伊藤昇

Title:
Crosscap number two alternaitng knots

Abstract:
In this talk, we determine the set of alternating knots with crosscap number two.  To obtain it, we give an upper bound of the crosscap number.  In the case of the crosscsp number two alternating knots, the bound implies the equality. 
This is a joint work with Yusuke Takimura (Gakushuin Boys' Junior High School).