I left university long ago and have forgotten most of what I learnt from classes. I am now struggling to re-learn mathematics.
Things to learn in 2021:
- undergraduate complex analysis,
- Daniell integral,
- some basic differential geometry and differential forms.
- Loomis and Sternberg, Advanced Calculus (I've been stuck at sec. 9.5 for a long time),
- Angus Taylor, General Theory of Functions and Integration,
- Henri Cartan, Elementary theory of analytic functions of one or several complex variables.