For a probability distribution $P$, Renyi fractal dimension is defined as
$$D_q = \lim_{\epsilon\rightarrow 0} \frac{R_q(P_\epsilon)}{\log(1/\epsilon)},$$ where $R_q$ is Renyi entropy of order $q$ and $P_\epsilon$ is the coarse-grained probability distribution (i.e. put in boxes of linear size $\epsilon$).
The question is if there are any phenomena, for which using non-trivial $q$ (i.e. $q\neq0,1,2,\infty$) is beneficial or naturally preferred?
The Rényi entropy of order $q = \frac{1}{2}$ apperas in several measures of pure states entanglement, please see for example: Karol Zyczkowski, Ingemar Bengtsson: Relatively Pure states entanglement. This entropy has the property that for three state systems, the equientropy trajectories form circles with respect to the the Bhattacharyya distance, please see for example: Bengtsson Zyczkowski: Geometry of quantum states, page 57.
