About
171
Publications
7,326
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,264
Citations
Introduction
Current institution
Additional affiliations
March 2014 - December 2014
Position
- Directeur de Recherches
October 1989 - September 2001
Publications
Publications (171)
Given a smooth genus three curve C , the moduli space of rank two stable vector bundles on C with trivial determinant embeds in ${\mathbb {P}}^8$ as a hypersurface whose singular locus is the Kummer threefold of C ; this hypersurface is the Coble quartic. Gruson, Sam and Weyman realized that this quartic could be constructed from a general skew-sym...
This note is devoted to a special Fano fourfold defined by a four-dimensional space of skew-symmetric forms in five variables. This fourfold appears to be closely related with the classical Segre cubic and its Cremona–Richmond configuration of planes. Among other exceptional properties, it is infinitesimally rigid and has Picard number six. We show...
Given a smooth genus three curve $C$, the moduli space of rank two stable vector bundles on C with trivial determinant embeds in $\mathbb{P}^8$ as a hypersurface whose singular locus is the Kummer threefold of $C$; this hypersurface is the Coble quartic. Gruson, Sam and Weyman realized that this quartic could be constructed from a general skew-symm...
We establish connections between the maximum likelihood degree (ML-degree) for linear concentration models, the algebraic degree of semidefinite programming (SDP), and Schubert calculus for complete quadrics. We prove a conjecture by Sturmfels and Uhler on the polynomiality of the ML-degree. We also prove a conjecture by Nie, Ranestad and Sturmfels...
We consider the problem of constructing matrices of linear forms of constant rank by focusing on the associated vector bundles on projective spaces. Important examples are given by the classical Steiner bundles, as well as some special (duals of) syzygy bundles that we call Dr{\'e}zet bundles. Using the classification of globally generated vector b...
We use representation theory to construct spaces of matrices of constant rank. These spaces are parametrized by the natural representation of the general linear group or the symplectic group. We present variants of this idea, with more complicated representations, and others with the orthogonal group. Our spaces of matrices correspond to vector bun...
This note is devoted to a special Fano fourfold defined by a four-dimensional space of skew-symmetric forms in five variables. This fourfold appears to be closely related with the classical Segre cubic and its Cremona-Richmond configuration of planes. Among other exceptional properties, it is infinitesimally rigid and has Picard number six. We show...
Given a general K3 surface $S$ of degree $18$, lattice theoretic considerations allow to predict the existence of an anti-symplectic birational involution of the Hilbert cube $S^{[3]}$. We describe this involution in terms of the Mukai model of $S$, with the help of the famous transitive action of the exceptional group $G_2(\mathbb{R})$ on the six-...
It was shown in Ferapontov et al. (Lett Math Phys 108(6):1525–1550, 2018) that the classification of n-component systems of conservation laws possessing a third-order Hamiltonian structure reduces to the following algebraic problem: classify n-planes H in ∧2(Vn+2) such that the induced map Sym2H⟶∧4Vn+2 has 1-dimensional kernel generated by a non-de...
Given a smooth hyperplane section H of a rational homogeneous space G/P with Picard number one, we address the question whether it is always possible to lift an automorphism of H to the Lie group G, or more precisely to Aut(G/P). Using linear spaces and quadrics in H, we show that the answer is positive up to a few well understood exceptions relate...
The projective variety of Lie algebra structures on a 4-dimensional vector space has four irreducible components of dimension 11. We compute their prime ideals in the polynomial ring in 24 variables. By listing their degrees and Hilbert polynomials, we correct an earlier publication and we answer a 1987 question by Kirillov and Neretin.
Tevelev has given a remarkable explicit formula for the discriminant of a complex simple Lie algebra, which can be defined as the equation of the dual hypersurface of the minimal nilpotent orbit, or of the so-called adjoint variety. In this paper we extend this formula to the setting of graded Lie algebras, and express the equation of the correspon...
Mukai varieties are Fano varieties of Picard number one and coindex three. In genus seven to ten they are linear sections of some special homogeneous varieties. We describe the generic automorphism groups of these varieties. When they are expected to be trivial for dimensional reasons, we show they are indeed trivial, up to three interesting and un...
We work out details of the extrinsic geometry for two Hilbert schemes of some contemporary interest: the Hilbert scheme Hilb2ℙ2 of two points on ℙ2 and the dense open set parametrizing non-planar clusters in the punctual Hilbert scheme Hilb04(A3) of clusters of length four on A3 with support at the origin. We find explicit equations in projective,...
