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We propose a general method for finding sharp constants in the imbeddings of the Hilbert Sobolev spaces of order m defined on a n-dimensional Riemann manifold into the space of bounded continuous functions, where m>n/2. The method is based…

Analysis of PDEs · Mathematics 2013-03-06 Alexei A. Ilyin , Sergey V. Zelik

We study the rigidity of Ricci-flat manifolds with quadratic curvature decay under conditions on the Green function. We show that if the gradient of the Green function is uniformly bounded from below, then the manifold is flat. Furthermore,…

Differential Geometry · Mathematics 2025-12-09 Sanghoon Lee , Jiewon Park

Linear singularly perturbed convection-diffusion problems with characteristic layers are considered in three dimensions. We demonstrate the sharpness of our recently obtained upper bounds for the associated Green's function and its…

Numerical Analysis · Mathematics 2013-06-28 Sebastian Franz , Natalia Kopteva

It has been recently established by the first and third author that on uniformly rectifiable sets the Green function is almost affine in the weak sense, and moreover, in some scenarios such Green function estimates are equivalent to the…

Analysis of PDEs · Mathematics 2021-01-29 Guy David , Joseph Feneuil , Svitlana Mayboroda

We study the existence of the Green function for an elliptic system in divergence form $-\nabla\cdot a\nabla$ in $\mathbb{R}^d$, with $d>2$. The tensor field $a=a(x)$ is only assumed to be bounded and $\lambda$-coercive. For almost every…

Analysis of PDEs · Mathematics 2020-06-09 Arianna Giunti , Felix Otto

We consider the Wulff-type energy functional $$ \mathcal{W}_\Omega(u) := \int_\Omega B(H(\nabla u (x))) - F(u(x)) \, dx, $$ where $B$ is positive, monotone and convex, and $H$ is positive homogeneous of degree 1. The critical points of this…

Analysis of PDEs · Mathematics 2014-12-23 Matteo Cozzi , Alberto Farina , Enrico Valdinoci

We extend the celebrated rigidity of the sharp first spectral gap under $Ric\ge0$ to compact infinitesimally Hilbertian spaces with non-negative (weak, also called synthetic) Ricci curvature and bounded (synthetic) dimension i.e. to…

Differential Geometry · Mathematics 2023-05-09 Christian Ketterer , Yu Kitabeppu , Sajjad Lakzian

We study the Neumann Green's function for second order parabolic systems in divergence form with time-dependent measurable coefficients in a cylindrical domain $\mathcal{Q}=\Omega\times (-\infty,\infty)$, where $\Omega\subset \mathbb{R}^n$…

Analysis of PDEs · Mathematics 2018-09-18 Jongkeun Choi , Seick Kim

We prove a sharp gradient estimate for the natural Green's function of a closed manifold with positive Ricci curvature. We also show that this estimate is closely related to a family of monotonicity formulae. These results extend those…

Differential Geometry · Mathematics 2025-12-08 Cosmin Manea

We prove that for an open domain $D \subset \mathbb{R}^d $ with $d \geq 2 $ , for every (measurable) uniformly elliptic tensor field $a$ and for almost every point $y \in D$ , there exists a unique Green's function centred in $ y $…

Analysis of PDEs · Mathematics 2016-06-03 Joseph G. Conlon , Arianna Giunti , Felix Otto

We approximate a Euclidean version of a D+1 dimensional manifold with a bifurcate Killing horizon by a product of a two-dimensional Rindler space and a D-1 dimensional manifold M. We obtain approximate formulas for the Green functions. We…

High Energy Physics - Theory · Physics 2007-09-12 Z. Haba

For a chordal SLE$_\kappa$ ($\kappa\in(0,8)$) curve in a domain $D$, the $n$-point Green's function valued at distinct points $z_1,\dots,z_n\in D$ is defined to be $$G(z_1,\dots,z_n)=\lim_{r_1,\dots,r_n\downarrow 0} \prod_{k=1}^n r_k^{d-2}…

Probability · Mathematics 2017-09-05 Mohammad A. Rezaei , Dapeng Zhan

In this paper we obtain the explicit expression of the Green's function related to a general $n$ order differential equation coupled to non-local linear boundary conditions. In such boundary conditions, a $n$ dimensional parameter…

Classical Analysis and ODEs · Mathematics 2021-07-13 Alberto Cabada , Lucía López-Somoza , Mouhcine Yousfi

Motivated by a wide variety of applications, ranging from stochastic optimization to dimension reduction through variable selection, the problem of estimating gradients accurately is of crucial importance in statistics and learning theory.…

Machine Learning · Computer Science 2020-06-29 Guillaume Ausset , Stephan Clémençon , François Portier

An alternative manner is provided for solving the classical linearised problem of the radiation and diffraction of regular water waves caused by oscillation of a floating body in deep water. It is shown that the singular wave integrals of…

Fluid Dynamics · Physics 2018-12-05 Zhi-Min Chen

We construct Green's functions for second order parabolic operators of the form $Pu=\partial_t u-{\rm div}({\bf A} \nabla u+ \boldsymbol{b}u)+ \boldsymbol{c} \cdot \nabla u+du$ in $(-\infty, \infty) \times \Omega$, where $\Omega$ is an open…

Analysis of PDEs · Mathematics 2022-01-13 Seick Kim , Longjuan Xu

For a pulsating free surface source in a three-dimensional finite depth fluid domain, the Green function of the source presented by John [F. John, On the motion of floating bodies II. Simple harmonic motions, Communs. Pure Appl. Math. 3…

Fluid Dynamics · Physics 2020-04-29 Zhi-Min Chen

The Green functions play a big role in the calculation of the local density of states of the carbon nanostructures. We investigate their nature for the variously oriented and disclinated graphene-like surface. Next, we investigate the case…

Mesoscale and Nanoscale Physics · Physics 2015-11-10 J. Smotlacha , R. Pincak , M. Pudlak

The quantum Hall effect in Graphene nano-ribbons (GNR) is investigated with the non-equilibrium Green s function (NEGF) based quantum transport model in the ballistic regime. The nearest neighbor tight-binding model based on pz orbital…

Mesoscale and Nanoscale Physics · Physics 2008-01-09 Roksana Golizadeh-Mojarad , A. N. M. Zainuddin , Gerhard Klimeck , Supriyo Datta

The aim of this paper is twofold. On the one hand, the study of gradient Schr\"{o}dinger operators on manifolds with density $\phi$. We classify the space of solutions when the underlying manifold is $\phi-$parabolic. As an application, we…

Differential Geometry · Mathematics 2015-03-26 Jose M. Espinar