# Bounds on bubble wall velocity and application to first-order QCD phase transition

- Institution: CERN
- Department: TH institutes
- Speaker: Benoit Laurent
- Year: 2025
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3021264)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Teens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

In this talk, I will take advantage of recent progress on wall speed determination to provide simple estimates that constrain the wall velocity between two opposite limits: local thermal equilibrium and ballistic. The description of the wall velocity in these limits is significantly simplified compared to conventional methods, which allows for the derivation of analytic formulas valid for slow walls. As an example, I will apply this new approach to the QCD phase transition, which can be made first-order with a large baryon chemical potential. Using these bounds on the wall velocity, I will show that previous studies greatly overestimated the amplitude of GWs produced by assuming luminal wall speeds..

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## Lectures

1. [Bounds on bubble wall velocity and application to first-order QCD phase transition](https://invisiblenetwork.ai/learn/cern/3021264/6f8db4b554b2), 46 min (CERN's player)