Auslander–Reiten sequences and t-structures on the homotopy category of an abelian category

We use t-structures on the homotopy category Kb(R-mod) for an artin algebra R and Wattsʼ representability theorem to give an existence proof for Auslander–Reiten sequences of R-modules. This framework naturally leads to a notion of generalized (or higher) Auslander–Reiten sequences.