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Concentration on the Discrete Torus Using Transportation

Published online by Cambridge University Press:  01 September 2009

M. SAMMER
Affiliation:
The Turing Center, University of Washington, Seattle, WA, USA (e-mail: [email protected])
P. TETALI
Affiliation:
School of Mathematics and School of Computer Science, Georgia Institute of Technology, Atlanta, GA 30332, USA (e-mail: [email protected])

Abstract

The sub-Gaussian constant of a graph arises naturally in bounding the moment-generating function of Lipschitz functions on the graph, with a given probability measure on the set of vertices. The closely related spread constant of a graph measures the maximal variance over all Lipschitz functions on the graph. As such they are both useful (as demonstrated in the works of Bobkov, Houdré and Tetali and Alon, Boppana and Spencer) for describing the concentration of measure phenomenon in product graphs. An equivalent formulation of the sub-Gaussian constant using a transportation inequality, introduced by Bobkov and Götze, is investigated here in depth, leading to a new way of bounding the sub-Gaussian constant. A tight concentration result for the discrete torus is given as a concrete application. An infinite family of graphs is also provided here to demonstrate that, typically, the spread and the sub-Gaussian constants differ by an order of magnitude.

Type
Paper
Copyright
Copyright © Cambridge University Press 2009

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References

[1]Alon, N. (1986) Eigenvalues and expanders. Combinatorica 6 8396.CrossRefGoogle Scholar
[2]Alon, N., Boppana, R. and Spencer, J. (1998) An asymptotic isoperimetric inequality. Geom. Funct. Anal. 8 411436.CrossRefGoogle Scholar
[3]Alon, N. and Milman, V. D. (1985) λ1, isoperimetric inequalities for graphs, and superconcentrators. J. Combin. Theory Ser. B 38 7388.CrossRefGoogle Scholar
[4]Bobkov, S. G. and Götze, F. (1999) Exponential integrability and transportation cost related to logarithmic Sobolev inequalities. J. Funct. Anal. 163 128.CrossRefGoogle Scholar
[5]Bobkov, S. G., Houdré, C. and Tetali, P. (2006) The subgaussian constant and concentration inequalities. Israel J. Math. 156 255283.CrossRefGoogle Scholar
[6]Bollobás, B. and Leader, I. (1990) An isoperimetric inequality on the discrete torus. SIAM J. Discrete Math. 3 3237.CrossRefGoogle Scholar
[7]Bollobás, B. and Leader, I. (1991) Compressions and isoperimetric inequalities. J. Combin. Theory Ser. A 56 4762.CrossRefGoogle Scholar
[8]Chen, G.-Y. and Sheu, Y.-C. (2003) On the log-Sobolev constant for the simple random walk on the n-cycle: The even cases. J. Funct. Anal. 202 473485.CrossRefGoogle Scholar
[9]Chvatal, V. (1983) Linear Programming, Freeman.Google Scholar
[10]Gangbo, W. and McCann, R. J. (1996) The geometry of optimal transportation. Acta Math. 177 113161.CrossRefGoogle Scholar
[11]Kantorovich, L. V. (1942) On the translocation of masses. Dokl. Akad. Nauk SSSR 37 227229.Google Scholar
[12]Ledoux, M. (2001) The Concentration of Measure Phenomenon, Vol. 89 of Mathematical Surveys and Monographs, AMS, Providence, RI.Google Scholar
[13]Riordan, O. (1998) An ordering on the even discrete torus. SIAM J. Discrete Math. 11 110127 (electronic).CrossRefGoogle Scholar