SIFT 2024: Strongly-Interacting Field Theories

Thursday 28 Nov 2024, 08:45 → 18:10 Europe/Berlin

This workshop is funded by the research training group RTG 2522 and aims to bring together researchers from different areas of theoretical physics who study manifestations and phenomena of strongly-interacting field theories, in order to allow for a transfer of knowledge and methods. This year's workshop plans to put a special emphasis on research topics related to the quantum theory and quantum field theory branch of the RTG.

The workshop intends to be a platform to stimulate a cross-fertilization between discrete and continuum approaches to strongly-interacting field theories - spanning the range from lattice gauge theory, functional renormalization group methods to gauge/gravity dualities.

08:50 → 09:00 Welcome

09:00 → 09:45 Trace Anomaly Matching -- the complete story

Speaker: Stefan Theisen

09:45 → 09:55 Q&A

09:55 → 10:40 Loops in de Sitter space

In spite of being maximally symmetric, quantum field theory in de Sitter space requires to reconsider a number of concepts familiar in flat space, such as regularisation, analyticity etc. I will describe some of them by considering cosmological correlation functions at 1-and 2-loop level.

Speaker: Ivo Sachs

10:40 → 10:50 Q&A

10:50 → 11:20 Break

11:20 → 12:05 Physics informed RG flows and the lower simplicity bound

Functional renormalisation group (RG) flows have been used since 50 years for the resolution of quantum field theories (QFT) in terms of their generating functionals such as the partition function, the Wilsonian effective action or the one-particle irreducible effective action. From early on, generalised functional RG flows have been devised that do not only accommodate the stepwise integration of fluctuations, commonly in terms of momentum shells, but also general reparameterisations of the theory.

In https://arxiv.org/abs/2409.13679 we introduced a new perspective on generalised RG flows: Instead of viewing them as a tool for the computation of the respective generating functional, one can view them as a tool for resolving the combined flow for the pair of the generating functional and the (composite) field, it is formulated in. This new perspective
opens up new playing fields, both in terms of computational efficiency as well as optimal expansions such as those about the ground state of the theory at hand. In short, this new perspective helps to find and use optimal formulations of the theory at hand, thus zooming in on the 'lower simplicity bound' of a given QFT.

In this talk I report on the structure and existence constraints of these general flows, illustrate its computational prowess within simple examples, discuss its application
within the standard approximation schemes as well as its augmentation with Machine-Learning architectures for efficient computations, and finally indicating its use for sampling algorithms on the lattice.

Speaker: Jan Pawlowski

12:05 → 12:15 Q&A

12:15 → 14:30 Lunch

14:30 → 15:15 Aspects of lattice field theory beyond the standard model

Speaker: Georg Bergner

15:15 → 15:25 Q&A

15:25 → 16:10 Continuous order-to-order transitions from fixed-point annihilation

Speaker: Lukas Janssen

2024-11-jena-janssen.pdf

16:10 → 16:20 Q&A

16:20 → 16:50 Break

16:50 → 17:35 Antiheavy-antiheavy-light-light tetraquarks from lattice QCD

Speaker: Marc Wagner

Slides.pdf

17:35 → 17:45 Q&A