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We present results of a pilot observational wide-field VLBI campaign on probing scattering properties of the partly ionized interstellar medium towards the Galactic plane sky region between $28^\circ<l<36^\circ$ and $|b|<1^\circ$. This…

The scattering of polarized light incident from one dielectric medium on its two-dimensional randomly rough interface with a second dielectric medium is studied. A reduced Rayleigh equation for the scattering amplitudes is derived for the…

Optical Very Long Baseline Interferometry (VLBI) offers the potential for unprecedented angular resolution in both astronomical imaging and precision measurements. Classical approaches, however, face significant limitations due to photon…

Quantum Physics · Physics 2025-12-24 Zixin Huang , Oleg Titov , Mikolaj K. Schmidt , Benjamin Pope , Gavin K. Brennen , Daniel Oi , Pieter Kok

Extending super-resolution imaging techniques to objects hidden in strongly scattering media potentially revolutionize the technical analysis for much broader categories of samples, such as biological tissues. The main challenge is the…

We propose a method to reconstruct the optical properties of a scattering medium with subwavelength resolution. The method is based on the solution to the inverse scattering problem with photoactivated internal sources. Numerical…

Optics · Physics 2018-08-01 Anna C. Gilbert , Howard W. Levinson , John C. Schotland

The optical conductance of a multiple scattering medium is the total transmitted light of a diffuse incoming beam. This quantity, very analogous to the electronic conductance, exhibits universal conductance fluctuations. We perform a…

Condensed Matter · Physics 2009-10-22 M. C. W. van Rossum , Th. M. Nieuwenhuizen , R. Vlaming

Very Long Baseline Interferometry, or VLBI, is the observing technique yielding the highest-resolution images today. Whilst a traditionally large fraction of VLBI observations is concentrating on Active Galactic Nuclei, the number of…

Astrophysics · Physics 2009-06-23 Enno Middelberg , Uwe Bach

We discuss a time-harmonic inverse scattering problem for the Helmholtz equation with compactly supported penetrable and possibly inhomogeneous scattering objects in an unbounded homogeneous background medium, and we develop a monotonicity…

Analysis of PDEs · Mathematics 2021-03-01 Roland Griesmaier , Bastian Harrach

This article is an attempt to elucidate the effect of a slowly varying refractive index on the temperature in a stratified atmosphere, with a particular focus on greenhouse gases such as CO2. It validates an iterative method for the vector…

Analysis of PDEs · Mathematics 2024-12-17 Olivier Pironneau

Diffuse soft X-ray line emission is commonly used to trace the thermal and chemical properties of the hot interstellar medium, as well as its content, in nearby galaxies. Although resonant line scattering complicates the interpretation of…

Astrophysics of Galaxies · Physics 2018-07-25 Yang Chen , Q. Daniel Wang , Gao-Yuan Zhang , Shuinai Zhang , Li Ji

The dispersive part of the refractive index of vanadium is determined by measuring the angular displacement of the first order diffraction peak of a V/Fe superlattice. The measurements were made using elliptically polarized synchrotron…

Materials Science · Physics 2012-01-04 Martin Magnuson , Coryn F. Hague

The scintillation of pulsars reveals small-scale structure of the interstellar medium. A powerful technique for characterizing the scintillating structures (screens) combines analysis of scintillation arcs and very long baseline…

High Energy Astrophysical Phenomena · Physics 2025-10-21 Ashley M. Stock , Fardin Syed , Marten H. van Kerkwijk , Rebecca Lin , Franz Kirsten , Ue-Li Pen

Gravitational waves propagating across gravitational potentials undergo lensing effects that, in the wave-optics regime, manifest as frequency-dependent amplitude and phase modulations. In this work, we revisit the diffraction integral…

High Energy Physics - Theory · Physics 2026-01-09 Mariana Carrillo Gonzalez , Valerio De Luca , Alice Garoffolo , Julio Parra-Martinez , Mark Trodden

This work aims to explore the possibilities of determining the long-period part of the precession-nutation of the Earth with techniques other than very long baseline interferometry (VLBI). Lunar laser ranging (LLR) is chosen for its…

Geophysics · Physics 2019-07-03 Yu-Ting Cheng , Jia-Cheng Liu , Zi Zhu

The recent development of $\theta\mhyphen\theta$ techniques in pulsar scintillometry has opened the door for new high resolution imaging techniques of the scattering medium. By solving the phase retrieval problem and recovering the…

Instrumentation and Methods for Astrophysics · Physics 2023-08-09 Daniel Baker , Walter Brisken , Marten H. van Kerkwijk , Rik van Lieshout , Ue-Li Pen

We show that surface waves along interstellar current sheets closely aligned with the line of sight lead to pulsar scintillation properties consistent with those observed. This mechanism naturally produces the length and density scales of…

Astrophysics of Galaxies · Physics 2015-06-15 Ue-Li Pen , Yuri Levin

Since the dawn of modern optics and electromagnetics, optical prism is one of the most fascinating optical elements for refracting light. Exploiting its frequency dispersive behaviour, a prism is able to refract different frequencies in…

Optics · Physics 2023-02-15 L. Stefanini , D. Ramaccia , A. Toscano , F. Bilotti

Radio waves are imprinted with propagation effects from ionized media through which they pass. Owing to electron density fluctuations, compact sources (pulsars, masers, and compact extragalactic sources) can display a wide variety of…

Astrophysics · Physics 2009-11-10 T. Joseph W. Lazio , J. M. Cordes , A. G. de Bruyn , J. -P. Macquart

The theoretical formulation of x-ray resonant magnetic scattering from rough surfaces and interfaces is given for specular reflectivity. A general expression is derived for both structurally and magnetically rough interfaces in the…

Materials Science · Physics 2009-11-10 D. R. Lee , D. Haskel , Y. Choi , J. C. Lang , S. A. Stepanov , G. Srajer , S. K. Sinha

We present an analytic model of the refractive index for matter waves propagating through atomic or molecular gases. The model, which combines a WKB treatment of the long range attraction with the Fraunhofer model treatment of the short…

Atomic Physics · Physics 2010-08-20 Mikhail Lemeshko , Bretislav Friedrich