{ "id": "2001.00904", "version": "v1", "published": "2020-01-03T17:39:35.000Z", "updated": "2020-01-03T17:39:35.000Z", "title": "Optimization of Mean-field Spin Glasses", "authors": [ "Ahmed El Alaoui", "Andrea Montanari", "Mark Sellke" ], "comment": "61 pages", "categories": [ "math.PR", "cond-mat.dis-nn", "math.OC" ], "abstract": "Mean-field spin glasses are families of random energy functions (Hamiltonians) on high-dimensional product spaces. In this paper we consider the case of Ising mixed $p$-spin models, namely Hamiltonians $H_N:\\Sigma_N\\to {\\mathbb R}$ on the Hamming hypercube $\\Sigma_N = \\{\\pm 1\\}^N$, which are defined by the property that $\\{H_N({\\boldsymbol \\sigma})\\}_{{\\boldsymbol \\sigma}\\in \\Sigma_N}$ is a centered Gaussian process with covariance ${\\mathbb E}\\{H_N({\\boldsymbol \\sigma}_1)H_N({\\boldsymbol \\sigma}_2)\\}$ depending only on the scalar product $\\langle {\\boldsymbol \\sigma}_1,{\\boldsymbol \\sigma}_2\\rangle$. The asymptotic value of the optimum $\\max_{{\\boldsymbol \\sigma}\\in \\Sigma_N}H_N({\\boldsymbol \\sigma})$ was characterized in terms of a variational principle known as the Parisi formula, first proved by Talagrand and, in a more general setting, by Panchenko. The structure of superlevel sets is extremely rich and has been studied by a number of authors. Here we ask whether a near optimal configuration ${\\boldsymbol \\sigma}$ can be computed in polynomial time. We develop a message passing algorithm whose complexity per-iteration is of the same order as the complexity of evaluating the gradient of $H_N$, and characterize the typical energy value it achieves. When the $p$-spin model $H_N$ satisfies a certain no-overlap gap assumption, for any $\\varepsilon>0$, the algorithm outputs ${\\boldsymbol \\sigma}\\in\\Sigma_N$ such that $H_N({\\boldsymbol \\sigma})\\ge (1-\\varepsilon)\\max_{{\\boldsymbol \\sigma}'} H_N({\\boldsymbol \\sigma}')$, with high probability. The number of iterations is bounded in $N$ and depends uniquely on $\\varepsilon$. More generally, regardless of whether the no-overlap gap assumption holds, the energy achieved is given by an extended variational principle, which generalizes the Parisi formula.", "revisions": [ { "version": "v1", "updated": "2020-01-03T17:39:35.000Z" } ], "analyses": { "keywords": [ "mean-field spin glasses", "parisi formula", "variational principle", "no-overlap gap assumption holds", "optimization" ], "note": { "typesetting": "TeX", "pages": 61, "language": "en", "license": "arXiv", "status": "editable" } } }