2025/05/26 by Evans, Emily J., Hendel, Russell Jay
#11B37 11B39 94C15 #Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.2505.20539
Barret, Evans, and Francis conjectured that if G is the straight linear 3-tree with n vertices and H is the straight linear 3-tree with n+1 vertices then limn→ ∞ rH (1, n+1) - rG(1,n) = (1)/(14), where rG(u,v) and rH(u,v) are the resistance distance between vertices u and v in graphs G and H respectively. In this paper, we prove the conjecture by looking at the determinants of deleted Laplacian matrices. The proof uses a Laplace expansion method on a family of determinants to determine the underlying recursion this family satisfies and then uses routine linear algebra methods to obtain an exact Binet formula for the n-th term.