Full relativity playlist:    • Relativity by eigenchris  
Powerpoint slide files: https://github.com/eigenchris/MathNot...
Leave me a tip: https://kofi.com/eigenchris

Ricci Curvature of 3sphere: https://www.physics.mcgill.ca/~rhb/ph...
Ricci Curvature of Hyperbolic plane: https://thatsmaths.files.wordpress.co...
Info on Hyperboloid Model: https://en.wikipedia.org/wiki/Hyperbo...
Hyperbolic Geometry video by Henry Segerman:    • Illuminating hyperbolic geometry  
Alex Flournoy video on FLRW metric:    • General Relativity Topic 26: Cosmolog...  
Dietterich Labs video on FLRW metric:    • Friedmann Equations From The Einstein...  

0:00 Introduction
1:10 Cosmological Principle
4:03 Flat universe and scale factor a(t)
6:52 Closed/spherical universe
12:22 Open/hyperbolic universe
17:55 Unifying the 3 metrics
22:58 ReducedCircumference Polar Coordinates