Nuclear matrix elements for dark matter searches, $\mu\to e$ conversion in nuclei, and lepton flavor violation

Precision measurements of low-energy observables can provide constraints on physics beyond the Standard Model that are complementary to direct searches at the energy frontier. However, in order to unambiguously establish anomalies that signal departures from the Standard Model or at least extract robust limits on the New-Physics parameter space, calculations of hadronic matrix elements with controlled uncertainties are becoming increasingly important. In the talk, these nuclear aspects of New-Physics searches will be discussed in the context of dark-matter direct-detection experiments as well as lepton flavor symmetries.