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The scattering of electromagnetic radiation by the particle gyrating in an external magnetic field is considered. Particular attention is paid to the low-frequency case, when the frequencies of incident radiation are much less than the…

Astrophysics · Physics 2009-11-13 S. A. Petrova

Bandwidth smearing is a chromatic aberration due to the finite frequency bandwidth. In long-baseline optical interferometry terms, it is when the angular extension of the source is greater than the coherence length of the interferogram. As…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Régis Lachaume , Jean-Philippe Berger

The low-frequency profiles of some pulsars manifest temporal broadening due to scattering, usually accompanied by flat polarization position angle (PA) curves. Assuming that the scattering works on the 4 Stokes parameters in the same way,…

Astrophysics · Physics 2008-11-26 X. H. Li , J. L. Han

The challenge of imaging low-density objects in an electron microscope without causing beam damage is significant in modern TEM. This is especially true for life science imaging, where the sample, rather than the instrument, still…

Optics · Physics 2025-01-29 Francisco Vega Ibáñez , Jo Verbeeck

Field distortion is widespread in imaging systems. If it cannot be measured and corrected well, it will affect the accuracy of photogrammetry. To this end, we proposed a general field distortion model based on Fredholm integration, which…

Image and Video Processing · Electrical Eng. & Systems 2022-05-19 Yunqi Sun , Jianfeng Zhou

We describe the symmetries present in the point-spread function (PSF) of an optical system either located in space or corrected by an adaptive o to Strehl ratios of about 70% and higher. We present a formalism for expanding the PSF to…

In papers on primary state diffusion (Percival 1994, 1995), numerical estimates suggested that fluctuations in the space-time metric on the scale of the Planck time (10^-44s) could be detected using atom interferometers. In this paper we…

Quantum Physics · Physics 2009-10-30 Ian C. Percival , Walter T. Strunz

We develop a general method for calculating statistical properties of the speckle pattern of coherent waves propagating in disordered media. In some aspects this method is similar to the Boltzmann-Langevin approach for the calculation of…

Mesoscale and Nanoscale Physics · Physics 2011-09-12 Oded Agam , A. V. Andreev , B. Spivak

We study Doppler effects in curved space-time, i.e. the frequency shifts induced on electromagnetic signals propagating in the gravitational field. In particular, we focus on the frequency shift due to the bending of light rays in weak…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Matteo Luca Ruggiero , Angelo Tartaglia , Lorenzo Iorio

The fractal properties of models of randomly placed $n$-dimensional spheres ($n$=1,2,3) are studied using standard techniques for calculating fractal dimensions in empirical data (the box counting and Minkowski-sausage techniques). Using…

Condensed Matter · Physics 2009-10-28 Daniel A. Hamburger , Ofer Biham , David Avnir

Free electrons in the interstellar medium cause frequency-dependent delays in pulse arrival times due to both scattering and dispersion. Multi-frequency measurements are used to estimate and remove dispersion delays. In this paper, we focus…

High Energy Astrophysical Phenomena · Physics 2015-06-23 M. T. Lam , J. M. Cordes , S. Chatterjee , T. Dolch

We introduce a method of estimating parameters associated with a fractal random scattering medium, which utilizes the multiscale properties of the scattered field. The example of ray-density fluctuations beyond a phase screen with fractal…

Optics · Physics 2012-04-04 John F. A. Fletcher

Despite spatial and temporal fluctuations in turbulent astrophysical systems, mean-field theories can be used to describe their secular evolution. However, observations taken over time scales much shorter than dynamical time scales capture…

High Energy Astrophysical Phenomena · Physics 2021-09-08 Hongzhe Zhou , Eric G. Blackman

We describe an optical technique based on the statistical analysis of the random intensity distribution due to the interference of the near-field scattered light with the strong transmitted beam. It is shown that, from the study of the…

Optics · Physics 2009-11-10 Doriano Brogioli , Alberto Vailati , Marzio Giglio

Point imaging by a photonic crystal slab due to the negative refraction is studied theoretically. By investigating the transfer function of the imaging system, the influence of the surface termination to the imaging quality is analyzed. It…

Classical Physics · Physics 2009-11-10 Sanshui Xiao , Min Qiu , Zhichao Ruan , Sailing He

Gravitational lensing of gravitational waves provides a powerful probe of the mass density distribution in the universe. Wave optics effects, such as diffraction, make the lensing effect sensitive to the structure around the Fresnel scale,…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-22 So Tanaka , Teruaki Suyama

Galaxy imaging surveys observe a vast number of objects that are affected by the instrument's Point Spread Function (PSF). Weak lensing missions, in particular, aim at measuring the shape of galaxies, and PSF effects represent an important…

Instrumentation and Methods for Astrophysics · Physics 2021-02-03 T. Liaudat , J. Bonnin , J. -L. Starck , M. A. Schmitz , A. Guinot , M. Kilbinger , S. D. J. Gwyn

Quantum gas microscopes, which image the atomic occupations in an optical lattice, have opened a new avenue to the exploration of many-body lattice systems. Imaging trapped systems after freezing the density distribution by ramping up a…

Quantum Gases · Physics 2019-05-10 Sven Krönke , Maxim Pyzh , Christof Weitenberg , Peter Schmelcher

Spatial phase-referencing in dual-field optical interferometry is reconsidered. Our analysis is based on the 2-sample variance of the differential phase between target and reference star. We show that averaging over time of the atmospheric…

Astrophysics · Physics 2009-11-07 Gerard Daigne , Jean-Francois Lestrade

The Surface Brightness Fluctuations (SBF) Method for distance determinations of elliptical galaxies is been modeled in order to investigate the effect of the Point Spread Function (PSF). We developed a method to simulate observations of SBF…

Astrophysics · Physics 2012-07-23 D. Gouliermis , W. Brandner , D. Butler , S. Hippler