Analysis of Resparsification
  We show that schemes for sparsifying matrices based on iteratively resampling rows yield guarantees matching classic 'offline' sparsifiers (see e.g. Spielman and Srivastava [STOC 2008]).   In particular, this gives a formal analysis of a scheme very similar to the one proposed by Kelner and Levin [TCS 2013]. 
Jakub Pachocki
cs.DS