arXiv subjects

Sinnou David

Publications and source records attributed to Sinnou David.

5 recordsLinked to original sources

arXiv2025

Linear independence of values of hypergeometric functions and arithmetic Gevrey series

We prove new linear independence results for the values of generalized hypergeometric functions ${}_pF_q$ at several distinct algebraic points, over suitable algebraic number fields. Our approach provides a uniform construction of Pad\'{e} approximants of type II, together with a novel non-vanishing argument for generalized Wronskians of Hermite type. This method applies uniformly across all parameter regimes. Even in the case $p = q+1$, we extend known results from single-point to multi-points settings over general number fields, in both complex and $p$-adic settings. When $p < q+1$, we establish linear independence results over arbitrary number fields; and for $p > q+1$, we confirm that the values do not satisfy global linear relations in the $p$-adic setting in a framework of arithmetic Gevrey series. The results generalize and strengthen earlier works, demonstrating the flexibility of our Pad\'{e} construction for families of contiguous hypergeometric functions, through a new non-vanishing proof for the determinant, that is crucial for the universality.

math.NT↗

arXiv2022

Generalized hypergeometric $G$-functions take linear independent values

In this article, we show a new general linear independence criterion related to values of $G$-functions, including the linear independence of values at algebraic points of contiguous hypergeometric functions, which is not known before. Let $K$ be any algebraic number field and $v$ be a place of $K$. Let $r\in\mathbb{Z}$ with $r\ge2$. Consider $a_1,\ldots,a_{r}, b_1,\ldots,b_{r-1}\in \mathbb{Q}\setminus\{0\}$ not being negative integers. Assume neither $a_k$ nor $a_k+1-b_j$ be strictly positive integers $(1\le k \le r, 1\le j \le r-1)$. Let $α_1,\ldots,α_m\in K\setminus\{0\}$ with $α_1,\ldots,α_m$ pairwise distinct. By choosing sufficiently large $β\in \mathbb{Z}$ depending on $K$ and $v$ such that the points $α_1/β,\ldots,α_m/β$ are closed enough to the origin, we prove that the $rm+1$ numbers~$:$ \begin{align*} &{}_{r}F_{r-1} \biggl(\begin{matrix} a_1,\ldots, a_r\\ b_1, \ldots, b_{r-1} \end{matrix} \biggm| \dfrac{α_i}β\biggr)\enspace, \ \ {}_{r}F_{r-1} \biggl(\begin{matrix} a_1+1,\ldots,\ldots,\ldots,a_r+1\\ b_1+1, \ldots, b_{r-s}+1,b_{r-s+1},\ldots,b_{r-1} \end{matrix} \biggm| \dfrac{α_i}β\biggr)\enspace\\ &(1\le i \le m, 1\le s \le r-1)\end{align*} and $1$ are linearly independent over $K$. The essential ingredient is our term-wise formal construction of type II of Padé approximants together with new non-vanishing argument for the generalized Wronskian.

math.NT↗

arXiv2022

Linear independence criteria for generalized polylogarithms with distinct shifts

For a given rational number $x$ and an integer $s\geq 1$, let us consider a generalized polylogarithmic function, often called the Lerch function, defined by $$\Phi_{s}(x,z)= \sum_{k=0}^{\infty}\frac{z^{k+1}}{(k+x+1)^s}\enspace.$$ We prove the linear independence over any number field $K$ of the numbers $1$ and $\Phi_{s_j}(x_j,\alpha_i)$ with any choice of distinct shifts $x_1,\ldots, x_d$ with $0\le x_1<\ldots<x_d<1$, as well as any choice of depths $1\leq s_1\leq r_1,\ldots, 1\leq s_d\leq r_d$, at distinct algebraic numbers $\alpha_1,\ldots,\alpha_m\in K$ subject to a metric condition. As is usual in the theory, the points $\alpha_i$ need to be chosen sufficiently close to zero with respect to a given fixed place $v_0$ of $K$, Archimedean or finite. This is the first linear independence result with distinct shifts $x_1, \ldots, x_d$ that allows values at different points for generalized polylogarithmic functions. Previous criteria were only for the functions with one fixed shift or at one point. Further, we establish another linear independence criterion for values of the generalized polylogarithmic function with cyclic coefficients. Let $q\geq 1$ be an integer and $\boldsymbol{a}=(a_1,\ldots, a_q)\in K^q$ be a $q$-tuple whose coordinates supposed to be cyclic with the period $q$. Consider the generalized polylogarithmc function with coefficients $$\Phi_{\boldsymbol{a},s}(x,z)= \sum_{k=0}^{\infty}\frac{a_{k+1\bmod(q)}\cdot z^{k+1}}{(k+x+1)^s}\enspace.$$ Under suitable condition, we show that the values of these functions are linearly independent over $K$. Our key tool is a new non-vanishing property for a generalized Wronskian of Hermite type associated to our explicit constructions of Pad\'e approximants for this family of generalized polylogarithmic function.

