Dynamical Borel-Cantelli lemmas and rates of growth of Birkhoff sums of   non-integrable observables on chaotic dynamical systems
  We consider implications of dynamical Borel-Cantelli lemmas for rates of growth of Birkhoff sums of non-integrable observables $\varphi(x) = d(x,p)^{-k}$, $k>0$, on ergodic dynamical systems $(T,X,\mu)$ where $\mu(X) = 1$. Some general results are given as well as some more concrete examples involving non-uniformly expanding maps, intermittent type maps as well as uniformly hyperbolic systems. 
Meagan Carney, Matthew Nicol
math.DS