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The electron density is a key parameter to characterize any plasma. Most of the plasma applications and research in the area of low-temperature plasmas (LTPs) are based on the accurate estimations of plasma density and plasma temperature.…

We investigate statistical equilibrium of Cr in the atmospheres of late-type stars. The main goal is to ascertain the reason for a systematic abundance discrepancy between Cr I and Cr II lines, which is often encountered in spectroscopic…

Solar and Stellar Astrophysics · Physics 2010-09-30 Maria Bergemann

The complex Langevin method (CLM) offers a potential solution to the sign problem in quantum field theories with complex actions, but can converge to incorrect results even when simulations appear stable. Existing diagnostics monitor drift…

High Energy Physics - Lattice · Physics 2025-10-30 Anosh Joseph , Arpith Kumar

In this article, we present a new approach to averaging in non-Hamiltonian systems with periodic forcing. The results here do not depend on the existence of a small parameter. In fact, we show that our averaging method fits into an…

Dynamical Systems · Mathematics 2010-06-15 Mickaël D. Chekroun , Michael Ghil , Jean Roux , Ferenc Varadi

We investigate the non-local thermodynamic equilibrium (NLTE) analysis for \ion{Cu}{1} lines with the updated model atom that includes quantum-mechanical rate coefficients of Cu\,$+$\,H and Cu$^+$\,$+$\,H$^-$ inelastic collisions from the…

Solar and Stellar Astrophysics · Physics 2022-08-31 Xiaodong Xu , Jianrong Shi , Xiaofeng Wang

This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE (ie when there is a departure from Local Thermodynamic…

Solar and Stellar Astrophysics · Physics 2011-05-10 N. Labrosse , P. Heinzel , J. -C. Vial , T. Kucera , S. Parenti , S. Gunar , B. Schmieder , G. Kilper

Aims: Aluminium is a key element to constrain the models of the chemical enrichment and the yields of the first supernovae. But obtaining precise Al abundances in extremely metal-poor (EMP) stars requires that the non-LTE effects be…

Astrophysics · Physics 2009-11-13 S. M. Andrievsky , M. Spite , S. A. Korotin , F. Spite , P. Bonifacio , R. Cayrel , V. Hill , P. François

Non-linear operations such as GELU, Layer normalization, and Softmax are essential yet costly building blocks of Transformer models. Several prior works simplified these operations with look-up tables or integer computations, but such…

Machine Learning · Computer Science 2021-12-07 Joonsang Yu , Junki Park , Seongmin Park , Minsoo Kim , Sihwa Lee , Dong Hyun Lee , Jungwook Choi

We perform the non-local thermodynamic equilibrium (NLTE) calculations for Ca I-II with the updated model atom that includes new quantum-mechanical rate coefficients for Ca I + H I collisions from two recent studies, that is, by Barklem and…

Solar and Stellar Astrophysics · Physics 2017-09-13 L. Mashonkina , T. Sitnova , A. K. Belyaev

We present new or improved methods for calculating NLTE, line-blanketed model atmospheres for hot stars with winds (spectral types A to O), with particular emphasis on a fast performance. These methods have been implemented into a previous,…

Astrophysics · Physics 2009-11-10 J. Puls , M. A. Urbaneja , R. Venero , T. Repolust , U. Springmann , A. Jokuthy , M. R. Mokiem

This paper presents two algorithms for calculating an ensemble of solutions to laminar natural convection problems. The ensemble average is the most likely temperature distribution and its variance gives an estimate of prediction…

Numerical Analysis · Mathematics 2017-08-03 Joseph A. Fiordilino , Sarah Khankan

With the goal of producing a reliable set of model atoms and singly-ionized ions for use in building NLTE model atmospheres, we have combined measured energy levels, critically-compiled line transition probabilities, and resonance-averaged…

Astrophysics · Physics 2009-11-07 C. Allende Prieto , D. L. Lambert , I. Hubeny , T. Lanz

Superlevel partitioning is combined with a simple relaxation procedure to construct an iterative technique for solving equations of statistical equilibrium. In treating an $N$-level model atom, the technique avoids the $N^{3}$ scaling in…

Astrophysics · Physics 2009-11-06 L. B. Lucy

While existing algorithms may be used to solve a linear system over a general field in matrix-multiplication time, the complexity of constructing a symmetric triangular factorization (LDL) has received relatively little formal study. The…

Numerical Analysis · Mathematics 2025-06-26 Edgar Solomonik

In the present paper we consider the full nonlocal thermodynamic equilibrium (non-LTE) radiation transfer problem. This formalism allows us to account for deviation from equilibrium distribution of both the radiation field and the massive…

Solar and Stellar Astrophysics · Physics 2024-10-09 M. Sampoorna , F. Paletou , V. Bommier , T. Lagache

We propose a computational framework named iterative local adaptive majorize-minimization (I-LAMM) to simultaneously control algorithmic complexity and statistical error when fitting high dimensional models. I-LAMM is a two-stage…

Statistics Theory · Mathematics 2017-04-06 Jianqing Fan , Han Liu , Qiang Sun , Tong Zhang

Quantum error correction allows inherently noisy quantum devices to emulate an ideal quantum computer with reasonable resource overhead. As a crucial component, decoding architectures have received significant attention recently. In this…

Quantum Physics · Physics 2025-09-05 Kai Zhang , Jubo Xu , Fang Zhang , Linghang Kong , Zhengfeng Ji , Jianxin Chen

A widely used strategy to reduce the computational cost in quantum-chemical calculations is to partition the system into an active subsystem, which is the focus of the computational efforts and an environment that is treated at a lower…

Chemical Physics · Physics 2023-06-19 Elena Kolodzeiski , Christopher J. Stein

Transformer-based large language models (LLMs) are comprised of billions of parameters arranged in deep and wide computational graphs. Several studies on LLM efficiency optimization argue that it is possible to prune a significant portion…

Computation and Language · Computer Science 2026-04-16 Corentin Kervadec , Iuliia Lysova , Marco Baroni , Gemma Boleda

This paper presents new low-complexity lattice-decoding algorithms for noncoherent block detection of QAM and PAM signals over complex-valued fading channels. The algorithms are optimal in terms of the generalized likelihood ratio test…

Information Theory · Computer Science 2009-11-13 Daniel J. Ryan , Iain B. Collings , I. Vaughan L. Clarkson