0.25

0.5

0.75

1.25

1.5

1.75

2

# From materials to cosmology Studying the early universe under the microscope

Published on Jan 31, 202058 Views

#### Related categories

#### Chapter list

From materials to cosmology Studying the early universe under the microscope - 100:00

From materials to cosmology Studying the early universe under the microscope - 200:12

Quiz01:47

“Standard Model” of Cosmology - 104:33

“Standard Model” of Cosmology - 205:33

Spontaneous symmetry lowering phase transition in a ferromagnet07:07

1. Choice of multiple equivalent low-symmetry states08:16

2. Defect formation at symmetry-lowering phase transitions - 109:21

2. Defect formation at symmetry-lowering phase transitions - 210:09

2. Defect formation at symmetry-lowering phase transitions - 310:13

2. Defect formation at symmetry-lowering phase transitions - 410:15

Defects in ferromagnets: Domain walls11:57

Spontaneous symmetry lowering at the Grand Unification Transition13:09

Different regions of the early universe choose different equivalent ground states - 114:19

Different regions of the early universe choose different equivalent ground states - 214:42

As the universe expands through the transition, the low symmetry regions grow…14:47

and eventually meet!14:50

The angle mismatch in the low-symmetry vacuum is a topologically protected one-dimensional defect (Kibble)14:53

A detail: How many cosmic strings should we have? 17:31

Do cosmic strings exist? How can we study them?18:55

How is Cosmic String Formation at the Grand Unification Transition studied? - 120:03

How is Cosmic String Formation at the Grand Unification Transition studied? - 220:37

Instead we will study the GUT in our laboratory!21:03

Where to find a suitable material? Multiferroics: Multiple ferroic orders…25:12

…and multiple defects from spontaneous symmetry-lowering transitions26:51

Our material: Multiferroic YMnO3 - 127:31

Our material: Multiferroic YMnO3 - 228:59

Look at these distortions in more detail: - 132:39

Look at these distortions in more detail: - 234:21

Calculate the form of the potential using symmetry analysis and density functional theory35:04

And the details of our “Mexican Hat-like” potential make it easy for us to measure! - 137:04

And the details of our “Mexican Hat-like” potential make it easy for us to measure! - 237:21

The meeting points of the ferroelectric domains are in fact one-dimensional “strings”38:10

The structural phase transition in multiferroic YMnO3 provides an analogue to the Grand Unification Transition38:27

What experiment would we like to do on the early universe?39:51

Testing the predicted “Kibble-Zurek scaling” for defect formation42:41

Comparison of predicted Kibble-Zurek scaling with experiment44:42

”Beyond-KZ regime” and unexpected dependence on chemistry45:52

Open questions:46:51

Summary48:22