math.NT↗

arXiv2020

Linear Forms in Polylogarithms

Let $r, \,m$ be positive integers. Let $x$ be a rational number with $0 \le x <1$. Consider $\Phi_s(x,z) =\displaystyle\sum_{k=0}^{\infty}\frac{z^{k+1}}{{(k+x+1)}^s}$ the $s$-th Lerch function with $s=1, 2, \cdots, r$. When $x=0$, this is a polylogarithmic function. Let $\alpha_1, \cdots, \alpha_m$ be pairwise distinct algebraic numbers of arbitrary degree over the rational number field, with $0<|\alpha_j|<1 \,\,\,(1\leq j \leq m)$. In this article, we show a criterion for the linear independence, over an algebraic number field containing $\mathbb{Q}(\alpha_1, \cdots, \alpha_m)$, of all the $rm+1$ numbers : $\Phi_1(x,\alpha_1)$, $\Phi_2(x,\alpha_1), $ $\cdots , \Phi_r(x,\alpha_1)$, $\Phi_1(x,\alpha_2)$, $\Phi_2(x,\alpha_2), $ $\cdots , \Phi_r(x,\alpha_2), \cdots, \cdots, \Phi_1(x,\alpha_m)$, $\Phi_2(x,\alpha_m)$, $\cdots , \Phi_r(x,\alpha_m)$ and $1$. This is the first result that gives a sufficient condition for the linear independence of values of the Lerch functions at several distinct algebraic points, not necessarily lying in the rational number field nor in quadratic imaginary fields. We give a complete proof with refinements and quantitative statements of the main theorem announced in [10], together with a proof in detail on the non-vanishing Wronskian of Hermite type.

math.NT↗

arXiv2019

Can polylogarithms at algebraic points be linearly independent?

Let $r,m$ be positive integers. Let $0\le x <1$ be a rational number. Let $\Phi_s(x,z)$ be the $s$-th Lerch function $\sum_{k=0}^{\infty}\tfrac{z^{k+1}}{(k+x+1)^s}$ with $s=1,2,\ldots ,r$. When $x=0$, this is the polylogarithmic function. Let $\alpha_1,\ldots ,\alpha_m$ be pairwise distinct algebraic numbers with $0<|\alpha_j|<1$ $(1 \le j \le m)$. In this article, we state a linear independence criterion over algebraic number fields of all the $rm+1$ numbers $:$ $\Phi_1(x,\alpha_1),\Phi_2(x,\alpha_1),\ldots, \Phi_r(x,\alpha_1),\Phi_1(x,\alpha_2),\Phi_2(x,\alpha_2),\ldots, \Phi_r(x,\alpha_2),\ldots,\Phi_1(x,\alpha_m),\Phi_2(x,\alpha_m),\ldots, \Phi_r(x,\alpha_m)$ and $1$. This is the first result that gives a sufficient condition for the linear independence of values of the $r$ Lerch functions $\Phi_1(x,z),\Phi_2(x,z),\ldots, \Phi_r(x,z)$ at $m$ distinct algebraic points without any assumption for $r$ and $m$, even for the case $x=0$, the polylogarithms. We give an outline of our proof and explain basic idea.

math.NT↗