Equivariant unknotting numbers of strongly invertible knots
数学专题报告
报告题目(Title)：Equivariant unknotting numbers of strongly invertible knots
报告人(Speaker)：陈文钊（上海科技大学）
地点(Place)：#腾讯会议：949-363-763
时间(Time)：2025年4月23日 10:00-11:00
邀请人(Inviter)：程志云
报告摘要
Strongly invertible knots are knots possessing a symmetry that preserves the orientation of the 3-sphere while reversing the knot’s orientation. This talk introduces equivariant unknotting numbers for strongly invertible knots. We will present a natural classification of equivariant crossing changes into type A, B, and C, depending on the interaction of the crossing changes with the symmetry. By examining each type of crossing change, we will see how it leads to the result that the equivariant unknotting number is not additive under the connected sum, in contrast to the long-standing open conjecture on the additivity of the unknotting number. We conclude with some open questions. This talk is based on joint work with Keegan Boyle.
