On Restricted Cohomology of Modular Classical Lie Algebras and Their Applications

In this paper, we study the restricted cohomology of Lie algebras of semisimple and simply connected algebraic groups in positive characteristics with coefficients in simple restricted modules and their applications in studying the connections between these cohomology with the corresponding ordinary...

Full description

Bibliographic Details
Main Authors: Sherali S. Ibraev, Larissa S. Kainbaeva, Angisin Z. Seitmuratov
Format: Article
Language:English
Published: MDPI AG 2022-05-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/10/10/1680
_version_ 1827668082532810752
author Sherali S. Ibraev
Larissa S. Kainbaeva
Angisin Z. Seitmuratov
author_facet Sherali S. Ibraev
Larissa S. Kainbaeva
Angisin Z. Seitmuratov
author_sort Sherali S. Ibraev
collection DOAJ
description In this paper, we study the restricted cohomology of Lie algebras of semisimple and simply connected algebraic groups in positive characteristics with coefficients in simple restricted modules and their applications in studying the connections between these cohomology with the corresponding ordinary cohomology and cohomology of algebraic groups. Let <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>G</mi></semantics></math></inline-formula> be a semisimple and simply connected algebraic group <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>G</mi></semantics></math></inline-formula> over an algebraically closed field of characteristic <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>p</mi><mo>></mo><mi>h</mi><mo>,</mo></mrow></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>h</mi></semantics></math></inline-formula> is a Coxeter number. Denote the first Frobenius kernel and Lie algebra of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>G</mi></semantics></math></inline-formula> by <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="fraktur">g</mi></semantics></math></inline-formula>, respectively. First, we calculate the restricted cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="fraktur">g</mi></semantics></math></inline-formula> with coefficients in simple modules for two families of restricted simple modules. Since in the restricted region the restricted cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="fraktur">g</mi></semantics></math></inline-formula> is equivalent to the corresponding cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub><mo>,</mo></mrow></semantics></math></inline-formula> we describe them as the cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> in terms of the cohomology for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> with coefficients in dual Weyl modules. Then, we give a necessary and sufficient condition for the isomorphisms <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><msub><mi>G</mi><mn>1</mn></msub><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>≅</mo><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><mi>G</mi><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><mi mathvariant="fraktur">g</mi><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>≅</mo><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><mi>G</mi><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>,</mo></mrow></semantics></math></inline-formula> and a necessary condition for the isomorphism <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><mi mathvariant="fraktur">g</mi><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>≅</mo><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><msub><mi>G</mi><mn>1</mn></msub><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>,</mo></mrow></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>V</mi></semantics></math></inline-formula> is a simple module with highest restricted weight. Using these results, we obtain all non-trivial isomorphisms between the cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>G</mi></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="fraktur">g</mi></semantics></math></inline-formula> with coefficients in the considered simple modules.
first_indexed 2024-03-10T03:29:14Z
format Article
id doaj.art-b684fbba60474fe7b044b2db3122f23e
institution Directory Open Access Journal
issn 2227-7390
language English
last_indexed 2024-03-10T03:29:14Z
publishDate 2022-05-01
publisher MDPI AG
record_format Article
series Mathematics
