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Related papers: The divisor class group of a discrete polymatroid

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In this paper, we describe a way to construct cycles which represent the Todd class of a toric variety. Given a lattice with an inner product we assign a rational number m(s) to each rational polyhedral cone s in the lattice, such that for…

Algebraic Geometry · Mathematics 2007-05-23 James Pommersheim , Hugh Thomas

We construct the moduli stack of torsors over the formal punctured disk in characteristic p > 0 for a finite group isomorphic to the semidirect product of a p-group and a tame cyclic group. We prove that the stack is a limit of separated…

Algebraic Geometry · Mathematics 2024-02-27 Fabio Tonini , Takehiko Yasuda

The reduced divisor class group of a normal Cohen--Macaulay graded domain together with its torsion number is introduced. They are studied in detail especially for normal affine semigroup rings.

Commutative Algebra · Mathematics 2023-09-18 Jürgen Herzog , Takayuki Hibi

We compute the Picard group of the moduli stack of smooth curves of genus $g$ for $3\leq g\leq 5$, using methods of equivariant intersection theory. We base our proof on the computation of some relations in the integral Chow ring of certain…

Algebraic Geometry · Mathematics 2020-07-21 Andrea Di Lorenzo

A general problem is to classify the real forms of a complex variety up to isomorphism. This paper introduces the polar group of a real form $X$ of a complex variety $Y$ as a tool to distinguish such real forms. This group is an invariant…

Algebraic Geometry · Mathematics 2018-04-30 Gene Freudenburg

For an affine toric variety X we compute the Poincare series of the multi-index filtration defined by a finite number of monomial divisorial valuations on the ring O_{X,0}. We give an alternative description of the Poincare series as an…

Algebraic Geometry · Mathematics 2007-05-23 Ann Lemahieu

We classify toroidal solenoids defined by non-singular $n\times n$-matrices $A$ with integer coefficients by studying associated first \^Cech cohomology groups. In a previous work, we classified the groups in the case $n=2$ using…

Number Theory · Mathematics 2022-09-30 Maria Sabitova

For a hyperelliptic curve of genus $g$, a divisor in general position of degree $g+1$ is given by polynomial equations. There is an action from an algebraic group on the representations of divisors by polynomials which fixes divisor…

Algebraic Geometry · Mathematics 2007-05-23 Victor Gonzalo Lopez Neumann

We introduce a space of stable meromorphic differentials with poles of prescribed orders and define its tautological cohomology ring. This space, just as the space of holomorphic differentials, is stratified according to the set of…

Algebraic Geometry · Mathematics 2019-06-05 Adrien Sauvaget

The rank of a $d$-dimensional polytope $P$ is defined by $F-(d+1)$, where $F$ denotes the number of facets of $P$. In this paper, We focus on the toric rings of $(0,1)$-polytopes with small rank. We study their normality, the…

Combinatorics · Mathematics 2023-03-24 Koji Matsushita

It has been conjectured that the toric ideal of the base ring of a discrete polymatroid is generated by symmetric exchange binomials. In the present paper, we give several classes of discrete polymatroids which yield toric ideals generated…

Commutative Algebra · Mathematics 2025-07-17 Takayuki Hibi , Seyed Amin Seyed Fakhari

Let $\chi(x)\in \mathbb{Z}[x]$ be a monic polynomial whose roots are distinct integers. We study the ideal class monoid and the ideal class group of the ring $\mathbb{Z}[x]/(\chi(x))$. We obtain formulas for the orders of these objects, and…

Number Theory · Mathematics 2025-12-01 Ruben Hambardzumyan , Mihran Papikian

Toric codes are obtained by evaluating rational functions of a nonsingular toric variety at the algebraic torus. One can extend toric codes to the so called generalized toric codes. This extension consists on evaluating elements of an…

Information Theory · Computer Science 2010-02-25 Diego Ruano

In this paper we use formal group rings to construct an algebraic model of the $T$-equivariant oriented cohomology of smooth toric varieties. Then we compare our model with known results of equivariant cohomology of toric varieties to…

Algebraic Geometry · Mathematics 2015-03-27 Wanshun Wong

We define the notion of the canonical module of a complex. We then consider Serre's conditions for a complex and study their relationship to the local cohomology of the canonical module and its ring of endomorphisms.

Commutative Algebra · Mathematics 2016-03-02 Maryam Akhavin , Eero Hyry

We introduce a cohomology set for groups defined by algebraic difference equations and show that it classifies torsors under the group action. This allows us to compute all torsors for large classes of groups. We also develop some tools for…

Algebraic Geometry · Mathematics 2016-07-26 Annette Bachmayr , Michael Wibmer

Differential modules over a commutative differential ring R which are finitely generated projective as ring modules, with differential homomorphisms, form an additive category, so their isomorphism classes form a monoid. We study the…

Commutative Algebra · Mathematics 2022-03-24 Lourdes Juan , Andy Magid

We explicitly describe the divisor class groups and semidualizing modules for ladder determinantal rings with coefficients in an arbitrary normal domain for arbitrary ladders, not necessarily connected, and all sizes of minors.

Commutative Algebra · Mathematics 2020-01-23 Sean K. Sather-Wagstaff , Tony Se , Sandra Spiroff

We introduce the notion of an arithmetic matroid, whose main example is given by a list of elements of a finitely generated abelian group. In particular we study the representability of its dual, providing an extension of the Gale duality…

Combinatorics · Mathematics 2011-07-26 Michele D'Adderio , Luca Moci

Cycle polytopes of matroids have been introduced in combinatorial optimization as a generalization of important classes of polyhedral objects like cut polytopes and Eulerian subgraph polytopes associated to graphs. Here we start an…

Combinatorics · Mathematics 2021-05-04 Tim Römer , Sara Saeedi Madani