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We present new results on the structure of the solar core, obtained with new sets of frequencies of solar low-degree p modes obtained from the BiSON network. We find that different methods used in extracting the different sets of…

Solar and Stellar Astrophysics · Physics 2009-07-22 Sarbani Basu , William J. Chaplin , Yvonne Elsworth , Roger New , Aldo M. Serenelli

We propose an algorithm to select parameter subset combinations that can be estimated using an ordinary least-squares (OLS) inverse problem formulation with a given data set. First, the algorithm selects the parameter combinations that…

Methodology · Statistics 2020-04-16 Ariel Cintrón-Arias , H. T. Banks , Alex Capaldi , Alun L. Lloyd

The region of the second ionization of helium in the Sun is a narrow layer near the surface. Ionization induces a local change of the adiabatic exponent $\Gamma_1$, which produces a characteristic signature in the frequencies of p-modes. By…

Astrophysics · Physics 2007-05-23 M. J. P. F. G. Monteiro , M. J. Thompson

Gravity modes are the best probes to infer the properties of the solar radiative zone that represents 98% of the Sun's total mass. It is usually assumed that high-frequency g modes give information about the structure of the solar interior…

Astrophysics · Physics 2008-04-01 R. A. Garcia , S. Mathur , J. Ballot

Machine learning has emerged as a promising approach for estimating material parameters in solar cells. Traditional methods for parameter extraction often rely on time-consuming numerical simulations that fail to capture the full complexity…

Materials Science · Physics 2025-06-17 Eunchi Kim , Paula Hartnagel , Barbara Urbano , Leonard Christen , Thomas Kirchartz

Asteroseismic inferences of main-sequence solar-like oscillators often rely on best-fit models. However, these models cannot fully reproduce the observed mode frequencies, suggesting that the internal structure of the model does not fully…

Solar and Stellar Astrophysics · Physics 2025-07-08 Lynn Buchele , Earl P. Bellinger , Saskia Hekker , Sarbani Basu

The data acquisition of solar radiation in a locality is essential for the development of efficient designs of systems, whose operation is based on solar energy. This paper presents a methodology to estimate solar irradiance using an…

Asteroseismic forward modelling techniques are being used to determine fundamental properties (e.g. mass, radius, and age) of solar-type stars. The need to take into account all possible sources of error is of paramount importance towards a…

Solar and Stellar Astrophysics · Physics 2018-05-02 B. Nsamba , T. L. Campante , M. J. P. F. G. Monteiro , M. S. Cunha , B. M. Rendle , D. R. Reese , K. Verma

The choice of the parameter value for regularized inverse problems is critical to the results and remains a topic of interest. This article explores a criterion for selecting a good parameter value by maximizing the probability of the data,…

Numerical Analysis · Mathematics 2020-02-11 Toby Sanders , Rodrigo B. Platte , Robert D. Skeel

The overall framework for the study of solar convection and oscillations is the spherically symmetric component of solar structure. I discuss those properties of the solar interior which depend on convection and other possible…

Astrophysics · Physics 2016-01-27 J. Christensen-Dalsgaard

The interior structure of the Sun can be studied with great accuracy using observations of its oscillations, similar to seismology of the Earth. Precise agreement between helioseismological measurements and predictions of theoretical solar…

Astrophysics · Physics 2009-11-11 Jeremy J. Drake Paola Testa

Rotation is an important, yet poorly-modelled phenomenon of stellar structure and evolution. Accurate estimates of internal rotation rates are therefore valuable for constraining stellar evolution models. We aim to assess the accuracy of…

Solar and Stellar Astrophysics · Physics 2025-01-29 F. Ahlborn , E. P. Bellinger , S. Hekker , S. Basu , D. Mokrytska

Context. Recently our ability to study stars using asteroseismic techniques has increased dramatically, largely through the use of space based photometric observations. Work has also been done using ground based spectroscopic observations…

Solar and Stellar Astrophysics · Physics 2018-10-03 Jesper Schou

We report our first results on comparing the variations of the solar internal rotation with solar activity, as predicted by non-linear solar dynamo modelling, with helioseismic measurements using the SOHO MDI data.

Astrophysics · Physics 2007-05-23 S. Vorontsov , R. Tavakol , E. Covas , D. Moss

Spectra of late-type stars are usually analyzed with static model atmospheres in local thermodynamic equilibrium (LTE) and a homogeneous plane-parallel or spherically symmetric geometry. The energy balance requires particular attention, as…

Astrophysics · Physics 2009-11-06 Carlos Allende Prieto , Paul S. Barklem , Martin Asplund , Basilio Ruiz Cobo

In this paper we focus on the empirical variable-selection peformance of subsample-ordered least angle regression (Solar) -- a novel ultrahigh dimensional redesign of lasso -- on the empirical data with complicated dependence structures…

Machine Learning · Statistics 2020-12-17 Ning Xu , Timothy C. G. Fisher , Jian Hong

We consider the inverse problem of recovering the spherically symmetric sound speed, density and attenuation in the Sun from the observations of the acoustic field randomly excited by turbulent convection. We show that observations at two…

Analysis of PDEs · Mathematics 2020-06-24 A. D. Agaltsov , T. Hohage , R. G. Novikov

Observations of the Sun with the LOWL instrument provide a homogeneous set of solar p-mode frequencies from low to intermediate degree which allows one to determine the structure of much of the solar interior avoiding systematic errors that…

Variational regularization of ill-posed inverse problems is based on minimizing the sum of a data fidelity term and a regularization term. The balance between them is tuned using a positive regularization parameter, whose automatic choice…

Numerical Analysis · Mathematics 2025-11-12 Markus Juvonen , Bjørn Jensen , Ilmari Pohjola , Yiqiu Dong , Samuli Siltanen

Solar seismology has allowed precision measurements of both the static and dynamic structure of our local star, the Sun. In the near future, seismology of solar-like stars of different ages and masses, necessarily restricted by angular…

Astrophysics · Physics 2007-05-23 George R. Isaak , Kate G. Isaak
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