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Related papers: Spectral Shift Functions of Lam\'{e} Operators

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An explicit solution of the spectral problem of the non-local Schr\"odinger operator obtained as the sum of the square root of the Laplacian and a quartic potential in one dimension is presented. The eigenvalues are obtained as zeroes of…

Functional Analysis · Mathematics 2017-12-29 Samuel O. Durugo , Jozsef Lörinczi

In this paper, we derive the sharp Bohr type inequality for the Ces\'aro operator, Bernardi integral operator, and discrete Fourier transform acting on the class of bounded analytic functions defined on shifted disks \beas…

Complex Variables · Mathematics 2026-04-14 Vasudevarao Allu , Raju Biswas , Rajib Mandal

The spectral torsion is defined by three vector fields and Dirac operators and the noncommutative residue. Motivated by the spectral torsion and the one form rescaled Dirac operator, we give some new spectral torsion which is the extension…

Differential Geometry · Mathematics 2025-05-30 Jian Wang , Yong Wang

A modified Green operator is proposed as an improvement of Fourier-based numerical schemes commonly used for computing the electrical or thermal response of heterogeneous media. Contrary to other methods, the number of iterations necessary…

Materials Science · Physics 2014-08-22 François Willot , Bassam Abdallah , Yves-Patrick Pellegrini

Fourier transforms are ubiquitous mathematical tools in basic and applied sciences. We here report classical and quantum optical realizations of the discrete fractional Fourier transform, a generalization of the Fourier transform. In the…

In this note, under a certain assumption on an affine space of operators, which admit embedded eigenvalues, it is shown that the singular part of the spectral shift function of any pair of operators from this space is an integer-valued…

Spectral Theory · Mathematics 2007-11-09 Nurulla Azamov

We consider solving a probably ill-conditioned linear operator equation, where the operator is not modeled by physical laws but is specified via training pairs (consisting of images and data) of the input-output relation of the operator. We…

Numerical Analysis · Mathematics 2024-08-21 Andrea Aspri , Leon Frischauf , Otmar Scherzer

We start with the Birman--Solomyak approach to define double operator integrals and consider applications in estimating operator differences $f(A)-f(B)$ for self-adjoint operators $A$ and $B$. We present the Birman--Solomyak approach to the…

Functional Analysis · Mathematics 2015-09-10 Vladimir Peller

We compute lattice renormalisation constants of one-link quark operators ({\it i.e.} operators with one covariant derivative) for overlap fermions and L\"uscher-Weisz gauge action in one-loop perturbation theory. Among others, such…

High Energy Physics - Lattice · Physics 2008-11-26 R. Horsley , H. Perlt , P. E. L. Rakow , G. Schierholz , A. Schiller

Let $L=-\Delta+V$ be a Schr\"odinger operator, where the potential $V$ belongs to the reverse H\"older class. By the subordinative formula, we introduce the fractional heat semigroup $\{e^{-t{L}^\alpha}\}_{t>0}, \alpha>0$, associated with…

Classical Analysis and ODEs · Mathematics 2021-04-06 P. Li , Z. Wang , T. Qian , C. Zhang

In this paper, we establish quantitative Green's function estimates for some higher dimensional lattice quasi-periodic (QP) Schr\"odinger operators. The resonances in the estimates can be described via a pair of symmetric zeros of certain…

Mathematical Physics · Physics 2023-03-16 Hongyi Cao , Yunfeng Shi , Zhifei Zhang

We investigate a class of spectral multipliers for an Ornstein-Uhlenbeck operator $\mathcal L$ in $\mathbb R^n$, with drift given by a real matrix $B$ whose eigenvalues have negative real parts. We prove that if $m$ is a function of Laplace…

Functional Analysis · Mathematics 2023-09-28 Valentina Casarino , Paolo Ciatti , Peter Sjögren

We describe a closed operator functional calculus in Banach modules over the group algebra $L^1(\mathbb R)$ and illustrate its usefulness with a few applications. In particular, we deduce a spectral mapping theorem for operators in the…

Functional Analysis · Mathematics 2021-09-06 Anatoly G. Baskakov , Ilya A. Krishtal , Natalia B. Uskova

We define a Fourier transform and a convolution product for functions and distributions on Heisenberg--Clifford Lie supergroups. The Fourier transform exchanges the convolution and a pointwise product, and is an intertwining operator for…

Representation Theory · Mathematics 2013-04-16 Alexander Alldridge , Joachim Hilgert , Martin Laubinger

We establish certain square function estimates for a class of oscillatory integral operators with homogeneous phase functions. These results are employed to deduce a refinement of a previous result of Mockenhaupt Seeger and Sogge…

Analysis of PDEs · Mathematics 2019-01-23 Chuanwei Gao , Changxing Miao , Jianwei-Urbain Yang

This paper considers composition operators on Zen spaces (a class of weighted Bergman spaces of the right half-plane related to weighted function spaces on the positive half-line by means of the Laplace transform). Generalizations are given…

Functional Analysis · Mathematics 2023-04-03 I. Chalendar , J. R. Partington

We obtain a bound on the expectation of the spectral shift function for alloy-type random Schr\"odinger operators on $\mathbb{R}^d$ in the region of localisation, corresponding to a change from Dirichlet to Neumann boundary conditions along…

Mathematical Physics · Physics 2019-01-29 Adrian Dietlein , Martin Gebert , Peter D. Hislop , Abel Klein , Peter Müller

The purpose of the paper is to obtain estimates for differences of functions of two pairs of commuting contractions on Hilbert space. In particular, Lipschitz type estimates, H\"older type estimates, Schatten--von Neumann estimates are…

Functional Analysis · Mathematics 2018-04-09 Vladimir Peller

We study concentration operators associated with either the discrete or the continuous Fourier transform, that is, operators that incorporate a spatial cut-off and a subsequent frequency cut-off to the Fourier inversion formula. Their…

Functional Analysis · Mathematics 2024-03-11 Felipe Marceca , José Luis Romero , Michael Speckbacher

In this paper we show variant of the spectral theorem using an algebraic Jordan-Schwinger map. The advantage of this approach is that we don't have restriction of normality on the class of operators we consider. On the other side, we have…

Functional Analysis · Mathematics 2023-04-17 Wolfgang Bock , Vyacheslav Futorny , Mikhail Neklyudov