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In this note we study a nonlocal version of the Sobolev inequality \begin{equation*} \int_{\mathbb{R}^N}|\nabla u|^2 dx \geq S_{HLS}\left(\int_{\mathbb{R}^N}\big(|x|^{-\alpha} \ast u^{2_\alpha^{\ast}}\big)u^{2_\alpha^{\ast}}…

Analysis of PDEs · Mathematics 2023-05-29 Shengbing Deng , Xingliang Tian , Minbo Yang , Shunneng Zhao

We perform accurate investigation of stability of localized vortices in an effectively two-dimensional ("pancake-shaped") trapped BEC with negative scattering length. The analysis combines computation of the stability eigenvalues and direct…

Other Condensed Matter · Physics 2009-11-11 Dumitru Mihalache , Dumitru Mazilu , Boris A. Malomed , Falk Lederer

We study the sharp constant in the Morrey inequality for fractional Sobolev-Slobodecki\u{\i} spaces on the whole $\mathbb{R}^N$. By generalizing a recent work by Hynd and Seuffert, we prove existence of extremals, together with some…

Analysis of PDEs · Mathematics 2023-09-13 Lorenzo Brasco , Francesca Prinari , Firoj Sk

In this paper, we establish the stability for the Hardy-Littlewood-Sobolev (HLS) inequalities with explicit lower bounds. By establishing the relation between the stability of HLS inequalities and the stability of fractional Sobolev…

Analysis of PDEs · Mathematics 2024-01-01 Lu Chen , Guozhen Lu , Hanli Tang

We establish optimal stability estimates in terms of the Fraenkel asymmetry with universal dimensional constants for a Lorentzian isoperimetric inequality due to Bahn and Ehrlich and, as a consequence, for a special version of a Lorentzian…

Differential Geometry · Mathematics 2026-05-05 Christian Lange , Jonas W. Peteranderl

Given a compact convex domain $C\subset \mathbb{R}^k$ and bounded measurable functions $f_1,\ldots,f_n:C\to \mathbb{R}$, define the sup-convolution $(f_1\ast \ldots \ast f_n)(z)$ to be the supremum average value of…

Functional Analysis · Mathematics 2023-07-20 Peter van Hintum , Hunter Spink , Marius Tiba

We address the optimal constants in the strong and the weak Stechkin inequalities, both in their discrete and continuous variants. These inequalities appear in the characterization of approximation spaces which arise from sparse…

Classical Analysis and ODEs · Mathematics 2021-07-01 Thomas Jahn , Tino Ullrich

We develop a comprehensive study on sharp potential type Riemannian Sobolev inequalities of order 2 by means of a local geometric Sobolev inequality of same kind and suitable De Giorgi-Nash-Moser estimates. In particular we discuss…

Analysis of PDEs · Mathematics 2010-11-29 Ezequiel R. Barbosa , Marcos Montenegro

The spinorial Sobolev inequality on the unit sphere states \begin{equation*} \Big(\int| D\psi|^{\frac{2n}{n+1}}\Big)^{\frac{n+1}{n}}-\frac{n}{2}\omega_{n}^{1/n}\int\langle D\psi,\psi\rangle \geq 0, \end{equation*} with equality if and only…

Differential Geometry · Mathematics 2025-08-21 Guofang Wang , Mingwei Zhang

Let $\Omega \subset \mathbb{R}^n$ be a convex domain and let $f:\Omega \rightarrow \mathbb{R}$ be a positive, subharmonic function (i.e. $\Delta f \geq 0$). Then $$ \frac{1}{|\Omega|} \int_{\Omega}{f dx} \leq \frac{c_n}{ |\partial \Omega| }…

In dimensions $d \in \{3,4,5,6,7\}$, we prove that the constant functions on the unit sphere $\mathbb{S}^{d-1}\subset \mathbb{R}^d$ maximize the weighted adjoint Fourier restriction inequality $$ \left| \int_{\mathbb{R}^d}…

Classical Analysis and ODEs · Mathematics 2024-10-15 Emanuel Carneiro , Giuseppe Negro , Diogo Oliveira e Silva

This study aims to construct a stable, high-order compact finite difference method for solving Sobolev-type equations with Dirichlet boundary conditions in one-space dimension. Approximation of higher-order mixed derivatives in some…

Numerical Analysis · Mathematics 2025-06-05 Lavanya V Salian , Samala Rathan , Rakesh Kumar

We prove an optimal order error bound in the discrete $H^2(\Omega)$ norm for finite difference approximations of the first boundary-value problem for the biharmonic equation in $n$ space dimensions, with $n \in \{2,\dots,7\}$, whose…

Numerical Analysis · Mathematics 2019-04-04 Stefan Müller , Florian Schweiger , Endre Süli

We consider the restriction placed by the Bogoliubov inequality on the nature of the Bose-Einstein condensates (BECs) for interacting atoms in a spatial dimension D </- 2 and in the presence of an external arbitrary potential, which may be…

Quantum Gases · Physics 2019-07-29 Moorad Alexanian

A stability version of the Blaschke-Santal\'o inequality and the affine isoperimetric inequality for convex bodies of dimension n>2 is proved. The first step is the reduction to the case when the convex body is o-symmetric and has axial…

Metric Geometry · Mathematics 2009-01-22 Károly J. Böröczky

We study sharp \(L^2\) bounds for the interior Cauchy transform \(C_D\) on a bounded planar domain \(D\) and clarify its connection with the Dirichlet spectrum. We analyze an approach that replaces fractional Dirichlet powers on \(D\) by…

Complex Variables · Mathematics 2026-02-17 David Kalaj

Log-Sobolev inequalities (LSIs) upper-bound entropy via a multiple of the Dirichlet form (i.e. norm of a gradient). In this paper we prove a family of entropy-energy inequalities for the binary hypercube which provide a non-linear…

Probability · Mathematics 2019-04-22 Yury Polyanskiy , Alex Samorodnitsky

In this paper we study the Sobolev inequality in the Dunkl setting using two new approaches which provide a simpler elementary proof of the classical case $p=2$, as well as an extension to the coefficient $p=1$ that was previously unknown.…

Functional Analysis · Mathematics 2019-03-20 Andrei Velicu

Let $(M,g)$ be a smooth compact Riemannian manifold of dimension $n \geq 2$. This paper concerns to the validity of the optimal Riemannian $L^1$-Entropy inequality \[ {\bf Ent}_{dv_g}(u) \leq n \log \left(A_{opt} \|D u\|_{BV(M)} +…

Analysis of PDEs · Mathematics 2014-09-30 Jurandir Ceccon , Leandro Cioletti

We prove the attainability of the best constant in the fractional Hardy--Sobolev inequality with boundary singularity for the Spectral Dirichlet Laplacian. The main assumption is the average concavity of the boundary at the origin.

Analysis of PDEs · Mathematics 2019-06-19 Nikita Ustinov