English

Infinitesimal dilogarithm on curves over truncated polynomial rings

Algebraic Geometry 2024-02-28 v1 K-Theory and Homology

Abstract

Let CC be a smooth and projective curve over the truncated polynomial ring km:=k[t]/(tm),k_m:=k[t]/(t^m), where kk is a field of characteristic 0. Using a candidate for the motivic cohomology group H\pazocalM3(C,Q(3)){\rm H}^{3}_{\pazocal{M}}(C,\mathbb{Q}(3)) based on the Bloch complex of weight 3, we construct regulators to kk for every m<r<2m.m<r<2m. Specializing this construction, we obtain an invariant ρm,r(fgh)\rho_{m,r}(f \wedge g \wedge h) of rational functions f,f, gg and hh on C.C. The current work is a twofold generalization of our work on the infinitesimal Chow dilogarithm: we sheafify the previous construction and therefore do not restrict ourselves to triples of rational functions and we construct the regulator for any m<r<2m,m<r<2m, rather than only for m=2.m=2. We also define regulators of cycles, which we expect to give a complete set of invariants for the infinitesimal part of CH2(km,3).{\rm CH}^{2}(k_{m},3). This generalizes Park's work, where the additive Chow cycles, namely the case of cycles close to 0, is handled for r=m+1.r=m+1. In this paper, we generalize the reciprocity theorem to pairs of cycles which are the same modulo (tm)(t^m) and for any m<r<2m.m<r<2m. We expect the theory of the paper to give regulators on categories of motives over rings with nilpotents.

Keywords

Cite

@article{arxiv.2002.00602,
  title  = {Infinitesimal dilogarithm on curves over truncated polynomial rings},
  author = {Sinan Unver},
  journal= {arXiv preprint arXiv:2002.00602},
  year   = {2024}
}
R2 v1 2026-06-23T13:28:45.116Z