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Two fundamental invariants attached to a projective variety are its classical algebraic degree and its Euclidean Distance degree (ED degree). In this paper, we study the asymptotic behavior of these two degrees of some Segre products and…

Algebraic Geometry · Mathematics 2021-06-18 Giorgio Ottaviani , Luca Sodomaco , Emuanuele Ventura

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

Let $\Sigma$ and $\Sigma'$ be two refinements of a fan $\Sigma_0$ and $f \colon X_{\Sigma} \dashrightarrow X_{\Sigma'}$ be the birational map induced by $X_{\Sigma} \rightarrow X_{\Sigma_0} \leftarrow X_{\Sigma'}$. We show that the graph…

Algebraic Geometry · Mathematics 2025-02-13 Tsung-Chen Chen , Hui-Wen Lin , Sz-Sheng Wang

In this paper, we study divisorial ideals of a Hibi ring which is a toric ring arising from a partially ordered set. We especially characterize the special class of divisorial ideals called conic using the associated partially ordered set.…

Representation Theory · Mathematics 2019-12-10 Akihiro Higashitani , Yusuke Nakajima

We propose an explicit formula for the Segre classes of monomial subschemes of nonsingular varieties, such as schemes defined by monomial ideals in projective space. The Segre class is expressed as a formal integral on a region bounded by…

Algebraic Geometry · Mathematics 2013-07-04 Paolo Aluffi

Let $X \subset Y$ be closed (possibly singular) subschemes of a smooth projective toric variety $T$. We show how to compute the Segre class $s(X,Y)$ as a class in the Chow group of $T$. Building on this, we give effective methods to compute…

Algebraic Geometry · Mathematics 2019-05-31 Corey Harris , Martin Helmer

The goal of this short note is to study the secant varieties of the triple Segre product of type (1,a,b) by means of the standard tools of combinatorial commutative algebra. We reprove and extend to arbitrary characteristic results of…

Commutative Algebra · Mathematics 2021-08-02 Aldo Conca , Emanuela De Negri , Željka Stojanac

We found a necessary and sufficient condition for the existence of the tensor product of modules over a vertex algebra. We defined the notion of vertex bilinear map and we provide two algebraic construction of the tensor product, where one…

Quantum Algebra · Mathematics 2016-09-27 Jose I. Liberati

We classify the orbits of elements of the tensor product spaces ${\mathbb{F}}^2\otimes {\mathbb{F}}^3 \otimes {\mathbb{F}}^3$ for all finite; real; and algebraically closed fields under the action of two natural groups. The result can also…

Combinatorics · Mathematics 2015-02-11 Michel Lavrauw , John Sheekey

In this article we consider the problem of finding generators of the toric ideal associated to a combinatorial object called a staged tree. Our main theorem states that toric ideals of staged trees that are balanced and stratified are…

Commutative Algebra · Mathematics 2021-04-21 Lamprini Ananiadi , Eliana Duarte

Motivated by the study of the secant variety of the Segre-Veronese variety we propose a general framework to analyze properties of the secant varieties of toric embeddings of affine spaces defined by simplicial complexes. We prove that…

Algebraic Geometry · Mathematics 2019-08-27 M. Azeem Khadam , Mateusz Michałek , Piotr Zwiernik

In this paper, we study toric ideals generated by circuits. For toric ideals which have squarefree quadratic initial ideals, a sufficient condition to be generated by circuits is given. In particular, squarefree Veronese subrings, the…

Commutative Algebra · Mathematics 2014-05-15 Hidefumi Ohsugi , Takayuki Hibi

In a previous paper we constructed rank and support variety theories for "quantum elementary abelian groups," that is, tensor products of copies of Taft algebras. In this paper we use both variety theories to classify the thick tensor…

Representation Theory · Mathematics 2015-01-29 Julia Pevtsova , Sarah Witherspoon

We characterize the seminormality of an affine semigroup ring in terms of the dualizing complex, and the normality of a Cohen-Macaulay semigroup ring by the "shape" of the canonical module. We also characterize the seminormality of a toric…

Commutative Algebra · Mathematics 2014-12-09 Kohji Yanagawa

We consider standard graded toric rings $R_{\Delta}$ whose generators correspond to the faces of a simplicial complex $\Delta$. When $R_{\Delta}$ is normal, it is shown that its divisor class group is free. For a flag complex $\Delta$ which…

Commutative Algebra · Mathematics 2023-10-11 Jürgen Herzog , Somayeh Moradi , Ayesha Asloob Qureshi

The content of a polynomial $f(t)$ is the ideal generated by its coefficients. Our aim here is to consider a beautiful formula of Dedekind-Mertens on the content of the product of two polynomials, to explain some of its features from the…

Commutative Algebra · Mathematics 2007-05-23 Alberto Corso , Wolmer V. Vasconcelos , Rafael Villarreal

A description of transitive actions of a semisimple algebraic group G on toric varieties is obtained. Every toric variety admitting such an action lies between a product of punctured affine spaces and a product of projective spaces. The…

Algebraic Geometry · Mathematics 2010-03-30 Ivan V. Arzhantsev , Sergey A. Gaifullin

We prove that the defining ideal of a sufficiently high Veronese subring of a toric algebra admits a quadratic Gr\"obner basis consisting of binomials. More generally, we prove that the defining ideal of a sufficiently high Veronese subring…

Commutative Algebra · Mathematics 2010-11-22 Takafumi Shibuta

The Cox construction presents a toric variety as a quotient of affine space by a torus. The category of coherent sheaves on the corresponding stack thus has an evident description as invariants in a quotient of the category of modules over…

Symplectic Geometry · Mathematics 2021-08-24 Vivek Shende

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