Department of Mathematics,  Iowa State University Christian G J Roettger

Office 382 Carver

Phone 294-9609

email roettger AT iastate.edu
Christian Roettger

Consulting Hours

Research

Amongst other things, I am interested in

Publications

Upcoming and Recent Events

The continuing story of zeta
ISU Combinatorics/Algebra seminar , Ames, Oct 9, 2006
We aim to give a particularly simple proof of the analytic continuation of the Riemann zeta function to the complex plane, obtaining the values of zeta(s) at negative integers in the process in terms of Bernoulli numbers.

Primitive Prime Divisors of Mersenne numbers via Uniform Distribution
MAA Central Section Meeting, ISU, Ames IA, Apr 7-8 2006
Given a sequence a of integers, a primitive divisor of a(n) is an integer which divides a(n) but no earlier term of the sequence. Last year, we presented a result about a weighted average of primitive prime divisors of the well-known Mersenne numbers M(n) = 2^n-1. This year, we have an entirely different, simple proof of a better result, using cyclotomic polynomials and uniform distribution. We are indebted to Carl Pomerance for helpful insights. We will also mention possible applications to other sequences like the Fibonacci numbers.

Families of Markov shifts determined by periodic point data
AMS Central Section Meeting , Lincoln, NE, Oct 21-23 2005
Here is an Abstract.

Primitive Prime Divisors of Mersenne Numbers and Other Sequences
ISU Combinatorics/Algebra Seminar , Ames, Oct 10, 2005
Work in progress - there was an error in the error term we presented. The best error term we can currently prove is O(T log^(2/3) T loglog^(4/3) T).

Counting matrices in the general linear group over algebraic integers
Workshop on Number Theory and Random Matrix Theory, Waterloo, June 1-3 2005

Families of Markov shifts determined by periodic point data
Canadian Mathematical Society Summer meeting, Ontario, June 4-6 2005

Prime Divisors of Mersenne numbers and Dirichlet Series
MAA Spring Meeting, Apr 1-2 in Pella, IA

Periodic Points determine a class of Markov shifts
Midwest Number Theory Conference for Postdocs and Recent PhDs II, Urbana-Champaign, February 5-6 2005

Teaching

Math 265: Calculus III

Math 307: Matrices and Linear Algebra

Past Courses

Some of the links in these pages will not work anymore. Please email me if you have a question concerning some particular item. But please note that I do not give out model solutions or programming code except to students registered in a particular class of mine.

Math 141/142 Trigonometry (and analytic geometry)

Math 165: Calculus I, Spring 2005

Math 195: Math for Elementary Education

Math 297: Intermediate Topics in Elementary Mathematics

Math 301: Algebra I

Math 314: Graphs and Networks

Math 317: Theory of Linear Algebra

Course notes for Analytic Number Theory

Personal Links

Pros and cons of metric vs imperial system.

This webpage is http://www.public.iastate.edu/~roettger/homepage.html

Comments to roettger AT iastate.edu