Explicit minimizers of some non-local anisotropic energies: a~short proof
Izvestiya. Mathematics , Tome 85 (2021) no. 3, pp. 468-482

Voir la notice de l'article provenant de la source Math-Net.Ru

In this paper we consider non-local energies defined on probability measures in the plane, given by a convolution interaction term plus a quadratic confinement. The interaction kernel is $-\log|z|+\alpha x^2/|z|^2$, $z=x+iy$, with $-1\alpha1$. This kernel is anisotropic except for the Coulomb case $\alpha=0$. We present a short compact proof of the known surprising fact that the unique minimizer of the energy is the normalized characteristic function of the domain enclosed by an ellipse with horizontal semi-axis $\sqrt{1-\alpha}$ and vertical semi-axis $\sqrt{1+\alpha}$. Letting $\alpha \to 1^-$, we find that the semicircle law on the vertical axis is the unique minimizer of the corresponding energy, a result related to interacting dislocations, and previously obtained by some of the authors. We devote the first sections of this paper to presenting some well-known background material in the simplest way possible, so that readers unfamiliar with the subject find the proofs accessible.
Keywords: non-local interaction, potential theory, maximum principle
Mots-clés : Plemelj formula.
@article{IM2_2021_85_3_a8,
     author = {J. E. Mateu and M. G. Mora and L. Rondi and L. Scardia and J. Verdera},
     title = {Explicit minimizers of  some non-local anisotropic energies: a~short proof},
     journal = {Izvestiya. Mathematics },
     pages = {468--482},
     publisher = {mathdoc},
     volume = {85},
     number = {3},
     year = {2021},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2021_85_3_a8/}
}
TY  - JOUR
AU  - J. E. Mateu
AU  - M. G. Mora
AU  - L. Rondi
AU  - L. Scardia
AU  - J. Verdera
TI  - Explicit minimizers of  some non-local anisotropic energies: a~short proof
JO  - Izvestiya. Mathematics 
PY  - 2021
SP  - 468
EP  - 482
VL  - 85
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_2021_85_3_a8/
LA  - en
ID  - IM2_2021_85_3_a8
ER  - 
%0 Journal Article
%A J. E. Mateu
%A M. G. Mora
%A L. Rondi
%A L. Scardia
%A J. Verdera
%T Explicit minimizers of  some non-local anisotropic energies: a~short proof
%J Izvestiya. Mathematics 
%D 2021
%P 468-482
%V 85
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_2021_85_3_a8/
%G en
%F IM2_2021_85_3_a8
J. E. Mateu; M. G. Mora; L. Rondi; L. Scardia; J. Verdera. Explicit minimizers of  some non-local anisotropic energies: a~short proof. Izvestiya. Mathematics , Tome 85 (2021) no. 3, pp. 468-482. http://geodesic.mathdoc.fr/item/IM2_2021_85_3_a8/