spelling doaj.art-b684fbba60474fe7b044b2db3122f23e2023-11-23T12:00:51ZengMDPI AGMathematics2227-73902022-05-011010168010.3390/math10101680On Restricted Cohomology of Modular Classical Lie Algebras and Their ApplicationsSherali S. Ibraev0Larissa S. Kainbaeva1Angisin Z. Seitmuratov2Department of Physics and Mathematics, Institute of Natural Science, Korkyt Ata Kyzylorda Univesity, Aiteke bie St. 29A, Kyzylorda 120014, KazakhstanDepartment of Physics and Mathematics, Institute of Natural Science, Korkyt Ata Kyzylorda Univesity, Aiteke bie St. 29A, Kyzylorda 120014, KazakhstanDepartment of Physics and Mathematics, Institute of Natural Science, Korkyt Ata Kyzylorda Univesity, Aiteke bie St. 29A, Kyzylorda 120014, KazakhstanIn this paper, we study the restricted cohomology of Lie algebras of semisimple and simply connected algebraic groups in positive characteristics with coefficients in simple restricted modules and their applications in studying the connections between these cohomology with the corresponding ordinary cohomology and cohomology of algebraic groups. Let <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>G</mi></semantics></math></inline-formula> be a semisimple and simply connected algebraic group <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>G</mi></semantics></math></inline-formula> over an algebraically closed field of characteristic <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>p</mi><mo>></mo><mi>h</mi><mo>,</mo></mrow></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>h</mi></semantics></math></inline-formula> is a Coxeter number. Denote the first Frobenius kernel and Lie algebra of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>G</mi></semantics></math></inline-formula> by <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="fraktur">g</mi></semantics></math></inline-formula>, respectively. First, we calculate the restricted cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="fraktur">g</mi></semantics></math></inline-formula> with coefficients in simple modules for two families of restricted simple modules. Since in the restricted region the restricted cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="fraktur">g</mi></semantics></math></inline-formula> is equivalent to the corresponding cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub><mo>,</mo></mrow></semantics></math></inline-formula> we describe them as the cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> in terms of the cohomology for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula> with coefficients in dual Weyl modules. Then, we give a necessary and sufficient condition for the isomorphisms <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><msub><mi>G</mi><mn>1</mn></msub><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>≅</mo><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><mi>G</mi><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><mi mathvariant="fraktur">g</mi><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>≅</mo><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><mi>G</mi><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>,</mo></mrow></semantics></math></inline-formula> and a necessary condition for the isomorphism <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><mi mathvariant="fraktur">g</mi><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>≅</mo><msup><mi>H</mi><mi>n</mi></msup><mrow><mo>(</mo><mrow><msub><mi>G</mi><mn>1</mn></msub><mo>,</mo><mi>V</mi></mrow><mo>)</mo></mrow><mo>,</mo></mrow></semantics></math></inline-formula> where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>V</mi></semantics></math></inline-formula> is a simple module with highest restricted weight. Using these results, we obtain all non-trivial isomorphisms between the cohomology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>G</mi></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>G</mi><mn>1</mn></msub></mrow></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="fraktur">g</mi></semantics></math></inline-formula> with coefficients in the considered simple modules.https://www.mdpi.com/2227-7390/10/10/1680Lie algebraalgebraic groupcohomologyrestricted cohomologysimple modules
spellingShingle Sherali S. Ibraev
Larissa S. Kainbaeva
Angisin Z. Seitmuratov
On Restricted Cohomology of Modular Classical Lie Algebras and Their Applications
Mathematics
Lie algebra
algebraic group
cohomology
restricted cohomology
simple modules
title On Restricted Cohomology of Modular Classical Lie Algebras and Their Applications
title_full On Restricted Cohomology of Modular Classical Lie Algebras and Their Applications
title_fullStr On Restricted Cohomology of Modular Classical Lie Algebras and Their Applications
title_full_unstemmed On Restricted Cohomology of Modular Classical Lie Algebras and Their Applications
title_short On Restricted Cohomology of Modular Classical Lie Algebras and Their Applications
title_sort on restricted cohomology of modular classical lie algebras and their applications
topic Lie algebra
algebraic group
cohomology
restricted cohomology
simple modules
url https://www.mdpi.com/2227-7390/10/10/1680
work_keys_str_mv AT sheralisibraev onrestrictedcohomologyofmodularclassicalliealgebrasandtheirapplications
AT larissaskainbaeva onrestrictedcohomologyofmodularclassicalliealgebrasandtheirapplications
AT angisinzseitmuratov onrestrictedcohomologyofmodularclassicalliealgebrasandtheirapplications