TITLE OF PROJECT : SELF-DIFFUSION MATRIX OF INTERACTING BROWNIAN MOTIONS

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We completed and published the paper that says the self-diffusion coefficient is positive for particles with convex hard cores in a multi-dimensional space, even if the density of the particle is very high. In order to prove this we use the variational formula of the self-diffusion coefficient and a fine estimate of Gibbs measures derived from a result on oriented site percolation.Interacting Brownian motion is a dynamics of the motion of infinite amount of Brownian particles with interaction. To construct such a dynamics has some difficulty because this is indeed a problem to construct infinitely dimensional diffusion. For this we have solved the problem and publised the paper under very mild assumption such as the coefficients are measurable functions. So far the results are known only the restrict assumption such that the coefficients are upper semicontinuous. We improve this in such a way that they are bounded from both of below and above by upper semicontinuous functions. We think this generalization is quite satisfactory.We prove the positivity of the capacity of the existence of two particles at the same position is necessary for the positivity of the one dimensional self-diffusion coefficient. Althogh we tried to prove this is also sufficient, it is in vain.While doing this research, we come to the new thema such that the same problem in the infinite volume path space. It is related to Log Sobolev inequality ; so I am now think this new problem is exciting.