Fibonacci Determinants -- A Combinatorial Approach
(based on joint work with A. Benjamin and J. Quinn)

Naiomi Cameron
Department of Mathematics, Occidental College

Abstract: The goal of this investigation is to provide combinatorial insight for some known determinantal identities involving the Fibonacci numbers. The method, due to Lindström-Gessel-Viennot, is to associate a determinantal value with the number of nonintersecting n-routes in a carefully chosen digraph. The advantage of this method is the ability to gain better insight into the nature of the identity, thereby allowing room to generalize the identity or even discover new related identities.

In this presentation, I intend to (i) provide the necessary background about basic graph theory and the Fibonacci numbers, (ii) discuss the theorem of Lindström-Gessel-Viennot which explains a relationship between non-intersecting path systems and determinants, (iii) present some known Fibonacci identities, including Cassini's identity, and (iv) show how one can understand and generalize these identities with creative applications of the Lindström-Gessel-Viennot theorem.