In 1968, Babai won a gold medal at the International Mathematical Olympiad. Babai studied mathematics at Faculty of Science of the Eötvös Loránd University from 1968 to 1973, received a PhD from the Hungarian Academy of Sciences in 1975, and received a DSc from the Hungarian Academy of Sciences in 1984.[1][2] He held a teaching position at Eötvös Loránd University since 1971; in 1987 he took joint positions as a professor in algebra at Eötvös Loránd and in computer science at the University of Chicago. In 1995, he began a joint appointment in the mathematics department at Chicago and gave up his position at Eötvös Loránd.[1]
We show that the Graph Isomorphism (GI) problem and the related problems of String Isomorphism[12] (under group action) (SI) and Coset Intersection (CI)[13][14] can be solved in quasipolynomial time. The best previous bound for GI was where is the number of vertices (Luks, 1983); for the other two problems, the bound was similar, where is the size of the permutation domain (Babai, 1983).
The algorithm builds on Luks's SI framework and attacks the barrier configurations for Luks's algorithm by group theoretic «local certificates» and combinatorial canonical partitioning techniques. We show that in a well-defined sense, Johnson graphs are the only obstructions to effective canonical partitioning.
Honors
In 1988, Babai won the Hungarian State Prize, in 1990 he was elected as a corresponding member of the Hungarian Academy of Sciences, and in 1994 he became a full member.[1] In 1999 the Budapest University of Technology and Economics awarded him an honorary doctorate.[1]
^Babai, László; Moran, Shlomo (1988), "Arthur-Merlin games: a randomized proof system, and a hierarchy of complexity class", J. Comput. Syst. Sci., 36 (2): 254–276, doi:10.1016/0022-0000(88)90028-1.