Structures in young planet-forming discs: an apparent contradiction between observations and theory

Observations over the last few years of protoplanetary discs – the birth environments of planets – have presented a startling revelation: ring and gap structures are common. The most intriguing and revolutionary of all observations is that such ring and gap features are present in extremely young discs(▯<0.5 million years old), which would be expected to be self-gravitating. However, such features in young discs are at odds with well-established theoretical expectations which show that their high masses should lead to characteristic spiral structures. In this talk I will present recent results that show how we may reconcile this apparent contradiction.