In view of differential geometry, the state space of thermodynamic parameters is investigated. Here the geometrical structures of the denormalized thermodynamic manifold are considered. The relation of their geometrical metrics is obtained. Moreover an example is used to illustrate our conclusions.
A new Riemannian metric for positive definite matrices is defined and its geometric structures are investigated by means of dual connections introduced to statistical analysis by S. Amari. A few interesting results are obtained and some of those obtained by other authors are extended in our research.
The random walk（RW）is investigated from the viewpoint of information geometry and shown to be an exponential family distribution.It has a dual coordinate system and a dual geometric structure.Then submanifolds of RW manifold is studied,and the e-flat hierarchical structure and the orthogonal foliations of RW manifold are obtained.Finally,using the Kullback-Leibler divergence,the projections are given from the RW manifold to its submanifolds.
The application of information geometry in the low density parity check（LDPC）codes based on the work of Ikeda and Amari is considered.The method is to turn the decoding process into the change of the parameter.When the LDPC decoding procedure converges,both the convergent probability distribution and the true probability distribution belong to the same submanifold,but this does not mean they are equimarginal,that points out the origin of the decoding error.
For a Riemannian manifold（Mn,g） with curvature tensor R,the Jacobi operator J（X） is give.In this paper,the flat Riemannian manifolds are characterized in terms of special commutation properties of their Jacobi operators.
In view of information geometry,the state space S of thermodynamic parameters is investigated.First a Riemannian metric for S is defined and then the α-geometric structures of S is given.Some of results obtained by other authors are extended.
