Seminars and discussions on non-relativistic effective field theories
The program is (Time zone is CET):
13.30 - 14.10: Tomas Brauner (University of Stavanger)
14.10 - 14.50: Diederik Roest (Groningen University)
14.50 - 15.00: short break
15.00 - 15.40: Kurt Hinterbichler (Case Western Reserve University)
15.40 - 16.00: break
16.00 - 17.00 discussion moderated by Natalia Pinzani-Fokeeva (Technion)
The titles of the talks and abstracts can be found below. Pdf files of the talks are linked to the tittles
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Speaker: Tomas Brauner
Title: Exceptional nonrelativistic effective field theories
Abstract: The relationship between spontaneous symmetry breaking and asymptotic properties of scattering amplitudes of Nambu–Goldstone bosons in the long-wavelength limit has attracted renewed interest in the last few years. I will report on one of the first attempts to extend the discussion of this relationship beyond the domain of Lorentz-invariant field theory. I will show how one can use the symmetry point of view to classify possible candidate “exceptional” theories, where the scaling of scattering amplitudes at low energies is expected to be enhanced beyond mere presence of the Adler zero. I will then conclude by briefly mentioning ongoing work, suggesting that the relationship between symmetries and scattering amplitudes is more intricate in the nonrelativistic domain than in the relativistic one.
Speaker: Diederik Roest
Title: Space-time symmetry breaking: Goldstone modes, soft limits and double copies
Abstract: I will outline the generalisation of spontaneously broken internal symmetries to the space-time symmetry case. This will take us from the non-linear sigma model for internal symmetries to the DBI theories and special Galileon for space-time symmetries. Along the way, I will highlight the differences, e.g. that Goldstone's theorem no longer strictly applies and that the soft limit of their amplitudes goes beyond the Adler zero, and outline their geometric interpretation. Time permitting, I will also sketch how the different theories are related by a double copy prescription.
Speaker: Kurt Hinterbichler
Title: Shift Symmetries in (A)dS space
Abstract: I will discuss generalizations of broken spacetime symmetries such as Galileon symmetries and extended Galileon symmetries to (A)dS space and to higher spin. Unlike flat space, these symmetries are present for particles with particular masses, and are related to partially massless symmetries. For the case of scalars, I will discuss non-linear extensions of the symmetries and invariant interactions. This leads to a unique ghost-free theory in (A)dS space that is an (A)dS extension of the special Galileon.
