Colloquium / Seminars
Topic：Four-points semidefinite bound for equiangular lines
Speaker：Prof. Yu, Wei-Hsuan
(Department of Mathematics, Nation Central University)
Date time：Mar. 1, 2022 14:00 ~15:00
We offer an alternate version of the three-points semidefinite programming formula for spherical codes and spherical $s$-distance sets. The alternative formulas would be simpler when applying on spherical $s$-distance sets. Furthermore, we use the four-points semidefinite programming method symbolically to sharpen the upper bounds on the cardinality of equiangular lines in $R^d$. Our results improve the bounds for infinitely many dimensions $d$ with prescribed angles.