Elements of algebraic geometry and the positive theory of partially commutative groups
The first main result of the paper is a criterion for a partially commutative group G to be a domain. It allows us to reduce the study of algebraic sets over G to the study of irreducible algebraic sets, and reduce the elementary theory of G (of a coordinate group over G) to the elementary theories...
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Format: | Journal article |
Language: | English |
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2010
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author | Casals-Ruiz, M Kazachkov, I |
author_facet | Casals-Ruiz, M Kazachkov, I |
author_sort | Casals-Ruiz, M |
collection | OXFORD |
description | The first main result of the paper is a criterion for a partially commutative group G to be a domain. It allows us to reduce the study of algebraic sets over G to the study of irreducible algebraic sets, and reduce the elementary theory of G (of a coordinate group over G) to the elementary theories of the direct factors of G (to the elementary theory of coordinate groups of irreducible algebraic sets). Then we establish normal forms for quantifier-free formulas over a non-abelian directly indecomposable partially commutative group H. Analogously to the case of free groups, we introduce the notion of a generalised equation and prove that the positive theory of H has quantifier elimination and that arbitrary first-order formulas lift from H to H * F, where F is a free group of finite rank. As a consequence, the positive theory of an arbitrary partially commutative group is decidable. ©Canadian Mathematical Society 2010. |
first_indexed | 2024-03-06T21:30:25Z |
format | Journal article |
id | oxford-uuid:4483f525-27c7-4d9e-9038-4c9f0cd35b60 |
institution | University of Oxford |
language | English |
last_indexed | 2024-03-06T21:30:25Z |
publishDate | 2010 |
record_format | dspace |
spelling | oxford-uuid:4483f525-27c7-4d9e-9038-4c9f0cd35b602022-03-26T15:01:58ZElements of algebraic geometry and the positive theory of partially commutative groupsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4483f525-27c7-4d9e-9038-4c9f0cd35b60EnglishSymplectic Elements at Oxford2010Casals-Ruiz, MKazachkov, IThe first main result of the paper is a criterion for a partially commutative group G to be a domain. It allows us to reduce the study of algebraic sets over G to the study of irreducible algebraic sets, and reduce the elementary theory of G (of a coordinate group over G) to the elementary theories of the direct factors of G (to the elementary theory of coordinate groups of irreducible algebraic sets). Then we establish normal forms for quantifier-free formulas over a non-abelian directly indecomposable partially commutative group H. Analogously to the case of free groups, we introduce the notion of a generalised equation and prove that the positive theory of H has quantifier elimination and that arbitrary first-order formulas lift from H to H * F, where F is a free group of finite rank. As a consequence, the positive theory of an arbitrary partially commutative group is decidable. ©Canadian Mathematical Society 2010. |
spellingShingle | Casals-Ruiz, M Kazachkov, I Elements of algebraic geometry and the positive theory of partially commutative groups |
title | Elements of algebraic geometry and the positive theory of partially commutative groups |
title_full | Elements of algebraic geometry and the positive theory of partially commutative groups |
title_fullStr | Elements of algebraic geometry and the positive theory of partially commutative groups |
title_full_unstemmed | Elements of algebraic geometry and the positive theory of partially commutative groups |
title_short | Elements of algebraic geometry and the positive theory of partially commutative groups |
title_sort | elements of algebraic geometry and the positive theory of partially commutative groups |
work_keys_str_mv | AT casalsruizm elementsofalgebraicgeometryandthepositivetheoryofpartiallycommutativegroups AT kazachkovi elementsofalgebraicgeometryandthepositivetheoryofpartiallycommutativegroups |