The extremal $t$-uniform unicyclic hypergraph on Estrada index

Abstract

For a $t$-uniform hypergraph $H=(V(H), E(H))$, the Estrada index $EE(H)$ of $H$ is defined as $\sum_{i\in [n]}e^{\theta_i}$, where   $\theta_1,\ldots, \theta_n$ are the eigevalues of the adjacent matrix of $H$. In this paper, the extremal $t$-uniform unicylic hypergraph which has maximum Estrada index are characterized.