I had the pleasure of attending the UChicago Mathematics REU, which was held from June 2021 to August 2021. I attended problem sessions and lectures on combinatorics, projective geometry, and abstract algebra, taught by UChicago professor Daniil Rudenko. My final expository paper, was on the Dollar Game on finite graphs, discussing winning algorithms and conditions for winnability. I also showed its application to a proof of the Riemann-Roch theorem for graphs, a graph-theoretic analogue of the Riemann-Roch theorem for surfaces.
The paper can be found here and the program homepage here.
I wrote down all the problem sets and my solutions in LaTeX (including figures in Tikz), which can be found in this repository in their respective directories.