English
Related papers

Related papers: Validity of NLFFF Optimization Reconstruction

200 papers

We present a new improved version of our force-free electrodynamics (FFE) numerical code in spherical coordinates that extrapolates the magnetic field in the inner solar corona from a photospheric vector magnetogram. The code satisfies the…

Solar and Stellar Astrophysics · Physics 2015-06-11 Ioannis Contopoulos

We report the evolution of magnetic field and its energy in NOAA active region 11158 over 5 days based on a vector magnetogram series from the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamic Observatory (SDO). Fast flux…

Solar and Stellar Astrophysics · Physics 2016-06-30 Xudong Sun , J. Todd Hoeksema , Yang Liu , Thomas Wiegelmann , Keiji Hayashi , Qingrong Chen , Julia Thalmann

The Potential Field Source Surface (PFSS) model is the most used approach for extrapolating the global coronal magnetic field, offering efficiency and strong performance at large scales. However, PFSS assumes a potential coronal field, so…

Solar and Stellar Astrophysics · Physics 2026-03-23 C. Antonio , I. Chifu , R. Gafeira , J. J. G. Lima

The phase diagram and thermodynamic properties of the (2+1)-dimensional Gross-Neveu model are studied in the presence of a constant magnetic field. The optimized perturbation theory (OPT) is used to obtain results going beyond the large-N…

High Energy Physics - Phenomenology · Physics 2013-08-07 Jean-Loic Kneur , Marcus Benghi Pinto , Rudnei O. Ramos

We performed two data-based magnetohydrodynamic (MHD) simulations for solar active region 12371 which produced an M6.5 flare. The first simulation is a full data-driven simulation where the initial condition is given by a nonlinear…

Solar and Stellar Astrophysics · Physics 2023-03-01 Satoshi Inoue , Keiji Hayashi , Takahiro Miyoshi , Ju Jing , Haimin Wang

We present a careful assess of the forced field extrapolation using Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI) magnetogram. The convergence property is checked by several metrics. The extrapolated field lines…

Solar and Stellar Astrophysics · Physics 2017-03-22 Xiaoshuai Zhu , Huaning Wang , Zhanle Du , Han He

Techniques to improve the data quality of interferometric radio observations are considered. Fundaments of fringe frequencies in the uv-plane are discussed and filters are used to attenuate radio-frequency interference (RFI) and off-axis…

Instrumentation and Methods for Astrophysics · Physics 2012-04-02 A. R. Offringa , A. G. de Bruyn , S. Zaroubi

The availability of vector magnetogram sequences with sufficient accuracy and cadence to estimate the time derivative of the magnetic field allows us to use Faraday's law to find an approximate solution for the electric field in the…

Solar and Stellar Astrophysics · Physics 2015-05-27 George H. Fisher , Brian T. Welsch , William P. Abbett

We address issues with extant formulations of dissipative effects in the effective field theory (EFT) which describes the post-Newtonian (PN) inspiral of two gravitating bodies by (re)formulating several parts of the theory. Novel…

High Energy Physics - Theory · Physics 2015-09-28 Ofek Birnholtz , Shahar Hadar , Barak Kol

Solar flares show remarkable variety of the energy partitioning between thermal and nonthermal components. Those with a prominent nonthermal component but only a modest thermal one are particularly well suited to study the direct effect of…

Solar and Stellar Astrophysics · Physics 2020-02-26 Galina G. Motorina , Gregory D. Fleishman , Eduard P. Kontar

The ever-increasing demand for processing data with larger machine learning models requires more efficient hardware solutions due to limitations such as power dissipation and scalability. Optics is a promising contender for providing lower…

Emerging Technologies · Computer Science 2022-08-11 Ilker Oguz , Jih-Liang Hsieh , Niyazi Ulas Dinc , Uğur Teğin , Mustafa Yildirim , Carlo Gigli , Christophe Moser , Demetri Psaltis

We use the Effective Field Theory (EFT) framework to compute the mass quadrupole moment, the equation of motion, and the power loss of inspiralling compact binaries at the second order in the Post-Newtonian (PN) approximation. We present…

General Relativity and Quantum Cosmology · Physics 2020-05-06 Adam K. Leibovich , Natália T. Maia , Ira Z. Rothstein , Zixin Yang

With increasing share of renewables in power generation mix, system operators would need to run Optimal Power Flow (OPF) problems closer to real-time to better manage uncertainty. Given that OPF is an expensive optimization problem to…

Signal Processing · Electrical Eng. & Systems 2020-12-22 Alex Robson , Mahdi Jamei , Cozmin Ududec , Letif Mones

Extrapolation codes in Cartesian geometry for modelling the magnetic field in the corona do not take the curvature of the Sun's surface into account and can only be applied to relatively small areas, e.g., a single active region. We compare…

Solar and Stellar Astrophysics · Physics 2015-06-11 Tilaye Tadesse , T. Wiegelmann , B. Inhester , P. MacNeice , A. Pevtsov , X. Sun

Recently we succeeded to make a reliable EFT prediction in a totally parameter-free manner for the $S$ factors for the solar $pp$ and $hep$ processes, $p+p\to d + e^+ +\nu_e$ and $\He3+p \to \He4 + e^+ + \nu_e$. The strategy used in there…

Nuclear Theory · Physics 2015-06-26 Tae-Sun Park

The observed solar photospheric magnetic fields and Doppler velocities are frequently used to quantify the Poynting flux and helicity flux. Multiple methods have been developed for this purpose, but their estimates of the Poynting flux and…

Solar and Stellar Astrophysics · Physics 2026-04-20 Jiayi Liu , Xudong Sun , Peter W. Schuck , Lars K. S. Daldorff

This paper proposes a component-based dual decomposition of the nonconvex AC optimal power flow (OPF) problem, where the modified dual function is solved in a distributed fashion. The main contribution of this work is that is demonstrates…

Distributed, Parallel, and Cluster Computing · Computer Science 2017-08-23 Sleiman Mhanna , Gregor Verbic , Archie Chapman

We study the relative helicity of active region (AR) NOAA~12673 during a ten-hour time interval centered around a preceding X2.2 flare (SOL2017-09-06T08:57) and also including an eruptive X9.3 flare that occurred three hours later…

Solar and Stellar Astrophysics · Physics 2020-11-25 Julia K. Thalmann , X. Sun , K. Moraitis , M. Gupta

We report an improved low-energy extrapolation of the cross section for the process Beryllium-7+proton -> Boron-8+photon, which determines the Boron-8 neutrino flux from the Sun. Our extrapolant is derived from Halo Effective Field Theory…

Nuclear Theory · Physics 2015-11-11 Xilin Zhang , Kenneth M. Nollett , D. R. Phillips

The optimal power flow (OPF) problem minimizes power system operating cost subject to both engineering and network constraints. With the potential to find global solutions, significant research interest has focused on convex relaxations of…

Optimization and Control · Mathematics 2014-02-03 Daniel K. Molzahn , Ian A. Hiskens