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We compare the performance of several dust models in reproducing the dust spectral energy distribution (SED) per unit extinction in the diffuse interstellar medium (ISM). We use our results to constrain the variability of the optical…

In an absorbing or an active host medium characterized by a complex refractive index $n_2=n_2'+{\rm i}n_2''$, our previously developed modified dipole long-wave approximation (MLWA) is shown to essentially overly with the exact Mie theory…

We derive periodic multilayer absorbers with effective uniaxial properties similar to perfectly matched layers (PML). This approximate representation of PML is based on the effective medium theory and we call it an effective medium PML…

Upscaling Klinkenberg-corrected gas permeability, k, in unconventional tight sandstones has numerous practical applications, particularly in gas exploration and production. In this study, we adapt the effective-medium approximation (EMA)…

Geophysics · Physics 2019-07-16 Behzad Ghanbarian , Carlos Torres-Verdin , Larry W. Lake , Michael Marder

We study the scattering of infrared light by small dielectric core-shell particles taking a sapphire sphere with a CaO core as an example. The extinction efficiency of such a particle shows two intense series of resonances attached,…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 E. Thiessen , F. X. Bronold , R. L. Heinisch , H. Fehske

A theoretical framework is presented that permits investigations of the relation between inelastic backscattering from microparticles and bulk samples of Raman-active materials. It is based on the Lorentz reciprocity theorem and no…

Optics · Physics 2018-03-06 Taras Plakhotnik , Jens Reichardt

An experiment is described that enables students to understand the properties of atmospheric extinction due to Rayleigh scattering. The experiment requires the use of red, green and blue lasers attached to a travelling microscope or similar…

Physics Education · Physics 2015-11-12 Stephen W. Hughes , Michael J. Cowley , Sean Powell , Joshua Carroll

The effective permittivity dyadic of a composite material containing particulate constituent materials with one constituent having the ability to display the Pockels effect is computed, using an extended version of the…

Optics · Physics 2009-11-13 Tom G. Mackay , Akhlesh Lakhtakia

We formally deduce closed-form expressions for the transmitted effective wavenumber of a material comprising multiple types of inclusions or particles (multi-species), dispersed in a uniform background medium. The expressions, derived here…

Classical Physics · Physics 2018-05-09 Artur L. Gower , Michael J. A. Smith , William J. Parnell , Ian David Abrahams

We consider a linearly elastic composite medium, which consists of a homogeneous matrix containing a statistically homogeneous set of multimodal spherical inclusions modeling the morphology of heterogeneous solid propellants (HSP).…

Materials Science · Physics 2012-09-21 V. A. Buryachenko

Exploring the interaction of light with time-varying media is an intellectual challenge that, in addition to fundamental aspects, provides a pathway to multiple promising applications. Time modulation constitutes here a fundamental handle…

In this work we examine the dispersion of conservative tracers (bromide and fluorescein) in an experimentally-constructed three-dimensional dual-porosity porous medium. The medium is highly heterogeneous ($\sigma_Y^2=5.7$), and consists of…

Fluid Dynamics · Physics 2018-03-14 Daniel Vogler , Sassan Ostvar , Rebecca Paustian , Brian Wood

Light scattering in disordered media plays an important role in various areas of applied science from biophysics to astronomy. In this paper we study two approaches to calculate scattering properties of semi-infinite densely packed media…

Computational Physics · Physics 2023-04-12 Sofia Ponomareva , Alexey A. Shcherbakov

An effective medium model is developed for disordered metamaterials containing a spatially random distribution of dielectric spheres. Similar to effective medium models for ordered metamaterials, this model predicts resonances in the…

Optics · Physics 2017-03-09 Brian A Slovick

We performed high-resolution Fourier-transform infrared (FTIR) spectroscopy of a polymethyl methacrylate (PMMA) sphere of unknown size in the Mie scattering region. Apart from a slow, oscillatory structure (wiggles), which is due to an…

Optics · Physics 2016-05-24 R. Blümel , M. Bağcıoğlu , R. Lukacs , A. Kohler

Soft, repulsive run-and-tumble particles display emergent effective interactions as they appear to stick to each other in spite of the absence of attractive forces. This effective attraction emerges at strong enough repulsion and large…

Statistical Mechanics · Physics 2026-05-05 Rosalba Garcia-Millan , Ziluo Zhang , Luca Cocconi , Marius Bothe , Letian Chen , Zigan Zhen , Gunnar Pruessner

The fixed energy scattering matrix is defined on a perturbed stratified medium, and for a class of perturbations, its main part is shown to be a Fourier integral operator on the sphere at infinity. This is facilitated by developing a…

Spectral Theory · Mathematics 2007-05-23 T. J. Christiansen , M. S. Joshi

In this work, we are concerned with the mathematical modeling of the electromagnetic (EM) scattering by arbitrarily shaped non-magnetic nanoparticles with high refractive indices. When illuminated by visible light, such particles can…

Mathematical Physics · Physics 2021-08-13 Habib Ammari , Bowen Li , Jun Zou

Fitting spectral distributions of total fluxes or image intensities are two standard methods for estimating the masses of starless cores and protostellar envelopes. These mass estimates, which are the main source and basis of our knowledge…

Instrumentation and Methods for Astrophysics · Physics 2016-09-28 Alexander Men'shchikov

We study the light scattering properties of random ballistic aggregates constructed in Shen et al. (Paper I). Using the discrete-dipole-approximation, we compute the scattering phase function and linear polarization for random aggregates…

Earth and Planetary Astrophysics · Physics 2011-02-11 Yue Shen , B. T. Draine , Eric T. Johnson