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We consider a possibility of the existence of intersection homology morphism, which would be associated to a map of analytic varieties. We assume that the map is an inclusion of codimension one. Then the existence of a morphism follows from…

Algebraic Geometry · Mathematics 2007-05-23 Andrzej Weber

We reproduce the quantum cohomology of toric varieties (and of some hypersurfaces in projective spaces) as the cohomology of certain vertex algebras with differential. The deformation technique allows us to compute the cohomology of the…

Algebraic Geometry · Mathematics 2007-05-23 F. Malikov , V. Schechtman

We describe and analyze a numerical algorithm for computing the homology (Betti numbers and torsion coefficients) of semialgebraic sets given by Boolean formulas. The algorithm works in weak exponential time. This means that outside a…

Computational Geometry · Computer Science 2021-10-14 Peter Bürgisser , Felipe Cucker , Josué Tonelli-Cueto

Some projective wonderful models for the complement of a toric arrangement in a n-dimensional algebraic torus T were constructed in [3]. In this paper we describe their integer cohomology rings by generators and relations.

Algebraic Topology · Mathematics 2019-02-13 Corrado De Concini , Giovanni Gaiffi

We show that for a complete complex algebraic variety the pure component of homology coincides with the image of intersection homology. Therefore pure homology is topologically invariant. To obtain slightly more general results we introduce…

Algebraic Geometry · Mathematics 2007-05-23 Andrzej Weber

We characterise and investigate co-Higgs sheaves and associated algebraic and combinatorial invariants on toric varieties. In particular, we compute explicit examples.

Algebraic Geometry · Mathematics 2020-10-20 Klaus Altmann , Frederik Witt

In this paper we survey geometric and arithmetic techniques to study the cohomology of semiprojective hyperkaehler manifolds including toric hyperkaehler varieties, Nakajima quiver varieties and moduli spaces of Higgs bundles on Riemann…

Algebraic Geometry · Mathematics 2013-09-20 Tamas Hausel , Fernando Rodriguez Villegas

We continue the study of engineered complete intersections (ECI) -- an umbrella generality for a number of important objects in combinatoiral and applied algebraic geometry (such as nondegenerate toric complete intersections, critical loci…

Algebraic Geometry · Mathematics 2025-04-23 Alexander Esterov

We reprove and generalize the result that the intersection cohomology groups of a toric variety with coefficient in a nontrivial rank one local system vanish. We prove a similar vanishing result for a certain class of varieties on which a…

Algebraic Geometry · Mathematics 2024-03-13 Yiyu Wang

In this review article, we report on some recent advances on the computational aspects of cohomology intersection numbers of GKZ systems developed in \cite{GM}, \cite{MH}, \cite{MT} and \cite{MT2}. We also discuss the relation between…

Algebraic Geometry · Mathematics 2020-11-19 Saiei-Jaeyeong Matsubara-Heo

We present an algorithm for explicitly computing the number of generators of the stable cohomology algebra of any rationally smooth partial toroidal compactification of ${\mathcal A}_g$, satisfying certain additivity and finiteness…

Algebraic Geometry · Mathematics 2017-02-22 Samuel Grushevsky , Klaus Hulek , Orsola Tommasi

We introduce the notion of a \emph{conic sequence} of a convex polytope. It is a way of building up a polytope starting from a vertex and attaching faces one by one with certain regulations. We apply this to a toric variety to obtain an…

Algebraic Topology · Mathematics 2021-06-09 Seonjeong Park , Jongbaek Song

We associate to each algebraic variety defined over $\mathbb{R}$ a filtered cochain complex, which computes the cohomology with compact supports and $\mathbb{Z}\_2$-coefficients of the set of its real points. This filtered complex is…

Algebraic Geometry · Mathematics 2016-02-01 Thierry Limoges , Fabien Priziac

Let X be a complex smooth quasi-projective variety with a fixed epimorphism $\nu\colon\pi_1(X)\twoheadrightarrow \mathbb{Z}$. In this paper, we consider the asymptotic behaviour of invariants such as Betti numbers with all possible field…

Algebraic Geometry · Mathematics 2025-05-09 Fenglin Li , Yongqiang Liu

We give several algorithms addressing computations of intersections of conjugate subgroups.

Group Theory · Mathematics 2018-11-13 Rita Gitik

We compute the intersection cohomology of the moduli spaces $M_{r,d}$ of semistable vector bundles having rank $r$ and degree $d$ over a curve. We do this by relating the Hodge-Deligne polynomial of the intersection cohomology of $M_{r,d}$…

Algebraic Geometry · Mathematics 2025-04-03 Sergey Mozgovoy , Markus Reineke

In this paper, we give an explicit description of tropical cohomology of smooth algebraic varieties over trivially valued fields. We also construct ``monodromy weight'' spectral sequences for tropical cohomology of geometric strictly…

Algebraic Geometry · Mathematics 2025-07-23 Ryota Mikami

Topological invariants of a dataset, such as the number of holes that survive from one length scale to another (persistent Betti numbers) can be used to analyze and classify data in machine learning applications. We present an improved…

Quantum Physics · Physics 2026-04-15 Sam McArdle , András Gilyén , Mario Berta

We describe the quantum cohomology rings of a class of toric varieties. The description includes, in addition to the (already known) ring presentations, the (new) analogues for toric varieties of the sorts of quantum Giambelli formulas…

Algebraic Geometry · Mathematics 2007-05-23 Andrew Kresch

We introduce a quantitative version of polynomial cohomology for discrete groups and show that it coincides with usual group cohomology when combinatorial filling functions are polynomially bounded. As an application, we show that Betti…

Group Theory · Mathematics 2026-02-11 Antonio López Neumann , Juan Paucar