Open Access
2023 On dimension-dependent concentration for convex Lipschitz functions in product spaces
Han Huang, Konstantin Tikhomirov
Author Affiliations +
Electron. J. Probab. 28: 1-23 (2023). DOI: 10.1214/23-EJP944
Abstract

Let n1, K>0, and let X=(X1,X2,,Xn) be a random vector in Rn with independent K–subgaussian components. We show that for every 1–Lipschitz convex function f in Rn (the Lipschitzness with respect to the Euclidean metric), t>0,

max(P{f(X)Medf(X)t},P{f(X)Medf(X)t})exp(ct2K2log(2+K2nt2)),

where c>0 is a universal constant. The estimates are optimal in the sense that for every nC˜ and t>0 there exist a product probability distribution X in Rn with K–subgaussian components, and a 1–Lipschitz convex function f, with

P{|f(X)Medf(X)|t}c˜exp(C˜t2K2log(2+K2nt2)).

The obtained deviation estimates for subgaussian variables are in sharp contrast with the case of variables with bounded Xiψp–quasi-norms for p(0,2).

References

1.

R. Adamczak, Logarithmic Sobolev inequalities and concentration of measure for convex functions and polynomial chaoses, Bull. Pol. Acad. Sci. Math. 53 (2005), no. 2, 221–238. MR2163396R. Adamczak, Logarithmic Sobolev inequalities and concentration of measure for convex functions and polynomial chaoses, Bull. Pol. Acad. Sci. Math. 53 (2005), no. 2, 221–238. MR2163396

2.

R. Adamczak and M. Strzelecki, On the convex Poincaré inequality and weak transportation inequalities, Bernoulli 25 (2019), no. 1, 341–374. MR3892322R. Adamczak and M. Strzelecki, On the convex Poincaré inequality and weak transportation inequalities, Bernoulli 25 (2019), no. 1, 341–374. MR3892322

3.

D. Bakry and M. Ledoux, Lévy-Gromov’s isoperimetric inequality for an infinite-dimensional diffusion generator, Invent. Math. 123 (1996), no. 2, 259–281. MR1374200D. Bakry and M. Ledoux, Lévy-Gromov’s isoperimetric inequality for an infinite-dimensional diffusion generator, Invent. Math. 123 (1996), no. 2, 259–281. MR1374200

4.

F. Barthe and B. Maurey, Some remarks on isoperimetry of Gaussian type, Ann. Inst. H. Poincaré Probab. Statist. 36 (2000), no. 4, 419–434. MR1785389F. Barthe and B. Maurey, Some remarks on isoperimetry of Gaussian type, Ann. Inst. H. Poincaré Probab. Statist. 36 (2000), no. 4, 419–434. MR1785389

5.

S. G. Bobkov, An isoperimetric inequality on the discrete cube, and an elementary proof of the isoperimetric inequality in Gauss space, Ann. Probab. 25 (1997), no. 1, 206–214. MR1428506S. G. Bobkov, An isoperimetric inequality on the discrete cube, and an elementary proof of the isoperimetric inequality in Gauss space, Ann. Probab. 25 (1997), no. 1, 206–214. MR1428506

6.

S. G. Bobkov, I. Gentil and M. Ledoux, Hypercontractivity of Hamilton-Jacobi equations, J. Math. Pures Appl. (9) 80 (2001), no. 7, 669–696. MR1846020S. G. Bobkov, I. Gentil and M. Ledoux, Hypercontractivity of Hamilton-Jacobi equations, J. Math. Pures Appl. (9) 80 (2001), no. 7, 669–696. MR1846020

7.

S. G. Bobkov and F. Götze, Discrete isoperimetric and Poincaré-type inequalities, Probab. Theory Related Fields 114 (1999), no. 2, 245–277. MR1701522S. G. Bobkov and F. Götze, Discrete isoperimetric and Poincaré-type inequalities, Probab. Theory Related Fields 114 (1999), no. 2, 245–277. MR1701522

8.

C. Borell, The Brunn-Minkowski inequality in Gauss space, Invent. Math. 30 (1975), no. 2, 207–216. MR0399402C. Borell, The Brunn-Minkowski inequality in Gauss space, Invent. Math. 30 (1975), no. 2, 207–216. MR0399402

9.

S. Boucheron, G. Lugosi and P. Massart, Concentration inequalities, Oxford University Press, Oxford, 2013. MR3185193S. Boucheron, G. Lugosi and P. Massart, Concentration inequalities, Oxford University Press, Oxford, 2013. MR3185193

10.

