English
Related papers

Related papers: An almost-almost-Schur lemma on the 3-sphere

200 papers

We study the quantitative stability for the classical Brezis-Nirenberg problem associated with the critical Sobolev embedding $H^1_0(\Omega) \hookrightarrow L^{\frac{2n}{n-2}}(\Omega)$ in a smooth bounded domain $\Omega \subset…

Analysis of PDEs · Mathematics 2025-06-10 Haixia Chen , Seunghyeok Kim , Juncheng Wei

Almost-isometries are quasi-isometries with multiplicative constant one. Lifting a pair of metrics on a compact space gives quasi-isometric metrics on the universal cover. Under some additional hypotheses on the metrics, we show that there…

Group Theory · Mathematics 2016-07-19 Aditi Kar , Jean-Francois Lafont , Benjamin Schmidt

We discuss the (in)stability of solitary waves for a quasi-linear Schr{\"o}dinger equation. The equation contains a quasi-linear term, responsible for a saturation effect, as well as a power nonlinearity. For different exponents of the…

Analysis of PDEs · Mathematics 2025-09-03 Meriem Bahhi , Jonas Lampart , Christian Klein , Simona Rota Nodari

In shape optimisation it is desirable to obtain deformations of a given mesh without negative impact on the mesh quality. We propose a new algorithm using least square formulations of the Cauchy-Riemann equations. Our method allows to…

Optimization and Control · Mathematics 2021-06-09 José A. Iglesias , Kevin Sturm , Florian Wechsung

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

Stable subgroups and the Morse boundary are two systematic approaches to collect and study the hyperbolic aspects of finitely generated groups. In this paper we unify and generalize these strategies by viewing any geodesic metric space as a…

Metric Geometry · Mathematics 2017-06-14 Matthew Cordes , David Hume

We prove a sharp stable $2$-systolic inequality for complex projective space under the scalar curvature lower bound of the normalized Fubini-Study metric. If $M$ is diffeomorphic to $\mathbb{C}\mathrm{P}^n$ and $\mathrm{scal}_g\ge 4n(n+1)$,…

Differential Geometry · Mathematics 2026-04-29 Simone Cecchini , Sven Hirsch , Rudolf Zeidler

In this article, we addressed the numerical solution of a non-linear evolutionary variational inequality, which is encountered in the investigation of quasi-static contact problems. Our study encompasses both the semi-discrete and…

Numerical Analysis · Mathematics 2024-01-05 Kamana Porwal , Tanvi Wadhawan

We prove a stability inequality associated to the reverse Sobolev inequality on the sphere $\mathbb S^n$, for the full admissible parameter range $s - \frac{n}{2} \in (0,1) \cup (1,2)$. To implement the classical proof of Bianchi and…

Analysis of PDEs · Mathematics 2025-05-09 Tobias König

We study metric spaces homeomorphic to the 2-sphere, and find conditions under which they are quasisymmetrically homeomorphic to the standard 2-sphere. As an application of our main theorem we show that an Ahlfors 2-regular, linearly…

Metric Geometry · Mathematics 2015-06-26 Mario Bonk , Bruce Kleiner

Given $N\geq 3,$ we consider the critical Hardy-Sobolev equation $-\Delta u-\frac{\gamma}{|x|^2}u=\frac{|u|^{2^*(s)-2}u}{|x|^s}$ in $\mathbb{R}^N\setminus \{0\},$ where $0<\gamma<\gamma_{H}:=\left(\frac{N-2}{2}\right)^2,\,s\in (0,2)$ and…

Analysis of PDEs · Mathematics 2024-03-12 Souptik Chakraborty

We refine the classical Lindeberg-Feller central limit theorem by obtaining asymptotic bounds on the Kolmogorov distance, the Wasserstein distance, and the parametrized Prokhorov distances in terms of a Lindeberg index. We thus obtain more…

Probability · Mathematics 2016-12-26 Ben Berckmoes , Geert Molenberghs

We prove a sharp result for the distortion of a hyperbolic type metric under $K$-quasiregular mappings of the upper half plane. The proof makes use of a new kind of Bernoulli inequality and the Schwarz lemma for quasiregular mappings.

Complex Variables · Mathematics 2025-03-14 Masayo Fujimura , Matti Vuorinen

We study almost complex surfaces in the nearly K\"ahler $S^3\times S^3$. We show that there is a local correspondence between almost complex surfaces and solutions of the H-surface equation introduced by Wente. We find a global holomorphic…

Differential Geometry · Mathematics 2014-01-13 John Bolton , Bart Dioos , Luc Vrancken

Dynamical mass generation of a two-component fermion in $QED_3$ with a Chern-Simons term is investigated by solving the Schwinger-Dyson equation formulated in the lowest ladder approximation. Dependence of the dynamical fermion mass on a…

High Energy Physics - Theory · Physics 2009-10-31 Toyoki Matsuyama , Hideko Nagahiro , Satoko Uchida

A result of Bangert states that the stable norm associated to any Riemannian metric on the $2$-torus $T^2$ is strictly convex. We demonstrate that the space of stable norms associated to metrics on $T^2$ forms a proper dense subset of the…

Differential Geometry · Mathematics 2010-10-08 Eran Makover , Hugo Parlier , Craig J. Sutton

The large-scale geometry of hyperbolic metric spaces exhibits many distinctive features, such as the stability of quasi-geodesics (the Morse Lemma), the visibility property, and the homeomorphism between visual boundaries induced by a…

Metric Geometry · Mathematics 2019-01-29 Bruce Kleiner , Urs Lang

Recently it has been shown that the unique locally perimeter minimizing partitioning of the plane into three regions, where one region has finite area and the other two have infinite measure, is given by the so-called standard lens…

Analysis of PDEs · Mathematics 2025-01-28 Marco Bonacini , Riccardo Cristoferi , Ihsan Topaloglu

The nonlinear asymptotic stability of shear flows in the 2D Euler equations has traditionally been linked to inviscid damping in the periodic setting. Since Gevrey regularity is required to suppress the ``echo'' phenomenon, asymptotic…

Analysis of PDEs · Mathematics 2026-03-23 Dengjun Guo , Xiaoyutao Luo

We introduce a new variational method for the study of stability in the isoperimetric inequality. The method is quite general as it relies on a penalization technique combined with the regularity theory for quasiminimizers of the perimeter.…

Analysis of PDEs · Mathematics 2010-07-23 Marco Cicalese , Gian Paolo Leonardi