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Related papers: Old and new Schr\"odinger eigenvalue localisation

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Hyperparameter optimization can be formulated as a bilevel optimization problem, where the optimal parameters on the training set depend on the hyperparameters. We aim to adapt regularization hyperparameters for neural networks by fitting…

Machine Learning · Computer Science 2019-03-08 Matthew MacKay , Paul Vicol , Jon Lorraine , David Duvenaud , Roger Grosse

We compare two established and a new method for the calculation of spectral bounds for Hessian matrices on hyperrectangles by applying them to a large collection of 1522 objective and constraint functions extracted from benchmark global…

Optimization and Control · Mathematics 2013-09-06 Moritz Schulze Darup , Martin Kastsian , Stefan Mross , Martin Mönnigmann

We consider the cubic nonlinear Schr\"odinger equation with a spatially rough potential, a key equation in the mathematical setup for nonlinear Anderson localization. Our study comprises two main parts: new optimal results on the…

Numerical Analysis · Mathematics 2024-03-26 Norbert J. Mauser , Yifei Wu , Xiaofei Zhao

The paper is concerned with space-time IgA approximations of parabolic initial-boundary value problems. We deduce guaranteed and fully computable error bounds adapted to special features of IgA approximations and investigate their…

Numerical Analysis · Mathematics 2018-02-20 Ulrich Langer , Svetlana Matculevich , Sergey Repin

In the hyperbolic community, discontinuous Galerkin approaches are mainly applied when finite element methods are considered. As the name suggested, the DG framework allows a discontinuity at the element interfaces, which seems for many…

Numerical Analysis · Mathematics 2021-04-20 Rémi Abgrall , Jan Nordström , Philipp Öffner , Svetlana Tokareva

The Cram\'er-Rao bound (CRB), a well-known lower bound on the performance of any unbiased parameter estimator, has been used to study a wide variety of problems. However, to obtain the CRB, requires an analytical expression for the…

Machine Learning · Computer Science 2022-10-11 Hai Victor Habi , Hagit Messer , Yoram Bresler

We here adapt an extended version of the adaptive cubic regularisation method with dynamic inexact Hessian information for nonconvex optimisation in [3] to the stochastic optimisation setting. While exact function evaluations are still…

Numerical Analysis · Mathematics 2020-09-15 Stefania Bellavia , Gianmarco Gurioli

Motivated by the construction of tractable robust estimators via convex relaxations, we present conditions on the sample size which guarantee an augmented notion of Restricted Eigenvalue-type condition for Gaussian designs. Such a notion is…

Statistics Theory · Mathematics 2018-12-04 Philip Thompson , Arnak S. Dalalyan

An adaptive direct collocation method is developed for solving optimal control problems constrained by parabolic partial differential equations. The partial differential equation is first reformulated in a variational setting, where the…

Optimization and Control · Mathematics 2026-03-18 Alexander M. Davies , Sara Pollock , Miriam E. Dennis , Anil V. Rao

We prove Lieb-Thirring inequalities for Schr\"odinger operators with a homogeneous magnetic field in two and three space dimensions. The inequalities bound sums of eigenvalues by a semi-classical approximation which depends on the strength…

Spectral Theory · Mathematics 2015-05-27 Rupert L. Frank , Rikard Olofsson

In this work, a boundary control problem for the following generalized Burgers-Huxley (GBH) equation: $$u_t=\nu u_{xx}-\alpha u^{\delta}u_x+\beta u(1-u^{\delta})(u^{\delta}-\gamma), $$ where $\nu,\alpha,\beta>0,$ $1\leq\delta<\infty$,…

Analysis of PDEs · Mathematics 2023-11-14 Shri Lal Raghudev Ram Singh , Manil T. Mohan

In this article, we introduce a general theoretical framework to analyze non-consistent approximations of the discrete eigenmodes of a self-adjoint operator. We focus in particular on the discrete eigenvalues laying in spectral gaps. We…

Functional Analysis · Mathematics 2012-05-03 Eric Cancès , Virginie Ehrlacher , Yvon Maday

Due to their importance in both data analysis and numerical algorithms, low rank approximations have recently been widely studied. They enable the handling of very large matrices. Tight error bounds for the computationally efficient…

Numerical Analysis · Mathematics 2023-04-06 Frank de Hoog , Markus Hegland

The gapped local alignment score of two random sequences follows a Gumbel distribution. If computers could estimate the parameters of the Gumbel distribution within one second, the use of arbitrary alignment scoring schemes could increase…

Statistics Theory · Mathematics 2009-09-04 Yonil Park , Sergey Sheetlin , John L. Spouge

The Schr\"odinger equation is at the heart of modern quantum mechanics. Since exact solutions of the ground state are typically intractable, standard approaches approximate Schr\"odinger equation as forms of nonlinear generalized eigenvalue…

Quantum Physics · Physics 2022-02-04 Xihan Li , Xiang Chen , Rasul Tutunov , Haitham Bou-Ammar , Lei Wang , Jun Wang

Computational modeling of pattern formation in nonequilibrium systems is a fundamental tool for studying complex phenomena in biology, chemistry, materials science and engineering. The pursuit for theoretical descriptions of some among…

Pattern Formation and Solitons · Physics 2022-02-08 D. L. Coelho , E. Vitral , J. Pontes , N. Mangiavacchi

In the research community, there exists the strong belief that a continuous Galerkin scheme is notoriously unstable and additional stabilization terms have to be added to guarantee stability. In the first part of the series [6], the…

Numerical Analysis · Mathematics 2019-12-19 Rémi Abgrall , Jan Nordström , Philipp Öffner , Svetlana Tokareva

A large class of quantum theories of gravity show that the Heisenberg's uncertainty principle is modified to the "Generalised Uncertainty Principle" (GUP) near the Planckian scale. It has also been shown that the GUP induces perturbative…

General Relativity and Quantum Cosmology · Physics 2021-08-12 Ashmita Das , Saurya Das , Elias C. Vagenas

The objective of this paper is to understand the superlinear convergence behavior of the GMRES method when the coefficient matrix has clustered eigenvalues. In order to understand the phenomenon, we analyze the convergence using the…

Numerical Analysis · Mathematics 2025-04-25 Zeyu Liao , Ken Hayami

Stochastic gradient descent (SGD) is perhaps the most prevalent optimization method in modern machine learning. Contrary to the empirical practice of sampling from the datasets without replacement and with (possible) reshuffling at each…

Optimization and Control · Mathematics 2024-02-08 Xufeng Cai , Cheuk Yin Lin , Jelena Diakonikolas