Transactions of the American Mathematical Society

Published by the American Mathematical Society since 1900, Transactions of the American Mathematical Society is devoted to longer research articles in all areas of pure and applied mathematics.

ISSN 1088-6850 (online) ISSN 0002-9947 (print)

The 2024 MCQ for Transactions of the American Mathematical Society is 1.48 .

What is MCQ? The Mathematical Citation Quotient (MCQ) measures journal impact by looking at citations over a five-year period. Subscribers to MathSciNet may click through for more detailed information.

 

Uniqueness of extremals for some sharp Poincaré-Sobolev constants
HTML articles powered by AMS MathViewer

by Lorenzo Brasco and Erik Lindgren;
Trans. Amer. Math. Soc. 376 (2023), 3541-3584
DOI: https://doi.org/10.1090/tran/8838
Published electronically: February 9, 2023

Abstract:

We study the sharp constant for the embedding of $W^{1,p}_0(\Omega )$ into $L^q(\Omega )$, in the case $2<p<q$. We prove that for smooth connected sets, when $q>p$ and $q$ is sufficiently close to $p$, extremal functions attaining the sharp constant are unique, up to a multiplicative constant. This in turn gives the uniqueness of solutions with minimal energy to the Lane-Emden equation, with super-homogeneous right-hand side.

The result is achieved by suitably adapting a linearization argument due to C.-S. Lin. We rely on some fine estimates for solutions of $p-$Laplace–type equations by L. Damascelli and B. Sciunzi.

References
Similar Articles
  • Retrieve articles in Transactions of the American Mathematical Society with MSC (2020): 35P30, 35A02, 35B65
  • Retrieve articles in all journals with MSC (2020): 35P30, 35A02, 35B65
Bibliographic Information
  • Lorenzo Brasco
  • Affiliation: Dipartimento di Matematica e Informatica, Università degli Studi di Ferrara, Via Machiavelli 35, 44121 Ferrara, Italy
  • MR Author ID: 884059
  • Email: lorenzo.brasco@unife.it
  • Erik Lindgren
  • Affiliation: Department of Mathematics, KTH – Royal Institute of Technology, 100 44 Stockholm, Sweden
  • MR Author ID: 818487
  • Email: eriklin@math.kth.se
  • Received by editor(s): February 16, 2022
  • Received by editor(s) in revised form: August 19, 2022, and October 10, 2022
  • Published electronically: February 9, 2023
  • Additional Notes: The second author was supported by the Swedish Research Council, grant no. 2017-03736.

  • Dedicated: To Peter Lindqvist, a gentleman and $p-$Laplacian master, on the occasion of his 70th birthday
  • © Copyright 2023 American Mathematical Society
  • Journal: Trans. Amer. Math. Soc. 376 (2023), 3541-3584
  • MSC (2020): Primary 35P30, 35A02, 35B65
  • DOI: https://doi.org/10.1090/tran/8838
  • MathSciNet review: 4577341