Semidefinite Programming Bounds for the Average Kissing Number
Speaker:
Alexander Kolpakov, Université de Neuchâtel
Date and Time:
Thursday, May 13, 2021 - 1:00pm to 1:30pm
Location:
Online
Abstract:
The average kissing number of $\mathbb{R}^n$ is the supremum of the average degrees of contact graphs of packings of finitely many balls (of any radii) in $\mathbb{R}^n$. We provide an upper bound for the average kissing number based on semidefinite programming that improves previous bounds in dimensions $3, \ldots, 9$. A very simple upper bound for the average kissing number is twice the kissing number: in dimensions $6, \ldots, 9$ our new bound is the first improvement since about 20 years. This is a joint work with Maria Dostert (KTH Stockholm) and Fernando Oliveira (TU Delft).