English

Optimal spinor selectivity for quaternion Bass orders

Number Theory 2021-02-19 v2

Abstract

Let AA be a quaternion algebra over a number field FF, and O\mathcal{O} be an OFO_F-order of full rank in AA. Let KK be a quadratic field extension of FF that embeds into AA, and BB be an OFO_F-order in KK. Suppose that O\mathcal{O} is a Bass order that is well-behaved at all the dyadic primes of FF. We provide a necessary and sufficient condition for BB to be optimally spinor selective for the genus of O\mathcal{O}. This partially generalizes previous results on optimal (spinor) selectivity by C. Maclachlan [Optimal embeddings in quaternion algebras. J. Number Theory, 128(10):2852-2860, 2008] for Eichler orders of square-free levels, and independently by M. Arenas et al. [On optimal embeddings and trees. J. Number Theory, 193:91-117, 2018] and by J. Voight [Chapter 31, Quaternion algebras, volume 288 of Graduate Texts in Mathematics. Springer-Verlag, 2021] for Eichler orders of arbitrary levels.

Cite

@article{arxiv.2012.01117,
  title  = {Optimal spinor selectivity for quaternion Bass orders},
  author = {Deke Peng and Jiangwei Xue},
  journal= {arXiv preprint arXiv:2012.01117},
  year   = {2021}
}

Comments

22 pages, made improvements and corrections, results unchanged

R2 v1 2026-06-23T20:40:05.149Z