In plain words: A restricted Boltzmann machine is a simple two-layer model of binary random variables, with hidden units linked to visible ones. Treating its possible probability patterns as geometric shapes, this study derives a dimension formula and shows the model is often uniquely determined by its data.
Abstract
The restricted Boltzmann machine is a graphical model for binary random variables. Based on a complete bipartite graph separating hidden and observed variables, it is the binary analog to the factor analysis model. We study this graphical model from the perspectives of algebraic statistics and tropical geometry, starting with the observation that its Zariski closure is a Hadamard power of the first secant variety of the Segre variety of projective lines. We derive a dimension formula for the tropicalized model, and we use it to show that the restricted Boltzmann machine is identifiable in many cases. Our methods include coding theory and geometry of linear threshold functions.
Maria Angelica Cueto, Jason Morton, Bernd Sturmfels
arXiv:0908.4425 · stat.ML, math.AG, math.MG · submitted Aug 30, 2009
abstract · pdf · html · 18 pages, 5 figures, 1 table