Mean trapping time for an arbitrary node on regular hyperbranched polymers

TL;DR

This paper analyzes the mean trapping time for random walks on regular hyperbranched polymers, deriving exact formulas and revealing how trap location and topology influence trapping efficiency.

Contribution

It introduces a method to label nodes and compute exact mean first-passage and trapping times on RHPs, highlighting the impact of topology on trapping efficiency.

Findings

Central node is the best trapping site.

Farthest nodes are the worst trapping sites.

Maximum MTT is about four times the minimum.

Abstract

The regular hyperbranched polymers (RHPs), also known as Vicsek fractals, are an important family of hyperbranched structures which have attracted a wide spread attention during the past several years. In this paper, we study the first-passage properties for random walks on the RHPs. Firstly, we propose a way to label all the different nodes of the RHPs and derive exact formulas to calculate the mean first-passage time (MFPT) between any two nodes and the mean trapping time (MTT) for any trap node. Then, we compare the trapping efficiency between any two nodes of the RHPs by using the MTT as the measures of trapping efficiency. We find that the central node of the RHPs is the best trapping site and the nodes which are the farthest nodes from the central node are the worst trapping sites. Furthermore, we find that the maximum of the MTT is about $4$ times more than the minimum of the MTT. The result is similar to the results in the recursive fractal scale-free trees and T-fractal, but it is quite different from that in the recursive non-fractal scale-free trees. These results can help understanding the influences of the topological properties and trap location on the trapping efficiency.