Rasmussen conducts research in arithmetic geometry and computational number theory. 

Rasmussen's work on the arithmetic of abelian varieties studies the absolute Galois group through its representation on geometric objects, such as the outer automorphism group of the projective line minus three points. His collaboration with Akio Tamagawa (RIMS, Kyoto University) seeks to demonstrate a natural scarcity among abelian varieties whose Galois representations have constrained image. 

His work in computational number theory, joint with Beth Malmskog (Colorado College), has determined a complete list of Picard curves over the rational numbers with good reduction away from 3. With Malmskog and other mathematicians, Rasmussen has implemented algorithms for the solution of S-unit equations over number fields in the free and open-source software platform, SageMath. (Follow SageTrac #22148 for more information.)

Christopher Rasmussen was born in Morgantown, West Virginia, and earned his PhD in Mathematics at the University of Arizona under Minhyong Kim. He has held post-doctoral appointments at William Marshall Rice University in Houston, Texas and at the Research Institute for the Mathematical Sciences in Kyoto, Japan.