Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X41220150401On spectral radius of strongly connected digraphs381387617ENJ.LiDepartment of Mathematics, South China Normal University,
and
Faculty of Applied
Mathematics,
Guangdong University of TechnologyB.ZhouDepartment of
Mathematics, South China Normal University, Guangzhou 510631, P. R. ChinaJournal Article20130608 It is known that the directed cycle of order $n$ uniquely achieves the minimum spectral
radius among all strongly connected digraphs of order $n\ge 3$.
In this paper, among others, we determine the digraphs which achieve the second, the third
and the fourth minimum spectral radii respectively among strongly connected
digraphs of order $n\ge 4$.
http://bims.iranjournals.ir/article_617_ba726fe1c4c511605c20112260ca365b.pdf