Seminario di fisica matematica
ore
16:00
presso Seminario I
Recent research has identified scaling regularities in the temporal
distribution of events such as earthquakes, wind gusts, and e-mail
submissions. These studies consistently report bursty deviations both
from random and regular processes, and together suggest the existence
of a dynamic counterpart to the long-known scaling laws in magnitude
and frequency distribution (e.g., Gutenberg-Richter's law and Zipf's
law). In this talk I will report on our recent investigations of the
temporal distribution of words. We found that
the distribution of distances between successive occurrences of the
same word display bursty deviations from a Poisson process and are
well characterized by a Weibull scaling.
We found that the burstiness of words depends more strongly on their
semantic type than on their frequency of occurrence. Finally, we propose a simplified generative model that explains our main
observations and fully determines the dynamics of word usage.
As an outlook, I will discuss some analogies and differences to the problem
of recurrence of extreme events in long-range correlated time series,
where similar Weibull distributions were recently reported by the
physics community.