  We review recent work [1, 2] on obtaining a realisation of the
$\Omega$-background in terms of a special series of higher-derivative
generalised F-terms in the effective $\mathcal{N}=2$ supergravity action. We
discuss the motivation behind the identification of these couplings, their
relation to the Nekrasov partition function and connect them to a worldsheet
approach towards the refined topological string. Presented by the authors at
the Corfu Summer Institute 2013 "Workshop on Noncommutative Field Theory and
Gravity", September 8-15, 2013 Corfu, Greece
