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In this paper we propose a multiscale method for the acoustic wave equation in highly oscillatory media. We use a higher-order extension of the localized orthogonal decomposition method combined with a higher-order time stepping scheme and…

Numerical Analysis · Mathematics 2024-07-23 Felix Krumbiegel , Roland Maier

Estimating the overlap between an approximate wavefunction and a target eigenstate of the system Hamiltonian is essential for the efficiency of quantum phase estimation. In this work, we derive upper and lower bounds on this overlap using…

Quantum Physics · Physics 2025-03-18 Junan Lin , Artur F. Izmaylov

Smoothed Wigner transforms have been used in signal processing, as a regularized version of the Wigner transform, and have been proposed as an alternative to it in the homogenization and / or semiclassical limits of wave equations. We…

Analysis of PDEs · Mathematics 2015-05-19 Agissilaos G. Athanassoulis , Norbert J. Mauser , Thierry Paul

We prove sharp smoothing properties of the averaging operator defined by convolution with a measure on a smooth nondegenerate curve $\gamma$ in $\mathbb R^d$, $d\ge 3$. Despite the simple geometric structure of such curves, the sharp…

Classical Analysis and ODEs · Mathematics 2022-04-01 Hyerim Ko , Sanghyuk Lee , Sewook Oh

Classical Laguerre spectral approximations are highly effective on the half-line when the target function is smooth in the usual polynomial scale. However, their accuracy deteriorates for nonsmooth functions. Such behavior appears naturally…

Numerical Analysis · Mathematics 2026-05-27 Mahmoud A. Zaky

The problem of measuring a time-varying phase, even when the statistics of the variation is known, is considerably harder than that of measuring a constant phase. In particular, the usual bounds on accuracy - such as the $1/(4\bar{n})$…

Quantum Physics · Physics 2018-05-01 Kiarn T. Laverick , Howard M. Wiseman , Hossien T. Dinani , Dominic W. Berry

We propose an adaptive accelerated smoothing technique for a nonsmooth convex optimization problem where the smoothing update rule is coupled with the momentum parameter. We also extend the setting to the case where the objective function…

Optimization and Control · Mathematics 2026-04-21 Reza Rahimi Baghbadorani , Sergio Grammatico , Peyman Mohajerin Esfahani

We prove estimates for solutions of the Cauchy problem for the inhomogeneous wave equation on $\R^{1+n}$ in a class of Banach spaces whose norms only depend on the size of the space-time Fourier transform. The estimates are local in time,…

Analysis of PDEs · Mathematics 2007-05-23 Sigmund Selberg

The paper introduces a new adaptive version of the Frank-Wolfe algorithm for relatively smooth convex functions. It is proposed to use the Bregman divergence other than half the square of the Euclidean norm in the formula for step-size.…

Optimization and Control · Mathematics 2024-07-23 Alexander Vyguzov , Fedor Stonyakin

Let $\{P_{\theta}:\theta \in {\mathbb R}^d\}$ be a log-concave location family with $P_{\theta}(dx)=e^{-V(x-\theta)}dx,$ where $V:{\mathbb R}^d\mapsto {\mathbb R}$ is a known convex function and let $X_1,\dots, X_n$ be i.i.d. r.v. sampled…

Statistics Theory · Mathematics 2021-08-03 Vladimir Koltchinskii , Martin Wahl

In this paper we study the quantitative homogenization of second-order parabolic systems with locally periodic (in both space and time) coefficients. The $O(\varepsilon)$ scale-invariant error estimate in $L^2(0, T;…

Analysis of PDEs · Mathematics 2021-12-03 Yao Xu

We propose to smooth the entire objective function, rather than only the check function, in a linear quantile regression context. Not only does the resulting smoothed quantile regression estimator yield a lower mean squared error and a more…

Econometrics · Economics 2019-08-16 Marcelo Fernandes , Emmanuel Guerre , Eduardo Horta

In this paper we focus on the validity of some fundamental estimates for time-degenerate Schr\"{o}dinger-type operators. On one hand we derive global homogeneous smoothing estimates for operators of any order by means of suitable comparison…

Analysis of PDEs · Mathematics 2024-02-19 Serena Federico , Michael Ruzhansky

This work provides the first convergence analysis for the Randomized Block Coordinate Descent method for minimizing a function that is both H\"older smooth and block H\"older smooth. Our analysis applies to objective functions that are…

Optimization and Control · Mathematics 2024-03-14 Leandro Farias Maia , David Huckleberry Gutman

This paper is a comprehensive study of $L_p$ estimates for time fractional wave equations of order $\alpha \in (1,2)$ in the whole space, a half space, or a cylindrical domain. We obtain weighted mixed-norm estimates and solvability of the…

Analysis of PDEs · Mathematics 2021-08-31 Hongjie Dong , Yanze Liu

Subject to suitable boundary conditions being imposed, sharp inequalities are obtained on integrals over a region $\Omega$ of certain special quadratic functions $f(\bf{E})$ where $\bf{E}(\bf{x})$ derives from a potential $\bf{U}(\bf{x})$.…

Analysis of PDEs · Mathematics 2014-11-14 Graeme W. Milton

We obtain sharp $L^p$ and H\"older estimates for the Neumann function of the operator $\nabla \cdot \gamma \nabla - ik$ on a bounded domain. We also obtain quantitative description of its singularity. We then apply these estimates to…

Analysis of PDEs · Mathematics 2012-04-26 Habib Ammari , Hyeonbae Kang , Seick Kim

We propose a two-stage procedure for estimating the location $\bolds{\mu}$ and size M of the maximum of a smooth d-variate regression function f. In the first stage, a preliminary estimator of $\bolds{\mu}$ obtained from a standard…

Statistics Theory · Mathematics 2013-02-20 Eduard Belitser , Subhashis Ghosal , Harry van Zanten

We introduce the notion of Schr\"odinger integral operators and prove sharp local and global regularity results for these (including propagators for the quantum mechanical harmonic oscillator). Furthermore we introduce general classes of…

Analysis of PDEs · Mathematics 2023-10-26 Alejandro J. Castro , Anders Israelsson , Wolfgang Staubach , Madi Yerlanov

Non-parametric estimation of functions as well as their derivatives by means of local-polynomial regression is a subject that was studied in the literature since the late 1970's. Given a set of noisy samples of a $\mathcal{C}^k$ smooth…

Statistics Theory · Mathematics 2021-07-15 Yariv Aizenbud , Barak Sober