We produce a list of 64 families of Fano fourfolds of K3 type, extracted from our database of at least 634 Fano fourfolds constructed as zero loci of general global sections of completely reducible homogeneous vector bundles on products of flag manifolds. We study the geometry of these Fano fourfolds in some detail, and we find the origin of their...
Given a smooth hyperplane section $H$ of a rational homogeneous space $G/P$ with Picard number one, we address the question whether it is always possible to lift an automorphism of $H$ to the Lie group $G$, or more precisely to Aut$(G/P)$. Using linear spaces and quadrics in $H$, we show that the answer is positive up to a few well understood excep...
We prove a conjecture of Sturmfels, Timme and Zwiernik on the ML-degrees of linear covariance models in algebraic statistics. As in our previous works on linear concentration models, the proof ultimately relies on the computation of certain intersection numbers on the varieties of complete quadrics.
We describe a remarkable rank 14 14 matrix factorization of the octic S p i n 14 \mathrm {Spin}_{14} -invariant polynomial on either of its half-spin representations. We observe that this representation can be, in a suitable sense, identified with a tensor product of two octonion algebras. Moreover the matrix factorisation can be deduced from a par...
Mukai varieties are Fano varieties of Picard number one and coindex three. In genus seven to ten they are linear sections of some special homogeneous varieties. We describe the generic automorphism groups of these varieties. When they are expected to be trivial for dimensional reasons, we show they are indeed trivial, up to three interesting and un...
We work out details of the extrinsic geometry for two Hilbert schemes of some contemporary interest: the Hilbert scheme of two points on the projective plane and the dense open set parametrizing non-planar clusters in the punctual Hilbert scheme of clusters of length four on affine three-space with support at the origin. We find explicit equations...
The Coble cubics were discovered more than a century ago in connection with genus two Riemann surfaces and theta functions. They have attracted renewed interest ever since. Recently, they were reinterpreted in terms of alternating trivectors in nine variables. Exploring this relation further, we show how the Hilbert scheme of pairs of points on an...
We present geometric realizations of horospherical two-orbit varieties, by showing that their blow-up along the unique closed-invariant orbit is the zero locus of a general section of a homogeneous vector bundle over some auxiliary variety. As an application, we compute the cohomology ring of the $G_2$-variety, including its quantum version. We als...
We establish connections between: the maximum likelihood degree (ML-degree) for linear concentration models, the algebraic degree of semidefinite programming (SDP), and Schubert calculus for complete quadrics. We prove a conjecture by Sturmfels and Uhler on the polynomiality of the ML-degree. We also prove a conjecture by Nie, Ranestad and Sturmfel...
This is a survey paper about a selection of results in complex algebraic geometry that appeared in the recent and less recent litterature, and in which rational homogeneous spaces play a prominent role. This selection is largely arbitrary and mainly reflects the interests of the author.
Complete intersections inside rational homogeneous varieties provide interesting examples of Fano manifolds. For example, if \(X = \cap _{i=1}^r D_i \subset G/P\) is a smooth complete intersection of r ample divisors such that \(K_{G/P}^* \otimes {\mathcal O}_{G/P}(-\sum _i D_i)\) is ample, then X is Fano. We first classify these Fano complete inte...
We study the smooth projective symmetric variety of Picard number one that compactifies the exceptional complex Lie group G2, by describing it in terms of vector bundles on the spinor variety of Spin(14). We call it the double Cayley Grassmannian because quite remarkably, it exhibits very similar properties to those of the Cayley Grassmannian (the...
This is a survey paper about a selection of results in complex algebraic geometry that appeared in the recent and less recent litterature, and in which rational homogeneous spaces play a prominent r{\^o}le. This selection is largely arbitrary and mainly reflects the interests of the author.
We compute the small cohomology ring of the Cayley Grassmannian, that parametrizes four-dimensional subalgebras of the complexified octonions. We show that all the Gromov–Witten invariants in the multiplication table of the Schubert classes are nonnegative and deduce Golyshev’s conjecture 𝒪 holds true for this variety. We also check that the quantu...
