The algebraic and combinatorial theory of shuffles, introduced by Chen and Ree, is further developed and applied to the study of multiple zeta values. In particular, we establish evaluations for certain sums of cyclically generated multiple zeta values. The boundary case of our result reduces to a former conjecture of Zagier.
Arborified zeta values are defined as iterated series and integrals using the universal properties of rooted trees. This approach allows to study their convergence domain and to relate them to multizeta values. Generalisations to rooted trees of the stuffle and shuffle products are defined and studied. It is further shown that arborifed zeta values are algebra morphisms for these new products on trees.
A large family of relations among multiple zeta values may be described using the combinatorics of shuffle and quasi-shuffle algebras. While the structure of shuffle algebras have been well understood for some time now, quasi-shuffle algebras were only formally studied relatively recently. In particular, Hoffman gives a thorough discussion of the algebraic structure, including a choice of algebra basis, and applies his results to produce families of relations among multiple zeta values and their generalisations. In a recent preprint, Hirose and Sato establish a family of relations coming from …
Regularised double shuffle relations for planar Arborified Zeta Values
Université de Montpellier, IMAG, Institut Montpelliérain Alexander Grothendieck（蒙彼利埃大学，IMAG，亚历山大·格罗滕迪克蒙彼利埃研究所）；Department of Mathematics, IRIMAS, Université de Haute Alsace（阿尔萨斯大学高等研究院数学系）；IRMA, Université de Strasbourg（斯特拉斯堡大学数学与离散数学研究所）；Graduate School of Mathematics, Nagoya University（名古屋大学大学院数学研究科）
Quasi-shuffle algebras have been a useful tool in studying multiple zeta values and related quantities, including multiple polylogarithms, finite multiple harmonic sums, and q-multiple zeta values. Here we show that two ideas previously considered only for multiple zeta values, the interpolated product of S. Yamamoto and the symmetric sum theorem, can be generalized to any quasi-shuffle algebra.
In this paper, we introduce the notion of generalized quasi-shuffle products and give a criterion for their associativity. These extend the quasi-shuffle products introduced by Hoffman, which are often used to describe the stuffle and shuffle product for multiple zeta values. For $q$-analogues of multiple zeta values, the description of an analogue for the shuffle product can often not be described with the classical notion of quasi-shuffle products. We show that our generalization gives a natural extension to also include these types of products and we prove a generalization of a duality betw…
We examine "partition zeta functions" analogous to the Riemann zeta function but summed over subsets of integer partitions. We prove an explicit formula for a family of partition zeta functions already shown to have nice properties -- those summed over partitions of fixed length -- which yields complete information about analytic continuation, poles and trivial roots of the zeta functions in the family. Then we present a combinatorial proof of the explicit formula, which shows it to be a zeta function analog of MacMahon's partial fraction decomposition of the generating function for partitions…
We introduce Schur multiple zeta functions which interpolate both the multiple zeta and multiple zeta-star functions of the Euler-Zagier type combinatorially. We first study their basic properties including a region of absolute convergence and the case where all variables are the same. Then, under an assumption on variables, some determinant formulas coming from theory of Schur functions such as the Jacobi-Trudi, Giambelli and dual Cauchy formula are established with the help of Macdonald's ninth variation of Schur functions. Moreover, we investigate the quasi-symmetric functions corresponding…
We describe some particular finite sums of multiple zeta values which arise from J. Ecalle's "arborification", a process which can be described as a surjective Hopf algebra morphism from the Hopf algebra of decorated rooted forests onto a Hopf algebra of shuffles or quasi-shuffles. This formalism holds for both the iterated sum picture and the iterated integral picture. It involves a decoration of the forests by the positive integers in the first case, by only two colours in the second case.
An exotic shuffle relation of $ζ(\{2\}^m)$ and $ζ(\{3,1\}^n)$
在这个简短的说明中，我们将提供一个新的和更短的证明，以下奇异的洗牌关系的多个zeta值：$$ζ(\{2\}^m \sha\{3,1\}^n)={2n+m\choose m} \frac{π^{4n+2m}}{(2n+1)\cdot (4n+2m+1)!}.$$这是证明了Zagier时，n=0，由布罗德赫斯特时，$m=0$，并由Borwein，布拉德利和布罗德赫斯特时，m=1。一般来说，这是由Bowman和Bradley在\emph{The algebra and combinatorics of shuffles and multiple zeta values}，J. of Combinatorial Theory，Series A，Vol. \textbf{97}（1）（2002），43- 63中证明的。在一般情况下，我们的想法是使用Borwein等人的方法，以减少上述一般关系到一些家庭的组合恒等式，可以验证的WZ-方法。
An $(a,b)$-Dyck path $P$ is a lattice path from $(0,0)$ to $(b,a)$ that stays above the line $y=\frac{a}{b}x$. The zeta map is a curious rule that maps the set of $(a,b)$-Dyck paths into itself; it is conjecturally bijective, and we provide progress towards proof of bijectivity in this paper, by showing that knowing zeta of $P$ and zeta of $¶$ conjugate is enough to recover $P$. Our method begets an area-preserving involution $χ$ on the set of $(a,b)$-Dyck paths when $ζ$ is a bijection, as well as a new method for calculating $ζ^{-1}$ on classical Dyck paths. For certain nice $(a,b)$-Dyck path…
Motivated by q-shuffle products determined by Singer from q-analogues of multiple zeta values, we build in this article a generalisation of the shuffle and stuffle products in terms of weak shuffle and stuffle products. Then, we characterise weak shuffle products and give as examples the case of an alphabet of cardinality two or three. We focus on a comparison between algebraic structures respected in the classical case and in the weak case. As in the classical case, each weak shuffle product can be equipped with a dendriform structure. However, they have another behaviour towards the quadri-a…
In this work we discuss a parameter $σ$ on weighted $k$-element multisets of $[n]= \{1,\dots ,n\}$. The sums of weighted $k$-multisets are related to $k$-subsets, $k$-multisets, as well as special instances of truncated interpolated multiple zeta values. We study properties of this parameter using symbolic combinatorics. We rederive and extend certain identities for $ζ^{t}_n(\{m\}_k)$. Moreover, we introduce random variables on the $k$-element multisets and derive their distributions, as well as limit laws for $k$ or $n$ tending to infinity.
Extending the descent-to-peak map and its applications
Shandong University（山东大学）；Research Center for Mathematics and Interdisciplinary Sciences, Shandong University（山东大学数学交叉前沿研究中心）；Frontiers Science Center for Nonlinear Expectations, Ministry of Education（教育部非线性期望前沿科学中心）
Partially commutative monoids provide a powerful tool to study graphs, viewingwalks as words whose letters, the edges of the graph, obey a specific commutation rule. A particularclass of traces emerges from this framework, the hikes, whose alphabet is the set of simple cycleson the graph. We show that hikes characterize undirected graphs uniquely, up to isomorphism, andsatisfy remarkable algebraic properties such as the existence and uniqueness of a prime factorization.Because of this, the set of hikes partially ordered by divisibility hosts a plethora of relations in directcorrespondence with…
From Black Box to Bijection: Interpreting Machine Learning to Build a Zeta Map Algorithm
Department of Mathematics, Temple University, Philadelphia, PA 19122, U.S.A.（特拉华大学数学系）；Department of Mathematics, University of Connecticut, Storrs, CT 06269, U.S.A.（康涅狄格大学数学系）；Korea Institute for Advanced Study, Seoul 02455, Republic of Korea（韩国高级研究院）
