Anatoly Vershik

Abstract:   Two examples of universal objects in combinatorics are the well-known Rado graph (1964), and the less known Urysohn universal metric space (1924). Both these objects are generic and random in a precise sense - due to Erdos-Renyi (1963) for the Rado graph, and to the speaker (2003) for the Urysohn space. Similar structures can be found in many other categories. We are mostly interested in the automorphism groups of these universal objects. No preliminary knowledge of the subject is assumed.

Here are some directions to Northeastern University. Lake Hall and Nightingale Hall can be best accessed from the entrance on the corner of Greenleaf Street and Leon Street. The two halls are connected, with no well-defined boundary in between. In particular, 509 Lake Hall is on the same corridor as 544 Nightingale Hall.

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