# Axion RG flows and a bound on axion excursions

- Institution: CERN
- Department: Conferences & Workshops
- Speaker: Lukas Witkowski
- Year: 2019
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3001136)
- 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)

I will discuss axionic holographic RG flow solutions in the context of general Einstein-Axion-Dilaton theories, where a non-trivial axion profile is dual to the (non-perturbative) running of the theta-term for the corresponding instanton density operator. I will show that a non-trivial axion solution is incompatible with a non-trivial (holographic) IR conformal fixed point. Imposing a suitable axion regularity condition allows to select the IR geometry in a unique way. Interestingly, the regularity condition always implies a finite allowed range for the axion source parameter in the UV. This translates into the existence of a finite (but large) number of saddle-points in the large N limit. This ties in well with axion-swampland conjectures..

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## Lectures

1. [Axion RG flows and a bound on axion excursions](https://invisiblenetwork.ai/learn/cern/3001136/fecadd4a7ffa), 16 min (CERN's player)