Congratulations to Jonah Varney (shown left) for passing his PhD viva! It took place today (Tuesday 2 November). Jonah’s thesis is entitled “Marginal Instability of Matrix Systems“. The External Examiner was Tom Kempton (Manchester) and the Internal was Jon Bevan. The project was supervised by Ian Morris (formerly Surrey, now at Queen Mary University London). Jonah‘s thesis is concerned with marginally unstable discrete linear inclusions and fibre-bunched linear cocycles.