Simple questions, difficult answers
Oliver Janzer is a mathematician who specialises in graphs – that is, collections of nodes that may or may not be connected, such as Facebook users. As part of his ETH Fellowship, the young researcher has been busy solving problems that had stumped mathematicians for decades.
Imagine a group of people. Some of them know each other; others have never met. If you connect all the pairs of individuals who know each other, while making no connections between strangers, you end up with a network of nodes and interconnections. Mathematicians refer to such a network as a graph. Social networks like Facebook can be considered as a graph. The theory of these networks is a subfield of combinatorics, a field of mathematics in which Oliver Janzer specialises. The 27-year-old scientist has been working as an ETH Fellow in the group of mathematics professor Benny Sudakov since the autumn of 2020.