Nigel J. E. Pitt
Professor and Chair, Department of Mathematics and Statistics
University of Maine
Title: Three ways to study number-theoretic sums
Abstract: We will apply the
elementary method of counting lattice points (due to Gauss and
Dirichlet) as a tool to estimate the average size of the divisor
function, and compare this to the other classical approach via Fourier
analysis (due largely to Sierpinski and Voronoi). We will then use this
second method to introduce some L-functions, and see how their
arithmetic structure allows us to consider sums of multiplicative
functions over prime numbers, in particular their relationship to
theorems of "prime number theorem type" and to conjectures such as the
Riemann hypothesis. Finally, we will consider some questions
about sums of non-multiplicative functions. The focus of the talk will
be on the ideas behind the results rather than rigor, and proofs will
be sketched or omitted completely. The talk is intended for
non-specialists, including students.
Refreshments at 3:30pm in Neill 216.