🤖 AI Summary
This work addresses the fastest-mixing reversible Markov chain problem on friendship graphs, balancing information propagation efficiency (i.e., convergence rate) against structural stability (i.e., constraints on transition probabilities). Methodologically, it integrates spectral graph theory, convex optimization, and symmetry reduction to derive, for the first time, an analytical solution for the fastest-mixing reversible chain on this graph class; via Lagrangian duality, it obtains a closed-form expression for the optimal transition matrix and rigorously characterizes the tight trade-off between spectral gap and transition probabilities. Theoretical contributions include a proven lower bound on mixing time. Empirically, the proposed chain accelerates convergence by over 40% compared to the uniform random walk on typical friendship graphs. The results provide a tractable, verifiable theoretical framework and constructive design methodology for accelerating consensus in structurally constrained networks.