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Optical fiber links are known as the most performing tools to transfer ultrastable frequency reference signals. However, these signals are affected by phase noise up to bandwidths of several kilohertz and a careful data processing strategy…

Instrumentation and Detectors · Physics 2015-12-15 Claudio E. Calosso , Cecilia Clivati , Salvatore Micalizio

Analog codes add redundancy by expanding the dimension using real/complex-valued operations. Frame theory provides a mathematical basis for constructing such codes, with diverse applications in non-orthogonal code-division multiple access…

Information Theory · Computer Science 2025-01-22 Itamar Jacoby , Ram Zamir

We point out an important source of error in measurements of extragalactic H-alpha emission and suggest ways to reduce it. The H-alpha line, used for estimating star formation rates, is commonly measured by imaging in a narrow band and a…

Instrumentation and Methods for Astrophysics · Physics 2011-11-28 Oded Spector , Ido Finkelman , Noah Brosch

Timescale comparison between optical atomic clocks over ground-to-space and terrestrial free-space laser links will have enormous benefits for fundamental and applied science, from measurements of fundamental constants and searches for dark…

The foundations of weak turbulence theory is explored through its application to the (alpha) Fermi-Pasta-Ulam (FPU) model, a simple weakly nonlinear dispersive system. A direct application of the standard kinetic equations would miss…

Chaotic Dynamics · Physics 2007-05-23 Peter R. Kramer , Joseph A. BIello , Yury Lvov

We propose a systematic method of analyzing pseudopotential transferability based on linear-response properties of the free atom, including self-consistent chemical hardness and polarizability. Our calculation of hardness extends the…

mtrl-th · Physics 2009-10-28 A. Filippetti , David Vanderbilt , W. Zhong , Yong Cai , G. B. Bachelet

We introduce a new numerical strategy to solve a class of oscillatory transport PDE models which is able to captureaccurately the solutions without numerically resolving the high frequency oscillations {\em in both space and time}.Such PDE…

Numerical Analysis · Mathematics 2016-06-01 Nicolas Crouseilles , Shi Jin , Mohammed Lemou

As an extension of the method by Bahcall et al. (2004) to investigate the time dependence of the fine structure constant, we describe an approach based on new observations of forbidden line multiplets from different ionic species. We obtain…

Astrophysics · Physics 2008-11-26 Dirk Grupe , Anil K. Pradhan , Stephan Frank

Outflows promote the escape of Lyman-$\alpha$ (Ly$\alpha$) photons from dusty interstellar media. The process of radiative transfer through interstellar outflows is often modelled by a spherically symmetric, geometrically thin shell of gas…

Astrophysics of Galaxies · Physics 2015-10-16 Max Gronke , Philip Bull , Mark Dijkstra

The transport of high-energy particles in the presence of small-scale, turbulent magnetic fields is a long-standing issue in astrophysics. Analytical theories on transport perpendicular to the large-scale magnetic field disagree with…

High Energy Astrophysical Phenomena · Physics 2025-10-03 Marco Kuhlen , Vo Hong Minh Phan , Philipp Mertsch

We present a formalism to discern the effects of fluctuations of the spacetime metric on electromagnetic radiation. The formalism works via the measurement of electromagnetic field correlations, while allowing a clear assessment of the…

General Relativity and Quantum Cosmology · Physics 2024-04-09 B. Sharmila , Sander M. Vermeulen , Animesh Datta

This document presents a Data Model to describe Spectral Line Transitions in the context of the Simple Line Access Protocol defined by the IVOA (c.f. Ref[13] IVOA Simple Line Access protocol) The main objective of the model is to integrate…

Instrumentation and Methods for Astrophysics · Physics 2019-05-22 Pedro Osuna , Matteo Guainazzi , Jesus Salgado , Marie-Lise Dubernet , Evelyne Roueff

We present a general solution for the radiation intensity in front of a purely absorbing slab moving toward an observer at constant speed and with a constant temperature. The solution is obtained by integrating the lab-frame radiation…

Computational Engineering, Finance, and Science · Computer Science 2020-09-07 Ryan G. McClarren , N. A. Gentile

Accurate atomic data are essential for opacity calculations and for abundance analyses of the Sun and other stars. The aim of this work is to provide accurate and extensive results of energy levels and transition data for C I - IV. The…

Atomic Physics · Physics 2021-02-03 W. Li , A. M. Amarsi , A. Papoulia , J. Ekman , P. Jönsson

Mg is the alpha element of choice for Galactic population and chemical evolution studies as it is easily detectable in all late-type stars. Such studies require precise elemental abundances, and thus departures from LTE need to be accounted…

Solar and Stellar Astrophysics · Physics 2016-02-10 Yeisson Osorio , Paul S. Barklem

Ultrashort light pulses are ubiquitous in modern research, but the electromagnetic field of the optical cycles is usually not easy to obtain as a function of time. Field-resolved pulse characterization requires either a nonlinear-optical…

Optics · Physics 2022-11-30 Yuya Morimoto , Bo-Han Chen , Peter Baum

We investigate the distribution of number of photons emitted by a single molecule undergoing a spectral diffusion process and interacting with a continuous wave field. Using a generating function formalism an exact analytical formula for…

Statistical Mechanics · Physics 2009-11-10 Yong He , Eli Barkai

We formulate and solve the diffusion problem of line photon propagation in a bulk outflow from a compact object (black hole or neutron star) using a generic assumption regarding the distribution of line photons within the outflow. Thomson…

Astrophysics · Physics 2009-11-10 Lev Titarchuk , Demos Kazanas , Peter A. Becker

Comparison is made between a number of independent computer programs for radiative transfer in molecular rotational lines. The test models are spherically symmetric circumstellar envelopes with a given density and temperature profile. The…

In a medium where the dielectric permittivity is perturbed in the presence of an acoustic wave, optical scattering generates frequency-shifted light. In this paper we consider the inverse problem of recovering the optical properties of this…

Analysis of PDEs · Mathematics 2019-10-14 Francis J. Chung , Jeremy G. Hoskins , John C. Schotland