E. B. Davies and B. Simon, Ultracontractivity and the heat kernel for Schrödinger operators and Dirichlet Laplacians, J. Funct. Anal. 59 (1984), no. 2, 335–395. MR0766493E. B. Davies and B. Simon, Ultracontractivity and the heat kernel for Schrödinger operators and Dirichlet Laplacians, J. Funct. Anal. 59 (1984), no. 2, 335–395. MR0766493

11.

A. Ehrhard, Symétrisation dans l’espace de Gauss, Math. Scand. 53 (1983), no. 2, 281–301. MR0745081A. Ehrhard, Symétrisation dans l’espace de Gauss, Math. Scand. 53 (1983), no. 2, 281–301. MR0745081

12.

N. Gozlan, A characterization of dimension free concentration in terms of transportation inequalities, Ann. Probab. 37 (2009), no. 6, 2480–2498. MR2573565N. Gozlan, A characterization of dimension free concentration in terms of transportation inequalities, Ann. Probab. 37 (2009), no. 6, 2480–2498. MR2573565

13.

N. Gozlan, C. Roberto and P.-M. Samson, From dimension free concentration to the Poincaré inequality, Calc. Var. Partial Differential Equations 52 (2015), no. 3-4, 899–925. MR3311918N. Gozlan, C. Roberto and P.-M. Samson, From dimension free concentration to the Poincaré inequality, Calc. Var. Partial Differential Equations 52 (2015), no. 3-4, 899–925. MR3311918

14.

N. Gozlan, C. Roberto, P.-M. Samson, P. Tetali, Kantorovich duality for general transport costs and applications, J. Funct. Anal. 273 (2017), no. 11, 3327–3405. MR3706606N. Gozlan, C. Roberto, P.-M. Samson, P. Tetali, Kantorovich duality for general transport costs and applications, J. Funct. Anal. 273 (2017), no. 11, 3327–3405. MR3706606

15.

N. Gozlan, C. Roberto, P.-M. Samson, Y. Shu, P. Tetali, Characterization of a class of weak transport-entropy inequalities on the line, Ann. Inst. Henri Poincaré Probab. Stat. 54 (2018), no. 3, 1667–1693. MR3825894N. Gozlan, C. Roberto, P.-M. Samson, Y. Shu, P. Tetali, Characterization of a class of weak transport-entropy inequalities on the line, Ann. Inst. Henri Poincaré Probab. Stat. 54 (2018), no. 3, 1667–1693. MR3825894

16.

M. Gromov and V. D. Milman, A topological application of the isoperimetric inequality, Amer. J. Math. 105 (1983), no. 4, 843–854. MR0708367M. Gromov and V. D. Milman, A topological application of the isoperimetric inequality, Amer. J. Math. 105 (1983), no. 4, 843–854. MR0708367

17.

L. Gross, Logarithmic Sobolev inequalities, Amer. J. Math. 97 (1975), no. 4, 1061–1083. MR0420249L. Gross, Logarithmic Sobolev inequalities, Amer. J. Math. 97 (1975), no. 4, 1061–1083. MR0420249

18.

R. Kaas and J.-M. Buhrman, Mean, Median, and Mode in Binomial Distribution, Statistica Neerlandica, 34 (1980), no. 1, 13–18.  MR0576005R. Kaas and J.-M. Buhrman, Mean, Median, and Mode in Binomial Distribution, Statistica Neerlandica, 34 (1980), no. 1, 13–18.  MR0576005

19.

Y. Klochkov and N. Zhivotovskiy, Uniform Hanson-Wright type concentration inequalities for unbounded entries via the entropy method, Electron. J. Probab. 25 (2020), Paper No. 22, 30 pp. MR4073683Y. Klochkov and N. Zhivotovskiy, Uniform Hanson-Wright type concentration inequalities for unbounded entries via the entropy method, Electron. J. Probab. 25 (2020), Paper No. 22, 30 pp. MR4073683

20.

R. Latała and K. Oleszkiewicz, Between Sobolev and Poincaré, in Geometric aspects of functional analysis, 147–168, Lecture Notes in Math., 1745, Springer, Berlin. MR1796718R. Latała and K. Oleszkiewicz, Between Sobolev and Poincaré, in Geometric aspects of functional analysis, 147–168, Lecture Notes in Math., 1745, Springer, Berlin. MR1796718

21.

M. Ledoux, The concentration of measure phenomenon, Mathematical Surveys and Monographs, 89, American Mathematical Society, Providence, RI, 2001. MR1849347M. Ledoux, The concentration of measure phenomenon, Mathematical Surveys and Monographs, 89, American Mathematical Society, Providence, RI, 2001. MR1849347

22.

