Thermal properties of structurally balanced systems on diluted and densified triangulations

TL;DR

This paper investigates how the structural balance of social networks on triangular lattices varies with network density and temperature, revealing phase transitions in dense networks and smooth cross-overs in sparser ones.

Contribution

It introduces a detailed analysis of structural balance dynamics on diluted and densified triangular lattices, highlighting the conditions for phase transitions and cross-over behaviors.

Findings

Balanced states depend on network density and temperature.

Dense networks exhibit first-order phase transitions.

Diluted and less dense networks show smooth cross-over behaviors.

Abstract

The dynamics of social relations and the possibility of reaching the state of structural balance (Heider balance) are discussed for various networks of interacting actors under the influence of the temperature modeling the social noise level. For that purpose, two main types of lattices are considered. The first is created by removing some links from a regular triangular lattice to produce a diluted triangular lattice, and the second by adding more links to create an enhanced triangular lattice. In both those cases, the full range of possible graph densities is discussed, limited by the extreme cases of networks which consist of a small number of separated triads and fully connected networks. It is shown that the existence of the balanced state is not possible if the average node degree is too close to the value characterizing the regular triangular lattice. Otherwise, both balanced (or partially balanced) and imbalanced states are possible, depending on the temperature. However, only for graphs which are dense enough a phase transition of the first kind is observed, while less enhanced networks (and all diluted) indicate a smooth cross-over between the two states. The cross-over temperatures are size-independent only for the diluted triangular lattices and depend on the size of the system for the enhanced triangular lattices, as is the case also for the critical temperatures of the phase transition observed in denser enhanced lattices.