Tag Archives: induced subgraphs

Induced subgraphs of power and commuting graphs

For those who like thinking about these things, here is a small observation and a few problems. As I have recently discussed, the power graph of a group is perfect. This means that all its induced subgraphs are perfect, and … Continue reading

Posted in open problems | Tagged , , | 3 Comments

British Mathematical Colloquium, days 3 and 4

The day began with the plenary talk by Paul Seymour, whom I’ve known for longer than almost anyone else at the meeting. He explained that there are many different “ordering” relations on graphs; the two he considers most important are … Continue reading

Posted in events | Tagged , , , , , | 3 Comments

London Combinatorics Colloquia

The second speaker at this year’s Queen Mary colloquium, János Pach, said at the start of his talk that he first came to Britain as a backpacker some years ago; at that time he never imagined that by now there … Continue reading

Posted in events | Tagged , , , , , , , | Leave a comment