English

Counting solutions without zeros or repetitions of a linear congruence and rarefaction in b-multiplicative sequences

Number Theory 2016-02-10 v2

Abstract

Consider a strongly bb-multiplicative sequence and a prime pp. Studying its pp-rarefaction consists in characterizing the asymptotic behaviour of the sums of the first terms indexed by the multiples of pp. The integer values of the "norm" 33-variate polynomial Np,i1,i2(Y0,Y1,Y2) ⁣:= ⁣j=1p1(Y0+ζpi1jY1+ζpi2jY2),\mathcal N_{p,i_1,i_2}(Y_0,Y_1,Y_2)\!:=\!\prod_{j=1}^{p-1}\left(Y_0{+}\zeta_p^{i_1j}Y_1{+}\zeta_p^{i_2j}Y_2\right), where ζp\zeta_p is a primitive pp-th root of unity, and i1,i2{1,2,,p1},i_1,i_2{\in}\{1,2,\dots,p{-}1\}, determine this asymptotic behaviour. It will be shown that a combinatorial method can be applied to Np,i1,i2(Y0,Y1,Y2).\mathcal N_{p,i_1,i_2}(Y_0,Y_1,Y_2). The method enables deducing functional relations between the coefficients as well as various properties of the coefficients of Np,i1,i2(Y0,Y1,Y2)\mathcal N_{p,i_1,i_2}(Y_0,Y_1,Y_2), in particular for i1=1,i2=2,3.i_1{=}1,i_2{=}2,3. This method provides relations between binomial coefficients. It gives new proofs of the two identities j=1p1(1ζpj)=p\prod_{j=1}^{p-1}\left(1{-}\zeta_p^j\right){=}p and j=1p1(1+ζpjζp2j)=Lp\prod_{j=1}^{p-1}\left(1{+}\zeta_p^j{-}\zeta_p^{2j}\right){=}L_p (the pp-th Lucas number). The sign and the residue modulo pp of the symmetric polynomials of 1+ζpζp21{+}\zeta_p{-}\zeta_p^2 can also be obtained. An algorithm for computation of coefficients of Np,i1,i2(Y0,Y1,Y2)\mathcal N_{p,i_1,i_2}(Y_0,Y_1,Y_2) is developed.

Keywords

Cite

@article{arxiv.1403.0542,
  title  = {Counting solutions without zeros or repetitions of a linear congruence and rarefaction in b-multiplicative sequences},
  author = {Alexandre Aksenov},
  journal= {arXiv preprint arXiv:1403.0542},
  year   = {2016}
}

Comments

31 pages, 2 figures. Published in Journal de Theorie des Nombres de Bordeaux