On sums of subsets of Chen primes
  In this paper we show that if $A$ is a subset of Chen primes with positive relative density $\alpha$, then $A+A$ must have positive upper density at least $c\alpha e^{-c^\prime\log(1/\alpha)^{2/3}(\log\log(1/\alpha))^{1/3}}$ in the natural numbers. 
Zhen Cui, Hongze Li and Boqing Xue
math.NT