I want to explore what's the relationship between graph walks and spectral radius. I read this result in a paper, however, I could not either find the material that the paper cite on the internet or prove it myself. Could someone help me with how to prove this result?
$$\exp\left(h(G)\right)=\rho(G)$$
where $h(G)=\lim_{n\rightarrow \infty}{\dfrac{1}{n}\ln\left(\#V^{n}\right)}$, $\#V^{n}$ represents the number of $n$-walks.