}^2$ where $X$ is a smooth rational compact surface and such that there exists a morphism of varieties $\Phi :X\to…

Algebraic Geometry · Mathematics 2019-04-25 Pierrette Cassou-Nogues , Daniel Daigle

We establish a natural and geometric 1-1 correspondence between projective toric varieties of dimension $n$ and horofunction compactifications of $\mathbb{R}^n$ with respect to rational polyhedral norms. For this purpose, we explain a…

Metric Geometry · Mathematics 2017-05-23 Lizhen Ji , Anna-Sofie Schilling

We show that a natural complexification and a mild generalization of the idea of completeness guarantee geodesic completeness of Clifton-Pohl torus; we explicitely compute all of its geodesics.

Complex Variables · Mathematics 2008-06-16 Claudio Meneghini

The purpose of this paper is to investigate order of contact on real hypersurfaces in ${\mathbb C}^n$ by using Newton polyhedra which are important notion in the study of singularity theory. To be more precise, an equivalence condition for…

Complex Variables · Mathematics 2022-05-11 Joe Kamimoto

For $T$ a compact torus and $E_T^*$ a generalized $T$-equivariant cohomology theory, we provide a systematic framework for computing $E_T^*$ in the context of equivariantly stratified smooth complex projective varieties. This allows us to…

Algebraic Topology · Mathematics 2019-08-15 Peter Crooks , Tyler Holden

Let $T$ be a compact torus. We prove that, up to equivariant rational equivalence, the category of $T$-simply connected, $T$-finite type $T$-spaces with finitely many isotropy types is completely described by certain finite systems of…

Algebraic Topology · Mathematics 2021-06-02 Leopold Zoller