English

Magic partition functions: Sign smoothing convolutions with Dirichlet invertible arithmetic functions

Number Theory 2026-03-10 v1

Abstract

Sign changes in sums of arithmetic functions and their inverses are a subtle topic with room to grow new results. Suppose that Sf(x):=nxf(n)S_f(x) := \sum_{n \leq x} f(n) is the summatory function of some arithmetic function ff such that f(1)1f(1) \neq 1. There are known lower bounds on the limiting growth of V(Sf,Y)V(S_f, Y) -- the number of sign changes of Sf(y)S_f(y) on the interval y(0,Y]y \in (0, Y] as YY \rightarrow \infty. We observe a partition theoretic sign smoothing by discrete convolution of the local oscillatory properties of the Dirichlet inverse of ff, Sf1(x)S_{f^{-1}}(x). These so-called invertible ``magic partition function`` encodings lead to a sequence of convolution sums which have predictable sign properties provided the sequence of f(n)f(n) (f1(n)f^{-1}(n), respectively) has reasonable asymptotic upper bounds with respect to nn.

Keywords

Cite

@article{arxiv.2603.06890,
  title  = {Magic partition functions: Sign smoothing convolutions with Dirichlet invertible arithmetic functions},
  author = {Maxie Dion Schmidt},
  journal= {arXiv preprint arXiv:2603.06890},
  year   = {2026}
}

Comments

Keywords: Arithmetic functions; Dirichlet inverse; Dirichlet convolution; Dirichlet series; sign changes of arithmetic function; smoothing transformations; Cauchy product; discrete convolution

R2 v1 2026-07-01T11:08:00.896Z