# Weyl Fermion Creation by Cosmic Perturbations at 1-loop

- Institution: CERN
- Department: TH institutes
- Speaker: Azadeh Maleknejad
- Year: 2024
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3019712)
- 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)

Weyl spin 1/2 fermions, when minimally coupled to Einstein's gravity, cannot be produced purely gravitationally in an expanding universe at tree level. However, this picture changes at the gravitational 1-loop level in the presence of cosmic perturbations, leading to a new and unavoidable mechanism for gravitational particle production. In this talk, I will explore the theory and phenomenological implications of this new effect..

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## Lectures

1. [Weyl Fermion Creation by Cosmic Perturbations at 1-loop](https://invisiblenetwork.ai/learn/cern/3019712/2eec1ad26896), 45 min (CERN's player)