Partition asymptotics; zeros of zeta functions; and Apéry-like numbers

PART I G. H. Hardy and S. Ramanujan established an asymptotic formula for the number of unrestricted partitions of a positive integer, and claimed a similar asymptotic formula for the number of partitions into perfect kth powers, which was later proved by E. M. Wright. Recently, R. C. Vaughan provided a simpler asymptotic formula in the case k = 2. In the first part of the thesis, we study the number of partitions into parts from a specific set Ak(a0; b0) :={mk : m 2 N;m _ a0 (mod b0)}, for fixed positive integers k, a0; and b0. Using the Hardy-Littlewood circle method, we give an asymptotic formula for the number of such partitions, thus generalizing the aforementioned results of Wright and Vaughan. We also consider the parity problem for such partitions and prove that the number of such partitions is even (odd) infinitely often, which generalizes O. Kolberg's theorem for the ordinary partition function. This material builds on the joint work with B. C. Berndt and A. Zaharescu. PART II The Riemann Hypothesis implies that the zeros of all the derivatives of the Riemann-_ function lie on the critical line. Results on the proportion of zeros on the critical line of derivatives of _(s) have been investigated before by B. Conrey, and I. Rezvyakova. The percentage of zeros of _(k)(s) on the critical line approaches 100% percent as k increases. The second part of this thesis builds on the joint work with S. Chaubey, N. Robles, and A. Zaharescu. We study the zeros of combinations of derivatives of _(s). Although such combinations do not always have all their zeros on the critical line, we show that the proportion of zeros on the critical line still tends to 1. PART III The third part of this thesis focuses on the work on Apéry-like numbers joint with Armin Straub. In 1982, Gessel showed that the Apéry numbers associated to the irrationality of _(3) satisfy Lucas congruences. Our main result is to prove corresponding congruences for all known sporadic Apéry-like sequences. In several cases, we are able to employ approaches due to McIntosh, Samol-van Straten and Rowland-Yassawi to establish these congruences. However, for the sequences labeled s18 and (_) we require a finer analysis. As an application, we investigate modulo which numbers these sequences are periodic. In particular, we show that the Almkvist-Zudilin numbers are periodic modulo 8, a special property which they share with the Apéry numbers. We also investigate primes which do not divide any term of a given Apéry -like sequence.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mathematics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2017

Author dc:creator

• Malik, Amita

Contributors dc:contributor

• Berndt, Bruce C.
• Zaharescu, Alexandru
• Diamond, Harold G.
• Ford, Kevin

• Riemann zeta function
• Partitions
• Arithmetic progressions
• Parity
• Asymptotics
• Zeros
• Proportion
• Apéry numbers

Statement dc:rights

• Copyright 2017 Amita Malik

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/98291

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/98291