|DATE:||Wednesday, October 25th|
|TIME:||12:00 PM - 1:00 PM|
|TITLE:||Non-Regular Square Bipartite Designs|
|SPEAKER:||Caterina De Simone, Istituto di Analidi dei Sistemi ed Informatica National Council of Research, Rome|
A square bipartite design is a pair of square 0-1 matrices A
and B satisfying the following matrix equation:
(A^T)B= lambda J + diag (d)
where J is a matrix filled with all ones, lambda is a positive integer, and d is a vector. We give a characterization of a class of non-regular square bipartite designs; our result generalize some earlier results of De Bruijn and Erdos, Lehman, and Gasparyan.
Joint with Grigor Gasparyan and Paolo Nobili.