We congratulate Dr. Christie Alappat on his doctorate
On February 4, 2026, Christie Louis Alappat successfully defended his PhD thesis. He worked for several years in our team and completed his doctoral studies under the supervision of Prof. Dr. Gerhard Wellein. His research interests included performance engineering, sparse matrix algorithms, graph algorithms, stencil algorithms, and eigenvalue solvers. Christie is the author of the RACE (Recursive Algebraic Coloring Engine) open-source software framework, which is used to accelerate challenging computations in sparse linear algebra on modern compute devices.
After Christie presented his work, “Recursive Algebraic Coloring Engine—Performance optimization and engineering of sparse linear algebra kernels using RACE,” to the PhD committee and a broader audience, the good news was announced by Prof. Rüde, the head of the PhD committee: Christie passed his PhD with distinction. Congratulations, Christie—well done! Following the defense (and the “post exam,” in which he had to identify sparse matrices by their scatter plots and CPU chips by their die shots), Christie celebrated with the committee, many former colleagues, project collaborators, group members from NHR@FAU, and friends.
Christie started his research within the ESSEX II project (Equipping Sparse Solvers for Exascale), which entered its second funding phase in 2016 as part of the DFG priority program SPPEXA. Beyond leading the effort on RACE, he also participated in research on performance engineering for stencil codes, performance modeling on modern CPU architectures like the Fujitsu A64FX, and graph clustering algorithms.
Thank you, Christie, for your invaluable scientific contributions, countless discussions, and for enriching our team over many years with fresh perspectives (and Indian food!). Your PhD is very well deserved.