Tomaszewski's problem on randomly signed sums, revisited

Let $v_1$, $v_2$, …, $v_n$ be real numbers whose squares add up to 1. Consider the $2^n$ signed sums of the form $S=\sum \pm v_i$. Boppana and Holzman (2017) proved that at least 13/32 of these sums satisfy $\mathrm{\mid }S\mathrm{\mid }\le 1$. Here we improve their bound to $0.427685$.