Information: All seminars and talks are presented in English, unless otherwise noted. Therefore, this page is only available in the English language.

ABSTRACT: 

One fundamental problem in decentralized networked systems is to coordinate activities of different nodes so that they reach a state of agreement. This global objective is typically obtained by local operations, for example, by employing gossip algorithms to achieve consensus over a set of agents, where several data exchanges are iteratively carried out between pairs of adjacent nodes. In these works the consensus is often given as a global function of all local observations, as for example an average of the same random process over all observing nodes. In contrast, we are interested in a generalization of this problem where consensus is meant in a broader sense of achieving coordinated actions by the network nodes, and therefore can be seen as an instance of distributed control in networks. This cooperative behavior is useful in a host of applications, for example in multi-agent systems for exploration of an unknown terrain, distributed surveillance applications, automatic vehicle control applications, or load balancing with divisible tasks in a large computer networks or power grids. We measure coordination by the ability to achieve a prescribed joint probability distribution of actions at all nodes in the network, and cooperation is measured by the communication rates required to achieve coordination.

In this talk we address the coordination of multiagent systems over point-to-point channels and small multiterminal networks. We specify inner and outer bounds for the coordination capacity region for the coordination of agents along a line and in a broadcast setting and show that for a given coordination demand the choice of the communication topology has a direct effect on the achievable rate. Finally, for point-to-point coordination a low complexity construction is presented based on polar codes which achieves a subset of the (strong) coordination capacity region.

BIO: