Ergodic recurrence and bounded gaps between primes
  Let $(X,B_X,\mu,T)$ be a measure-preserving probability system with $T$ is invertible. Suppose that $A\in B_X$ with $\mu(A)>0$ and $\epsilon>0$. For any $m\geq 1$, there exist infinitely many primes $p_0,p_1,\ldots,p_m$ with $p_0<\cdots<p_m$ such that $$ \mu(A\cap T^{-(p_i-1)}A)\geq \mu(A)^2-\epsilon $$ for each $0\leq i\leq m$ and $$ p_m-p_0<C_m, $$ where $C_m>0$ is a constant only depending on $m$, $A$ and $\epsilon$. 
Hao Pan
math.NT math.DS