Mathematics – Representation Theory
Scientific paper
2007-10-03
Mathematics
Representation Theory
Scientific paper
Let $\gg$ be a complex reductive Lie algebra and $\kk\subset\gg$ be any reductive in $\gg$ subalgebra. We call a $(\gg,\kk)$-module $M$ bounded if the $\kk$-multiplicities of $M$ are uniformly bounded. In this paper we initiate a general study of simple bounded $(\gg,\kk)$-modules. We prove a strong necessary condition for a subalgebra $\kk$ to be bounded (Corollary \ref{cor1.6}), i.e. to admit an infinite-dimensional simple bounded $(\gg,\kk)$-module, and then establish a sufficient condition for a subalgebra $\kk$ to be bounded (Theorem \ref{thGroups2}). As a result we are able to classify all maximal bounded reductive subalgebras of $\gg=\sl(n)$. In the second half of the paper we describe in detail simple bounded infinite-dimensional $(\gg,\sl(2))$-modules, and in particular compute their characters and minimal $\sl(2)$-types. We show that if $\sl(2)$ is a bounded subalgebra of $\gg$ which is not contained in a proper ideal of $\gg$, then $\gg\simeq \sl(2)\oplus \sl(2), \sl(3),\sp(4)$; alltogether, up to conjugation there are five possible embeddings of $\sl(2)$ as a bounded subalgebra into $\gg$ as above. In two of these cases $\sl(2)$ is a symmetric subalgebra, and many results about simple bounded $(\gg,\sl(2))$-modules are known. A case where our results are entirely new is the case of a principal $\sl(2)$-subalgebra in $\sp(4)$.
Penkov Ivan
Serganova Vera
No associations
LandOfFree
Bounded generalized Harish-Chandra modules does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Bounded generalized Harish-Chandra modules, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bounded generalized Harish-Chandra modules will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-562927