English

Explicit Generators for the Unit Group of the Burnside ring

Rings and Algebras 2025-09-09 v1 Representation Theory

Abstract

To the best of our knowledge, there is no explicit, constructive description of the generating set for the unit group A(G)×A(G)^\times of the Burnside ring associated with a finite group GG. We resolve this long-standing open question, proving that A(G)×A(G)^\times is generated by the set of \emph{basic degrees} -- canonical Burnside ring elements arising from the GG-equivariant degree of the identity map on irreducible GG-representations. In particular, we demonstrate that every unit in A(G)A(G) is realized as the equivariant degree of a linear GG-isomorphism on a suitable orthogonal GG-representation which, in turn, can be described as the Burnside ring product of a finite number of basic degrees, establishing a concrete link between the multiplicative structure of the Burnside ring and the field of equivariant topology.

Keywords

Cite

@article{arxiv.2509.05432,
  title  = {Explicit Generators for the Unit Group of the Burnside ring},
  author = {Ziad Ghanem},
  journal= {arXiv preprint arXiv:2509.05432},
  year   = {2025}
}
R2 v1 2026-07-01T05:23:46.088Z