Talks
Spring 2016

Learning by Local Entropy Maximization

Tuesday, May 3rd, 2016 11:45 am12:30 pm

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Location: 

Calvin Lab

We will discuss the role that subdominant states play in the design of algorithms for large-scale  learning problems. We shall take as representative case the problem of learning random patterns with discrete  synapses in feedforward networks. The standard statistical physics results show that this problem is exponentially dominated by metastable states and by isolated solutions that are extremely hard to find algorithmically.  
 
A large deviation analysis  based on a  local entropy  measure allows us to  find analytical evidence for the existence of subdominant and extremely dense regions of solutions.  We show numerically that these dense regions are surprisingly accessible by simple learning protocols. The large deviation measure introduced for the analytic study can be used as an objective function for  a simple Monte Carlo Markov Chain which finds solutions efficiently.