English

Lerch's $\Phi$ and the Polylogarithm at the Positive Integers

Number Theory 2021-04-02 v9

Abstract

We review the closed-forms of the partial Fourier sums associated with HPk(n)HP_k(n) and create an asymptotic expression for HP(n)HP(n) as a way to obtain formulae for the full Fourier series (if bb is such that b<1|b|<1, we get a surprising pattern, HP(n)H(n)k2(1)kζ(k)bk1HP(n) \sim H(n)-\sum_{k\ge 2}(-1)^k\zeta(k)b^{k-1}). Finally, we use the found Fourier series formulae to obtain the values of the Lerch transcendent function, Φ(em,k,b)\Phi(e^m,k,b), and by extension the polylogarithm, Lik(em)\mathrm{Li}_{k}(e^{m}), at the positive integers kk.

Keywords

Cite

@article{arxiv.2006.08406,
  title  = {Lerch's $\Phi$ and the Polylogarithm at the Positive Integers},
  author = {Jose Risomar Sousa},
  journal= {arXiv preprint arXiv:2006.08406},
  year   = {2021}
}

Comments

Great simplifications previously unnoticed were applied

R2 v1 2026-06-23T16:20:11.530Z