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Modality of representations and geometry of θ-groups

Ch. 16. P. 459–479.
Vladimir L. Popov

We first establish several general properties of modality of algebraic group
actions. In particular,we introduce the notion of a modality-regular action and prove
that every visible action is modality-regular. Then, using these results, we classify irreducible
linear representations of connected simple algebraic groups of every fixed
modality < 3. Next, exploring a finer geometric structure of linear actions, we generalize
to the case of any cyclically graded semisimple Lie algebra the notion of a
packet (or a Jordan/decomposition class) and establish the properties of packets.

Language: English
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Keywords: representation theorymodalityalgebraic grouporbit

In book

Lie Groups, Geometry, and Representation Theory. A Tribute to the Life and Work of Bertram Kostant
Lie Groups, Geometry, and Representation Theory. A Tribute to the Life and Work of Bertram Kostant
Kac, V., Popov, Vladimir L. Vol. 326. , Copyright Holder Springer Nature Switzerland AG, 2018.
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