English

$q$-Hodge complexes and refined $\operatorname{TC}^-$

Algebraic Topology 2025-10-09 v4 Algebraic Geometry

Abstract

As a consequence of Efimov's proof of rigidity of the \infty-category of localising motives, Efimov and Scholze have constructed refinements of localising invariants such as THH\operatorname{THH} and TC\operatorname{TC}^-. These refinements often contain vastly more information than the original invariant. In this article we explain a general recipe how to compute the refinements in certain situations. We then apply this recipe to compute the homotopy groups of TC,ref(kuQ/ku)\operatorname{TC}^{-,\mathrm{ref}}(\mathrm{ku}\otimes\mathbb Q/\mathrm{ku}) and TC,ref(KUQ/KU)\operatorname{TC}^{-,\mathrm{ref}}(\mathrm{KU}\otimes\mathbb Q/\mathrm{KU}). The result has a rather surprising geometric description and contains non-trivial information modulo any prime, in contrast to the unrefined TC\operatorname{TC}^-.

Keywords

Cite

@article{arxiv.2410.23115,
  title  = {$q$-Hodge complexes and refined $\operatorname{TC}^-$},
  author = {Samuel Meyer and Ferdinand Wagner},
  journal= {arXiv preprint arXiv:2410.23115},
  year   = {2025}
}

Comments

57 pages, 1 figure. Rewrite of the original version: The material about q-Hodge filtrations has been removed and turned into a separate paper. A section on general computation of refined invariants has been added