Geometric influences

Nathan Keller, Elchanan Mossel, Arnab Sen

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


We present a new definition of influences in product spaces of continuous distributions. Our definition is geometric, and for monotone sets it is identical with the measure of the boundary with respect to uniform enlargement. We prove analogs of the Kahn-Kalai-Linial (KKL) and Talagrand's influence sum bounds for the new definition. We further prove an analog of a result of Friedgut showing that sets with small "influence sum" are essentially determined by a small number of coordinates. In particular, we establish the following tight analog of the KKL bound: for any set in R{double struk} n of Gaussian measure t, there exists a coordinate i such that the ith geometric influence of the set is at least ct (1 -t) √log n/n, where c is a universal constant. This result is then used to obtain an isoperimetric inequality for the Gaussian measure on R{double struk} n and the class of sets invariant under transitive permutation group of the coordinates.

Original languageEnglish
Pages (from-to)1135-1166
Number of pages32
JournalAnnals of Probability
Issue number3
StatePublished - May 2012
Externally publishedYes


  • Gaussian measure
  • Influences
  • Isoperimetric inequality
  • Kahn-Kalai-Linial influence bound
  • Product space


Dive into the research topics of 'Geometric influences'. Together they form a unique fingerprint.

Cite this