Differential Geometry
Justin Solomon’s introduction:
https://www.youtube.com/watch?v=S_bUBfdffRU&list=PLaLOVNqqD-2GZm2y9Y0c1o9jhoMo0gmta
Eigenchris tensors & tensor calculus:
Tensors: https://www.youtube.com/watch?v=TvxmkZmBa-k&list=PLJHszsWbB6hrkmmq57lX8BV-o-YIOFsiG&index=3
Tensor Calculus: https://www.youtube.com/watch?v=kGXr1SF3WmA&list=PLJHszsWbB6hpk5h8lSfBkVrpjsqvUGTCx
Riemannian geometry & optimization: https://www.nicolasboumal.net/book/