Cube invariance of higher Chow groups with modulus

TL;DR

This paper establishes cube invariance for higher Chow groups with modulus, generalizing known homotopy invariance, and introduces a nilpotent version with a Witt ring module structure, enhancing understanding of their invariance properties.

Contribution

It proves cube invariance for higher Chow groups with modulus and introduces a nilpotent version with a Witt ring module structure, advancing the theory's invariance properties.

Findings

Proved cube invariance of higher Chow groups with modulus.

Introduced nilpotent higher Chow groups with a Witt ring module structure.

Showed $ ext{A}^1$-homotopy invariance implies independence from modulus multiplicity.

Abstract

The higher Chow group with modulus was introduced by Binda-Saito as a common generalization of Bloch's higher Chow group and the additive higher Chow group. In this paper, we study invariance properties of the higher Chow group with modulus. First, we formulate and prove "cube invariance," which generalizes $\mathbb{A}^1$-homotopy invariance of Bloch's higher Chow group. Next, we introduce the nilpotent higher Chow group with modulus, as an analogue of the nilpotent algebraic $K$-group, and define a module structure on it over the big Witt ring of the base field. We deduce from the module structure that the higher Chow group with modulus with appropriate coefficients satisfies $\mathbb{A}^1$-homotopy invariance. We also prove that $\mathbb{A}^1$-homotopy invariance implies independence from the multiplicity of the modulus divisors.