Abstract

We compute the null cusp anomalous dimension of ABJM theory at strong coupling up to two- loop order. This is done by evaluating corrections to the corresponding superstring partition function, weighted by the AdS(4) x CP3 action in AdS light- cone gauge. We compare our result, where we use an anomalous shift in the AdS4 radius, with the cusp anomaly of N = 4 SYM, and extract the two- loop contribution to the non- trivial integrable coupling h(.) of ABJM theory. It coincides with the strong coupling expansion of the exact expression for h(.) recently conjectured by Gromov and Sizov. Our work provides thus a non- trivial perturbative check for the latter, as well as evidence for two- loop UV- finiteness and quantum integrability of the Type IIA AdS4 x CP3 superstring in this gauge.