# Fixed points of 4D quantum field theories - and what they can do for us

- Institution: CERN
- Department: Theory Colloquia
- Speaker: Daniel Litim
- Year: 2024
- Language: English
- Subjects: Physics
- Source: [CERN](https://videos.cern.ch/record/3006710)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

Fixed points in quantum and statistical field theory are responsible for a large variety of phenomena. Low energy fixed points often entail quantum, thermal, or topological phase transitions, (chiral) symmetry breaking, or the generation of mass, while high energy fixed points are at the root of a fundamental definition of QFT such as in asymptotic freedom or safety.

In this talk, I discuss the prospects for UV and IR fixed points in general 4d quantum field theories. This covers an overview of rigorous results at weak coupling including strict no-go theorems and concrete examples. I also explain the central role of non-abelian gauge fields, and how strongly interacting fixed points can be identified with the help of supersymmetry. Links with conformal field theory and new directions for model building are indicated. If time permits, I'll also report on the status for fixed points in quantum gravity. .

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## Lectures

1. [Fixed points of 4D quantum field theories - and what they can do for us](https://invisiblenetwork.ai/learn/cern/3006710/7bb9f7e6f29d), 1 h 17 min (CERN's player)