Using geometrical correspondences induced by projections and two-steps flag varieties, and a generalization of Orlov's projective bundle theorem, we relate the Hodge structures and derived categories of subvarieties of different Grassmannians. We construct isomorphisms between Calabi-Yau subHodge structures of hyperplane sections of Gr(3,n) and tho...
We suggest a way to associate to each Lie algebra of type G2,D4,F4,E6\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$G_2,D_4,F_4,E_6$$\end{document}, E7,E8\documentclas...
We compute the small cohomology ring of the Cayley Grassmannian, that parametrizes four-dimensional subalgebras of the complexified octonions. We show that all the Gromov-Witten invariants in the multiplication table of the Schubert classes are non negative and deduce Golyshev's conjecture O holds true for this variety. We also check that the quant...
The Coble cubics were discovered more than a century ago in connection with genus two Riemann surfaces and theta functions. They have attracted renewed interest ever since. Recently, they were reinterpreted in terms of alternating trivectors in nine variables. Exploring this relation further, we show how the Hilbert scheme of pairs of points on an...
We describe a remarkable rank fourtenn matrix factorization of the octic Spin(14)-invariant polynomial on either of its half-spin representations. We observe that this representation can be, in a suitable sense, identified with a tensor product of two octonion algebras. Moreover the matrix factorisation can be deduced from a particular Z-grading of...
It was shown in \cite{FPV} that the classification of $n$-component systems of conservation laws possessing a third-order Hamiltonian structure reduces to the following algebraic problem: classify $n$-planes $H$ in $\wedge^2(V_{n+2})$ such that the induced map $Sym^2H\longrightarrow \wedge^4V_{n+2}$ has 1-dimensional kernel generated by a non-degen...
Complete intersections inside rational homogeneous varieties provide interesting examples of Fano manifolds. For example, if $X = \cap_{i=1}^r D_i \subset G/P$ is a general complete intersection of $r$ ample divisors such that $K_{G/P}^* \otimes \mathcal{O}_{G/P}(-\sum_i D_i)$ is ample, then $X$ is Fano. We first classify these Fano complete inters...
We use certain special prehomogeneous representations of algebraic groups in order to construct aCM vector bundles, possibly Ulrich, on certain families of hypersurfaces. Among other results, we show that a general cubic hypersurface of dimension seven admitsan indecomposable Ulrich bundle of rank nine, and that a general cubic fourfold admits an u...
We use certain special prehomogeneous representations of algebraic groups in order to construct aCM vector bundles, possibly Ulrich, on certain families of hypersurfaces. Among other results, we show that a general cubic hypersurface of dimension seven admitsan indecomposable Ulrich bundle of rank nine, and that a general cubic fourfold admits an u...
In [BFMT17] we introduced orbital degeneracy loci as generalizations of degeneracy loci of morphisms between vector bundles. Orbital degeneracy loci can be constructed from any stable subvariety of a representation of an algebraic group. In this paper we show that their canonical bundles can be conveniently controlled in the case where the affine c...
In [BFMT17] we introduced orbital degeneracy loci as generalizations of degeneracy loci of morphisms between vector bundles. Orbital degeneracy loci can be constructed from any stable subvariety of a representation of an algebraic group. In this paper we show that their canonical bundles can be conveniently controlled in the case where the affine c...
Consider the ten-dimensional spinor variety in the projectivization of a
half-spin representation of dimension sixteen. The intersection X of two
general translates of this variety is a smooth Calabi-Yau fivefold, as well as
the intersection Y of their projective duals. We prove that although X and Y
are not birationally equivalent, they are derive...
Consider the ten-dimensional spinor variety in the projectivization of a half-spin representation of dimension sixteen. The intersection X of two general translates of this variety is a smooth Calabi-Yau fivefold, as well as the intersection Y of their projective duals. We prove that although X and Y are not birationally equivalent, they are derive...
Degeneracy loci of morphisms between vector bundles have been used in a wide variety of situations. We introduce a vast generalization of this notion, based on orbit closures of algebraic groups in their linear representations. A preferred class of our orbital degeneracy loci is characterized by a certain crepancy condition on the orbit closure, th...
Degeneracy loci of morphisms between vector bundles have been used in a wide variety of situations. We introduce a vast generalization of this notion, based on orbit closures of algebraic groups in their linear representations. A preferred class of our orbital degeneracy loci is characterized by a certain crepancy condition on the orbit closure, th...
