Extrinsic Geometry and Linear Differential Equations

We give a unified method for the general equivalence problem of extrinsic geometry, based on our formulation of a general extrinsic geometry as that of an osculating map : (, f) → /⁰ ⊂ Flag(, ) from a filtered manifold (, f) to a homogeneous space /⁰ in a flag variety Flag(, ), where L is a finite-d...

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Published in:Symmetry, Integrability and Geometry: Methods and Applications
Date:2021
ISSN:1815-0659
Main Authors: Doubrov, Boris, Machida, Yoshinori, Morimoto, Tohru
Format: Article
Language:English
Published: Інститут математики НАН України 2021
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/211362
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Journal Title:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Cite this:Extrinsic Geometry and Linear Differential Equations. Boris Doubrov, Yoshinori Machida and Tohru Morimoto. SIGMA 17 (2021), 061, 60 pages

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Doubrov, Boris
Machida, Yoshinori
Morimoto, Tohru
author_facet Doubrov, Boris
Machida, Yoshinori
Morimoto, Tohru
citation_txt Extrinsic Geometry and Linear Differential Equations. Boris Doubrov, Yoshinori Machida and Tohru Morimoto. SIGMA 17 (2021), 061, 60 pages
collection DSpace DC
container_title Symmetry, Integrability and Geometry: Methods and Applications
description We give a unified method for the general equivalence problem of extrinsic geometry, based on our formulation of a general extrinsic geometry as that of an osculating map : (, f) → /⁰ ⊂ Flag(, ) from a filtered manifold (, f) to a homogeneous space /⁰ in a flag variety Flag(, ), where L is a finite-dimensional Lie group and ⁰ its closed subgroup. We establish an algorithm to obtain complete systems of invariants for the osculating maps that satisfy a reasonable regularity condition, namely, a constant symbol of type (₋, gr , ). We show the categorical isomorphism between the extrinsic geometries in flag varieties and the (weighted) involutive systems of linear differential equations of finite type. Therefore, we also obtain a complete system of invariants for a general involutive system of linear differential equations of finite type and of constant symbol. The invariants of an osculating map (or an involutive system of linear differential equations) are proved to be controlled by the cohomology group ¹₊(₋, /¯) which is defined algebraically from the symbol of the osculating map (resp. involutive system), and which, in many cases (in particular, if the symbol is associated with a simple Lie algebra and its irreducible representation), can be computed by the algebraic harmonic theory, and the vanishing of which gives rigidity theorems in various concrete geometries. We also extend the theory to the case when is infinite-dimensional.
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institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
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language English
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spelling Doubrov, Boris
Machida, Yoshinori
Morimoto, Tohru
2025-12-30T15:56:04Z
2021
Extrinsic Geometry and Linear Differential Equations. Boris Doubrov, Yoshinori Machida and Tohru Morimoto. SIGMA 17 (2021), 061, 60 pages
1815-0659
2020 Mathematics Subject Classification: 53A55; 53C24; 53C30; 53D10
arXiv:1904.05687
https://nasplib.isofts.kiev.ua/handle/123456789/211362
https://doi.org/10.3842/SIGMA.2021.061
We give a unified method for the general equivalence problem of extrinsic geometry, based on our formulation of a general extrinsic geometry as that of an osculating map : (, f) → /⁰ ⊂ Flag(, ) from a filtered manifold (, f) to a homogeneous space /⁰ in a flag variety Flag(, ), where L is a finite-dimensional Lie group and ⁰ its closed subgroup. We establish an algorithm to obtain complete systems of invariants for the osculating maps that satisfy a reasonable regularity condition, namely, a constant symbol of type (₋, gr , ). We show the categorical isomorphism between the extrinsic geometries in flag varieties and the (weighted) involutive systems of linear differential equations of finite type. Therefore, we also obtain a complete system of invariants for a general involutive system of linear differential equations of finite type and of constant symbol. The invariants of an osculating map (or an involutive system of linear differential equations) are proved to be controlled by the cohomology group ¹₊(₋, /¯) which is defined algebraically from the symbol of the osculating map (resp. involutive system), and which, in many cases (in particular, if the symbol is associated with a simple Lie algebra and its irreducible representation), can be computed by the algebraic harmonic theory, and the vanishing of which gives rigidity theorems in various concrete geometries. We also extend the theory to the case when is infinite-dimensional.
The third author is partially supported by JSPS KAKENHI Grant Number 17K05232.
en
Інститут математики НАН України
Symmetry, Integrability and Geometry: Methods and Applications
Extrinsic Geometry and Linear Differential Equations
Article
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spellingShingle Extrinsic Geometry and Linear Differential Equations
Doubrov, Boris
Machida, Yoshinori
Morimoto, Tohru
title Extrinsic Geometry and Linear Differential Equations
title_full Extrinsic Geometry and Linear Differential Equations
title_fullStr Extrinsic Geometry and Linear Differential Equations
title_full_unstemmed Extrinsic Geometry and Linear Differential Equations
title_short Extrinsic Geometry and Linear Differential Equations
title_sort extrinsic geometry and linear differential equations
url https://nasplib.isofts.kiev.ua/handle/123456789/211362
work_keys_str_mv AT doubrovboris extrinsicgeometryandlineardifferentialequations
AT machidayoshinori extrinsicgeometryandlineardifferentialequations
AT morimototohru extrinsicgeometryandlineardifferentialequations