%0 Journal Article
%T Sums of four squares of primes
%A Angel V. Kumchev
%A Lilu Zhao
%J Mathematics
%D 2015
%I arXiv
%X Let $E(N)$ denote the number of positive integers $n \le N$, with $n \equiv 4 \pmod{24}$, which cannot be represented as the sum of four squares of primes. We establish that $E(N)\ll N^{11/32}$, thus improving on an earlier result of Harman and the first author, where the exponent $7/20$ appears in place of $11/32$.
%U http://arxiv.org/abs/1503.01799v1