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Two actions of the Hecke algebra of type A on the corresponding polynomial ring are studied. Both are deformations of the natural action of the symmetric group on polynomials, and keep symmetric functions invariant. We give an explicit…

Representation Theory · Mathematics 2007-05-23 Ron M. Adin , Alexander Postnikov , Yuval Roichman

We provide a programmable recursive algorithm for the $\mathbb{S}_n$-representations on the cohomology of the moduli spaces $\overline{\mathcal M}_{0,n}$ of $n$-pointed stable curves of genus 0. As an application, we find explicit inductive…

Algebraic Geometry · Mathematics 2024-08-21 Jinwon Choi , Young-Hoon Kiem , Donggun Lee

In this paper Fourier transform of multivariate orthogonal polynomials on the simplex is presented. A new family of multivariate orthogonal functions is obtained by using the Parseval's identity and several recurrence relations are derived.

Classical Analysis and ODEs · Mathematics 2021-01-12 Esra Güldoğan-Lekesiz , Rabia Aktaş , Iván Area

Given a symplectic cohomology class of degree 1, we define the notion of an equivariant Lagrangian submanifold. The Floer cohomology of equivariant Lagrangian submanifolds has a natural endomorphism, which induces a grading by generalized…

Symplectic Geometry · Mathematics 2012-10-24 Paul Seidel , Jake P. Solomon

In any symmetric monoidal category, the $n$-th (co)equalizer symmetric power of an object $A$ is the (co)equalizer of all the permutations from $A^{\otimes n}$ to itself. If the symmetric monoidal category is $\mathbb{Q}_{\ge 0}$-linear,…

Category Theory · Mathematics 2025-11-26 Jean-Baptiste Vienney

We construct a concrete isomorphism from the permutohedral variety to the regular semisimple Hessenberg variety associated to the Hessenberg function $h_+(i)=i+1$, $1\le i\le n-1$. In the process of defining the isomorphism, we introduce a…

Algebraic Geometry · Mathematics 2022-10-13 Jan-Li Lin

We prove two results on convex subsets of Euclidean spaces invariant under an orthogonal group action. First, we show that invariant spectrahedra admit an equivariant spectrahedral description, i.e., can be described by an equivariant…

Algebraic Geometry · Mathematics 2025-11-05 Renato G. Bettiol , Mario Kummer , Ricardo A. E. Mendes

We introduce a Bredon motivic cohomology theory for smooth schemes defined over a field and equipped with an action by a finite group. These cohomology groups are defined for finite dimensional representations as the hypercohomology of…

Algebraic Geometry · Mathematics 2014-08-12 Jeremiah Heller , Mircea Voineagu , Paul Arne Ostvaer

Let $K$ be a field and let $\mathbb N = \{1,2, \dots \}$. Let $R_n=K[x_{ij} \mid 1\le i\le n, j\in \mathbb N]$ be the ring of polynomials in $x_{ij}$ $(1 \le i \le n, j \in \mathbb N)$ over $K$. Let $S_n = Sym (\{1,2, \ldots, n \})$ and…

Rings and Algebras · Mathematics 2015-09-30 Eudes Antonio da Costa , Alexei Krasilnikov

Let $ (\rho, V) $ be an irreducible representation of the symmetric group $ S_n$ (or the alternating group $ A_n$), and let $ g $ be a permutation on $n$ letters with each of its cycle lengths divides the length of its largest cycle. We…

Representation Theory · Mathematics 2024-12-31 Velmurugan S

Permutation invariant polynomial functions of matrices have previously been studied as the observables in matrix models invariant under $S_N$, the symmetric group of all permutations of $N$ objects. In this paper, the permutation invariant…

High Energy Physics - Theory · Physics 2022-08-24 George Barnes , Adrian Padellaro , Sanjaye Ramgoolam

We present an algorithm that, given finite simplicial sets $X$, $A$, $Y$ with an action of a finite group $G$, computes the set $[X,Y]^A_G$ of homotopy classes of equivariant maps $\ell \colon X \to Y$ extending a given equivariant map $f…

Algebraic Topology · Mathematics 2022-11-28 Marek Filakovský , Lukáš Vokřínek

We prove several results on symplectic varieties with a Hamiltonian action of a reductive group having invariant Lagrangian subvarieties. Our main result states that the images of the moment maps of a Hamiltonian variety and of the…

Symplectic Geometry · Mathematics 2011-09-27 Dmitry A. Timashev , Vladimir S. Zhgoon

We study equivariant embeddings with small boundary of a given homogeneous space $G/H$, where $G$ is a connected, linear algebraic group with trivial Picard group and only trivial characters, and $H \subset G$ is an extension of a connected…

Algebraic Geometry · Mathematics 2007-05-23 Ivan V. Arzhantsev , Juergen Hausen

One of the classical notions of group theory is the notion of the exponent of a group. The exponent of a group is the least common multiple of orders of its elements. In this paper we generalize the notion of exponent to Hopf algebras. We…

Quantum Algebra · Mathematics 2007-05-23 Pavel Etingof , Shlomo Gelaki

By a $B$-regular variety, we mean a smooth projective variety over $C$ admitting an algebraic action of the upper triangular Borel subgroup $B \subset SL_2(C)$ such that the unipotent radical in $B$ has a unique fixed point. A result of M.…

Algebraic Geometry · Mathematics 2008-09-09 James B. Carrell , Kiumars Kaveh

We construct a generalization of the theory of symmetric functions involving functions of commuting and anticommuting (Grassmannian) variables. These new functions, called symmetric functions in superspace, are invariant under the diagonal…

Combinatorics · Mathematics 2007-05-23 P. Desrosiers , L. Lapointe , P. Mathieu

We consider a class of homogeneous manifolds including all semisimple coadjoint orbits. We describe manifolds of that class admitting deformation q uantizations equivariant under the action of $G$ and the corresponding quantum group. We…

Quantum Algebra · Mathematics 2009-11-07 Joseph Donin , Vadim Ostapenko

Let n be a positive integer greater than or equal to 2, and q a complex number, transcendental over Q. In this paper, we give an algorithmic construction of an ordered bijection between the set of H-primes of n \times n quantum matrices and…

Rings and Algebras · Mathematics 2007-05-23 Stéphane Launois

Let R_n be the ring of coinvariants for the diagonal action of the symmetric group S_n. It is known that the character of R_n as a doubly-graded S_n module can be expressed using the Frobenius characteristic map as \nabla e_n, where e_n is…

Combinatorics · Mathematics 2007-05-23 J. Haglund , M. Haiman , N. Loehr , J. B. Remmel , A. Ulyanov