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Related papers: Spectral sum rules on a $d$--sphere

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We propose a technique for calculating and understanding the eigenvalue distribution of sums of random matrices from the known distribution of the summands. The exact problem is formidably hard. One extreme approximation to the true density…

Quantum Physics · Physics 2017-10-27 Ramis Movassagh , Alan Edelman

Based on the classical Lorentz model of the index of refraction, a new method is presented for the extraction of the complex index of refraction from the extinction efficiency of homogeneous and layered dielectric spheres that…

Optics · Physics 2022-06-28 Kalpa de Silva , Proity Akbar , Reinhold Blümel

We consider the problem of the recovery of a Robin coefficient on a part $\gamma \subset \partial \Omega$ of the boundary of a bounded domain $\Omega$ from the principal eigenvalue and the boundary values of the normal derivative of the…

Analysis of PDEs · Mathematics 2020-07-08 Matteo Santacesaria , Toshiaki Yachimura

Hard X-ray spectra in solar flares provide knowledge of the electron spectrum that results from acceleration and propagation in the solar atmosphere. However, the inference of the electron spectra from solar X-ray spectra is an ill-posed…

Astrophysics · Physics 2009-11-10 E. P. Kontar , M. Piana , A. M. Massone , A. G. Emslie , J. C. Brown

Consider the two-dimensional inverse elastic wave scattering by an infinite rough surface with a Dirichlet boundary condition. A non-interative sampling technique is proposed for detecting the rough surface by taking elastic wave…

Analysis of PDEs · Mathematics 2020-12-15 Tielei Zhu , Jiaqing Yang

We demonstrate the ability to calculate electromagnetic sum rules with the \textit{ab initio} symmetry-adapted no-core shell model. By implementing the Lanczos algorithm, we compute non-energy weighted, energy weighted, and inverse energy…

Nuclear Theory · Physics 2020-07-28 R. B. Baker , K. D. Launey , S. Bacca , N. Nevo Dinur , T. Dytrych

The distribution of the sum of r-th power of standard normal random variables is a generalization of the chi-squared distribution. In this paper, we represent the probability density function of the random variable by an one-dimensional…

Classical Analysis and ODEs · Mathematics 2018-06-25 Tamio Koyama

We determine masses of light quarks ($m_u$,$m_d$,$m_s$) using Borel-Laplace sum rules and renormalization group summed perturbation theory (RGSPT) from the divergence of the axial vector current. The RGSPT significantly reduces the scale…

High Energy Physics - Phenomenology · Physics 2023-10-17 M. S. A. Alam Khan

Circle- and sphere-valued data play a significant role in inverse problems like magnetic resonance phase imaging and radar interferometry, in the analysis of directional information, and in color restoration tasks. In this paper, we aim to…

Numerical Analysis · Mathematics 2024-04-23 Robert Beinert , Jonas Bresch

Three well known photonuclear sum rules (SR), i.e. the Thomas-Reiche-Kuhn, the bremsstrahlungs and the polarizability SR are calculated for 4He with the realistic nucleon-nucleon potential Argonne V18 and the three-nucleon force Urbana IX.…

Nuclear Theory · Physics 2008-11-26 Doron Gazit , Nir Barnea , Sonia Bacca , Winfried Leidemann , Giuseppina Orlandini

In this paper, a sum rule means a relationship between a functional defined on a subset of all probability measures on $\mathbb{R}$ involving the reverse Kullback-Leibler divergence with respect to a particular distribution and recursion…

Probability · Mathematics 2015-06-23 Fabrice Gamboa , Jan Nagel , Alain Rouault

We derive four sum-rule expressions for spectra measured in electron energy-loss near edge structure experiments. These sum-rules permit the determination spin and orbital magnetic moments, spin-orbit interaction and number of states,…

Materials Science · Physics 2009-11-13 Ján Rusz , Olle Eriksson , Pavel Novák , Peter M. Oppeneer

We derive the explicit values of all regularization parameters (RP) for a scalar particle in an arbitrary geodesic orbit around a Schwarzschild black hole. These RP are required within the previously introduced mode-sum method, for…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Leor Barack , Amos Ori

We derive two sum rules by studying the low energy Compton scattering on a target of arbitrary (nonzero) spin j. In the first sum rule, we consider the possibility that the intermediate state in the scattering can have spin |j \pm 1| and…

High Energy Physics - Theory · Physics 2012-10-11 Hovhannes R. Grigoryan , Massimo Porrati

Two properties of the radiation emitted by a relativistic electron in an external field, in the classical approximation, are presented in details: 1) spectral sum rules and their relationship with the sum rules for oscillator strength in…

High Energy Physics - Phenomenology · Physics 2020-06-24 Xavier Artru

This paper investigates the problem of reconstructing a random source from statistical phaseless data for the two-dimensional Helmholtz equation. The major challenge of this problem is non-uniqueness, which we overcome through a reference…

Numerical Analysis · Mathematics 2025-09-01 Qiao-Ping Chen , Hongyu Liu , Zejun Sun , Li-Li Wang , Guang-Hui Zheng

We propose a general inverse formula for extracting inflationary parameters from the observed power spectrum of cosmological perturbations. Under the general slow-roll scheme, which helps to probe the properties of inflation in a model…

Astrophysics · Physics 2009-11-10 Minu Joy , Ewan D. Stewart , Jinn-Ouk Gong , Hyun-Chul Lee

An Ewald decomposition of the two-dimensional Yukawa potential and its derivative is presented for both the periodic and the free-space case. These modified Bessel functions of the second kind of zeroth and first degrees are used e.g. when…

Computational Engineering, Finance, and Science · Computer Science 2019-11-15 Sara Pålsson , Anna-Karin Tornberg

We derive sum rules involving the spectral density of the stress-energy tensor in N=4 super-Yang-Mills theory and pure Yang-Mills theory. The sum rules come from the hydrodynamic behavior at small momenta and the conformal (in the case of…

High Energy Physics - Phenomenology · Physics 2009-11-06 Paul Romatschke , Dam Thanh Son

A novel perturbative method, proposed by Panda {\it et al.} [1] to solve the Helmholtz equation in two dimensions, is extended to three dimensions for general boundary surfaces. Although a few numerical works are available in the literature…

Mathematical Physics · Physics 2016-06-21 Subhasis Panda , S. Pratik Khastgir