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MaxEnt 07’. Information Geometry of MaxEnt Principle. Shun-ichi Amari RIKEN Brain Science Institute. Information Geometry. Systems Theory. Information Theory. Statistics. Neural Networks. Combinatorics. Physics. Information Sciences. Math. AI. Riemannian Manifold
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MaxEnt 07’ Information Geometry of MaxEnt Principle Shun-ichi Amari RIKEN Brain Science Institute
Information Geometry Systems Theory Information Theory Statistics Neural Networks Combinatorics Physics Information Sciences Math. AI Riemannian Manifold Dual Affine Connections Manifold of Probability Distributions
Information Geometry ? Riemannian metric Dual affine connections
Invariance 1. Invariant under reparameterization 2. Invariant under different representation
Two Structures Riemannian metric—Fisher information Affine connection -- geodesic, straight line how curved is the manifold?
Kullback-Leibler Divergence quasi-distance
KL-divergence and RiemannianStructure relation Fisher information matrix
AffineConnection covariant derivative straight line
Renyi-Tasallis Exponential connection Entropy KL-divergence Mixture connection Levi-Civita (Riemannian)
Affine Connections e-geodesic m-geodesic
Duality Y X Y X Riemannian geometry:
Dually flat manifold S = {p(x), x discrete}
Dually Flat Manifold 1. Potential Functions ---convex (Legendre transformation) 2. Divergence KL-divergence 3. Pythagoras Theorem 4. Projection Theorem
Projection Theorem m-geodesic e-geodesic
Applications to Statistics curved exponential family: : estimation : testing
High-Order Asymptotics :Cramér-Rao
Other Applications • Systems theory • Information theory • Neuromanifold • Belief propagation • Boosting (Murata-Eguchi) • Higher-order correlations • Mathematics --- Orlicz space (Pistone, Gracceli) • Physics --- Amari-Nagaoka, Methods of Information Geometry, AMS & Oxford U., 2000 Amari, Differential-Geometrical Methods of Statistics, Springer, 1985 Kass and Vos, Geomtrical Foundations of Asymptotic Inference, Wiley, 1997 Murrey and Rice, Differential Geometry and Statistics, Chapman, 1993
Exponential Family : dually flat Two coordinate systems
Exponential Family example (1) : discrete distributions Negative entropy
example (2) : Gaussian distributions example (3) : AR model
Divergence Pythagorean Theorem m-flat e-flat
Divergence and Entropy equi-divergence: equi-entropy
Dual Foliation Pythagorean theorem
Geometry Potentials
Rényi-Tsallis entropy Manifold of positive measures m(x)
Entropy (alpha-entropy) is a fundamental quantity---- It is given rise to from a fundamental geometrical structure. KL-divergence is derived therefrom.