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For $N\geq 2$, a bounded smooth domain $\Omega$ in $\mathbb{R}^N$, and $g_0, V_0 \in L^1_{loc}(\Omega)$, we study the optimization of the first eigenvalue for the following weighted eigenvalue problem: \begin{align*} -\Delta_p \phi + V…

Analysis of PDEs · Mathematics 2025-06-03 Nirjan Biswas , Ujjal Das , Mrityunjoy Ghosh

We consider the torsion function for the Dirichlet Laplacian $-\Delta$, and for the Schr\"odinger operator $- \Delta + V$ on an open set $\Omega\subset \R^m$ of finite Lebesgue measure $0<|\Omega|<\infty$ with a real-valued, non-negative,…

Analysis of PDEs · Mathematics 2023-06-22 M. van den Berg , D. Bucur , T. Kappeler

We shall study the following initial value problem: \begin{equation}{\bf i}\partial_t u - \Delta u + V(x) u=0, \hbox{} (t, x) \in {\mathbf R} \times {\mathbf R}^n, \end{equation} $$u(0)=f,$$ where $V(x)$ is a real short--range potential,…

Analysis of PDEs · Mathematics 2009-11-13 Luis Vega , Nicola Visciglia

We prove an upper and a lower bound on the rank of the spectral projections of the Schr\"odinger operator $-\Delta + V$ in terms of the volume of the sublevel sets of an effective potential $\frac{1}{u}$. Here, $u$ is the `landscape…

Mathematical Physics · Physics 2023-12-11 Sven Bachmann , Richard Froese , Severin Schraven

In this short note, we present an easy to implement and fast algorithm for the computation of the steady solitary gravity wave solution of the free surface Euler equations in irrotational motion. First, the problem is reformulated in a…

Fluid Dynamics · Physics 2020-02-20 Didier Clamond , Denys Dutykh

We investigate that a potential $V$ in the fractional Schr\"odinger equation $( (-\Delta_g )^s +V ) u=f$ can be recovered locally by using the local source-to-solution map on smooth connected closed Riemannian manifolds. To achieve this…

Analysis of PDEs · Mathematics 2024-09-04 Yi-Hsuan Lin

We consider the localization in the eigenfunctions of regular Sturm-Liouville operators. After deriving non-asymptotic and asymptotic lower and upper bounds on the localization coefficient of the eigenfunctions, we characterize the…

Classical Analysis and ODEs · Mathematics 2023-06-29 Mirza Karamehmedović , Faouzi Triki

We construct a real-valued solution to the eigenvalue problem $-\text{div}(A\nabla u)=\lambda u$, $\lambda>0,$ in the cylinder $\mathbb{T}^2\times \mathbb{R}$ with a real, uniformly elliptic, and uniformly $C^1$ matrix $A$ such that…

Analysis of PDEs · Mathematics 2025-01-28 S. Krymskii , A. Logunov , F. Pagano

We study the minimization of a convex function $f(X)$ over the set of $n\times n$ positive semi-definite matrices, but when the problem is recast as $\min_U g(U) := f(UU^\top)$, with $U \in \mathbb{R}^{n \times r}$ and $r \leq n$. We study…

Machine Learning · Statistics 2016-04-19 Srinadh Bhojanapalli , Anastasios Kyrillidis , Sujay Sanghavi

We consider the question of when the Laplace eigenfunctions on an arbitrary flat torus $\mathbf{T}_\Gamma:=\mathbf{R}^d/\Gamma$ are flexible enough to approximate, over the natural length scale of order $1/\sqrt\lambda$, where $\lambda\gg1$…

Spectral Theory · Mathematics 2021-11-15 Alberto Enciso , Alba García-Ruiz , Daniel Peralta-Salas

This paper concerns the numerical approximation of low-energy eigenstates of the linear random Schr\"odinger operator. Under oscillatory high-amplitude potentials with a sufficient degree of disorder it is known that these eigenstates…

Numerical Analysis · Mathematics 2019-11-11 Robert Altmann , Daniel Peterseim

We propose a local Legendre frame (LLF) method for function approximation from equispaced data on a finite interval. Motivated by the difficulty of stable high-order polynomial approximation at equispaced points, especially in the presence…

Numerical Analysis · Mathematics 2026-05-12 Benxue Gong , Zhenyu Zhao , Chenyang Wang

Multi-task dense prediction, which aims to jointly solve tasks like semantic segmentation and depth estimation, is crucial for robotics applications but suffers from domain shift when deploying models in new environments. While unsupervised…

Computer Vision and Pattern Recognition · Computer Science 2026-03-10 Beomseok Kang , Niluthpol Chowdhury Mithun , Mikhail Sizintsev , Han-Pang Chiu , Supun Samarasekera

Scale-invariance, good localization and robustness to noise and distortions are the main properties that a local feature detector should possess. Most existing local feature detectors find excessive unstable feature points that increase the…

Computer Vision and Pattern Recognition · Computer Science 2021-02-03 Morteza Ghahremani , Yonghuai Liu , Bernard Tiddeman

For a Hamiltonian ${\hat H}$ containing a position-dependent (disordered) potential, we introduce a sequence of landscape functions $u_n(\vec{r})$ obeying ${\hat H} u_n(\vec{r}) = u_{n-1}(\vec{r})$ with $u_0(\vec{r}) = 1$. For $n \to…

Disordered Systems and Neural Networks · Physics 2024-12-31 Sergey E. Skipetrov

We provide a priori error estimates for variational approximations of the ground state eigenvalue and eigenvector of nonlinear elliptic eigenvalue problems of the form $-{div} (A\nabla u) + Vu + f(u^2) u = \lambda u$, $\|u\|_{L^2}=1$. We…

Numerical Analysis · Mathematics 2009-06-05 Eric Cancès , Rachida Chakir , Yvon Maday

We develop arguments on the critical point theory for locally Lipschitz functionals on Orlicz-Sobolev spaces, along with convexity and compactness techniques to investigate existence of solution of the multivalued equation $\displaystyle -…

Analysis of PDEs · Mathematics 2013-10-23 J. V. Goncalves , M. L. Carvalho

We show that ground state solutions to the nonlinear, fractional problem \begin{align*} \left\{ \begin{array}{ll} (-\Delta)^{s} u + V(x) u = f(x,u) &\quad \mathrm{in} \ \Omega, \newline u = 0 &\quad \mathrm{in} \ \mathbb{R}^N \setminus…

Analysis of PDEs · Mathematics 2023-02-28 Bartosz Bieganowski , Simone Secchi

We consider a non-self adjoint operator of the form $-h^2 \Delta + i(V(x) + \alpha(x)y)$ on the upper half plane $y > 0$ with Dirichlet boundary conditions on $\{y = 0\}$ with $V \geq 0$, $V$ admitting a non-degenerate minimum at $x = 0$…

Mathematical Physics · Physics 2025-12-24 Martin Averseng , Nicolas Frantz , Frédéric Hérau , Nicolas Raymond

We introduce efficient $(1+\varepsilon)$-approximation algorithms for the binary matrix factorization (BMF) problem, where the inputs are a matrix $\mathbf{A}\in\{0,1\}^{n\times d}$, a rank parameter $k>0$, as well as an accuracy parameter…

Data Structures and Algorithms · Computer Science 2023-06-06 Ameya Velingker , Maximilian Vötsch , David P. Woodruff , Samson Zhou