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Related papers: Gr\"obner geometry for regular nilpotent Hessenber…

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Let $k$ be a commutative ring and $S=k[x_0, \ldots, x_n]$ be a polynomial ring over $k$ with a monomial order. For any monomial ideal $J$, there exists an affine $k$-scheme of finite type, called Gr\"obner scheme, which parameterizes all…

Algebraic Geometry · Mathematics 2019-09-27 Yuta Kambe

A universal Gr\"obner basis of an ideal is the union of all its reduced Gr\"obner bases. It is contained in the Graver basis, the set of all primitive elements. Obtaining an explicit description of either of these sets, or even a sharp…

Commutative Algebra · Mathematics 2007-11-22 Sonja Petrović

Let $H$ be a finite dimensional pointed rank one Hopf algebra of nilpotent type. We first determine all finite dimensional indecomposable $H$-modules up to isomorphism, and then establish the Clebsch-Gordan formulas for the decompositions…

Representation Theory · Mathematics 2013-09-10 Zhihua Wang , Libin Li , Yinhuo Zhang

In this paper, we introduce Schubert decompositions for quiver Grassmannians and investigate example classes of quiver Grassmannians with a Schubert decomposition into affine spaces. The main theorem puts the cells of a Schubert…

Algebraic Geometry · Mathematics 2013-03-29 Oliver Lorscheid

We consider quantum Schubert cells in the quantum grassmannian and give a cell decomposition of the prime spectrum via the Schubert cells. As a consequence, we show that all primes are completely prime in the generic case where the…

Quantum Algebra · Mathematics 2007-08-07 S Launois , T H Lenagan , L Rigal

The representation theory of rational Cherednik algebras of type A at t=0 gives rise, by considering supports, to a natural family of smooth Lagrangian subvarieties of the Calogero-Moser space. The goal of this article is to make precise…

Representation Theory · Mathematics 2013-12-31 Gwyn Bellamy

Regular nilpotent Hessenberg varieties form a family of subvarieties of the flag variety arising in the study of quantum cohomology, geometric representation theory, and numerical analysis. In this paper we construct a paving by affines of…

Algebraic Geometry · Mathematics 2007-06-13 Julianna S. Tymoczko

We construct a canonical isomorphism between the Bethe algebra acting on a multiplicity space of a tensor product of evaluation gl_N[t]-modules and the scheme-theoretic intersection of suitable Schubert varieties. Moreover, we prove that…

Quantum Algebra · Mathematics 2007-11-27 E. Mukhin , V. Tarasov , A. Varchenko

We initiate the study of average intersection theory in real Grassmannians. We define the expected degree $\textrm{edeg} G(k,n)$ of the real Grassmannian $G(k,n)$ as the average number of real $k$-planes meeting nontrivially $k(n-k)$ random…

Algebraic Geometry · Mathematics 2018-01-22 Peter Bürgisser , Antonio Lerario

The Hilbert function of standard graded algebras are well understood by Macaulay's theorem and very little is known in the local case, even if we assume that the local ring is a complete intersection. An extension to the power series ring…

Commutative Algebra · Mathematics 2012-05-25 J. Elias , M. E. Rossi , G. Valla

Let G be a simply-connected simple compact Lie group over the complex numbers. The affine Grassmannian is a projective ind-variety, homotopy-equivalent to the loop space of G and closely analogous to a maximal flag variety of the classical…

Algebraic Geometry · Mathematics 2007-12-19 Sara C. Billey , Stephen A. Mitchell

Using combinatorial properties of symmetric polynomials, we compute explicitly the Soergel modules for some permutations whose corresponding Schubert varieties are rationally smooth. We build from them diagram algebras whose module…

Representation Theory · Mathematics 2013-11-28 Antonio Sartori

We develop numerical homotopy algorithms for solving systems of polynomial equations arising from the classical Schubert calculus. These homotopies are optimal in that generically no paths diverge. For problems defined by hypersurface…

alg-geom · Mathematics 2025-10-20 Birkett Huber , Frank Sottile , Bernd Sturmfels

In this paper we prove a new generic vanishing theorem for $X$ a complete homogeneous variety with respect to an action of a connected algebraic group. Let $A, B_0\subset X$ be locally closed affine subvarieties, and assume that $B_0$ is…

Algebraic Geometry · Mathematics 2023-03-27 Jörg Schürmann , Connor Simpson , Botong Wang

Over a field of characteristic $0$, we construct a minimal set of generators of the defining ideals of closures of nilpotent conjugacy class in the set of $n \times n$ matrices. This modifies a conjecture of Weyman and provides a complete…

Algebraic Geometry · Mathematics 2020-08-10 Hang Huang

In this article we produce Groebner bases for the defining ideal of a monomial curve that corresponds to an almost arithmetic sequence of positive integers, correcting previous work of Sengupta,(2003).

Commutative Algebra · Mathematics 2007-05-23 Ibrahim Al-Ayyoub

We consider the problem of determining Gr\"obner bases of binomial ideals associated with linear error correcting codes. Computation of Gr\"obner bases of linear codes have become a topic of interest to many researchers in coding theory…

Information Theory · Computer Science 2017-07-25 Arunkumar R. Patil , Nitin S. Darkunde

We study Hilbert-Samuel multiplicity for points of Schubert varieties in the complete flag variety, by Groebner degenerations of the Kazhdan-Lusztig ideal. In the covexillary case, we give a positive combinatorial rule for multiplicity by…

Algebraic Geometry · Mathematics 2011-11-08 Li Li , Alexander Yong

Sets of zero-dimensional ideals in the polynomial ring $k[x,y]$ that share the same leading term ideal with respect to a given term ordering are known to be affine spaces called Gr\"obner cells. Conca-Valla and Constantinescu parametrize…

Commutative Algebra · Mathematics 2021-05-05 Roser Homs , Anna-Lena Winz

Inspired by the work of Ulrich and Huneke-Ulrich, we describe a pattern to show that the ideals of certain opposite embedded Schubert varieties defined by this pattern arise by taking residual intersections of two geometrically linked…

Algebraic Geometry · Mathematics 2024-11-21 Sara Angela Filippini , Xianglong Ni , Jacinta Torres , Jerzy Weyman