# Superradiant interactions of cosmic relics

- Institution: CERN
- Speaker: Marios Galanis
- Year: 2026
- Language: English
- Subjects: Physics
- Source: [CERN](https://videos.cern.ch/record/3026886)
- Licence: [CERN](https://copyright.web.cern)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

A large ensemble of two-level systems where each is prepared in an equal superposition of ground and excited states is the quantum analogue of a classical oscillating dipole. Scattering of weakly interacting particles off such a dipole is dramatically enhanced due to collective effects analogous to Dicke superradiance, where the de-excitation and excitation rates of the ensemble scale as the square of the number of particles in the system, $N^2$. The term ``superradiant interactions'' was coined to describe these coherent inelastic processes. Furthermore, because of this collective enhancement, scattering can quickly become non-perturbative, as $N$ is increased. In this talk, I will explain the theory behind coherent inelastic processes, both in the perturbative and non-perturbative regimes, and derive observables appropriate for table-top experiments. Next, I will discuss a forthcoming proposal for demonstrating these effects utilizing thermal neutrons. Finally, if time permits, I will introduce a quantum protocol for nuclear spin squeezing that may allow us to probe a variety of Beyond the Standard Model particles, including QCD axion Dark Matter and the irreducible abundance of millicharged particles.

00:00:00 Slide 1

00:02:26 Slide 2

00:03:29 Slide 3

00:03:54 Slide 4

00:04:08 Slide 5

00:04:28 Slide 6

00:05:23 Slide 7

00:05:48 Slide 8

00:06:19 Slide 9

00:08:20 Slide 10

00:09:39 Slide 11

00:10:46 Slide 12

00:12:13 Slide 13

00:14:08 Slide 14

00:14:40 Slide 15

00:25:45 Slide 16

00:26:01 Slide 17

00:27:58 Slide 18

00:29:12 Slide 19

00:30:15 Slide 20

00:34:10 Slide 21

00:34:26 Slide 22

00:36:16 Slide 23

00:39:10 Slide 24

00:39:23 Slide 25

00:41:40 Slide 26

00:42:04 Slide 27

00:43:22 Slide 28

00:44:12 Slide 29

00:49:32 Slide 30

00:49:46 Slide 31

00:49:59 Slide 32

00:50:32 Slide 33

00:52:07 Slide 34

00:55:16 Slide 35

00:55:54 Slide 36

00:56:11 Slide 37

00:58:10 Slide 38

00:58:44 Slide 39

00:59:48 Slide 40

01:00:21 Slide 41…

## Lectures

1. [Superradiant interactions of cosmic relics](https://invisiblenetwork.ai/learn/cern/3026886/eeeb5a34a116), 1 h 3 min (CERN's player)