We suggest a way to associate to each Lie algebra of type G2, D4, F4, E6, E7, E8 a family of polarized hyperkahler fourfolds, constructed as parametrizing certain families of cycles of hyperplane sections of certain homogeneous or quasi-homogeneous varieties. These cycles are modeled on the Legendrian varieties studied by Freudenthal in his geometr...
We study the projective variety CG parametrizing four dimensional subalgebras of the complex octonions, which we call the Cayley Grass-mannian. We prove that it is a spherical G2-variety with only three orbits that we describe explicitely. Its cohomology ring has a basis of Schubert type classes and we determine the intersection product completely.
We study the projective variety CG parametrizing four dimensional subalgebras of the complex octonions, which we call the Cayley Grass-mannian. We prove that it is a spherical G2-variety with only three orbits that we describe explicitely. Its cohomology ring has a basis of Schubert type classes and we determine the intersection product completely.
Lie algebras of dimension $n$ are defined by their structure constants ,
which can be seen as sets of $N = n^2 (n -- 1)/2$ scalars (if we take into
account the skew-symmetry condition) to which the Jacobi identity imposes
certain quadratic conditions. Up to rescaling, we can consider such a set as a
point in the projective space $P^{N--1}$. Suppose...
We introduce and we study a class of odd dimensional compact complex manifolds whose Hodge structure in middle dimension looks like that of a Calabi-Yau threefold. We construct several series of interesting examples from rational homogeneous spaces with special properties.
K{\"u}chle classified the Fano fourfolds that can be obtained as zero loci of
global sections of homogeneous vector bundles on Grassmannians. Surprisingly,
his classification exhibits two families of fourfolds with the same discrete
invariants. Kuznetsov asked whether these two types of fourfolds are
deformation equivalent. We show that the answer...
K{\"u}chle classified the Fano fourfolds that can be obtained as zero loci of global sections of homogeneous vector bundles on Grassmannians. Surprisingly, his classification exhibits two families of fourfolds with the same discrete invariants. Kuznetsov asked whether these two types of fourfolds are deformation equivalent. We show that the answer...
Contemporary research in algebraic geometry is the focus of this collection, which presents articles on modern aspects of the subject. The list of topics covered is a roll-call of some of the most important and active themes in this thriving area of mathematics: the reader will find articles on birational geometry, vanishing theorems, complex geome...
Kronecker coefficients encode the tensor products of complex irreducible
representations of symmetric groups. Their stability properties have been
considered recently by several authors (Vallejo, Pak and Panova, Stembridge).
We describe a geometric method, based on Schur-Weyl duality, that allows to
produce huge series of instances of this phenomen...
We give a short proof of Weintraub’s conjecture (Weintraub J Algebra 129:103–114, 1990), first proved in Bürgisser et al. (J Algebra 328:322–329, 2011), by constructing explicit highest weight vectors in the plethysms S
p
( ∧ 2q
W).
We study the geometry of the secant and tangential variety of a cominuscule
and minuscule variety, e.g. a Grassmannian or a spinor variety. Using methods
inspired by statistics we provide an explicit local isomorphism with a product
of an affine space with a variety which is the Zariski closure of the image of
a map defined by generalized determina...
Mukai proved that most prime Fano fourfolds of degree 10 and index 2 are
contained in a Grassmannian G(2,5). They are all unirational and some are
rational, as remarked by Roth in 1949. We show that their middle cohomology is
of K3 type and that their period map is dominant, with smooth 4-dimensional
fibers, onto a 20-dimensional bounded symmetric...
These notes are intended as an introduction to the theory of prehomogeneous spaces, under the perspective of projective geometry. This is motivated by the fact that in the classification of irreducible prehomogeneous spaces (up to castling transforms) that was obtained by Sato and Kimura, most cases are of parabolic type. This means that they are r...
We determine set-theoretic defining equations for the variety of hypersurfaces of degree d in an N-dimensional complex vector space that have dual variety of dimension at most k. We apply these equations to the Mulmuley-Sohoni variety, the GL_{n^2} orbit closure of the determinant, showing it is an irreducible component of the variety of hypersurfa...
We give a short proof of Weintraub's conjecture by constructing explicit
highest weight vectors in the symmetric power of an even exterior power.
We find a full strongly exceptional collection for the Cayley plane OP2, the
simplest rational homogeneous space of the exceptional group E6. This
collection, closely related to the one given by the second author in [J.
