Quantum cohomology of G/P and homology of affine Grassmannian

By Thomas Lam, Mark Shimozono. 2007

152 citations recorded by the source corpus.

Let G be a simple and simply-connected complex algebraic group, P ⊂ G a parabolic subgroup. We prove an unpublished result of D. Peterson which states that the quantum cohomology QH*(G/P) of a flag variety is, up to localization, a quotient of the homology H*(GrG) of the affine Grassmannian GrG of G. As a consequence, all three-point genus-zero Gromov–Witten invariants of G/P are identified with homology Schubert structure constants of H*(GrG), establishing the equivalence of the quantum and homology affine Schubert calculi.For the case G = B, we use Mihalcea’s equivariant quantum Chevalley formula for QH*(G/B), together with relationships between the quantum Bruhat graph of Brenti, Fomin and Postnikov and the Bruhat order on the affine Weyl group. As byproducts we obtain formulae for affine Schubert homology classes in terms of quantum Schubert polynomials. We give some applications in quantum cohomology.Our main results extend to the torus-equivariant setting.

Subfields: Discrete Mathematics and Combinatorics, Geometry and Topology, Mathematical Physics

View Paper: https://www.semanticscholar.org/paper/5ada7e77e3e427cfb0eb32334688f2171e1f57cf

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In Discrete Mathematics and Combinatorics

In Geometry and Topology

In Mathematical Physics

Citations in the corpus

Curve neighborhoods of Schubert varieties (2013, methodology): “This has been applied by Lam and Shimozono to prove that the equivariant GromovWitten invariants of X coincide with certain structure constants of the equivariant homology of the affine Grassmannian [20].”
k-Schur Functions and Affine Schubert Calculus (2013, background): “Peterson’s “quantum equals affine” theorem [131, 88] (see Chapter 4, Section 4.”