@article{eprints2774, year = {2015}, month = {July}, journal = {IEEE Transactions on Network Science and Engineering}, volume = {2}, pages = {97--111}, publisher = {IEEE}, author = {Giorgio Gnecco and Rita Morisi and Alberto Bemporad}, title = {Sparse Solutions to the Average Consensus Problem via Various Regularizations of the Fastest Mixing Markov-Chain Problem}, number = {3}, url = {http://eprints.imtlucca.it/2774/}, abstract = {In the consensus problem on multi-agent systems, in which the states of the agents represent opinions, the agents aim at reaching a common opinion (or consensus state) through local exchange of information. An important design problem is to choose the degree of interconnection of the subsystems to achieve a good trade-off between a small number of interconnections and a fast convergence to the consensus state, which is the average of the initial opinions under mild conditions. This paper addresses this problem through l{$_1$} -norm and l{$_0$} -?pseudo-norm? regularized versions of the well-known Fastest Mixing Markov-Chain (FMMC) problem. We show that such versions can be interpreted as robust forms of the FMMC problem and provide results to guide the choice of the regularization parameter.}, keywords = {Artificial neural networks; Convergence; Convex functions; Eigenvalues and eigenfunctions; Optimization; Symmetric matrices; Wireless sensor networks; Consensus; Fastest Mixing Markov-Chain problem; Optimization; Regularization; Sparsity} }