English

Comparison of Motivic Homotopy Theories

Algebraic Geometry 2026-03-13 v1 Algebraic Topology K-Theory and Homology

Abstract

We construct a comparison functor from the dual category of motivic homotopy category SH\mathcal{SH} to the category of A1\mathbb{A}^1-invariant localizing motives MotlocA1\operatorname{Mot}_{\operatorname{loc}}^{\mathbb{A}^1} in the sense of Blumberg, Gepner and Tabuada (with A1\mathbb{A}^1-invariance imposed). We as well construct its non-A1\mathbb{A}^1-invariant analogue: a functor from the dual category of Annala-Iwasa-Hoyois's non-A1\mathbb{A}^1-invariant motivic homotopy category MS\mathcal{MS} to Motloc\operatorname{Mot}_{\operatorname{loc}}. After the Barr-Beck argument, these functors factor through categories of modules over a dual version of (A1\mathbb{A}^1-invariant) K-theory spectrum KGL(A1)\operatorname{KGL}^{(\mathbb{A}^1)}. Over a field that admits resolution of singularities, we show that the A1\mathbb{A}^1-invariant factored functor is fully-faithful, while the non-A1\mathbb{A}^1-invariant one is not in general.

Keywords

Cite

@article{arxiv.2603.11753,
  title  = {Comparison of Motivic Homotopy Theories},
  author = {Tianjian Tan},
  journal= {arXiv preprint arXiv:2603.11753},
  year   = {2026}
}