Expertise
In probability, he is working on population genetics.
In information theory, he is working on active information, based on Bernoulli's Principle of Insufficient Reason.
In machine learning, he has currently begun to work with Sunil Rao and Hemant Ishwaran on the problem of learnability, which depends on a concept called stability.
In theoretical statistics, together with Rao and Dazard, he is working to understand when in learning settings, mainly regression, the rotation (not the projection of the space) to principal components of the explanatory variables makes sense to explain the response.
Probability
Information Theory
Machine Learning
Statistical Theory