Scale-invariant random spatial networks

We study the implications of assuming scale-invariance in a mathematical model of road networks. Intuitively, scale-invariance says that the statistics of the network within a window of an online map do not depend on whether the width is 5 miles or 500 miles. Mathematically, scale-invariance forces us to work in the continuum rather than (as in most existing models of spatial networks) on discrete vertex-sets, raising novel foundational issues. One interesting consequence of scale-invariance is a convenient quantification of where a given road section lies on the major road – minor road spectrum. In particular, we introduce a non-obvious numerical statistic p(1) (perhaps very loosely analogous to entropy as a non-obvious statistic of a stationary process?) measuring the density of long-distance routes. This has an intriguing connection with the effectiveness of the route-finding algorithms used by your car’s GPS device.

Speaker Details

David Aldous is a professor at U.C. Berkeley who is visiting MSR for the year, and is a Fellow of the Royal Society. He specializes in mathematical probability; a central theme is the study of large finite random structures, obtaining asymptotic behavior as the size tends to infinity via consideration of some suitable infinite random structure. His current focus is on spatial random networks. Aldous is best known for the unfinished monograph “Reversible Markov chains and random walks on graphs”.

Date:
Speakers:
David Aldous
Affiliation:
MSR and UC Berkeley
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      Jeff Running