K. Marton, A simple proof of the blowing-up lemma, IEEE Trans. Inform. Theory 32 (1986), no. 3, 445–446. MR0838213K. Marton, A simple proof of the blowing-up lemma, IEEE Trans. Inform. Theory 32 (1986), no. 3, 445–446. MR0838213

23.

K. Marton, Bounding d-distance by informational divergence: a method to prove measure concentration, Ann. Probab. 24 (1996), no. 2, 857–866. MR1404531K. Marton, Bounding d-distance by informational divergence: a method to prove measure concentration, Ann. Probab. 24 (1996), no. 2, 857–866. MR1404531

24.

S. Mendelson and N. Tomczak-Jaegermann, A subgaussian embedding theorem, Israel J. Math. 164 (2008), 349–364. MR2391154S. Mendelson and N. Tomczak-Jaegermann, A subgaussian embedding theorem, Israel J. Math. 164 (2008), 349–364. MR2391154

25.

V. D. Milman and G. Schechtman, Asymptotic theory of finite-dimensional normed spaces, Lecture Notes in Mathematics, 1200, Springer-Verlag, Berlin, 1986. MR0856576V. D. Milman and G. Schechtman, Asymptotic theory of finite-dimensional normed spaces, Lecture Notes in Mathematics, 1200, Springer-Verlag, Berlin, 1986. MR0856576

26.

E. Nelson, The free Markoff field, J. Functional Analysis 12 (1973), 211–227. MR0343816E. Nelson, The free Markoff field, J. Functional Analysis 12 (1973), 211–227. MR0343816

27.

F. Otto and C. Villani, Generalization of an inequality by Talagrand and links with the logarithmic Sobolev inequality, J. Funct. Anal. 173 (2000), no. 2, 361–400. MR1760620F. Otto and C. Villani, Generalization of an inequality by Talagrand and links with the logarithmic Sobolev inequality, J. Funct. Anal. 173 (2000), no. 2, 361–400. MR1760620

28.

Y. Shu and M. Strzelecki, A characterization of a class of convex log-Sobolev inequalities on the real line, Ann. Inst. Henri Poincaré Probab. Stat. 54 (2018), no. 4, 2075–2091. MR3865667Y. Shu and M. Strzelecki, A characterization of a class of convex log-Sobolev inequalities on the real line, Ann. Inst. Henri Poincaré Probab. Stat. 54 (2018), no. 4, 2075–2091. MR3865667

29.

V. N. Sudakov and B. S. Tsirelson, Extremal properties of half-spaces for spherically invariant measures, Zap. Naučn. Sem. Leningrad. Otdel. Mat. Inst. Steklov. (LOMI) 41 (1974), 14–24, 165. MR0365680V. N. Sudakov and B. S. Tsirelson, Extremal properties of half-spaces for spherically invariant measures, Zap. Naučn. Sem. Leningrad. Otdel. Mat. Inst. Steklov. (LOMI) 41 (1974), 14–24, 165. MR0365680

30.

M. Talagrand, Concentration of measure and isoperimetric inequalities in product spaces, Inst. Hautes Études Sci. Publ. Math. No. 81 (1995), 73–205. MR1361756M. Talagrand, Concentration of measure and isoperimetric inequalities in product spaces, Inst. Hautes Études Sci. Publ. Math. No. 81 (1995), 73–205. MR1361756

31.

M. Talagrand, A new look at independence, Ann. Probab. 24 (1996), no. 1, 1–34. MR1387624M. Talagrand, A new look at independence, Ann. Probab. 24 (1996), no. 1, 1–34. MR1387624

32.

M. Talagrand, Transportation cost for Gaussian and other product measures, Geom. Funct. Anal. 6 (1996), no. 3, 587–600. MR1392331M. Talagrand, Transportation cost for Gaussian and other product measures, Geom. Funct. Anal. 6 (1996), no. 3, 587–600. MR1392331

33.

R. van Handel, Probability in High Dimension, Lecture notes,  https://web.math.princeton.edu/rvan/APC550.pdfR. van Handel, Probability in High Dimension, Lecture notes,  https://web.math.princeton.edu/rvan/APC550.pdf
Han Huang and Konstantin Tikhomirov "On dimension-dependent concentration for convex Lipschitz functions in product spaces," Electronic Journal of Probability 28(none), 1-23, (2023). https://doi.org/10.1214/23-EJP944
Received: 24 June 2021; Accepted: 31 March 2023; Published: 2023
Vol.28 • 2023
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