# Best constants for the isoperimetric inequality in quantitative form

created by cicalese on 30 Dec 2010
modified on 21 Dec 2013

[BibTeX]

Published Paper

Inserted: 30 dec 2010
Last Updated: 21 dec 2013

Journal: J. Eur. Math. Soc. (JEMS)
Volume: 15
Number: 3
Pages: 1101-1129
Year: 2013

Abstract:

We prove existence and regularity of minimizers for a class of functionals defined on Borel sets in $R^n$. Combining these results with a refinement of the selection principle introduced by the authors in a previous paper, we describe a method suitable for the determination of the best constants in the quantitative isoperimetric inequality with higher order terms. Then, applying Bonnesen's annular symmetrization in a very elementary way, we show that, for $n=2$, the above-mentioned constants can be explicitly computed through a one-parameter family of convex sets known as \textit{ovals}. This proves a further extension of a conjecture posed by Hall in J. Reine Angew. Math. 428 (1992).