A concavity property for the measure of product sets in groups
Ruzsa, Imre
Fundamenta Mathematicae, Tome 141 (1992), p. 247-254 / Harvested from The Polish Digital Mathematics Library
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Let G be a connected locally compact group with a left invariant Haar measure μ. We prove that the function ξ(x) = inf μ̅(AB): μ(A) = x is concave for any fixed bounded set B ⊂ G. This is used to give a new proof of Kemperman’s inequality μ̲(AB)≥min(μ̲(A)+μ̲(B),μ(G)) for unimodular G.

Publié le : 1992-01-01
EUDML-ID : urn:eudml:doc:211944 
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     journal = {Fundamenta Mathematicae},
     volume = {141},
     year = {1992},
     pages = {247-254},
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     language = {en},
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Ruzsa, Imre. A concavity property for the measure of product sets in groups. Fundamenta Mathematicae, Tome 141 (1992) pp. 247-254. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-fmv140i3p247bwm/

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