English

Mixed Tensor Products, Capelli Berezinians, and Newton's Formula for $\mathfrak{gl}(m|n)$

Representation Theory 2025-03-25 v2

Abstract

In this paper, we extend the results of Grantcharov and Robitaille in 2021 on mixed tensor products and Capelli determinants to the superalgebra setting. Specifically, we construct a family of superalgebra homomorphisms φR:U(gl(m+1n))D(mn)U(gl(mn))\varphi_R : U(\mathfrak{gl}(m+1|n)) \rightarrow \mathcal{D}'(m|n) \otimes U(\mathfrak{gl}(m|n)) for a certain space of differential operators D(mn)\mathcal{D}'(m|n) indexed by a central element RR of D(mn)U(gl(mn))\mathcal{D}'(m|n) \otimes U(\mathfrak{gl}(m|n)). We then use this homomorphism to determine the image of Gelfand generators of the center of U(gl(m+1n))U(\mathfrak{gl}(m+1|n)). We achieve this by first relating φR\varphi_R to the corresponding Harish-Chandra homomorphisms and then proving a super-analog of Newton's formula for gl(m)\mathfrak{gl}(m) relating Capelli generators and Gelfand generators. We also use the homomorphism φR\varphi_R to obtain representations of U(gl(m+1n))U(\mathfrak{gl}(m+1|n)) from those of U(gl(mn))U(\mathfrak{gl}(m|n)), and find conditions under which these inflations are simple. Finally, we show that for a distinguished central element R1R_1 in D(mn)U(gl(mn))\mathcal{D}'(m|n)\otimes U(\mathfrak{gl}(m|n)), the kernel of φR1\varphi_{R_1} is the ideal of U(gl(m+1n))U(\mathfrak{gl}(m+1|n)) generated by the first Gelfand invariant G1G_1.

Keywords

Cite

@article{arxiv.2409.02422,
  title  = {Mixed Tensor Products, Capelli Berezinians, and Newton's Formula for $\mathfrak{gl}(m|n)$},
  author = {Sidarth Erat and Arun S. Kannan and Shihan Kanungo},
  journal= {arXiv preprint arXiv:2409.02422},
  year   = {2025}
}