The $$\xi $$ ξ -stability on the affine grassmannian

Autor: Zongbin Chen
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Popis: We introduce a notion of $$\xi $$ ξ -stability on the affine grassmannian $${\fancyscript{X}}$$ X for the classical groups, this is the local version of the $$\xi $$ ξ -stability on the moduli space of Higgs bundles on a curve introduced by Chaudouard and Laumon. We prove that the quotient $${\fancyscript{X}}^{\xi }/T$$ X ξ / T of the stable part $${\fancyscript{X}}^{\xi }$$ X ξ by the maximal torus $$T$$ T exists as an ind- $$k$$ k -scheme, and we introduce a reduction process analogous to the Harder-Narasimhan reduction for vector bundles over an algebraic curve. For the group $${\mathrm {SL}}_{d}$$ SL d , we calculate the Poincaré series of the quotient $${\fancyscript{X}}^{\xi }/T$$ X ξ / T .
Databáze: OpenAIRE