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In quantum materials, basic observables such as spectral functions and susceptibilities are determined by Green's functions and their complex quasiparticle spectrum rather than by bare electrons. Even in closed many-body systems, this makes…

Mesoscale and Nanoscale Physics · Physics 2024-10-22 Carl Lehmann , Tommaso Micallo , Jan Carl Budich

A one-parameter random matrix model is proposed for describing the statistics of the local amplitudes and phases of electron eigenfunctions in a mesoscopic quantum dot in an arbitrary magnetic field. Comparison of the statistics obtained…

Condensed Matter · Physics 2009-10-28 E. Kanzieper , V. Freilikher

In this paper, we address the theoretical limitations in reconstructing sparse signals (in a known complete basis) using compressed sensing framework. We also divide the CS to non-blind and blind cases. Then, we compute the Bayesian…

Information Theory · Computer Science 2010-05-25 Hadi Zayyani , Massoud Babaie-Zadeh , Christian Jutten

Autoencoders are a prominent model in many empirical branches of machine learning and lossy data compression. However, basic theoretical questions remain unanswered even in a shallow two-layer setting. In particular, to what degree does a…

Machine Learning · Computer Science 2024-02-08 Kevin Kögler , Alexander Shevchenko , Hamed Hassani , Marco Mondelli

While nuclear magnetic resonance diffusion experiments are widely used to resolve structures confining the diffusion process, it has been elusive whether they can exactly reveal these structures. This question is closely related to X-ray…

Medical Physics · Physics 2012-05-09 Frederik Bernd Laun , Tristan Anselm Kuder , Wolfhard Semmler , Bram Stieltjes

There are a variety of elementary and collective terahertz-frequency excitations in condensed matter whose magnetic field dependence contains significant insight into the states and dynamics of the electrons involved. Often, determining the…

We introduce the longitudinal and transverse static surface modes and use them to solve the full-wave electromagnetic scattering problem from penetrable objects. The longitudinal static modes are the eigenmodes with zero surface curl of the…

Mesoscale and Nanoscale Physics · Physics 2023-08-16 Carlo Forestiere , Giovanni Gravina , Giovanni Miano , Guglielmo Rubinacci , Antonello Tamburrino

Gravitational clustering is an intrinsically non-linear process that generates significant non-Gaussian signatures in the density field. We consider how these affect power spectrum determinations from galaxy and weak-lensing surveys.…

Astrophysics · Physics 2008-11-26 Roman Scoccimarro , Matias Zaldarriaga , Lam Hui

Primordial gravitational waves could be non-Gaussian, just like primordial scalar perturbations. Although the tensor two-point function has thus-far remained elusive, the three-point function could, in principle, be large enough to be…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-14 Oliver H. E. Philcox , Maresuke Shiraishi

We consider a second order self-adjoint operator in a domain which can be bounded or unbounded. The boundary is partitioned into two parts with Dirichlet boundary condition on one of them, and Neumann condition on the other. We assume that…

Spectral Theory · Mathematics 2018-09-28 Denis Borisov , Ivan Veselic'

Natural signals and images are well-known to be approximately sparse in transform domains such as Wavelets and DCT. This property has been heavily exploited in various applications in image processing and medical imaging. Compressed sensing…

Machine Learning · Computer Science 2015-10-26 Saiprasad Ravishankar , Yoram Bresler

We theoretically investigate the transverse magnetization and ferroaxial moments induced by electric field gradients arising from the geometry of finite systems. Based on the Kubo formalism and real-time numerical simulations for a finite…

Mesoscale and Nanoscale Physics · Physics 2026-05-12 Akane Inda , Satoru Hayami

Modal expansions are useful to understand wave propagation in an infinite electromagnetic transmission line or waveguide. They can also be used to construct generalized Dirichlet-to-Neumann maps that can be used to provide artificial…

Analysis of PDEs · Mathematics 2023-02-24 Martin Halla , Peter Monk

In the light-front description of nucleon structure the electromagnetic form factors are expressed in terms of frame-independent transverse densities of charge and magnetization. Recent work has studied the transverse densities at…

High Energy Physics - Phenomenology · Physics 2015-06-17 C. Granados , C. Weiss

(Abridged) This paper introduces the formalism which connects between rotation measure ($\RM$) measurements for extragalactic sources and the cosmological magnetic field power spectrum. It is shown that the amplitude and shape of the…

Astrophysics · Physics 2016-08-30 Tsafrir Kolatt

We consider the nonlinear transverse magnetic moment that arises in the Meissner state of superconductors with strongly anisotropic order parameter. We compute this magnetic moment as a function of applied field and geometry, assuming…

Condensed Matter · Physics 2009-10-28 Igor Zutic , Oriol T. Valls

We consider a non-self adjoint operator of the form $-h^2 \Delta + i(V(x) + \alpha(x)y)$ on the upper half plane $y > 0$ with Dirichlet boundary conditions on $\{y = 0\}$ with $V \geq 0$, $V$ admitting a non-degenerate minimum at $x = 0$…

Mathematical Physics · Physics 2025-12-24 Martin Averseng , Nicolas Frantz , Frédéric Hérau , Nicolas Raymond

We establish Lieb-Thirring type inequalities for non self-adjoint relatively compact perturbations of certain operators of mathematical physics. We apply our results to quantum Hamiltonians of Schr{\"o}dinger and Pauli with constant…

Mathematical Physics · Physics 2016-03-16 Diomba Sambou

Tensor models play an increasingly prominent role in many fields, notably in machine learning. In several applications, such as community detection, topic modeling and Gaussian mixture learning, one must estimate a low-rank signal from a…

Machine Learning · Statistics 2022-06-16 José Henrique de Morais Goulart , Romain Couillet , Pierre Comon

We consider a periodic system of domains coupled by small windows. In such domain we study the band spectrum of a Schroedinger operator subject to Neumann condition. We show that near each isolated eigenvalue of the similar operator but in…

Spectral Theory · Mathematics 2013-12-31 Denis Borisov