The spread of a graph is defined to be the difference between the greatest eigenvalue and the least eigenvalue of the adjacency matrix of the graph. In this paper we determine the unique graph with minimum least eigenvalue among all connected bicyclic graphs of order n. Also, we determine the unique graph with maximum spread in this class for each n ≥ 28. © 2008 Elsevier Inc. All rights reserved.
Petrović, M., Borovićanin, B., & Aleksić, T. (2009). Bicyclic graphs for which the least eigenvalue is minimum. Linear Algebra and Its Applications, 430(4), 1328–1335. https://doi.org/10.1016/j.laa.2008.10.026