Combinatorics seminar
Combinatorics Seminar  Fall 2014
Tuesday, 1011am
Room 209, Goldsmith building
The Combinatorics Seminar is an introductory seminar for combinatorics. The talk should be accesible to first year graduate students.

Tuesday September 30
Speaker: Yan Zhuang
Title: Counting Permutations by Alternating Descents
Abstract: We find the exponential generating function for permutations with all valleys even and all peaks odd, and use it to determine the asymptotics for its coefficients, answering a question posed by Liviu Nicolaescu. We give two proofs for the generating function. The first proof uses a system of differential equations whose solution gives the generating function. For the second proof, we develop a new method for counting permutations by alternating descents using noncommutative symmetric functions. This is joint work with Ira Gessel.

Tuesday October 7
Speaker: TBA
Title: TBA
Abstract: TBA

Tuesday October 14
Speaker: TBA
Title: TBA
Abstract: TBA
Previous semesters:
Spring 2014,
Fall 2013.