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In a complete metric space equipped with a doubling measure supporting a $p$-Poincar\'e inequality, we prove sharp growth and integrability results for $p$-harmonic Green functions and their minimal $p$-weak upper gradients. We show that…

Analysis of PDEs · Mathematics 2023-10-05 Anders Björn , Jana Björn , Juha Lehrbäck

An exact representation of the causal QED fermion Green's function, in an arbritrary external electromagnetic field, derived by Fried, Gabellini and McKellar, and which naturally allows for non-perturbative approximations, is here used to…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. K. J. Daniel , B. H. J. McKellar

We describe a method to prove new integral inequalities for stable minimal hypersurfaces in Euclidean space. As an application, we give a simple proof that complete, two sided, stable minimal hypersurfaces in $\mathbb{R}^4$ are hyperplanes.…

Differential Geometry · Mathematics 2026-04-17 Xavier Cabre , Giovanni Catino , Luciano Mari , Paolo Mastrolia , Alberto Roncoroni

The main objective of the work is to provide sharp two-sided estimates of $\lambda$-Green function of hyperbolic Brownian motion of a half-space. We strongly rely on recent results obtained by K. Bogus and J. Malecki [3], regarding precise…

Probability · Mathematics 2015-02-05 Kamil Bogus , Tomasz Byczkowski , Jacek Malecki

On a complete $p$-nonparabolic $3$-dimensional manifold with non-negative scalar curvature and vanishing second homology, we establish a sharp monotonicity formula for the proper $p$-Green function along its level sets for $1<p<3$. This can…

Analysis of PDEs · Mathematics 2022-03-01 Pak-Yeung Chan , Jianchun Chu , Man-Chun Lee , Tin-Yau Tsang

We study the one-dimensional Schr\"odinger equation and derive exact expressions for the Green function in terms of reflection coefficients which are defined for semi-infinite intervals. We also discuss the relation between our results and…

Mathematical Physics · Physics 2011-12-30 Toru Miyazawa

The non-equilibrium Green's function (NEGF) approach offers a practical framework for simulating various phenomena in mesoscopic systems. As the dimension of electronic devices shrinks to just a few nanometers, the need for new…

Mesoscale and Nanoscale Physics · Physics 2025-04-09 Vahid Mosallanejad , Kuei-Lin Chiu , Wenjie Dou

The purpose of this paper is to find optimal estimates for the Green function of a half-space of {\it the relativistic $\alpha$-stable process} with parameter $m$ on $\Rd$ space. This process has an infinitesimal generator of the form…

Probability · Mathematics 2011-07-06 Tomasz Grzywny , Michał Ryznar

We consider a random, uniformly elliptic coefficient field $a(x)$ on the $d$-dimensional integer lattice $\mathbb{Z}^d$. We are interested in the spatial decay of the quenched elliptic Green function $G(a;x,y)$. Next to stationarity, we…

Probability · Mathematics 2014-01-14 Daniel Marahrens , Felix Otto

Let $(M,g)$ be a $3$--dimensional, complete, one--ended Riemannian manifold, with a minimal, compact and connected boundary. We assume that $M$ has a simple topology and that the scalar curvature of $(M,g)$ is non--negative. Moreover, we…

Differential Geometry · Mathematics 2025-04-08 Francesca Oronzio

We consider a random, uniformly elliptic coefficient field $a$ on the lattice $\mathbb{Z}^d$. The distribution $\langle \cdot \rangle$ of the coefficient field is assumed to be stationary. Delmotte and Deuschel showed that the gradient and…

Probability · Mathematics 2014-01-21 Daniel Marahrens , Felix Otto

We study the Green function of the Poisson equation in two, three and four dimensions. The solution g of the equation nabla^2 g(x - x') = delta^(D)(x - x'), where x and x are D-dimensional position vectors, is customarily expanded into…

Mathematical Physics · Physics 2018-04-03 U. D. Jentschura , J. Sapirstein

We present a quantitative geometric rigidity estimate in dimensions $d=2,3$ generalizing the celebrated result by Friesecke, James, and M\"uller to the setting of variable domains. Loosely speaking, we show that for each $y \in…

Analysis of PDEs · Mathematics 2023-04-12 Manuel Friedrich , Leonard Kreutz , Konstantinos Zemas

Through this article we will use a notation \begin{equation}\label{alfaLap} T_{\alpha}u(x)=(1-|x|^2)\Delta u(x)+2 \alpha \langle x,\nabla u(x)\rangle + (n-2-\alpha) \alpha u(x). \end{equation} Here, $|x|<1$ and $\alpha>-1$. Also, for…

Complex Variables · Mathematics 2024-10-03 M. Mateljević , N. Mutavdžić , B. Purtić

By using various properties of the complete elliptic integrals, we have derived an alternative expression for the gravitational potential of axially symmetric bodies, which is free of singular kernel in contrast with the classical form.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 A. Trova , J. M. Huré , F. Hersant

The retarded Green function of a wave equation on a 4-dimensional curved background spacetime is a (generalized) function of two spacetime points and diverges when these are connected by a null geodesic. The Hadamard form makes explicit the…

General Relativity and Quantum Cosmology · Physics 2023-08-17 Marc Casals , Brien Nolan

We study the Green function gr_\Gamma\ for the Laplace operator on the quotient of the hyperbolic plane by a cofinite Fuchsian group \Gamma. We use a limiting procedure, starting from the resolvent kernel, and lattice point estimates for…

Analysis of PDEs · Mathematics 2012-07-20 Peter Bruin

Motivated by recent experimental refinements of stellar reaction rates, we establish a non-perturbative Green's function formalism based on the exact solution of the Dyson equation for sub-barrier proton-nucleus resonant scattering. By…

Nuclear Theory · Physics 2026-03-19 Bahruz Suleymanli , Kutsal Bozkurt

A classical problem of free-space Green's function $G_{0\Lambda}$ representations of the Helmholtz equation is studied in various quasi-periodic cases, i.e., when an underlying periodicity is imposed in less dimensions than is the dimension…

Mathematical Physics · Physics 2007-05-23 Alexander Moroz

We study gradient testing and gradient estimation of smooth functions using only a comparison oracle that, given two points, indicates which one has the larger function value. For any smooth $f\colon\mathbb R^n\to\mathbb R$,…

Machine Learning · Computer Science 2026-02-20 Xiwen Tao , Chenyi Zhang , Helin Wang , Yexin Zhang , Tongyang Li