  In previous investigations, it was found that four-sided polygonal light-like
Wilson loops in ABJM theory calculated to two-loop order have the same form as
the corresponding Wilson loop in N = 4 SYM at one-loop order. Here we study
light-like polygonal Wilson loops with n cusps in planar three-dimensional
Chern-Simons and ABJM theory to two loops. Remarkably, the result in ABJM
theory precisely agrees with the corresponding Wilson loop in N = 4 SYM at
one-loop order for arbitrary n. In particular, anomalous conformal Ward
identites allow for a so-called remainder function of conformal cross ratios,
which is found to be trivial at two loops in ABJM theory in the same way as it
is trivial in N = 4 SYM at one-loop order. Furthermore, the result for
arbitrary n obtained here, allows for a further investigation of a Wilson loop
/ amplitude duality in ABJM theory, for which non-trivial evidence was recently
found by a calculation of four-point amplitudes that match the Wilson loop in
ABJM theory.
