Cohomological Consequences of the Pattern Map
نویسندگان
چکیده
Billey and Braden defined maps on flag manifolds that are the geometric counterpart of permutation patterns. A section of their pattern map is an embedding of the flag manifold of a Levi subgroup into the full flag manifold. We give two expressions for the induced map on cohomology. One is in terms of generators and the other is in terms of the Schubert basis. We show that the coefficients in the second expression are naturally Schubert structure constants and therefore positive. Similar results hold for K-theory, generalizing known formulas in type A for cohomology and K-theory.
منابع مشابه
Arens regularity and cohomological properties of Banach lattice algebra
A Banach lattice algebra is a Banach lattice, an associative algebra with a sub-multiplicative norm and the product of positive elements should be positive. In this note we study the Arens regularity and cohomological properties of Banach lattice algebras.
متن کاملSome Examples in Cohomological Dimension Theory
It is well-known that dimX ≤ n if and only if every map of a closed subspace of X into the n-dimensional sphere Sn can be extended over X. It is also well-known that for the cohomological dimension dimGX of X with respect to an abelian coefficient group G, dimGX ≤ n if and only if every map of a closed subspace of X into the Eilenberg-Mac Lane complex K(G,n) extends over X. These properties giv...
متن کاملAffine Stratifications and equivariant vector bundles on
of the Dissertation Affine Stratifications and equivariant vector bundles on the moduli of principally polarized abelian varieties by Anant Atyam Doctor of Philosophy in Mathematics Stony Brook University 2014 We explicitly construct a locally closed affine stratification of the coarse moduli space of principally polarized complex abelian four folds A4 and using [32], produce an upper bound for...
متن کاملUPPER BOUNDS FOR FINITENESS OF GENERALIZED LOCAL COHOMOLOGY MODULES
Let $R$ be a commutative Noetherian ring with non-zero identity and $fa$ an ideal of $R$. Let $M$ be a finite $R$--module of finite projective dimension and $N$ an arbitrary finite $R$--module. We characterize the membership of the generalized local cohomology modules $lc^{i}_{fa}(M,N)$ in certain Serre subcategories of the category of modules from upper bounds. We define and study the properti...
متن کاملA Stronger Derived Torelli Theorem for K3 Surfaces
In an earlier paper the notion of a filtered derived equivalence was introduced, and it was shown that if two K3 surfaces admit such an equivalence then they are isomorphic. In this paper we study more refined aspects of filtered derived equivalences related to the action on the cohomological realizations of the Mukai motive. It is shown that if a filtered derived equivalence between K3 surface...
متن کامل