Publications

Peer-reviewed research in statistical physics and complex systems

Voter model on heterogeneous graphs

V. Sood, S. Redner

Physical Review Letters 94, 178701 (2005)

Network Theory

Abstract

We investigate the voter model on heterogeneous networks and find that on scale-free networks with degree exponent 2 < gamma < 3, the consensus time is sublinear in the number of nodes, while for gamma > 3 it is linear, as on regular lattices.

Voter models on heterogeneous networks

V. Sood, T. Antal, S. Redner

Physical Review E 77, 041121 (2008)

Network Theory

Abstract

Extended study of voter dynamics on artificial scale-free networks and real networks, finding scaling regimes for consensus time that depend on the degree distribution exponent, explained through random walk analysis and the role of network hubs.

Evolutionary dynamics on degree-heterogeneous graphs

T. Antal, S. Redner, V. Sood

Physical Review Letters 96, 188104 (2006)

Evolutionary Dynamics

Abstract

We study fixation probability of mutants on graphs under two regulation mechanisms. For the Moran process on any graph, fixation probability equals that of a well-mixed population. For the voter model, it depends on structure via a surprisingly simple expression.

First-passage properties of the Erdos-Renyi random graph

V. Sood, S. Redner, D. ben-Avraham

Journal of Physics A 38, 109 (2004)

Random Walks

Abstract

We investigate first-passage times on Erdos-Renyi random graphs using the connection to resistance in analogous resistor networks, finding scaling with N/z above the critical point and N^(2/3) at criticality.

Localization transition of biased random walks on random networks

V. Sood, P. Grassberger

Physical Review Letters 99, 098701 (2007)

Random Walks

Abstract

We discover a localization transition at critical bias alpha_c = 1 for random walks on scale-free networks. Above the critical value, the walker localizes around the highest-degree hub; below, it is delocalized across the network.

Complex network analysis of state spaces for random Boolean networks

A. Shreim, A. Berdahl, V. Sood, P. Grassberger, M. Paczuski

New Journal of Physics 10, 013028 (2008)

Boolean Networks

Abstract

We analyze the state space of random Boolean networks as a complex network, finding broad distributions with scaling behavior for component sizes, basin sizes, and cycle lengths, suggesting critical dynamics.

Random sequential renormalization of networks: Application to critical trees

G. Bizhani, V. Sood, M. Paczuski, P. Grassberger

Physical Review E 83, 036110 (2011)

Network Theory

Abstract

We introduce a random sequential renormalization method for networks and apply it to critical trees, obtaining exact results for the renormalization flow and fixed points.