English

Prime injections and quasipolarities

Number Theory 2014-05-23 v2

Abstract

Let pp be a prime number. Consider the injection ι:Z/nZZ/pnZ:xpx, \iota:\mathbb{Z}/n\mathbb{Z}\to\mathbb{Z}/pn\mathbb{Z}:x\mapsto px, and the elements eu.v:=(u,v)Z/nZZ/nZ×e^{u}.v:=(u,v)\in \mathbb{Z}/n\mathbb{Z}\rtimes \mathbb{Z}/n\mathbb{Z}^{\times} and ew.r:=(w,r)ZpnZpn×e^{w}.r:=(w,r)\in \mathbb{Z}_{p n}\rtimes \mathbb{Z}_{p n}^{\times}. Suppose eu.vZ/nZZ/nZ×e^{u}.v\in \mathbb{Z}/n\mathbb{Z}\rtimes \mathbb{Z}/n\mathbb{Z}^{\times} is seen as an automorphism of Z/nZ\mathbb{Z}/n\mathbb{Z} by eu.v(x)=vx+ue^{u}.v(x)=vx+u; then eu.ve^{u}.v is a quasipolarity if it is an involution without fixed points. In this brief note give an explicit formula for the number of quasipolarites of Z/nZ\mathbb{Z}/n\mathbb{Z} in terms of the prime decomposition of nn, and we prove sufficient conditions such that (ew.r)ι=ι(eu.v)(e^{w}.r)\circ \iota =\iota\circ (e^{u}.v), where ew.re^{w}.r and eu.ve^{u}.v are quasipolarities.

Cite

@article{arxiv.1302.6874,
  title  = {Prime injections and quasipolarities},
  author = {Octavio Alberto Agustín-Aquino},
  journal= {arXiv preprint arXiv:1302.6874},
  year   = {2014}
}
R2 v1 2026-06-21T23:33:44.748Z