Sparse domination of sharp variational truncations
  We provide a versatile formulation of Lacey's recent sparse pointwise domination technique with a local weak type estimate on a nontangential maximal function as the only hypothesis. We verify this hypothesis for sharp variational truncations of singular integrals in the case when unweighted $L^2$ estimates are available. This extends previously known sharp weighted estimates for smooth variational truncations to the case of sharp variational truncations. We also include a sparse domination result for iterated commutators of multilinear operators with BMO functions. 
Fernanda Clara de Fran\c{c}a Silva and Pavel Zorin-Kranich
math.CA