Separating invariants and local cohomology

The study of separating invariants is a recent trend in invariant theory. For a finite group acting linearly on a vector space, a separating set is a set of invariants whose elements separate the orbits of G. In some ways, separating sets often exhibit better behavior than generating sets for the ri...

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Main Authors: Dufresne, Emilie, Jeffries, Jack
Format: Article
Published: Elsevier 2015
Subjects:
Online Access:https://eprints.nottingham.ac.uk/47066/
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author Dufresne, Emilie
Jeffries, Jack
author_facet Dufresne, Emilie
Jeffries, Jack
author_sort Dufresne, Emilie
building Nottingham Research Data Repository
collection Online Access
description The study of separating invariants is a recent trend in invariant theory. For a finite group acting linearly on a vector space, a separating set is a set of invariants whose elements separate the orbits of G. In some ways, separating sets often exhibit better behavior than generating sets for the ring of invariants. We investigate the least possible cardinality of a separating set for a given G-action. Our main result is a lower bound that generalizes the classical result of Serre that if the ring of invariants is polynomial then the group action must be generated by pseudoreflections. We find these bounds to be sharp in a wide range of examples.
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spelling nottingham-470662020-05-04T16:59:44Z https://eprints.nottingham.ac.uk/47066/ Separating invariants and local cohomology Dufresne, Emilie Jeffries, Jack The study of separating invariants is a recent trend in invariant theory. For a finite group acting linearly on a vector space, a separating set is a set of invariants whose elements separate the orbits of G. In some ways, separating sets often exhibit better behavior than generating sets for the ring of invariants. We investigate the least possible cardinality of a separating set for a given G-action. Our main result is a lower bound that generalizes the classical result of Serre that if the ring of invariants is polynomial then the group action must be generated by pseudoreflections. We find these bounds to be sharp in a wide range of examples. Elsevier 2015-01-31 Article PeerReviewed Dufresne, Emilie and Jeffries, Jack (2015) Separating invariants and local cohomology. Advances in Mathematics, 270 . pp. 565-581. ISSN 1090-2082 Invariant theory separating invariants local cohomology arrangements of linear subspaces simplicial homology poset topology. http://www.sciencedirect.com/science/article/pii/S0001870814003788 doi:10.1016/j.aim.2014.11.003 doi:10.1016/j.aim.2014.11.003
spellingShingle Invariant theory
separating invariants
local cohomology
arrangements of linear subspaces
simplicial homology
poset topology.
Dufresne, Emilie
Jeffries, Jack
Separating invariants and local cohomology
title Separating invariants and local cohomology
title_full Separating invariants and local cohomology
title_fullStr Separating invariants and local cohomology
title_full_unstemmed Separating invariants and local cohomology
title_short Separating invariants and local cohomology
title_sort separating invariants and local cohomology
topic Invariant theory
separating invariants
local cohomology
arrangements of linear subspaces
simplicial homology
poset topology.
url https://eprints.nottingham.ac.uk/47066/
https://eprints.nottingham.ac.uk/47066/
https://eprints.nottingham.ac.uk/47066/