Abstract

We study the diameter, or the mean distance between sites, in a scale-free network, having N sites and degree distribution p(k) proportional, variant k(-lambda), i.e., the probability of having k links outgoing from a site. In contrast to the diameter of regular random networks or small-world networks, which is known to be d approximately ln(N, we show, using analytical arguments, that scale-free networks with 2<lambda<3 have a much smaller diameter, behaving as d approximately ln(ln(N. For lambda=3, our analysis yields d approximately ln(N/ln(ln(N, as obtained by Bollobas and Riordan, while for lambda>3, d approximately ln(N. We also show that, for any lambda>2, one can construct a deterministic scale-free network with d approximately ln(ln(N, which is the lowest possible diameter.

Keywords

PhysicsLambdaCombinatoricsDegree (music)Quantum mechanicsMathematics

Affiliated Institutions

Related Publications

Flicker (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mfrac><mml:mrow><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>f</mml:mi></mml:mrow></mml:mfrac></mml:math>) noise: Equilibrium temperature and resistance fluctuations

We have measured the $\frac{1}{f}$ voltage noise in continuous metal films. At room temperature, samples of pure metals and bismuth (with a carrier density smaller by ${10}^{5}$...

1976 Physical review. B, Solid state 485 citations

Publication Info

Year
2003
Type
article
Volume
90
Issue
5
Pages
058701-058701
Citations
799
Access
Closed

External Links

Social Impact

Altmetric

Social media, news, blog, policy document mentions

Citation Metrics

799
OpenAlex

Cite This

Reuven Cohen, Shlomo Havlin (2003). Scale-Free Networks Are Ultrasmall. Physical Review Letters , 90 (5) , 058701-058701. https://doi.org/10.1103/physrevlett.90.058701

Identifiers

DOI
10.1103/physrevlett.90.058701