  New model-independent compact representations of imaginary-time data are
presented in terms of the intermediate representation (IR) of analytical
continuation. This is motivated by a recent numerical finding by the authors
[J. Otsuki et al., arXiv:1702.03056]. We demonstrate the efficiency of the IR
through continuous-time quantum Monte Carlo calculations of an Anderson
impurity model. We find that the IR yields a significantly compact form of
various types of correlation functions. The present framework will provide
general ways to boost the power of cutting-edge diagrammatic/quantum Monte
Carlo treatments of many-body systems.
