Anomalous diffusion in the citation time series of scientific publications

TL;DR

This study investigates the anomalous diffusion patterns in citation time series across physics, social science, and technology, revealing non-stationarity, long-range correlations, and heterogeneity in citation dynamics.

Contribution

It provides a detailed analysis of factors causing anomalous citation diffusion, including non-stationarity, correlations, and distribution fat tails, across different scientific fields.

Findings

Citation trajectories diffuse anomalously with Hurst exponent not equal to 0.5

High heterogeneity in citation statistics across fields and citation levels

Citation data shows high correlation and non-stationarity, with most papers fading over time

Abstract

We analyze the citation time-series of manuscripts in three different fields of science; physics, social science and technology. The evolution of the time-series of the yearly number of citations, namely the citation trajectories, diffuse anomalously, their variance scales with time $\propto t^{2H}$, where $H\neq 1/2$. We provide detailed analysis of the various factors that lead to the anomalous behavior: non-stationarity, long-ranged correlations and a fat-tailed increment distribution. The papers exhibit high degree of heterogeneity, across the various fields, as the statistics of the highest cited papers is fundamentally different from that of the lower ones. The citation data is shown to be highly correlated and non-stationary; as all the papers except the small percentage of them with high number of citations, die out in time.