Hermitian K-theory of Lagrangian Grassmannians via reducible Gorenstein models

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Huang, Tao, Xie, Heng
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866913982841880576
author Huang, Tao
Xie, Heng
author_facet Huang, Tao
Xie, Heng
contents We construct a family of moduli spaces, called generalized Lagrangian flag schemes, that are reducible Gorenstein (hence singular), and that admit well-behaved pushforward and pullback operations in Hermitian $K$-theory. These schemes arise naturally in our computations. Using them, we prove that the Hermitian $K$-theory of a Lagrangian Grassmannian over a regular base splits as a direct sum of copies of the base's (Hermitian) $K$-theory, indexed by certain shifted Young diagrams. The isomorphism is realized via pullback to each generalized Lagrangian flag scheme followed by pushforward to the Lagrangian Grassmannian. This yields an unusual example in which both the base and the target are regular schemes, while the intermediate reducible Gorenstein models remain sufficient to allow explicit computations in Hermitian K-theory of regular schemes.
format Preprint
id arxiv_https___arxiv_org_abs_2508_07166
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Hermitian K-theory of Lagrangian Grassmannians via reducible Gorenstein models
Huang, Tao
Xie, Heng
Algebraic Geometry
Algebraic Topology
K-Theory and Homology
We construct a family of moduli spaces, called generalized Lagrangian flag schemes, that are reducible Gorenstein (hence singular), and that admit well-behaved pushforward and pullback operations in Hermitian $K$-theory. These schemes arise naturally in our computations. Using them, we prove that the Hermitian $K$-theory of a Lagrangian Grassmannian over a regular base splits as a direct sum of copies of the base's (Hermitian) $K$-theory, indexed by certain shifted Young diagrams. The isomorphism is realized via pullback to each generalized Lagrangian flag scheme followed by pushforward to the Lagrangian Grassmannian. This yields an unusual example in which both the base and the target are regular schemes, while the intermediate reducible Gorenstein models remain sufficient to allow explicit computations in Hermitian K-theory of regular schemes.
title Hermitian K-theory of Lagrangian Grassmannians via reducible Gorenstein models
topic Algebraic Geometry
Algebraic Topology
K-Theory and Homology
url https://arxiv.org/abs/2508.07166