Path Spectra and Forbidden Families

Allen G. Fuller1, Ronald J. Gould2
1Division OF NATURAL SCIENCES AND NURSING, GORDON COLLEGE, BARNESVILLE, GA 30204
2DEPARTMENT OF MATHEMATICS AND COMPUTER SCIENCE, EMorRY UNIVERSITY, AT- LANTA, GA 30322

Abstract

The path spectrum, \(\operatorname{sp}(G)\), of a graph \(G\) is the set of all lengths of maximal paths in \(G\). The path spectrum is continuous if \(\operatorname{sp}(G) = \{\ell, \ell1, \dots, \ell\}\) for some \(\ell \leq m\). A graph whose path spectrum consists of a single element is called scent and is by definition continuous. In this paper, we determine when a \(\{K_{1, 3}, S\}\)-free graph has a continuous path spectrum where \(S\) is one of \(C_3, P_4, P_5, P_6, Z_1, Z_2, Z_3, N, B\), or \(W\).