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Yoshinori Mishiba

Publications and source records attributed to Yoshinori Mishiba.

10 recordsLinked to original sources
arXiv2026

Involution on a quotient space of multiple zeta values in positive characteristic

In this paper, we introduce $*$-inverse multiple zeta values and $*$-inverse Carlitz multiple polylogarithms in positive characteristic and study their algebraic structures and relations. Using special values of Carlitz multiple polylogarithms, we show that a natural quotient of the space of multiple zeta values in positive characteristic admits a Hopf algebra structure and that the original space admits a compatible comodule structure over this quotient. These structures may be regarded as function field analogues of the Hopf algebra and comodule structures arising from motivic multiple zeta values in characteristic zero. In particular, the antipode on this quotient gives a non-trivial involution corresponding to the $*$-inverse operation. We also establish, in certain cases, the $q$-shuffle product formula and linear relations for $*$-inverse multiple zeta values, providing evidence for our conjectures on their relations. Finally, we consider another characteristic-zero analogue of our construction, based on the Hopf algebra structure given by the harmonic product and the deconcatenation coproduct, and formulate a related problem.

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arXiv2022

On Thakur's basis conjecture for multiple zeta values in positive characteristic

In this paper, we study multiple zeta values (abbreviated as MZV's) over function fields in positive characteristic. Our main result is to prove Thakur's basis conjecture, which plays the analogue of Hoffman's basis conjecture for real MZV's. As a consequence, we derive Todd's dimension conjecture, which is the analogue of Zagier's dimension conjecture for classical real MZV's.

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arXiv2020

Taylor coefficients of Anderson-Thakur series and explicit formulae

For each positive characteristic multiple zeta value (defined by Thakur), the first and third authors constructed a $t$-module together with an algebraic point such that a specified coordinate of the logarithmic vector of the algebraic point is a rational multiple of that multiple zeta value. The objective of this paper is to use the Taylor coefficients of Anderson-Thakur series and $t$-motivic Carlitz multiple star polylogarithms to give explicit formulae for all of the coordinates of this logarithmic vector.

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arXiv2020

Algebra structure of multiple zeta values in positive characteristic

This paper is a culmination of [CM20] on the study of multiple zeta values (MZV's) over function fields in positive characteristic. For any finite place $v$ of the rational function field $k$ over a finite field, we prove that the $v$-adic MZV's satisfy the same $\bar{k}$-algebraic relations that their corresponding $\infty$-adic MZV's satisfy. Equivalently, we show that the $v$-adic MZV's form an algebra with multiplication law given by the $q$-shuffle product which comes from the $\infty$-adic MZV's, and there is a well-defined $\bar{k}$-algebra homomorphism from the $\infty$-adic MZV's to the $v$-adic MZV's.

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arXiv2017

On multiple polylogarithms in characteristic $p$: $v$-adic vanishing versus $\infty$-adic Eulerianness

In this paper, we give a simultaneous vanishing principle for the $v$-adic Carlitz multiple polylogarithms (abbreviated as CMPLs) at algebraic points, where $v$ is a finite place of the rational function field over a finite field. This principle establishes the fact that the $v$-adic vanishing of CMPLs at algebraic points is equivalent to its $\infty$-adic counterpart being Eulerian. This reveals a nontrivial connection between the $v$-adic and $\infty$-adic worlds in positive characteristic.

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arXiv2016

On finite Carlitz multiple polylogarithms

In this paper, we define finite Carlitz multiple polylogarithms and show that every finite multiple zeta value over the rational function field $\mathbb{F}_{q}(θ)$ is an $\mathbb{F}_{q}(θ)$-linear combination of finite Carlitz multiple polylogarithms at integral points. It is completely compatible with the formula for Thakur MZV's established in [C14].

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arXiv2014

On algebraic independence of certain multizeta values in characteristic p

In this paper, we study multizeta values over function fields in characteristic $p$. For each $d \geq 2$, we show that when the constant field has cardinality $> 2$, the field generated by all multizeta values of depth $d$ is of infinite transcendence degree over the field generated by all single zeta values. As a special case, this gives an affirmative answer to the function field analogue of a question of Y.\ André.

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arXiv2013

Algebraic independence of the Carlitz period and the positive characteristic multizeta values at n and (n,n)

Let $k$ be the rational function field over the finite field of $q$ elements and $\bar{k}$ its fixed algebraic closure. In this paper, we study algebraic relations over $\bar{k}$ among the fundamental period $\widetildeπ$ of the Carlitz module and the positive characteristic multizeta values $ζ(n)$ and $ζ(n,n)$ for an "odd" integer $n$, where we say that $n$ is "odd" if $q-1$ does not divide $n$. We prove that either they are algebraically independent over $\bar{k}$ or satisfy some simple relation over $k$. We also prove that if $2n$ is "odd" then they are algebraically independent over $\bar{k}$.

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arXiv2011

On v-adic periods of t-motives

In this paper, we prove the equality between the transcendental degree of the field generated by the v-adic periods of a t-motive M and the dimension of the Tannakian Galois group for M, where v is a "finite" place of the rational function field over a finite field. As an application, we prove the algebraic independence of certain "formal" polylogarithms.

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