Algebra, 330:177-187, 2011], consists of 27 vector bundles which are
homogeneous for the group E6, and is a Lefschetz collection w...
We prove that the deformations of a smooth complex Fano threefold X with Picard number 1, index 1, and degree 10, are unobstructed. The differential of the period map has two-dimensional kernel. We construct two two-dimensional components of the fiber of the period map through X: one is isomorphic to the variety of conics in X, modulo an involution...
We consider the problem of constructing triangulations of projective planes
over Hurwitz algebras with minimal numbers of vertices. We observe that the
numbers of faces of each dimension must be equal to the dimensions of certain
representations of the automorphism groups of the corresponding Severi
varieties. We construct a complex involving these...
We prove that the geometric Satake correspondence admits quantum corrections
for minuscule Grassmannians of Dynkin types $A$ and $D$. We find, as a
corollary, that the quantum connection of a spinor variety $OG(n,2n)$ can be
obtained as the half-spinorial representation of that of the quadric
$Q_{2n-2}$. We view the (quantum) cohomology of these Gr...
Cubic sevenfolds are examples of Fano manifolds of Calabi-Yau type. We study
them in relation with the Cartan cubic, the $E_6$-invariant cubic in
$\PP^{26}$. We show that a generic cubic sevenfold $X$ can be described as a
linear section of the Cartan cubic, in finitely many ways. To each such "Cartan
representation" we associate a rank nine vector...
We introduce and we study a class of odd dimensional compact complex
manifolds whose Hodge structure in middle dimension looks like that of a
Calabi-Yau threefold. We construct several series of interesting examples from
rational homogeneous spaces with special properties.
Cubic sevenfolds are examples of Fano manifolds of Calabi-Yau type. We study them in relation with the Cartan cubic, the $E_6$-invariant cubic in $\PP^{26}$. We show that a generic cubic sevenfold $X$ can be described as a linear section of the Cartan cubic, in finitely many ways. To each such ''Cartan representation'' we associate a rank nine vect...
We discuss the geometry of orbit closures and the asymptotic behavior of Kronecker coefficients in the context of the Geometric Complexity Theory program to prove a variant of Valiant's algebraic analog of the P not equal to NP conjecture. We also describe the precise separation of complexity classes that their program proposes to demonstrate.
We prove explicit formulas for Chern classes of tensor products of virtual vector bundles, whose coefficients are given by certain universal polynomials in the ranks of the two bundles.
It is well known that the Fano scheme of lines on a cubic 4-fold is a symplectic variety. We generalize this fact by constructing a closed (2n - 4)-form on the Fano scheme of lines on a (2n - 2)-dimensional hypersurface Yn of degree n. We provide several definitions of this form — via the Abel–Jacobi map, via Hochschild homology, and via the linkag...
We study the geometry and the period map of nodal complex prime Fano
threefolds with index 1 and degree 10. We show that these threefolds are
birationally isomorphic to Verra solids (hypersurfaces of bidegree $(2,2)$ in $
\P^2\times \P^2$). Using Verra's results on the period map for these solids and
on the Prym map for double \'etale covers of pla...
We determine set-theoretic defining equations for the variety of hypersurfaces of degree d in an N-dimensional complex vector space that have dual variety of dimension at most k. We apply these equations to the Mulmuley-Sohoni variety, the GL_{n^2} orbit closure of the determinant, showing it is an irreducible component of the variety of hypersurfa...
We study the secant variety of the spinor variety, focusing on its equations of degree three and four. We show that in type Dn, cubic equations exist if and only if n ≥ 9. In general the ideal has generators in degrees at least three and four. Finally we observe that the other Freudenthal varieties exhibit strikingly similar behaviors.
We show that rectangular Kronecker coefficients stabilize when the lengths of the sides of the rectangle grow, and we give an explicit formula for the limit values in terms of invariants of $\fsl_n$.
We describe a maximal exceptional collection on the Cayley plane, the minimal homogeneous projective variety of $E_6$. This collection consists in a sequence of 27 irreducible homogeneous bundles.
O'Grady showed that certain special sextics in $\mathbb{P}^5$ called EPW sextics admit smooth double covers with a holomorphic symplectic structure. We propose another perspective on these symplectic manifolds, by showing that they can be constructed from the Hilbert schemes of conics on Fano fourfolds of degree ten. As applications, we construct f...
