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A three-step model for calculating the magnetic field generated by coils inside cuboid-shaped shields like magnetically shielded rooms (MSRs) is presented. The shield is modelled as two parallel plates of infinite width and one tube of…

Applied Physics · Physics 2020-11-17 Tianhao Liu , Allard Schnabel , Jens Voigt , Zhiyin Sun , Liyi Li

The nature of stacking faults - whether intrinsic or extrinsic - plays a pivotal role in defect-mediated processes in crystalline materials. Yet, current electron microscopy techniques for their reliable analysis remain limited to either…

The brightest southern quasar above redshift $z=1$, HE 0515$-$4414, with its strong intervening metal absorption-line system at $z_{abs}=1.1508$, provides a unique opportunity to precisely measure or limit relative variations in the…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-07 Srđan M. Kotuš , Michael T. Murphy , Robert F. Carswell

Aims. To obtain limits on the variation of the fine-structure constant alpha and the electron-to-proton mass ratio mu over different cosmological epochs. Methods. A new approach based on the comparison of redshifts of far infrared (FIR)…

Astrophysics · Physics 2009-09-01 S. A. Levshakov , D. Reimers , M. G. Kozlov , S. G. Porsev , P. Molaro

We derive error estimates of a finite element method for the approximation of solutions to a seven-fields formulation of a magnetohydrodynamics model, which preserves the energy of the system, and the magnetic and cross helicities on the…

Numerical Analysis · Mathematics 2025-03-04 L. Beirao da Veiga , K. Hu , L. Mascotto

All coronagraphic instruments for exoplanet high-contrast imaging need wavefront correction systems to reject optical aberrations and create sufficiently dark holes. Since the most efficient wavefront correction algorithms (controllers and…

Instrumentation and Methods for Astrophysics · Physics 2018-10-09 He Sun , N. Jeremy Kasdin , Robert Vanderbei

Abnormal event detection is critical in the safe operation of power system. In this paper, using the data collected from phasor measurement units (PMUs), two methods based on Fisher random matrix are proposed to detect faults in power…

Systems and Control · Electrical Eng. & Systems 2022-08-10 Ke Chen , Dandan Jiang , Bo Wang , Hongxia Wang

We apply a method recently introduced to the statistical literature to directly estimate the precision matrix from an ensemble of samples drawn from a corresponding Gaussian distribution. Motivated by the observation that cosmological…

Instrumentation and Methods for Astrophysics · Physics 2016-05-25 Nikhil Padmanabhan , Martin White , Harrison H. Zhou , Ross O'Connell

Context: The detection and characterization of Earth-like exoplanets (exoEarths) from space requires exquisite wavefront stability at contrast levels of $10^{-10}$. On segmented telescopes in particular, aberrations induced by cophasing…

It is demonstrated that finite-pressure, approximately quasi-axisymmetric stellarator equilibria can be directly constructed (without numerical optimization) via perturbations of given axisymmetric equilibria. The size of such perturbations…

Plasma Physics · Physics 2022-06-22 G. G. Plunk

We present an analysis of 23 absorption systems along the lines of sight towards 18 quasars in the redshift range of $0.4 \leq z_{abs} \leq 2.3$ observed on the Very Large Telescope (VLT) using the Ultraviolet and Visual Echelle…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-04 Michael R. Wilczynska , John K. Webb , Julian A. King , Michael T. Murphy , Matthew B. Bainbridge , Victor V. Flambaum

We present evidence for variations in the fine-structure constant from Keck/HIRES spectra of 143 quasar absorption systems over the redshift range 0.2 < z_abs < 4.2. This includes 15 new systems, mostly at high-z (z_abs > 1.8). Our most…

Astrophysics · Physics 2009-08-18 M. T. Murphy , V. V. Flambaum , J. K. Webb , V. V. Dzuba , J. X. Prochaska , A. M. Wolfe

Traditional Statistical Process Control methodologies face several challenges when monitoring defects in complex geometries, such as those of products obtained via Additive Manufacturing techniques. Many approaches cannot be applied in…

Applications · Statistics 2024-04-12 Sara Bonacina , Daniele Zago , Giovanna Capizzi , Bianca Maria Colosimo

We propose a novel approach for estimating the location of block boundaries (change-points) in a random matrix consisting of a block wise constant matrix observed in white noise. Our method consists in rephrasing this task as a variable…

Applications · Statistics 2016-03-14 Vincent Brault , Julien Chiquet , Céline Lévy-Leduc

The critical behavior of the Ising model on a fractal lattice, which has the Hausdorff dimension $\log_{4} 12 \approx 1.792$, is investigated using a modified higher-order tensor renormalization group algorithm supplemented with automatic…

Statistical Mechanics · Physics 2023-03-22 Jozef Genzor

In this paper, single-stage stellarator optimization is combined with stochastic coil optimization to improve the robustness of the stellarator as compared to deterministic methods. The plasma boundary, solved with an MHD solver in…

Plasma Physics · Physics 2026-03-13 Pedro F. Gil , Jason Smoniewski , Rogerio Jorge , Paul Huslage , Eve V. Stenson

We study degeneracies between cosmological parameters and measurement errors from cosmic shear surveys using a principal component analysis of the Fisher matrix. We simulate realistic survey topologies with non-uniform sky coverage, and…

Astrophysics · Physics 2009-11-13 Dipak Munshi , Martin Kilbinger

We present a method to calibrate wavefront distortion of the spatial light modulator setup by registering far field images of several Gaussian beams diffracted off the modulator. The Fourier transform of resulting interference images…

Optics · Physics 2016-03-22 Adam Leszczyński , Wojciech Wasilewski

We investigate an additive perturbation of a complex Wishart random matrix and prove that a large deviation principle holds for the spectral measures. The rate function is associated to a vector equilibrium problem coming from logarithmic…

Probability · Mathematics 2013-03-14 Adrien Hardy , Arno B. J. Kuijlaars

Identification of the parameters of stable linear dynamical systems is a well-studied problem in the literature, both in the low and high-dimensional settings. However, there are hardly any results for the unstable case, especially…

Systems and Control · Computer Science 2018-06-06 Mohamad Kazem Shirani Faradonbeh , Ambuj Tewari , George Michailidis