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Related papers: Modelling CH$_3$OH masers: Sobolev approximation a…

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A method combining the Lagrange-mesh and the complex Kohn variational methods is developed for computing the $\mathcal{S}$ matrix of a 2$+$1 elastic scattering in the frame of three-body Coulomb systems. Resonance parameters can be obtained…

Quantum Physics · Physics 2024-05-28 Jean Servais , Jérémy Dohet-Eraly

We demonstrate a hard x-ray probe of laser-aligned small molecules. To align small molecules with optical lasers, high intensities at nonresonant wavelengths are necessary. We use 95 ps pulses focused to 40 mum from an 800 nm Ti:sapphire…

This work is concerned with the formulation of a general framework for the analysis of meshfree approximation schemes and with the convergence analysis of the Local Maximum-Entropy (LME) scheme as a particular example. We provide conditions…

Numerical Analysis · Mathematics 2011-08-01 Agustin Bompadre , Bernd Schmidt , Michael Ortiz

A novel finite element framework is proposed for the numerical simulation of two phase flows with surface tension. The Level-Set (LS) method with piece-wise quadratic (P2) interpolation for the liquid-gas interface is used in order to reach…

Computational Engineering, Finance, and Science · Computer Science 2020-10-27 Modesar Shakoor , Chung Hae Park

The Lagrange-mesh method is an approximate variational approach having the form of a mesh calculation because of the use of a Gauss quadrature. Although this method provides accurate results in many problems with small number of mesh…

Quantum Physics · Physics 2016-10-05 Jérémy Dohet-Eraly

Methyl acetate (CH_3COOCH_3) has been recently observed by IRAM 30 m radio telescope in Orion though the presence of its deuterated isotopomers is yet to be confirmed. We therefore study the properties of various forms of methyl acetate,…

Astrophysics of Galaxies · Physics 2015-08-06 Ankan Das , Liton Majumdar , Dipen Sahu , Prasanta Gorai , B Sivaraman , Sandip K. Chakrabarti

Over the past decade the in-medium similarity renormalization group (IMSRG) approach has proven to be a powerful and versatile ab initio many-body method for studying medium-mass nuclei. So far, the IMSRG was limited to the approximation in…

Nuclear Theory · Physics 2021-04-27 M. Heinz , A. Tichai , J. Hoppe , K. Hebeler , A. Schwenk

The class II masers of methanol are associated with the early stages of formation of high-mass stars. Modelling of these dense, dusty environments has demonstrated that pumping by infrared radiation can account for the observed masers.…

Astrophysics · Physics 2009-11-11 D. M. Cragg , A. M. Sobolev , P. D. Godfrey

Machine learning (ML) has become a standard tool for the exploration of chemical space. Much of the performance of such models depends on the chosen database for a given task. Here, this aspect is investigated for "chemical tasks" including…

Chemical Physics · Physics 2025-04-03 Luis Itza Vazquez-Salazar , Markus Meuwly

Aims. We aimed at investigating the structure and kinematics of the gaseous disk and outflows around the massive YSO S255 NIRS3 in the S255IR-SMA1 dense clump. Methods. Observations of the S255IR region were carried out with ALMA at two…

Astrophysics of Galaxies · Physics 2017-10-11 I. Zinchenko , S. -Y. Liu , Y. -N. Su , A. M. Sobolev

The Lambda-doublet transitions in CH at 3.3 and 0.7 GHz are unusually sensitive to variations in the fine-structure constant and the electron-to-proton mass ratio. We describe methods used to measure the frequencies of these transitions…

Atomic Physics · Physics 2015-06-18 S. Truppe , R. J. Hendricks , S. K. Tokunaga , E. A. Hinds , M. R. Tarbutt

The use of realistic input models has gained popularity in the theory community. Assuming a realistic input model often precludes complicated hypothetical inputs, and the analysis yields bounds that better reflect the behaviour of…

Computational Geometry · Computer Science 2022-11-15 Joachim Gudmundsson , Zijin Huang , Sampson Wong

Methanol masers at 6.7 GHz are well known tracers of high-mass star-forming regions. However, their origin is still not clearly understood. We aimed to determine the morphology and velocity structure for a large sample of the maser emission…

Astrophysics of Galaxies · Physics 2016-03-02 Anna Bartkiewicz , Marian Szymczak , Huib J. van Langevelde

The Vlasov-Poisson system, modeling the evolution of non-collisional plasmas in the electrostatic limit, is approx- imated by a Semi-Lagrangian technique. Spectral methods of periodic type are implemented through a collocation approach.…

Numerical Analysis · Mathematics 2019-03-27 Lorella Fatone , Daniele Funaro , Gianmarco Manzini

At centimeter wavelengths, single-dish observations have suggested that the Sagittarius (Sgr) B2 molecular cloud at the Galactic Center hosts weak maser emission from several organic molecules, including CH$_2$NH, HNCNH, and HCOOCH$_3$.…

Astrophysics of Galaxies · Physics 2024-04-22 Ci Xue , Anthony Remijan , Alexandre Faure , Emmanuel Momjian , Todd R. Hunter , Ryan A. Loomis , Eric Herbst , Brett McGuire

We present the first EVN maps of 6.7 GHz methanol masers of three high-mass protostar candidates selected from the Torun unbiased survey of the Galactic plane. A variety of linear and arc like structures was detected. A number of maser…

Astrophysics · Physics 2007-05-23 A. Bartkiewicz , M. Szymczak , H. J. van Langevelde

We present the results of an interferometric study of 38 millimeter-wave lines of CH3OH in the region around the water maser source W3(H2O) and a region extending about 30" to the south and west of the hydroxyl maser source W3(OH). The…

We develop a framework that allows the use of the multi-level Monte Carlo (MLMC) methodology (Giles2015) to calculate expectations with respect to the invariant measure of an ergodic SDE. In that context, we study the (over-damped) Langevin…

Numerical Analysis · Mathematics 2019-08-13 Michael B. Giles , Mateusz B. Majka , Lukasz Szpruch , Sebastian Vollmer , Konstantinos Zygalakis

For explicit interface tracking in three dimensions, we propose a linear MARS method that (a) represents the interface by a partially ordered set of glued surfaces and approximates each glued surface with a triangular mesh, (b) maintains an…

Numerical Analysis · Mathematics 2025-12-12 Yunhao Qiu , Qinghai Zhang

Obtainable computational efficiency is evaluated when using an Adaptive Mesh Refinement (AMR) strategy in time accurate simulations governed by sets of conservation laws. For a variety of 1D, 2D, and 3D hydro- and magnetohydrodynamic…

Astrophysics · Physics 2009-11-10 R. Keppens , M. Nool , G. Toth , J. P. Goedbloed
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