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On André periods of mixed Tate motives

Ishai Dan-Cohen

TL;DR

This work shows that André periods, as defined by Ancona–Frăţilă, coincide with classical $p$-adic periods in the mixed Tate setting and then connects them to Coleman integration via Frobenius-fixed de Rham paths, which are shown to be motivic for MTM. By comparing the André-period torsor $ ext{O}H(Z)$ with the classical de Rham torsor $ ext{O}U_{ ext{dR}}(Z)$ in a Tannakian framework, the authors produce an isomorphism of $K$-algebras that preserves the two period maps. They further establish that Frobenius-fixed paths arising in the unipotent fundamental group are motivic in the mixed Tate world, and demonstrate explicitly that $p$-adic iterated integrals, including $p$-adic multiple polylogarithms, arise as André periods of motivic path torsors. This provides a concrete bridge between André periods and established $p$-adic period theories, with implications for evaluating special values via motivic methods beyond the mixed Tate setting.

Abstract

In this note, we show that the $p$-adic periods of motives introduced recently by Ancona and Frăţilă (``André periods'') reduce to the classically studied notion in the case of Mixed Tate motives. We also connect André periods with Coleman integration by observing that the Frobenius-fixed de Rham paths of Besser and Vologodsky come from motivic paths in characteristic $p$ (unconditionally in the mixed Tate setting, conditionally in general). We use this to realize special values of $p$-adic multiple polylogarithms as André periods in a concrete way.

On André periods of mixed Tate motives

TL;DR

This work shows that André periods, as defined by Ancona–Frăţilă, coincide with classical -adic periods in the mixed Tate setting and then connects them to Coleman integration via Frobenius-fixed de Rham paths, which are shown to be motivic for MTM. By comparing the André-period torsor with the classical de Rham torsor in a Tannakian framework, the authors produce an isomorphism of -algebras that preserves the two period maps. They further establish that Frobenius-fixed paths arising in the unipotent fundamental group are motivic in the mixed Tate world, and demonstrate explicitly that -adic iterated integrals, including -adic multiple polylogarithms, arise as André periods of motivic path torsors. This provides a concrete bridge between André periods and established -adic period theories, with implications for evaluating special values via motivic methods beyond the mixed Tate setting.

Abstract

In this note, we show that the -adic periods of motives introduced recently by Ancona and Frăţilă (``André periods'') reduce to the classically studied notion in the case of Mixed Tate motives. We also connect André periods with Coleman integration by observing that the Frobenius-fixed de Rham paths of Besser and Vologodsky come from motivic paths in characteristic (unconditionally in the mixed Tate setting, conditionally in general). We use this to realize special values of -adic multiple polylogarithms as André periods in a concrete way.

Paper Structure

This paper contains 6 sections, 7 theorems, 74 equations.

Key Result

Theorem 4.1

There exists an isomorphism of $K$-algebras of "formal periods" commuting with the two period maps, as in the following diagram:

Theorems & Definitions (15)

  • Theorem 4.1
  • Proposition 4.2
  • proof
  • Proposition 4.4
  • proof
  • Proposition 4.5
  • proof
  • Proposition 4.6
  • proof
  • proof : Proof of Theorem \ref{['A7']}
  • ...and 5 more