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The HRT (Heil-Ramanathan-Topiwala) conjecture asks whether a finite collection of time-frequency shifts of a non-zero square integrable function on $\mathbb{R}$ is linearly independent. This longstanding conjecture remains largely open even…

Classical Analysis and ODEs · Mathematics 2018-12-21 Kasso A. Okoudjou

We consider perturbed discrete tight-binding models in $\ell^2(\mathbb{Z_h},\mathcal{G})$ describing union of quantum particles with localized interactions, where $\mathbb{Z_h}$ is the 1D lattice $h\mathbb{Z_h}$, $h > 0$, and $\mathcal G$…

Spectral Theory · Mathematics 2025-10-23 Marouane Assal , Olivier Bourget , Diomba Sambou , Amal Taarabt

The new representation formula for the spectral shift function due to F.Gesztesy and K.A.Makarov is considered. This formula is extended to the case of relatively trace class perturbations.

Spectral Theory · Mathematics 2007-05-23 Alexander Pushnitski

In this note the notions of trace compatible operators and infinitesimal spectral flow are introduced. We define the spectral shift function as the integral of infinitesimal spectral flow. It is proved that the spectral shift function thus…

Functional Analysis · Mathematics 2007-06-13 Nurulla Azamov , Fyodor Sukochev

This paper resolves affirmatively Koplienko's conjecture of 1984 on existence of higher order spectral shift measures. Moreover, the paper establishes absolute continuity of these measures and, thus, existence of the higher order spectral…

Functional Analysis · Mathematics 2012-11-06 Denis Potapov , Anna Skripka , Fedor Sukochev

We apply upper and lower compensated convex transforms, which are `tight' one-sided approximations of a given function, to the extraction of fine geometric singularities from semiconvex/semiconcave functions and DC-functions in…

Optimization and Control · Mathematics 2016-10-06 Kewei Zhang , Elaine Crooks , Antonio Orlando

The spectral norm of a Boolean function $f:\{0,1\}^n \to \{-1,1\}$ is the sum of the absolute values of its Fourier coefficients. This quantity provides useful upper and lower bounds on the complexity of a function in areas such as learning…

Computational Complexity · Computer Science 2012-05-25 Anil Ada , Omar Fawzi , Hamed Hatami

This paper proposes a novel, rigorous and simple Fourier-transformation approach to study resonances in a perfectly conducting slab with finite number of subwavelength slits of width $h\ll 1$. Since regions outside the slits are variable…

Numerical Analysis · Mathematics 2020-12-29 Jiaxin Zhou , Wangtao Lu

We explore conformal primary wavefunctions for all half integer spins up to the graviton. Half steps are related by supersymmetry, integer steps by the classical double copy. The main results are as follows: we 1) introduce a convenient…

High Energy Physics - Theory · Physics 2021-10-27 Sabrina Pasterski , Andrea Puhm

We consider the numerical evaluation of a class of double integrals with respect to a pair of self-similar measures over a self-similar fractal set (the attractor of an iterated function system), with a weakly singular integrand of…

Numerical Analysis · Mathematics 2023-09-07 Andrew Gibbs , David P. Hewett , Botond Major

We study the cosmological implications of the space-space noncommutative inflation and present formulae for the spectral index and its running. Our results show that deviations from the spectral index and its running depend on the…

Astrophysics · Physics 2009-11-10 S. A. Alavi , Forough Nasseri

We study the coalescence of two bound energy eigenstates embedded in the continuous spectrum of a real Hamiltonian $H[4]$ and the singular point produced by this coalescence. At the singular point, the two unnormalized Jost eigenfunctions…

Quantum Physics · Physics 2017-02-21 E. Hernández , A. Jáuregui , D. Lohr , A. Mondragón

In this paper, we prove the pointwise convergence and the rate of pointwise convergence for a family of singular integral operators in two-dimensional setting in the following form: \begin{equation*} L_{\lambda }\left( f;x,y\right)…

Functional Analysis · Mathematics 2017-01-26 Mine Menekse Yilmaz , Lakshmi Narayan Mishra , Gumrah Uysal

We introduce the concept of a spectral shift operator and use it to derive Krein's spectral shift function for pairs of self-adjoint operators. Our principal tools are operator-valued Herglotz functions and their logarithms. Applications to…

Spectral Theory · Mathematics 2007-05-23 Fritz Gesztesy , Konstantin A. Makarov , Serguei N. Naboko

We consider the Schr\"odinger operator with constant magnetic field defined on the half-plane with a Dirichlet boundary condition, $H_0$, and a decaying electric perturbation $V$. We analyze the spectral density near the Landau levels,…

Spectral Theory · Mathematics 2017-06-23 Vincent Bruneau , Pablo Miranda

We prove sharp Lieb-Thirring type inequalities for the eigenvalues of a class of one-dimensional functional difference operators associated to mirror curves. We furthermore prove that the bottom of the essential spectrum of these operators…

Functional Analysis · Mathematics 2021-12-07 Ari Laptev , Lukas Schimmer

This paper is concerned with inverse scattering problems of determining the support of an isotropic and homogeneous penetrable body from knowledge of multi-static far-field patterns in acoustics and in linear elasticity. The normal…

Analysis of PDEs · Mathematics 2024-04-11 Chun Liu , Guanghui Hu , Jianli Xiang , Jiayi Zhang

We compute all N-point primordial curvature correlation functions from inflation at tree-level up to N of order ten or more depending on the choice of parameters. This is achieved for resonant inflationary models in which the inflaton…

High Energy Physics - Theory · Physics 2011-05-31 Louis Leblond , Enrico Pajer

We review previous work on spectral flow in connection with certain self-adjoint model operators $\{A(t)\}_{t\in \mathbb{R}}$ on a Hilbert space $\mathcal{H}$, joining endpoints $A_\pm$, and the index of the operator $D_{A}^{}= (d/d t) + A$…

Analysis of PDEs · Mathematics 2017-02-21 Alan Carey , Fritz Gesztesy , Harald Grosse , Galina Levitina , Denis Potapov , Fedor Sukochev , Dmitriy Zanin

Scaling-invariant functions preserve the order of points when the points are scaled by the same positive scalar (with respect to a unique reference point). Composites of strictly monotonic functions with positively homogeneous functions are…

Optimization and Control · Mathematics 2021-09-09 Cheikh Touré , Armand Gissler , Anne Auger , Nikolaus Hansen