Paul Romatschke (Vienna): What if phi^4 theory in 4 dimensions is non-trivial in the continuum

Dienstag, 4. November 2025 14:00

Ort: Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock

Traditionally, scalar phi^4 theory in four dimensions is thought to be quantum trivial in the continuum. In this talk, I critically review what quantum triviality is, and in particular which parts of the idea have actually been mathematically proved as opposed to just assumed to be true. I go on to exploit loopholes in the mathematical
proofs, notably multi-component fields, to present a concrete calculation that avoids quantum triviality in scalar phi4 theory in the continuum. There is a price to pay to avoid triviality, but there are also potentially rich rewards. Your mileage will vary.
Whatever the outcome, it is great fun to work on this subject!

Location:

Erwin-Schrödinger-Hörsaal, Boltzmanngasse 5, 5. Stock