A universal group-theoretic characterisation of $p$-typical Witt vectors
Abstract
For a prime and a commutative ring with unity, let denote the group of -typical Witt vectors. The group is endowed with a Verschiebung operator and a Teichm\"{u}ller map . One of the properties satisfied by is that the map given by is an additive map. In this paper we show that for , this property essentially characterises the functor . Unlike other characterisations, this is a group-theoretic characterisation, in the sense that it does not use the ring structure of . Most constructions of the group of -typical Witt vectors of non-commutative rings do not have a ring structure, and hence the above characterisation is more suitable for generalisation to the non-commutative setup.
Keywords
Cite
@article{arxiv.2405.12680,
title = {A universal group-theoretic characterisation of $p$-typical Witt vectors},
author = {Supriya Pisolkar and Biswanath Samanta},
journal= {arXiv preprint arXiv:2405.12680},
year = {2026}
}
Comments
Revised version(8 pages). The non-commutative part of the previous version has been removed due to an error