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A toric variety is called fibered if it can be represented as a total space of fibre bundle over toric base and with toric fiber. Fibered toric varieties form a special case of toric variety bundles. In this note we first give an…

Algebraic Geometry · Mathematics 2023-11-06 Askold Khovanskii , Leonid Monin

Given any polynomial system with fixed monomial term structure, we give explicit formulae for the generic number of roots with specified coordinate vanishing restrictions. For the case of affine space minus an arbitrary union of coordinate…

Algebraic Geometry · Mathematics 2016-09-06 J. Maurice Rojas

Let $\mathcal{E}$ be a locally free sheaf of rank $r$ on a smooth projective surface $S$. The Quot scheme $\mathrm{Quot}^{l}_{S}(\mathcal{E})$ of length $l$ coherent sheaf quotients of $\mathcal{E}$ is a natural higher rank generalization…

Algebraic Geometry · Mathematics 2023-01-02 Samuel Stark

Let G be a complex reductive group and X a projective spherical G-variety. Moreover, assume that the subalgebra A of the cohomology ring H^*(X, R) generated by the Chern classes of line bundles has Poincare duality. We give a description of…

Algebraic Geometry · Mathematics 2012-04-04 Kiumars Kaveh

We present a class of toric varieties $V$ which, over any algebraically closed field of characteristic zero, are defined by codim $V$+1 binomial equations.

Algebraic Geometry · Mathematics 2007-05-23 Margherita Barile

We prove that the atom spectrum, which is a topological space associated to an arbitrary abelian category introduced by Kanda, of the category of finitely presented graded modules over a graded ring $R$ is given as a union of the…

Algebraic Geometry · Mathematics 2020-10-15 Sebastian Posur

We compute the sheaf cohomology with constant $\mathbb{Z}_2$ coefficients of a concrete class of locally profinite sets of independent interest. We introduce $k$-sheer partitions to aid in constructions. It is also shown that questions of…

Logic · Mathematics 2026-04-14 Mark Schachner

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 compute the sheaf homology of the intersection lattice of a hyperplane arrangement with coefficients in the graded exterior sheaf of the natural sheaf. This builds on the results of our previous paper, where this homology was computed…

Algebraic Topology · Mathematics 2023-12-22 Brent Everitt , Paul Turner

The purpose of this paper is to give an explicit formula which allows one to compute the dimension of the cohomology groups of the sheaf $\Omega_{\P}^p(D)$ of p-th differential forms of Zariski twisted by an ample invertible sheaf on a…

Algebraic Geometry · Mathematics 2007-05-23 Evgeny Materov

Let $X_{\Sigma}$ be a smooth complete toric variety defined by a fan $\Sigma$ and let $V=V(I)$ be a subscheme of $X_{\Sigma}$ defined by an ideal $I$ homogeneous with respect to the grading on the total coordinate ring of $X_{\Sigma}$. We…

Algebraic Geometry · Mathematics 2017-11-15 Martin Helmer

In this paper we construct a spectral sequence computing a modified version of morphic cohomology of a toric variety (even when it is singular) in terms of combinatorial data coming from the fan of the toric variety.

Algebraic Geometry · Mathematics 2010-01-19 Abdó Roig-Maranges

We study constraints on the Chern classes of a vector bundle on a singular variety. We use this constraint to study a variety which carries a Hodge cycle that are not a linear combination of Chern classes of vector bundles on it.

Algebraic Geometry · Mathematics 2013-04-02 Donu Arapura , Xi Chen , Su-Jeong Kang

We describe categories of equivariant vector bundles on certain toroidal spherical varieties in linear algebra terms: vector spaces equipped with filtrations, group and Lie algebra actions, and linear maps preserving these structures.

Algebraic Geometry · Mathematics 2009-08-28 Aravind Asok , James Parson

In this paper we study general hyperplane sections of adjoint and coadjoint varieties. We show that these are the only sections of homogeneous varieties such that a maximal torus of the automorphism group of the ambient variety stabilizes…

Algebraic Geometry · Mathematics 2022-07-06 Vladimiro Benedetti , Nicolas Perrin

We find the sharp bounds on $h^0(F)$ for one-dimensional semistable sheaves $F$ on a projective variety $X$ by using the spectrum of semistable sheaves. The result generalizes the Clifford theorem. When $X$ is the projective plane…

Algebraic Geometry · Mathematics 2015-05-29 Jinwon Choi , Kiryong Chung

We express the Segre class of a monomial scheme -- or, more generally, a scheme monomially supported on a set of divisors cutting out complete intersections -- in terms of an integral computed over an associated body in euclidean space. The…

Algebraic Geometry · Mathematics 2021-02-08 Paolo Aluffi

We call a sheaf on an algebraic variety immaculate if it lacks any cohomology including the zero-th one, that is, if the derived version of the global section functor vanishes. Such sheaves are the basic tools when building exceptional…

Algebraic Geometry · Mathematics 2018-08-29 Klaus Altmann , Jarosław Buczyński , Lars Kastner , Anna-Lena Winz

We show that the cohomology of canonical extensions of automorphic vector bundles over toroidal compactifications of Shimura varieties can be computed by relative Lie algebra cohomology of automorphic forms. Our result is inspired by and…

Number Theory · Mathematics 2024-07-31 Jun Su

Let X be a smooth complete complex toric variety such that the boundary is a simple normal crossing divisor, and let E be a holomorphic vector bundle on X. We prove that E admits an equivariant structure if and only if E admits a…

Algebraic Geometry · Mathematics 2013-03-20 I. Biswas , V. Muñoz , J. Sánchez