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Related papers: Smooth approximation of Lipschitz projections

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We introduce a proximal subdifferential and develop a calculus for nonsmooth functions defined on any Riemannian manifold $M$. We give several applications of this theory, concerning: 1) differentiability and geometrical properties of the…

Differential Geometry · Mathematics 2007-05-23 Daniel Azagra , Juan Ferrera

Approximating a manifold-valued function from samples of input-output pairs consists of modeling the relationship between an input from a vector space and an output on a Riemannian manifold. We propose a function approximation method that…

Numerical Analysis · Mathematics 2025-04-18 Hang Wang , Raf Vandebril , Joeri Van der Veken , Nick Vannieuwenhoven

We introduce Lipschitz continuous and $C^{1,1}$ geometric approximation and interpolation methods for sampled bounded uniformly continuous functions over compact sets and over complements of bounded open sets in $\mathbb{R}^n$ by using…

Metric Geometry · Mathematics 2016-09-29 Kewei Zhang , Elaine Crooks , Antonio Orlando

We study a class of optimization problems on Riemannian manifolds, where the objective function consists of a smooth term and quasi-norm type penalties with exponent $p \in (0, 1]$. The essential difficulty lies in the fact that the…

Optimization and Control · Mathematics 2026-04-21 Lei Wang , Xiaojun Chen

In this paper it is hown that given any smooth, positive function f on a closed, smooth manifold of dimension greater than four and with positive Paneitz invariant, there exists a metric on M such that $Q_g$ = f.

Differential Geometry · Mathematics 2010-03-30 David Raske

We provide comparison principles for convex functions through its proximal mappings. Consequently, we prove that the norm of the proximal operator determines a convex the function up to a constant. A new characterization of Lipschitzianity…

Optimization and Control · Mathematics 2020-07-30 Emilio Vilches

In this paper we prove some approximation results for biLipschitz maps in the Heisenberg group. Namely, we show that a biLipschitz map with biLipschitz constant close to one can be pointwise approximated, quantitatively on any fixed ball,…

Metric Geometry · Mathematics 2008-01-15 Nicola Arcozzi , Daniele Morbidelli

Let M be a smooth compact manifold without boundary. We consider two smooth Sub-Semi-Riemannian metrics on M. Under suitable conditions, we show that they are almost conformally isometric in an Lp sense. Assume also that M carries a…

Differential Geometry · Mathematics 2017-01-20 Erwann Delay

We show that the Lipschitz-Free Space over a connected orientable $n$-di\-men\-sio\-nal Riemannian manifold $M$ is isometrically isomorphic to a quotient of $L^1(M,TM)$, the integrable sections of the tangent bundle $TM$, if $M$ is either…

Functional Analysis · Mathematics 2025-09-18 Franz Luggin

We prove the equivalence of several natural notions of conformal maps between sub-Riemannian manifolds. Our main contribution is in the setting of those manifolds that support a suitable regularity theory for subelliptic $p$-Laplacian…

Analysis of PDEs · Mathematics 2017-01-06 Luca Capogna , Giovanna Citti , Enrico Le Donne , Alessandro Ottazzi

On any symplectic manifold of dimension greater than 2, we construct a pair of smooth functions, such that on the one hand, the uniform norm of their Poisson bracket equals to 1, but on the other hand, this pair cannot be reasonably…

Symplectic Geometry · Mathematics 2013-08-21 Lev Buhovsky

We prove that a compactly supported homeomorphism of a smooth manifold of dimension greater or equal to 5 can be approximated uniformly by compactly supported diffeomorphisms if and only if it is isotopic to a diffeomorphism. If the given…

Dynamical Systems · Mathematics 2016-07-28 Stefan Müller

A systematic and comprehensive study of p-adic refinement equations and subdivision scheme associated with a finitely supported refinement mask are carried out in this paper. The Lq -convergence of the subdivision scheme is characterized in…

Numerical Analysis · Mathematics 2024-06-12 Athira N , Lineesh M C

In this paper we present a cubic regularized Newton's method to minimize a smooth function over a Riemannian manifold. The proposed algorithm is shown to reach a second-order $\epsilon$-stationary point within…

Optimization and Control · Mathematics 2018-05-16 Junyu Zhang , Shuzhong Zhang

We use discrete holomorphic polynomials to prove that, given a refining sequence of critical maps of a Riemann surface, any holomorphic function can be approximated by a converging sequence of discrete holomorphic functions.

Mathematical Physics · Physics 2007-05-23 Christian Mercat

We prove the Quantitative Fatou Theorem for Lipschitz domains on complete Riemannian manifolds. This requires extending the $\varepsilon$-approximation lemma to the manifold setting. Our studies apply to harmonic functions, as well as to a…

Analysis of PDEs · Mathematics 2023-09-21 Marcin Gryszówka

In this paper, we prove a finite dimensional approximation scheme for the Wiener measure on closed Riemannian manifolds, establishing a generalization for $L^{1}$-functionals, of the approach followed by Andersson and Driver on [1]. We…

Differential Geometry · Mathematics 2022-01-28 Juan Carlos Sampedro

We propose novel smooth approximations to the classical rounding function, suitable for differentiable optimization and machine learning applications. Our constructions are based on two approaches: (1) localized sigmoid window functions…

Machine Learning · Computer Science 2025-04-29 Stanislav Semenov

We prove that every smooth closed manifold admits a smooth real-valued function with only two critical values. We call a function of this type a \emph{Reeb function}. We prove that for a Reeb function we can prescribe the set of minima (or…

Geometric Topology · Mathematics 2025-06-02 Antonio Lerario , Chiara Meroni , Daniele Zuddas

We introduce the notion of log-Riemann surfaces. These are Riemann surfaces given by cutting and pasting planes together isometrically, and come equipped with a holomorphic local diffeomorphism to C called the projection map, and a…

Complex Variables · Mathematics 2015-12-14 Kingshook Biswas , Ricardo Perez-Marco