4 papers
math.RT2025
Lower semicontinuity of bounded property in the branching problem and sphericity of flag variety
Masatoshi Kitagawa
Vinberg--Kimel'fel'd [Funct. Anal. Appl., 1978] established that a quasi-projective normal -variety is spherical if and only if -modules on the spaces …
math.RT2024
Construction of Irreducible -Modules and Discretely Decomposable Restrictions
Masatoshi Kitagawa
In this paper, we study the irreducibility of -modules on the spaces of intertwining operators in the branching problem of reductive Lie algebras, a…
math.RT2024
Cartan subalgebras for restrictions of -modules
Masatoshi Kitagawa
In this paper, we deal with the -action on a -module on which a larger algebra acts irreducibly. Under a mild condition, we w…
math.RT2024
-modules on the basic affine space and large -modules
Masatoshi Kitagawa
In this paper, we treat -modules on the basic affine space and their global sections for a semisimple complex algebraic group . Our aim is to prepare basic re…