Redondo Beach, California
Nov. 12, 2000 to Nov. 14, 2000
J. Toran , Abteilung Theor. Inf., Ulm Univ., Germany
We show that the graph isomorphism problem is hard under logarithmic space many-one reductions for the complexity classes NL, PL (probabilistic logarithmic space), for every logarithmic space modular class Mod/sub k/L and for the class DET of problems NC/sup 1/ reducible to the determinant. These are the strongest existing hardness results for the graph isomorphism problem, and imply a randomized logarithmic space reduction from the perfect matching problem to graph isomorphism.
computational complexity; encoding; graph theory; hardness; graph isomorphism; logarithmic space many-one reductions; complexity classes; probabilistic logarithmic space; determinant; hardness results; randomized logarithmic space reduction; perfect matching
J. Toran, "On the hardness of graph isomorphism", FOCS, 2000, 2013 IEEE 54th Annual Symposium on Foundations of Computer Science, 2013 IEEE 54th Annual Symposium on Foundations of Computer Science 2000, pp. 180, doi:10.1109/SFCS.2000.892080