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The Hard Lefschetz theorem for intersection cohomology of nonrational polytopes was recently proved by K. Karu [Ka]. This theorem implies the conjecture of R. Stanley on the unimodularity of the generalized $h$-vector. In this paper we…

Algebraic Geometry · Mathematics 2007-05-23 P. Bressler , V. A. Lunts

This thesis develops the theory of sheaves and cosheaves with an eye towards applications in science and engineering. To provide a theory that is computable, we focus on a combinatorial version of sheaves and cosheaves called cellular…

Algebraic Topology · Mathematics 2014-12-18 Justin Curry

In a previous article, we proved tight lower bounds for the coefficients of the generalized $h$-vector of a centrally symmetric rational polytope using intersection cohomology of the associated projective toric variety. Here we present a…

Algebraic Geometry · Mathematics 2007-05-23 Annette A'Campo-Neuen

We introduce the notion of a quasicoherent sheaf on a complex noncommutative two-torus $T$ as an ind-object in the category of holomorphic vector bundles on $T$. Extending the results of math.QA/0211262 and math.QA/0308136 we prove that the…

Quantum Algebra · Mathematics 2007-05-23 Alexander Polishchuk

We give several characterizations of stable intersections of tropical cycles and establish their fundamental properties. We prove that the stable intersection of two tropical varieties is the tropicalization of the intersection of the…

Algebraic Geometry · Mathematics 2016-08-12 Anders Jensen , Josephine Yu

Intersection cohomology is a way to enhance classical cohomology, allowing us to use a famous result called Poincar\'e duality on a large class of spaces known as stratified pseudomanifolds. There is a theoretically powerful way to arrive…

Algebraic Topology · Mathematics 2022-12-08 Sebastian Cea

Toric varieties are a special class of rational varieties defined by equations of the form {\it monomial = monomial}. For a good brief survey of the history and role of toric varieties see [10]. Any toric variety $X$ contains a cover by…

alg-geom · Mathematics 2008-02-03 Frank DeMeyer , Tim Ford , Rick Miranda

We say that a tropical fan is homologically smooth if each of its open subsets verify tropical Poincare duality. A tropical homology manifold is a tropical variety that is locally modelled by open subsets of homologically smooth tropical…

Algebraic Geometry · Mathematics 2024-05-10 Omid Amini , Matthieu Piquerez

In a series of papers the authors introduced the so-called blown-up intersection cochains. These cochains are suitable to study products and cohomology operations of intersection cohomology of stratified spaces. The aim of this paper is to…

Algebraic Topology · Mathematics 2020-09-22 David Chataur , Martintxo Saralegi-Aranguren , Daniel Tanré

In this article we study the equivariant elliptic cohomology of complex toric varieties. We prove a partial reconstruction theorem showing that equivariant elliptic cohomology encodes considerable non-trivial information on the equivariant…

Algebraic Geometry · Mathematics 2022-10-21 Sarah Scherotzke , Nicolo Sibilla

We study the Hartogs extension phenomenon in non-compact toric varieties and its relation to the first cohomology group with compact support. We show that a toric variety admits this phenomenon if at least one connected component of the fan…

Complex Variables · Mathematics 2021-08-17 Sergey Feklistov , Alexey Shchuplev

We generalize classical results about the topology of toric varieties to the case of projective Q-factorial T-varieties of complexity one using the language of divisorial fans. We describe the Hodge-Deligne polynomial in the smooth case,…

Algebraic Geometry · Mathematics 2017-12-07 Antonio Laface , Alvaro Liendo , Joaquín Moraga

We study Gorenstein categories. We show that such a category has Tate cohomological functors and Avramov-Martsinkovsky exact sequences connecting the Gorenstein relative, the absolute and the Tate cohomological functors. We show that such a…

Category Theory · Mathematics 2007-11-09 Edgar Enochs , Sergio Estrada , J. R. Garcia-Rozas

Toric prevarieties are non-separated analogues of toric varieties. Perling \cite{Perling_equivariant_sheaves_tor_var} provided a combinatorial description of equivariant quasicoherent sheaves on toric varieties, extending earlier ideas of…

Algebraic Geometry · Mathematics 2026-05-05 Jyoti Dasgupta , Kartik Roy

We develop a theory of quasicoherent sheaves on dagger analytic varieties based on Ind-Banach spaces. We show that they satisfy descent in the analytic topology. We define compactly supported pushforwards and produce an adjunction $f_!…

Algebraic Geometry · Mathematics 2025-02-20 Arun Soor

We generalize Givental's Theorem for complete intersections in smooth toric varieties in the Fano case. In particular, we find Gromov--Witten invariants of Fano varieties of dimension $\geq 3$, which are complete intersections in weighted…

Algebraic Geometry · Mathematics 2018-08-07 Victor Przyjalkowski

Let $X$ be a complete toric variety. We give a criterion to decide whether $X$ decomposes as a product of complete toric varieties by analyzing the $1$-skeleton of its fan. More precisely, we prove that any direct-sum decomposition of the…

Algebraic Geometry · Mathematics 2026-01-30 Gabriel Barría Galland

We study global primary decompositions in the category of sheaves on a scheme which are equivariant under the action of an algebraic group. We show that equivariant primary decompositions exist if the group is connected. As main application…

Algebraic Geometry · Mathematics 2012-01-30 Markus Perling , Guenther Trautmann

Given a proper toric variety and a line bundle on it, we describe the morphism on singular cohomology given by the cup product with the Chern class of that line bundle in terms of the data of the associated fan. Using that, we relate the…

Algebraic Geometry · Mathematics 2025-06-29 Hyunsuk Kim , Sridhar Venkatesh

The space of torus translations and degenerations of a projective toric variety forms a toric variety associated to the secondary fan of the integer points in the polytope corresponding to the toric variety. This is used to identify a…

Algebraic Geometry · Mathematics 2020-12-22 Ata Pir , Frank Sottile
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