New bounds for equiangular lines and Balla's conjecture

Chuanyuan Ge, Shiping Liu

Let $N_{\alpha }(d)$ denote the maximum number of equiangular lines in ${\mathbb{R}}^d$ with common angle $\arccos (\alpha )$. Balla conjectured that, if the spectral radius order $κ_{\frac{1-α}{2α…