# Sept. 26: Zach Teitler, Algebra, Geometry, Cryptology

When: 2:30-3:20 p.m. Friday, Sept. 26
Where: Math Building, Room 136
Who: Zach Teitler, Boise State
Title: “The addition of residue classes modulo n” (part 2)

Abstract: Teitler will finish his presentation of Ryavec’s elementary proof in 1968 of the following theorem. Let a_1,..,a_m be m distinct, nonzero residues modulo n, where n is any natural number and where m is greater than or equal to 3sqrt(6n)exp{c sqrt(log n) / log log n}, where c > 0 is some large constant. Then there is a nonempty subset of the a_i which sums to 0 modulo n. Note that the bound for m is O(n^epsilon) for all epsilon>0. This answers a question of Erdos.