The Ozsv{\'a}th-Szab{\'o} and Rasmussen concordance invariants are not   equal
  In this paper we present several counterexamples to Rasmussen's conjecture that the concordance invariant coming from Khovanov homology is equal to twice the invariant coming from Ozsv{\'a}th-Szab{\'o} Floer homology. The counterexamples are twisted Whitehead doubles of the (2,2n+1) torus knots. 
Matthew Hedden and Philip Ording