Impact of binary interactions and mergers on core-collapse supernova progenitors

As many young massive stars are found in close binaries, many core-collapse supernova progenitors are expected to experience binary interaction before exploding. SN progenitors experience some kind of mass exchange with a companion, including mass stripping, mass accretion, and/or merging. In this talk I will focus mainly on the merger progenitors of hydrogen-rich core-collapse supernovae, their expected rates, and the possible observational implications of these. The variety of the binary evolutionary scenarios, mostly mergers, may potentially help explain the diversity in the observed properties of type II SN and may account for a portion of some peculiar type II subclasses. I will also discuss these results in the context of the red supergiant problem, i.e., the lack of direct observational detections of high mass progenitors of Type II SNe.