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Autori principali: Graham, William, Larson, Scott Joseph
Natura: Preprint
Pubblicazione: 2024
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Accesso online:https://arxiv.org/abs/2412.20863
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author Graham, William
Larson, Scott Joseph
author_facet Graham, William
Larson, Scott Joseph
contents We study the torus-equivariant cohomology of weighted flag varieties, and prove a positivity property in the equivariant cohomology and Chow groups of weighted flag varieties, analogous to the non-weighted positivity proved in [Graham 2001]. Our result strengthens and generalizes the positivity proved for weighted Grassmannians by [Abe-Matsumura 2015]. The positivity property is expressed in terms of weighted roots, which are used to describe weights of torus equivariant curves in weighted flag varieties. This provides a geometric interpretation of the parameters used in [Abe-Matsumura 2015]. We approach weighted flag varieties from a uniform Lie-theoretic point of view, providing a more general definition than has appeared previously, and prove other general results about weighted flag varieties in this setting, including a Borel presentation of the equivariant cohomology. In addition, we generalize some results obtained for weighted Grassmannians or more generally type $A$ ([Abe-Matsumura 2015], [Azam-Nazir-Qureshi 2020]); in particular, we obtain a weighted Chevalley formula, descriptions of restrictions to fixed points, the GKM description of the cohomology, and a weighted Chevalley formula.
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spellingShingle Positivity in Weighted Flag Varieties
Graham, William
Larson, Scott Joseph
Algebraic Geometry
Representation Theory
55N91 (Primary), 14L24 (Secondary), 14C15 (Secondary)
We study the torus-equivariant cohomology of weighted flag varieties, and prove a positivity property in the equivariant cohomology and Chow groups of weighted flag varieties, analogous to the non-weighted positivity proved in [Graham 2001]. Our result strengthens and generalizes the positivity proved for weighted Grassmannians by [Abe-Matsumura 2015]. The positivity property is expressed in terms of weighted roots, which are used to describe weights of torus equivariant curves in weighted flag varieties. This provides a geometric interpretation of the parameters used in [Abe-Matsumura 2015]. We approach weighted flag varieties from a uniform Lie-theoretic point of view, providing a more general definition than has appeared previously, and prove other general results about weighted flag varieties in this setting, including a Borel presentation of the equivariant cohomology. In addition, we generalize some results obtained for weighted Grassmannians or more generally type $A$ ([Abe-Matsumura 2015], [Azam-Nazir-Qureshi 2020]); in particular, we obtain a weighted Chevalley formula, descriptions of restrictions to fixed points, the GKM description of the cohomology, and a weighted Chevalley formula.
title Positivity in Weighted Flag Varieties
topic Algebraic Geometry
Representation Theory
55N91 (Primary), 14L24 (Secondary), 14C15 (Secondary)
url https://arxiv.org/abs/2412.20863