English

Profinite tensor powers

Rings and Algebras 2026-04-07 v1 Geometric Topology

Abstract

We discuss the problem of defining a tensor product of profinitely many copies of a vector space VV, and propose a definition XmccV\bigotimes_X^{\mathrm{mcc}} V in the special situation that (1) VV is finite-dimensional over F2\mathbf{F}_2, and (2) the profinite XX indexing the tensor factors is acted on with finitely many orbits by a pro-22-group. The "mcc" on the tensor sign stands for "magnetized and conditionally convergent." A variant construction makes sense when VV is a bimodule over a ring of the form F2××F2\mathbf{F}_2 \times \cdots \times \mathbf{F}_2, and the index set XX has the profinite version of a cyclic order. The definition organizes some computations in Heegaard Floer homology: it can be pitched as a computation of the Heegaard Floer theory of some pro-33-manifolds, though we do not know how to define such a thing.

Keywords

Cite

@article{arxiv.2604.04367,
  title  = {Profinite tensor powers},
  author = {David Treumann and C. -M. Michael Wong},
  journal= {arXiv preprint arXiv:2604.04367},
  year   = {2026}
}

Comments

36 pages, 3 figures

R2 v1 2026-07-01T11:54:52.081Z