Refinements of the One Dimensional Free Poincare Inequality
We present two extensions of the one dimensional free Poincaré inequality similar in spirit to two classical refinements.
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Publications and source records attributed to Christian Houdre.
We present two extensions of the one dimensional free Poincaré inequality similar in spirit to two classical refinements.
Nonparametric methods for the estimation of the Levy density of a Levy process are developed. Estimators that can be written in terms of the ``jumps'' of the process are introduced, and so are discrete-data based approximations. A model selection approach made up of two steps is investigated. The first step consists in the selection of a good estimator from a linear model of proposed Levy densities, while the second is a data-driven selection of a linear model among a given collection of linear models. By providing lower bounds for the minimax risk of estimation over Besov Levy densities, our estimators are shown to achieve the ``best'' rate of convergence. A numerical study for the case of histogram estimators and for variance Gamma processes, models of key importance in risky asset price modeling driven by Levy processes, is presented.
Concentration of measure is studied, and obtained, for stable and related random vectors.