Domains of definition of Monge-Amp\`ere operators on compact K\"ahler manifolds

Let $(X,\omega)$ be a compact K\"ahler manifold. We introduce and study the largest set $DMA(X,\omega)$ of $\omega$-plurisubharmonic (psh) functions on which the complex Monge-Amp\`ere operator is well defined. It is much larger than the corresponding local domain of definition, though still a proper subset of the set $PSH(X,\om)$ of all $\om$-psh functions. We prove that certain twisted Monge-Amp\`ere operators are well defined for all $\omega$-psh functions. As a consequence, any $\om$-psh function with slightly attenuated singularities has finite weighted Monge-Amp\`ere energy.