[17.09.07] What is a good bijection? A case study on pattern-avoiding permutations
- 홍미혜
- 조회수2085
- 2017-09-07
What is a good bijection? A case study on pattern-avoiding permutations
▣ 연 사 : Sergey Kitaev (University of Strathclyde)
▣ 일 시 : 2017년 9월 7일(목) 4:30 - 5:30
▣ 장 소 : 31356A호 (수학과 대학원 세미나실)
▣ 대 상 : 수학과 학부생 및 대학원생
▣ 다 과 : 4시 20분부터
Abstract
A bijection is a one-to-one correspondence between two sets. Usually, there is more than one way to build a bijection between equinumerous sets (and there are of course many if the sets aren't very small and we don't care whether the bijections are intelligible). What is a good bijection between two sets? Is it one that is easy to describe? Or, is it one that better illuminates structural similarity between the sets in question? Even though the answer “it depends” is acceptable here, much more can be said under certain assumptions in certain situations. I will illustrate this idea by going through a remarkable story of a problem in the theory of permutation patterns.
This talk will be accessible for a general audience.