English
Related papers

Related papers: Optimal Algorithms for Quantifying Spectral Size w…

200 papers

We present an amelioration of current known algorithms for optimal spectral partitioning problems. The idea is to use the advantage of a representation using density functions while decreasing the computational time. This is done by…

Optimization and Control · Mathematics 2017-05-25 Beniamin Bogosel

There are self-adjoint operators which determine both spectral and semispectral measures. These measures have very different commutativity and covariance properties. This fact poses a serious question on the physical meaning of such a…

Quantum Physics · Physics 2010-10-19 D. A. Dubin , M. A. Hennings , P. Lahti , J. -P. Pellonpaa

We present an algorithm for reliably and systematically proving the existence of spectral gaps in Hamiltonians with quasicrystalline order, based on numerical calculations on finite domains. We apply this algorithm to prove that the…

Quantum Physics · Physics 2022-10-25 Paul Hege , Massimo Moscolari , Stefan Teufel

In this work, we present a complete spectral study of a family of non-normal operators arising in Reggeon field theory. This family of operators is an original example who permit us to discover the recent theory of physical requirement of…

Mathematical Physics · Physics 2023-01-02 Abdelkader Intissar

We have developed a method for constructing spectral approximations for convolution operators of Fredholm type. The algorithm we propose is numerically stable and takes advantage of the recurrence relations satisfied by the entries of such…

Numerical Analysis · Mathematics 2024-05-15 Xiaolin Liu , Kuan Deng , Kuan Xu

The moment operators of a semispectral measure having the structure of the convolution of a positive measure and a semispectral measure are studied, with paying attention to the natural domains of these unbounded operators. The results are…

Quantum Physics · Physics 2009-11-13 Jukka Kiukas , Pekka Lahti , Kari Ylinen

We derive a necessary and sufficient condition for the possibility of achieving the Heisenberg scaling in general adaptive multi-parameter estimation schemes in presence of Markovian noise. In situations where the Heisenberg scaling is…

Quantum Physics · Physics 2020-07-08 Wojciech Gorecki , Sisi Zhou , Liang Jiang , Rafal Demkowicz-Dobrzanski

Proper splittings of operators are commonly used to study the convergence of iterative processes. In order to approximate solutions of operator equations, in this article we deal with proper splittings of closed range bounded linear…

Functional Analysis · Mathematics 2024-03-18 Guillermina Fongi , María Celeste Gonzalez

Optimized meson operators in the distillation framework are used to study the charmonium spectrum in two ensembles with two heavy dynamical quarks at half the physical charm quark mass but different lattice spacings. The use of optimal…

High Energy Physics - Lattice · Physics 2022-12-20 Juan Andrés Urrea-Niño , Francesco Knechtli , Tomasz Korzec , Michael Peardon

The goal of this paper is to combine ideas from the theory of mixed spectral problems for differential operators with new results in the area of the Uncertainty Principle in Harmonic Analysis (UP). Using recent solutions of Gap and Type…

Spectral Theory · Mathematics 2017-12-29 Nikolai Makarov , Alexei Poltoratski

The spectrum of one-dimensional discrete Schr\"odinger operators associated to strictly ergodic dynamical systems is shown to coincide with the set of zeros of the Lyapunov exponent if and only if the Lyapunov exponent exists uniformly.…

Mathematical Physics · Physics 2009-11-07 Daniel Lenz

A numerical scheme to compute the spectrum of a large class of self-adjoint extensions of the Laplace-Beltrami operator on manifolds with boundary in any dimension is presented. The algorithm is based on the characterisation of a large…

Numerical Analysis · Mathematics 2017-08-23 A. López-Yela , J. M. Pérez-Pardo

This paper presents a methodology for using varying sample sizes in sequential quadratic programming (SQP) methods for solving equality constrained stochastic optimization problems. The first part of the paper deals with the delicate issue…

Optimization and Control · Mathematics 2023-03-23 Albert S. Berahas , Raghu Bollapragada , Baoyu Zhou

Let $H$ be a quasiperiodic Schr\"{o}dinger operator generated by a monotone potential, as defined in [16]. Following [20], we study the connection between the Lyapunov exponent $L\left(E\right)$, arithmetic properties of the frequency…

Spectral Theory · Mathematics 2025-04-23 Netanel Levi

We show that some spectral properties of the almost Mathieu operator with frequency well approximated by rationals can be as poor as at all possible in the class of all one-dimensional discrete Schroedinger operators. For the class of…

Mathematical Physics · Physics 2023-03-31 Artur Avila , Yoram Last , Mira Shamis , Qi Zhou

We give a family of examples of discrete Schr\"odinger operators whose spectral dimension is not invariant under sieving. The examples are produced from the Fibonacci Hamiltonian, which is one of the main models of a one-dimensional…

Spectral Theory · Mathematics 2025-05-14 Jake Fillman , Alexandro Luna

Energy spectroscopy is a powerful tool with diverse applications across various disciplines. The advent of programmable digital quantum simulators opens new possibilities for conducting spectroscopy on various models using a single device.…

The main purpose of these lectures is to discuss briefly recent methods of calculation of statistical properties of quantum eigenvalues for chaotic systems based on semi-classical trace formulas. Under the assumption that periodic orbit…

Chaotic Dynamics · Physics 2007-05-23 E. Bogomolny

Let $L$ be a linear, closed, densely defined in a Hilbert space operator, not necessarily selfadjoint. Consider the corresponding wave equations &(1) \quad \ddot{w}+ Lw=0, \quad w(0)=0,\quad \dot{w}(0)=f, \quad \dot{w}=\frac{dw}{dt}, \quad…

Analysis of PDEs · Mathematics 2012-06-27 A. G. Ramm

We develop a Sequential Quadratic Optimization (SQP) algorithm for minimizing a stochastic objective function subject to deterministic equality constraints. The method utilizes two different stepsizes, one which exclusively scales the…

Optimization and Control · Mathematics 2024-08-30 Michael J. O'Neill