English

Some remarks on real minimal nilpotent orbits and symmetric pairs

Representation Theory 2024-09-26 v2

Abstract

For a non-compact simple Lie algebra g\mathfrak{g} over R\mathbb{R}, we denote by Omin,gC\mathcal{O}^{\mathbb{C}}_{\min,\mathfrak{g}} the unique complex nilpotent orbit in gRC\mathfrak{g} \otimes_\mathbb{R} \mathbb{C} containing all minimal real nilpotent orbits in g\mathfrak{g}. In this paper, we give a complete classification of symmetric pairs (g,h)(\mathfrak{g},\mathfrak{h}) such that Omin,gCgd=\mathcal{O}^{\mathbb{C}}_{\min,\mathfrak{g}} \cap \mathfrak{g}^d = \emptyset, where gd\mathfrak{g}^d denotes the dual Lie algebra of (g,h)(\mathfrak{g},\mathfrak{h}). Furthermore, for symmetric pairs (G,H)(G,H) with real simple Lie group GG, we apply our classification to theorems given by T. Kobayashi [J. Lie Theory (2023)], and study bounded multiplicity properties of restrictions on HH of infinite-dimensional irreducible GG-representations with minimum Gelfand--Kirillov dimension.

Keywords

Cite

@article{arxiv.2407.00675,
  title  = {Some remarks on real minimal nilpotent orbits and symmetric pairs},
  author = {Takayuki Okuda},
  journal= {arXiv preprint arXiv:2407.00675},
  year   = {2024}
}

Comments

11 pages; to appear in the Springer-Proms volume in honor of Professor T. Kobayashi (accepted at Sept. 24, 2024)