Gaussian concentration implies modified logarithmic Sobolev inequalities under Ricci curvature bounds

Let (X,Q,π)(\mathcal{X},Q,\pi) be a Markov chain with invariant measure π\pi, and suppose that a concentration property with respect to the distance dWd_{\mathcal{W}} holds with profile

α(r)=Meρr2.\alpha(r)=Me^{-\rho r^2}.

Assume that Ric(X,Q,π)κ\operatorname{Ric}(\mathcal{X},Q,\pi)\geq-\kappa for some κ>0\kappa>0. Gaussian-concentration modified logarithmic Sobolev conjecture. There exists a constant τ(M)\tau(M) and a constant λ(κ,M,ρ)\lambda(\kappa,M,\rho) such that, if

κρ<τ(M),\frac{\kappa}{\rho}<\tau(M),

then MLSI(λ(κ,M,ρ))\operatorname{MLSI}\bigl(\lambda(\kappa,M,\rho)\bigr) holds. If moreover Ric(X,Q,π)0\operatorname{Ric}(\mathcal{X},Q,\pi)\geq0, then MLSI(cMρ)\operatorname{MLSI}(cM\rho) holds for some universal constant cc. The open aspect identified in the source is the value of the constant.

Sources & referencesView supporting material

Primary source

Matthias Erbar and Max Fathi, “Poincaré, modified logarithmic Sobolev and isoperimetric inequalities for Markov chains with non-negative Ricci curvature”, arXiv:1612.00514 (2016).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.