English

Near-Rings and Skew Braces

Group Theory 2026-08-05 v1 Rings and Algebras

Abstract

This paper adapts Rump's correspondence between radical rings and braces to a more general setting, utilizing a suitable class of near-rings. Given a right near-ring (R,+,)(R,+,\circ) with a multiplicative identity, we define a new operation that yields a monoid. Under natural compatibility conditions expressed via a filtration, this monoid becomes a topological group, yielding a topological right skew brace. This generalization recovers radical-ring braces and successfully applies to near-rings of maps under composition. We provide several explicit applications, demonstrating that the Nottingham group, groups of triangular functions, iterated wreath products of arbitrary groups, and groups of IA-automorphisms of free nilpotent groups naturally arise as multiplicative groups of such topological skew braces.

Keywords

Cite

@article{arxiv.2608.04874,
  title  = {Near-Rings and Skew Braces},
  author = {Riccardo Aragona and Norberto Gavioli and Martina Iannaccone and Giuseppe Nozzi},
  journal= {arXiv preprint arXiv:2608.04874},
  year   = {2026}
}