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We explore quantum-based optical polarimetry as a potential diagnostic tool for biological tissues by developing a theoretical and experimental framework to understand polarization-entangled photon behavior in scattering media. We…

We develop a new Monte Carlo method that solves hyperbolic transport equations with stiff terms, characterized by a (small) scaling parameter. In particular, we focus on systems which lead to a reduced problem of parabolic type in the limit…

Numerical Analysis · Mathematics 2017-08-01 G. Dimarco , L. Pareschi , G. Samaey

Can Monte Carlo (MC) solvers be directly used in gradient-based methods for PDE-constrained optimization problems? In these problems, a gradient of the loss function is typically presented as a product of two PDE solutions, one for the…

Numerical Analysis · Mathematics 2022-09-27 Qin Li , Li Wang , Yunan Yang

We investigate the effect of ellipticity ratio of the polarized radiation field on optoelectronic properties of a two-dimensional (2D) semi-Dirac (SD) system. The optical conductivity is calculated within the energy balance equation…

Mesoscale and Nanoscale Physics · Physics 2022-03-23 H. Y. Zhang , Y. M. Xiao , Q. N. Li , L. Ding , B. Van Duppen , W. Xu , F. M. Peeters

We describe a general radiative equilibrium and temperature correction procedure for use in Monte Carlo radiation transfer codes with sources of temperature-independent opacity, such as astrophysical dust. The technique utilizes the fact…

Astrophysics · Physics 2010-04-08 J. E. Bjorkman , Kenneth Wood

Quantitative photoacoustic tomography aims at estimating optical parameters from photoacoustic images that are formed utilizing the photoacoustic effect caused by the absorption of an externally introduced light pulse. This optical…

Medical Physics · Physics 2020-10-02 Aleksi Leino , Tuomas Lunttila , Meghdoot Mozumder , Aki Pulkkinen , Tanja Tarvainen

We propose a method of simulation that is based on the averaging of formal solutions of the transfer equation by taking the integral by the Monte Carlo method. This method is used to compute two models, which correspond to the limiting…

Astrophysics · Physics 2007-05-23 Maxim A. Voronkov

We present results of a Monte Carlo study of temperature-programmed desorption in a model system with attractive lateral interactions. It is shown that even for weak interactions there are large shifts of the peak maximum temperatures with…

chem-ph · Physics 2009-10-28 A. P. J. Jansen

Anomalous radiative transfer (ART) theory is a generalization of classical radiative transfer theory. The present tutorial wants to show how Monte Carlo (MC) codes describing photons transport in anomalous media can be implemented. It is…

Computational Physics · Physics 2022-06-02 Tiziano Binzoni , Fabizio Martelli

We investigate the ionization of the diffuse interstellar medium by cosmic rays by modeling their propagation along the wandering magnetic fields using a Monte Carlo method. We study how low-energy cosmic rays propagate in turbulent,…

High Energy Astrophysical Phenomena · Physics 2022-12-05 Riccardo Franceschi , Steven Neil Shore

We present the results of a Monte Carlo radiative transfer code that calculates the polarization produced by multiple Thomson scattering and variable absorptive opacity in a circumstellar disk around one component of a close detached binary…

Astrophysics · Physics 2009-11-10 Jennifer L. Hoffman , Barbara A. Whitney , Kenneth H. Nordsieck

We present synthetic dust polarisation maps of 3D magneto-hydrodynamical simulations of molecular clouds before the onset of stellar feedback. The clouds are modelled within the SILCC-Zoom project and are embedded in their galactic…

Astrophysics of Galaxies · Physics 2018-10-31 D. Seifried , S. Walch , S. Reissl , J. C. Ibáñez-Mejía

ALMA observations revealed recently polarised radiation of several protoplanetary disks in the (sub-)millimetre wavelength range. Besides self-scattering of large particles, thermal emission by elongated grains is a potential source for the…

Earth and Planetary Astrophysics · Physics 2019-07-10 Florian Kirchschlager , Gesa H. -M. Bertrang , Mario Flock

In a cyclotron-based proton therapy facility, the energy changes are performed by means of a degrader of variable thickness. The interaction of the proton beam with the degrader creates energy tails and increases the beam emittance. A…

Accelerator Physics · Physics 2018-06-13 V. Rizzoglio , A. Adelmann , C. Baumgarten , D. Meer , J. Snuverink , V. Talanov

The properties of polarization in scattered light by aligned ellipsoidal grains are investigated with the Fredholm integral equation method (FIM) and the T-matrix method (Tmat), and the results are applied to the observed circular…

Astrophysics of Galaxies · Physics 2010-01-15 Masafumi Matsumura , Pierre Bastien

We analyze the line radiative transfer in protoplanetary disks using several approximate methods and a well-tested Accelerated Monte Carlo code. A low-mass flaring disk model with uniform as well as stratified molecular abundances is…

Astrophysics · Physics 2009-11-13 Ya. Pavlyuchenkov , D. Semenov , Th. Henning , St. Guilloteau , V. Pietu , R. Launhardt , A. Dutrey

We consider the application of multilevel Monte Carlo methods to steady state Darcy flow in a random porous medium, described mathematically by elliptic partial differential equations with random coefficients. The levels in the multilevel…

Numerical Analysis · Mathematics 2015-06-16 Minho Park , Aretha Teckentrup

We consider the scattering of light in participating media composed of sparsely and randomly distributed discrete particles. The particle size is expected to range from the scale of the wavelength to the scale several orders of magnitude…

Graphics · Computer Science 2021-02-25 Jie Guo , Bingyang Hu , Yanjun Chen , Yuanqi Li , Yanwen Guo , Ling-Qi Yan

A fast and general Bayesian inference framework to infer the physical properties of dichroic polarization using mid-infrared imaging- and spectro-polarimetric observations is presented. The Bayesian approach is based on a hierarchical…

Instrumentation and Methods for Astrophysics · Physics 2015-12-02 E. Lopez-Rodriguez

We aim to investigate the polarization properties of a starless core in a very early evolutionary stage. Linear polarization data reveal the properties of the dust grains in the distinct phases of the interstellar medium. Our goal is to…

Solar and Stellar Astrophysics · Physics 2014-09-17 Felipe Alves , Pau Frau , Josep M. Girart , Gabriel A. P. Franco , Fábio P. Santos , Helmut Wiesemeyer