Concentration inequalities for Markov processes via coupling
Jean Rene Chazottes (CPHT, Ecole Polytechnique, Paris)
Abstract
We obtain moment and Gaussian bounds for general coordinate-wise Lipschitz functions evaluated along the sample path of a Markov chain. We treat Markov chains on general (possibly unbounded) state spaces via a coupling method. If the first moment of the coupling time exists, then we obtain a variance inequality. If a moment of order $1+a$ $(a > 0)$ of the coupling time exists, then depending on the behavior of the stationary distribution, we obtain higher moment bounds. This immediately implies polynomial concentration inequalities. In the case that a moment of order $1+ a$ is finite, uniformly in the starting point of the coupling, we obtain a Gaussian bound. We illustrate the general results with house of cards processes, in which both uniform and non-uniform behavior of moments of the coupling time can occur.
Full Text: Download PDF | View PDF online (requires PDF plugin)
Pages: 1162-1180
Publication Date: May 31, 2009
DOI: 10.1214/EJP.v14-657
References
- R. Adamczak, A tail inequality for suprema of unbounded empirical processes with applications to Markov chains. Electron. J. Prob. 13, 1000-1034, (2008). 2424985
- S. Bobkov and F. G"otze. Exponential integrability and transportation cost related to logarithmic Sobolev inequalities. J. Funct. Anal. 163 (1999), 1--28. J. Funct. Anal. 163 (1999), 1--28. 1682772
- S. Boucheron, O. Bousquet, G. Lugosi and P. Massart, Moment inequalities for functions of independent random variables. Ann. Prob. 33, 514-560, (2005). 2123200
- X. Bressaud, R. Fern'andez, and A. Galves. Decay of correlations for non-H"olderian dynamics. A coupling approach. Electron. J. Probab. 4 (1999), no. 3 (19 pp.). 1675304
- D.L. Burkholder. Sharp inequalities for martingales and stochastic integrals. Colloque Paul L'evy sur les Processus Stochastiques (Palaiseau, 1987). Ast'erisque No. 157-158 (1988), 75--94. 0976214
- S. Chatterjee. Stein's method for concentration inequalities. Probab. Theory Related Fields 138 (2007), no. 1-2, 305--321. 2288072
- J.-R. Chazottes, P. Collet, C. K"ulske and F. Redig. Concentration inequalities for random fields via coupling. Probab. Theory Related Fields 137 (2007), no. 1-2, 201--225. 2278456
- P. Collet. Variance and exponential estimates via coupling. Bull. Braz. Math. Soc. 37 (2006), no. 4, 461--475. 2284882
- H. Djellout, A. Guillin and L. Wu. Transportation cost-information inequalities and applications to random dynamical systems and diffusions. Ann. Probab. 32 (2004), no. 3B, 2702--2732. 2078555
- R. Douc, A. Guillin and E. Moulines. Bounds on Regeneration Times and Limit Theorems for Subgeometric Markov Chains. Annales Inst. H. Poincar'e, to appear.
- R. Douc, G. Fort, E. Moulines and P. Soulier, Practical drift conditions for subgeometric rates of convergence. Ann. Appl. Prob. 14 , 1353-1377, (2004). 2071426
- R. Douc, E. Moulines and P. Soulier, Computable convergence rates for sub-geometric ergodic Markov chains. Bernoulli 13 , 831-848 (2007). 2348753
- A. Fey-den Boer, R. Meester, Ronald, C. Quant, and F. Redig. A probabilistic approach to Zhang's sandpile model. Comm. Math. Phys. 280 , 351--388, (2008). 2395474
- S. Goldstein. A note on specifications. Z. Wahrsch. Verw. Gebiete, 46 , 45-51 (1978/79). 0512331
- L. Kontorovich and K. Ramanan. Concentration Inequalities for Dependent Random Variables via the Martingale Method, prepint (2007), to appear in Ann. Probab. Mathreview number not available
- L. Kontorovich. Obtaining Measure Concentration from Markov Contraction, preprint, 2007 (arXiv:0711.0987). Mathreview number not available
- M. Ledoux. The concentration of measure phenomenon, Mathematical Surveys and Monographs 89 American Mathematical Society, Providence R.I., 2001. 1849347
- T.M. Liggett, Interacting particle systems. Reprint of the 1985 original. Classics in Mathematics. Springer-Verlag, Berlin, 2005. 2108619
- C. McDiarmid. On the method of bounded differences, Surveys in Combinatorics 1989, Cambridge University Press, Cambridge (1989) 148--188. 1036755
- K. Marton. Bounding D-distance by informational divergence: a method to prove measure concentration. Ann. Probab. 24 (1996), no. 2, 857--866. 1404531
- K. Marton. A measure concentration inequality for contracting Markov chains. Geom. Funct. Anal. 6 (1996), no. 3, 556--571. [Erratum: Geom. Funct. Anal. 7 (1997), no. 3, 609--613.] 1392329
- K. Marton. Measure concentration for a class of random processes. Probab. Theory Related Fields 110 (1998), no. 3, 427--439. 1616492
- Y.H. Mao, Convergence rates in strong ergodicity for Markov processes. Stochastic Process. Appl. 116 , no. 12, 1964--1976, (2006). 2307067
- E. Rio. In'egalit'es de Hoeffding pour les fonctions lipschitziennes de suites d'ependantes. [Hoeffding inequalities for Lipschitz functions of dependent sequences] C. R. Acad. Sci. Paris S'er. I Math. 330 (2000), no. 10, 905--908. 1771956
- P.-M. Samson. Concentration of measure inequalities for Markov chains and $Phi$-mixing processes. Ann. Probab. 28 (2000), no. 1, 416--461. 1756011
- H. Thorisson. Coupling, stationarity, and regeneration. Probability and its Applications (New York). Springer-Verlag, New York, 2000. 1741181

This work is licensed under a Creative Commons Attribution 3.0 License.