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Cohomological invariants of root stacks and admissible double coverings

Part of: Curves Cycles and subschemes (Co)homology theory

Published online by Cambridge University Press:  02 November 2021

Andrea Di Lorenzo  and
Roberto Pirisi Open the ORCID record for Roberto Pirisi [Opens in a new window]
Andrea Di Lorenzo
Affiliation:
Department of Mathematics, Humboldt-Universität zu Berlin, Berlin, Germany e-mail: dilorena@hu-berlin.de
Roberto Pirisi*
Affiliation:
Dipartimento di Matematica Guido Castelnuovo, Sapienza Università di Roma, Rome, Italy
*
e-mail: roberto.pirisi@uniroma1.it
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Abstract

We give a formula for the cohomological invariants of a root stack, which we apply to compute the cohomological invariants and the Brauer group of the compactification of the stacks of hyperelliptic curves given by admissible double coverings.

Keywords

Cohomological invariantsroot stackshyperelliptic curvesadmissible coverings

MSC classification

Primary: 14F22: Brauer groups of schemes
Secondary: 14H10: Families, moduli (algebraic) 14C15: (Equivariant) Chow groups and rings; motives
Type
Article
Information
Canadian Journal of Mathematics , Volume 75 , Issue 1 , February 2023 , pp. 202 - 224
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Copyright
© Canadian Mathematical Society 2021

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