We discuss the geometry of orbit closures and the asymptotic behavior of
Kronecker coefficients in the context of the Geometric Complexity Theory
program to prove a variant of Valiant's algebraic analog of the P not equal to
NP conjecture. We also describe the precise separation of complexity classes
that their program proposes to demonstrate.
We describe a maximal exceptional collection on the Cayley plane, the minimal homogeneous projective variety of E6. This collection consists in a sequence of 27 irreducible homogeneous bundles.
We show that a refined version of Golyshev's canonical strip hypothesis does hold for the Hilbert polynomials of complete intersections in rational homogeneous spaces.
We study the secant variety of the spinor variety, focusing on its equations of degree three and four. We show that in type $D_n$, cubic equations exist if and only if $n\ge 9$. In general the ideal has generators in degrees at least three and four. Finally we observe that the other Freudenthal varieties exhibit strikingly similar behaviors.
Starting from a cubic form, we give a general construction of a quasi-complete homogeneous manifold endowed with a natural contact structure. We show that it can be compactified into a projective contact manifold if and only if the cubic form is the determinant of a simple cubic Jordan algebra.
We study, after Logachev, the geometry of smooth complex Fano threefolds X X with Picard number 1 1 , index 1 1 , and degree 10 10 , and their period map to the moduli space of 10-dimensional principally polarized abelian varieties. We prove that a general such X X has no nontrival automorphisms. By a simple deformation argument and a parameter cou...
We prove an explicit formula for the tensor product with itself of an irreducible complex representation of the symmetric group defined by a rectangle of height two. We also describe part of the decomposition for the tensor product of representations defined by rectangles of heights two and four. Our results are deduced, through Schur-Weyl duality,...
It is well known that the Fano scheme of lines on a cubic 4-fold is a symplectic variety. We generalize this fact by constructing a closed p-form with p=2n-4 on the Fano scheme of lines on a (2n-2)-dimensional hypersurface Y of degree n. We provide several definitions of this form - via the Abel-Jacobi map, via Hochschild homology, and via the link...
We study the quantum cohomology of (co)minuscule homogeneous varieties under a unified perspective. We show that three points
Gromov–Witten invariants can always be interpreted as classical intersection numbers on auxiliary varieties. Our main combinatorial
tools are certain quivers, in terms of which we obtain a quantum Chevalley formula and a hig...
Let $X$ be a rational homogeneous space and let $QH^*(X)_{loc}^\times$ be the group of invertible elements in the small quantum cohomology ring of $X$ localised in the quantum parameters. We generalise results of arXiv:math/0609796 and realise explicitly the map $\pi_1({\rm Aut}(X))\to QH^*(X)_{loc}^\times$ described in arXiv:dg-ga/9511011. We even...
For a general K3 surface S of genus g, with 2 ≤ g ≤ 10, we prove that the intermediate Jacobians of the family of prime Fano threefolds of genus g containing S as a hyperplane section, form generically an algebraic completely integrable Hamiltonian system.
We prove that the quantum cohomology ring of any minuscule or cominuscule homogeneous space, specialized at q=1, is semisimple. This implies that complex conjugation defines an algebra automorphism of the quantum cohomology ring localized at the quantum parameter. We check that this involution coincides with the strange duality defined in a previou...
We investigate the geometry of Legendrian complex projective manifolds $X\subset\PP V$. By definition, this means $V$ is a complex vector space of dimension $2n+2$, endowed with a symplectic form, and the affine tangent space to $X$ at each point is a maximal isotropic subspace. We establish basic facts about their geometry and exhibit examples of...
We extend the Cayley–Sylvester formula for symmetric powers of SL2(C)-modules to plethysms defined by rectangle partitions. Ordinary partitions are replaced by plane partitions, and an extension of the Hermite reciprocity law follows.
We prove that the quantum cohomology ring of any minuscule or cominuscule homogeneous space, once localized at the quantum
parameter, has a nontrivial involution mapping Schubert classes to multiples of Schubert classes. This can be stated as a
strange duality property for the Gromov–Witten invariants, which turn out to be very symmetric.
We study the quantum cohomology of (co)minuscule homogeneous varieties under a unified perspective. We show that three points Gromov-Witten invariants can always be interpreted as classical intersection numbers on auxiliary varieties. Our main combinatorial tools are certain quivers, in terms of which we obtain a quantum Chevalley formula and a hig...