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Related papers: On the Use of Vector Spherical Harmonics

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The mathematical representations of data in the Spherical Harmonic (SH) domain has recently regained increasing interest in the machine learning community. This technical report gives an in-depth introduction to the theoretical foundation…

Machine Learning · Computer Science 2023-07-10 Janis Keuper

Comparison of stellar catalogues with position and proper motion components using a decomposition on a set of orthogonal vector spherical harmonics. We show the theoretical and practical advantages of this technique as a result of…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Francois Mignard , Sergei Klioner

In the rest of this volume Lahav and Fisher have presented the method of Spherical Harmonic Analysis (SHA) and its use in estimating cosmologically interesting parameters. Here I demonstrate the use of SHA in cross-correlating galazy…

Astrophysics · Physics 2007-05-23 Caleb. A. Scharf

Scalar, vector and tensor harmonics on the three-sphere were introduced originally to facilitate the study of various problems in gravitational physics. These harmonics are defined as eigenfunctions of the covariant Laplace operator which…

General Relativity and Quantum Cosmology · Physics 2017-11-01 Lee Lindblom , Nicholas W. Taylor , Fan Zhang

The wave equation for vectors and symmetric tensors in spherical coordinates is studied under the divergence-free constraint. We describe a numerical method, based on the spectral decomposition of vector/tensor components onto spherical…

General Relativity and Quantum Cosmology · Physics 2009-11-23 Jerome Novak , Jean-Louis Cornou , Nicolas Vasset

Vectorial forms of structured light that are non-separable in their spatial and polarisation degrees of freedom have become topical of late, with an extensive toolkit for their creation and control. In contrast, the toolkit for quantifying…

Hierarchical clustering is a common algorithm in data analysis. It is unique among many clustering algorithms in that it draws dendrograms based on the distance of data under a certain metric, and group them. It is widely used in all areas…

Instrumentation and Methods for Astrophysics · Physics 2022-11-14 Heng Yu , Xiaolan Hou

The orthonormal set of Spherical Harmonics provides a natural way of expanding whole sky redshift and peculiar velocity surveys.

Astrophysics · Physics 2009-09-25 Ofer Lahav

Vector spherical harmonics on the unit sphere of $\mathbb{R}^3$ have broad applications in geophysics, quantum mechanics and astrophysics. In the representation of a tangent vector field, one needs to evaluate the expansion and the Fourier…

Numerical Analysis · Mathematics 2021-03-25 Quoc T. Le Gia , Ming Li , Yu Guang Wang

Spherical harmonics (SH) have been extensively used as a basis for analyzing the morphology of particles in granular mechanics. The use of SH is facilitated by mapping the particle coordinates onto a unit sphere, in practice often a…

Soft Condensed Matter · Physics 2024-11-14 Mahmoud Shaqfa , Wim M. van Rees

This survey is devoted to recent developments in the statistical analysis of spherical data, with a view to applications in Cosmology. We will start from a brief discussion of Cosmological questions and motivations, arguing that most…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-28 Javier Carrón Duque , Domenico Marinucci

We apply the mathematical formalism of vector spherical harmonics decomposition to convective stellar velocity fields from multi-dimensional hydrodynamics simulations, and show that the resulting power spectra furnish a robust and stable…

Solar and Stellar Astrophysics · Physics 2015-06-19 Emmanouil Chatzopoulos , Carlo Graziani , Sean M. Couch

Orbital solutions for binary or multiple stellar systems that combine astrometry (e.g., position angles and angular separations) with spectroscopy (radial velocities) have important advantages over astrometric-only or spectroscopic-only…

Astrophysics · Physics 2007-05-23 Guillermo Torres

We present in this paper a spectrally accurate numerical method for computing the spherical/vector spherical harmonic expansion of a function/vector field with given (elemental) nodal values on a spherical surface. Built upon suitable…

Numerical Analysis · Mathematics 2017-09-18 Bo Wang , Li-Lian Wang , Ziqing Xie

Clustering is an effective tool for astronomical spectral analysis, to mine clustering patterns among data. With the implementation of large sky surveys, many clustering methods have been applied to tackle spectroscopic and photometric data…

Instrumentation and Methods for Astrophysics · Physics 2022-12-19 Haifeng Yang , Chenhui Shi , Jianghui Cai , Lichan Zhou , Yuqing Yang , Xujun Zhao , Yanting He , Jing Hao

We present a comprehensive construction of scalar, vector and tensor harmonics on maximally symmetric three-dimensional spaces. Our formalism relies on the introduction of spin-weighted spherical harmonics and a generalized helicity basis…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Cyril Pitrou , Thiago S. Pereira

Recent microscopy imaging techniques allow to precisely analyze cell morphology in 3D image data. To process the vast amount of image data generated by current digitized imaging techniques, automated approaches are demanded more than ever.…

Computer Vision and Pattern Recognition · Computer Science 2020-10-26 Dennis Eschweiler , Malte Rethwisch , Simon Koppers , Johannes Stegmaier

The proper scientific analysis of a large amount of stellar spectra requires certain capabilities of the analysing tool (e.g. precise semi-automatic fitting for normalisation of the continuum or line-list assisted measurement of spectral…

Instrumentation and Methods for Astrophysics · Physics 2011-12-14 Petr Škoda

A vector field s on a Riemannian manifold M is said to be harmonic if there exists a member of a 2-parameter family of generalised Cheeger-Gromoll metrics on TM with respect to which s is a harmonic section. If M is a simply-connected…

Differential Geometry · Mathematics 2013-01-28 M. Benyounes , E. Loubeau , C. M. Wood

Photometric and astrometric monitoring of directly imaged exoplanets will deliver unique insights into their rotational periods, the distribution of cloud structures, weather, and orbital parameters. As the host star is occulted by the…

Instrumentation and Methods for Astrophysics · Physics 2020-07-01 Steven P. Bos
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