[Seminar] What is Negative Coupling Field Theory? | Prof. Paul Romatschke (TU Wien)

The speaker:Prof. Paul Romatschke (TU Wien)

Title: What is Negative Coupling Field Theory?

Abstract: Quantum Field Theory is a mature technology that is highly predictive. Most textbooks construct quantum field theory as an expansion for small positive coupling around classically stable vacua, which is a perfectly reasonable thing to do. However, history tells us that quantum mechanics sometimes does not conform to classical intuition. For instance, the hydrogen atom does not have a classically stable ground state, but is stable quantum mechanically. Similarly, negative coupling systems typically have upside-down potentials that do not possess a classically stable ground state. In this talk, I will give arguments why some negative coupling systems nevertheless are stable and physically acceptable quantum mechanically. In these theories, physical observables behave reasonably, with no indication of instabilities despite the missing classical intuition. I will point out the curious implications for our understanding of quantum field theory as well as for high energy physics observables that arise from treating negative coupling field theories as acceptable continuum descriptions of nature.

Date and time: 10th February Tuesday at 16:00

Location: TBA