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This article is cited in 6 scientific papers (total in 6 papers)
Algebraic independence of certain almost polyadic series
V. Yu. Matveev
Abstract:
The paper describes the arithmetic nature of the values at integer points of series from the so-called class of F-series which constitute a solution of a system of linear differential equations with coefficients — rational functions in z.
We consider a subclass of the series consisting of the series of the form
∞∑n=0an⋅n!zn
where an∈Q, |an|≤ec1n, n=0,1,… with some constant c1. Besides there exists a sequence of positive integers dn such that dnak∈Z, k=0,…,n and dn=d0,ndn, d0,n∈N, n=0,1,…,d∈N and for any n the number d0,n is divisible only by primes p such that p⩽c2n. Moreover
ordpn≤c3(logpn+np2).
We say then that the considered series belongs to the class F(Q,c1,c2,c3,d).
Such series converge at a point z∈Z, z≠0 in the field Qp for almost all primes p.
The direct product of the rings Zp of p-adic integers over all primes p is called the ring of polyadic integers. It's elements have the form
a=∞∑n=0an⋅n!,an∈Z
and they can be considered as vectors with coordinates a(p) which are equal to the sum of the series a in the field Qp (This direct product is infinite).
For any polynomial P(x) with integer coefficients we define P(a) as the vector with coordinates P(a(p)) in Qp. According to the classification, described in V. G. Chirskii's works we call polyadic numbers a1,…,am infinitely algebraically independent, if for any nonzero polynomial P(x1,…,xm) with integer coefficients there exist infinitely many primes p such that
P(a(p)1,…,a(p)m)≠0
in Qp.
The present paper states that if the considered F-series f1,…,fm satisfy a system of differential equations of the form
P1,iy′i+P0,iyi=Qi,i=1,…,m
where the coefficients P0,i,P1,i,Qi are rational functions in z and if ξ∈Z, ξ≠0, ξ is not a pole of any of these functions and if
exp(∫(P0,i(z)P1,i(z)−P0,j(z)P1,j(z))dz)∉C(z)
then
f1(ξ),…,fm(ξ) are infinitely algebraically independent almost polyadic numbers.
For the proof we use a modification of the Siegel–Shidlovsky's method and V. G. Chirskii's. Salikhov's approach to prove the algebraic independence of functions, constituting a solution of the above system of differential equations.
Bibliography: 30 titles.
Keywords:
algebraic independence, almost polyadic numbers.
Received: 30.06.2016 Accepted: 13.09.2016
Citation:
V. Yu. Matveev, “Algebraic independence of certain almost polyadic series”, Chebyshevskii Sb., 17:3 (2016), 166–177
Linking options:
https://www.mathnet.ru/eng/cheb504 https://www.mathnet.ru/eng/cheb/v17/i3/p166
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