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, 202069 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