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Unfriendly Partitions of Graphs

February 21, 2024, 12:15 PM - 1:15 PM

Location:

Mathematics Graduate Student Lounge -- 7th Floor

Rutgers University

Hill Center

Mathematics Department

110 Frelinghuysen Road

Piscataway, NJ 08854

Caleb Fong, Rutgers University

The Unfriendly Partition Conjecture posits that every countable graph can be bipartitioned in such a way that each vertex has more neighbours outside its own part (i.e., has an unfriendly partition). This is still wide open, so I will also talk about some variations of this study in the context of directed graphs and list colouring. We will hopefully encounter different flavours of proof (compactness, probabilistic, linear algebraic) and several open problems.