Zusammenfassung
Fractal scaling and self-similar connectivity behaviour of scale-free
(SF) networks are reviewed and investigated in diverse aspects. We
first recall an algorithm of box-covering that is useful and easy to
implement in SF networks, the so-called random sequential
box-covering. Next, to understand the origin of the fractal scaling,
fractal networks are viewed as comprising of a skeleton and shortcuts.
The skeleton, embedded underneath the original network, is a spanning
tree specifically based on the edge-betweenness centrality or load. We
show that the skeleton is a non-causal tree, either critical or
supercritical. We also study the fractal scaling property of the
k-core of a fractal network and find that as k increases, not only
does the fractal dimension of the k-core change but also eventually
the fractality no longer holds for large enough k. Finally, we study
the self-similarity, manifested as the scale-invariance of the degree
distribution under coarse-graining of vertices by the box-covering
method. We obtain the condition for self-similarity, which turns out
to be independent of the fractality, and find that some non-fractal
networks are self-similar. Therefore, fractality and self-similarity
are disparate notions in SF networks.
Nutzer