Multiplicity One for Unitary Ginzburg--Rallis Models over Local Fields
Abstract
We prove multiplicity at most one for the unitary similitude Ginzburg--Rallis model over local fields of characteristic zero, for both the quasi-split and non-quasi-split groups. The theorem holds for all irreducible smooth representations over non-Archimedean fields and all irreducible Casselman--Wallach representations over the real field. We first describe the decomposition into parabolic double cosets and compute the required stabilizers. Over a non-Archimedean field we use character obstructions, localization, and transpose symmetry. Over the real field we use a Casimir identity and explicit normal vectors to prove the corresponding statement for distributions with prescribed infinitesimal character. The Gelfand--Kazhdan criterion and a dualizing involution then give the multiplicity bound.
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BibTeX
@misc{ge2026multiplicity,
title = {{Multiplicity One for Unitary Ginzburg--Rallis Models over Local Fields}},
author = {Yuxuan Ge and Sagnik Mukherjee and Junyi Zhai},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.36294},
eprint = {2610.36294},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.36294},
}
RIS
TY - UNPB
TI - Multiplicity One for Unitary Ginzburg--Rallis Models over Local Fields
AU - Yuxuan Ge
AU - Sagnik Mukherjee
AU - Junyi Zhai
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2610.36294
UR - https://arxiv.org/abs/2610.36294
AB - We prove multiplicity at most one for the unitary similitude Ginzburg--Rallis model over local fields of characteristic zero, for both the quasi-split and non-quasi-split groups. The theorem holds for all irreducible smooth representations over non-Archimedean fields and all irreducible Casselman--Wallach representations over the real field. We first describe the decomposition into parabolic double cosets and compute the required stabilizers. Over a non-Archimedean field we use character obstructions, localization, and transpose symmetry. Over the real field we use a Casimir identity and explicit normal vectors to prove the corresponding statement for distributions with prescribed infinitesimal character. The Gelfand--Kazhdan criterion and a dualizing involution then give the multiplicity bound.
ER -