α-mutual information

Renyi entropy and Renyi divergence evidence a long track record of usefulness in information theory and its applications. Alfred Rényi never got around to generalizing mutual information in a similar way. In fact, in the literature there are several possible ways to accomplish such generalization, most notably those suggested by Suguru Arimoto, Imre Csiszár, and Robin Sibson. We collect several interesting properties and applications of the proposal by Sibson, hopefully making a case for its more widespread adoption.