What Makes a Distributed Problem Truly Local?

International audienceIn this talk we attempt to identify the characteristics of a task of distributed network computing, which make it easy (or hard) to solve by meansof fast local algorithms. We look at specific combinatorial tasks within the LOCAL model of distributed computation, and rephrase some recent algorithmic results in a framework of constraint satisfaction. Finally, we discuss the issue of efficient computability for relaxed variants of the LOCAL model, involving the so-called non-signaling property