Interplay of choice and topology in percolation on mediation-driven attachment networks
Nilomber Roy, M. M. B. Sheraj, M. K. Hassan
TL;DR
The paper studies bond percolation on mediation-driven attachment (MDA) networks under a generalized best-of-$M$ Achlioptas process. It shows that the critical point $t_c$ and the associated exponents $(α,β,γ)$ depend weakly on the degree exponent $ω$ but strongly on the choice parameter $M$, with $M=2$ producing a non-explosive continuous transition and $M=3,4$ yielding explosively sharp but continuous transitions due to an entropic powder-keg mechanism. Finite-size scaling extracts $ u$, $α$, $β$, and $γ$, revealing that $β/ν$ decreases while $α/ν$ and $γ/ν$ increase with $M$, indicating different universality classes across $M$ and $m$; the Rushbrooke inequality $α+2β+γ\,=\,2$ is satisfied. The work highlights how topology and competitive link occupation jointly shape percolation, with practical implications for robustness and controllability in scale-free-like networks and for understanding entropy-driven explosive transitions.
Abstract
We investigate bond percolation on mediation-driven attachment (MDA) networks under the generalized Achlioptas process, where $M>1$ candidate bonds are sampled and the one that minimizes the resulting cluster size is selected the best-of-$M$ rule. This framework offers a systematic approach to investigate how network topology and choice mechanisms jointly shape percolation behavior. We analyze the effects of the degree exponent $ω$ and the choice parameter $M$ on the critical point $t_c$ and the critical exponents ($β,α,γ$), which define universality classes and obey the Rushbrooke inequality $α+ 2β+ γ\geq 2$. Using entropy, the order parameter, and their derivatives (representing specific heat and susceptibility respectively), we show that both $t_c$ and the universality class depend only weakly on $ω$ but strongly on $M$, while the Rushbrooke inequality remains valid throughout. For $M=2$, the order parameter varies continuously without a clear order-disorder transition. By contrast, $M=3$ and $M=4$ display explosive percolation that still corresponds to a continuous phase transition, with $M=4$ producing a significantly sharper and clearer order-disorder transition. This sharpening is traced to an enhanced powder-keg effect at larger $M$, underscoring the entropic origin of explosive percolation.
