# No-Go theorems for ekpyrosis from ten-dimensional supergravity

- Institution: CERN
- Department: Conferences & Workshops
- Speaker: Kunihito Uzawa
- Year: 2019
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3019309)
- 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, we present whether the new ekpyrotic scenario can be embedded into ten-dimensional supergravity. We use that the scalar potential obtained from flux compactifications of type II supergravity with sources has a universal scaling with respect to the dilaton and the volume mode. Similar to the investigation of inflationary models, we find very strong constraints ruling out ekpyrosis from analyzing the fast-roll conditions. We conclude that flux compactifications tend to provide potentials that are neither too flat and positive (inflation) nor too steep and negative (ekpyrosis)..

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## Lectures

1. [No-Go theorems for ekpyrosis from ten-dimensional supergravity](https://invisiblenetwork.ai/learn/cern/3019309/847fcc62b4c3), 13 min (CERN's player)