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Conversion of gravitational energy into radiation in accretion discs and the origin of large scale magnetic fields in astrophysical rotators have often been distinct topics of research. In semi-analytic work on both problems it has been…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Eric G. Blackman

It is well known that magnetic fields dominate the dynamics in the solar corona, and new generation of numerical modelling of the evolution of coronal magnetic fields, as featured with boundary conditions driven directly by observation…

Solar and Stellar Astrophysics · Physics 2021-04-16 Chaowei Jiang , Xinkai Bian , Tingting Sun , Xueshang Feng

Data assimilation addresses the problem of identifying plausible state trajectories of dynamical systems given noisy or incomplete observations. In geosciences, it presents challenges due to the high-dimensionality of geophysical dynamical…

Machine Learning · Statistics 2023-11-03 François Rozet , Gilles Louppe

The field equations of modified gravity theories, when considering a homogeneous and isotropic cosmological model, always become autonomous differential equations. This relies on the fact that in such models all variables only depend on…

General Relativity and Quantum Cosmology · Physics 2023-02-03 Christian G. Boehmer , Erik Jensko , Ruth Lazkoz

A complex system comprises multiple interacting entities whose interdependencies form a unified whole, exhibiting emergent behaviours not present in individual components. Examples include the human brain, living cells, soft matter, Earth's…

Data assimilation plays a crucial role in modern weather prediction, providing a systematic way to incorporate observational data into complex dynamical models. The paper addresses continuous data assimilation for a model arising as a…

Analysis of PDEs · Mathematics 2026-02-03 Eduard Feireisl , Piotr Gwiazda , Agnieszka Świerczewska-Gwiazda

Estimating motion from spatiotemporal geoscientific data is a fundamental component of many environmental modeling and forecasting tasks. In this work, we propose a physics-informed deep learning framework for estimating altitude-wise…

Machine Learning · Computer Science 2026-04-30 Peter Pavlík , Anna Bou Ezzeddine , Viera Rozinajová

This note is concerned with potentially misleading concepts in the treatment of cosmological magnetic fields by magnetohydrodynamical (MHD) modelling. It is not a criticism of MHD itself but rather a cautionary comment on the validity of…

Astrophysics · Physics 2009-11-13 Luis F. A. Teodoro , Declan A. Diver , Martin A. Hendry

A spacetime interval connecting two neighbouring points can be measured in different unit systems. For instance, it can be measured in atomic unit defined in terms of fundamental constants existing in quantum theories. It is also possible…

General Relativity and Quantum Cosmology · Physics 2020-03-25 Yousef Bisabr

There is increasingly strong observational evidence that slow magnetoacoustic modes arise in the solar atmosphere. Solar magneto-seismology is a novel tool to derive otherwise directly un-measurable properties of the solar atmosphere when…

Solar and Stellar Astrophysics · Physics 2015-06-04 M. Luna-Cardozo , G. Verth , R. Erdélyi

SUMMARY We report a new method to infer continuous time series of the declination, inclination and intensity of the magnetic field from archeomagnetic data. Adopting a Bayesian perspective, we need to specify a priori knowledge about the…

Geophysics · Physics 2015-06-22 G. Hellio , N. Gillet , C. Bouligand , D. Jault

Optical sensors can capture dynamic environments and derive depth information in near real-time. The quality of these digital reconstructions is determined by factors like illumination, surface and texture conditions, sensing speed and…

Robotics · Computer Science 2024-01-31 Simone Müller , Dieter Kranzlmüller

(Abridged) Based on the rapidly increasing all-sky data of Faraday rotation measures and polarised synchrotron radiation, the Milky Way's magnetic field is now modelled with an unprecedented level of detail and complexity. We aim to…

Astrophysics of Galaxies · Physics 2015-06-17 Oliver Gressel , Detlef Elstner , Udo Ziegler

When modeling global satellite data to recover a planetary magnetic or gravitational potential field and evaluate it elsewhere, the method of choice remains their analysis in terms of spherical harmonics. When only regional data are…

Geophysics · Physics 2017-10-11 Alain Plattner , Frederik J. Simons

There exists a correlation between geospatial activity temporal patterns and type of land use. A novel self-supervised approach is proposed to stratify landscape based on mobility activity time series. First, the time series signal is…

Computer Vision and Pattern Recognition · Computer Science 2024-01-18 Yi Cao , Swetava Ganguli , Vipul Pandey

The idea that the seed primordial magnetic fields can be explained by the nonminimal coupling between gravitational and electromagnetic fields is discussed. The predicted values of the magnetic field of the spiral galaxies are in agreement…

General Relativity and Quantum Cosmology · Physics 2007-05-23 R. Opher , U. F. Wichoski

Hamiltonian systems are differential equations which describe systems in classical mechanics, plasma physics, and sampling problems. They exhibit many structural properties, such as a lack of attractors and the presence of conservation…

Numerical Analysis · Mathematics 2022-01-14 Christian Offen , Sina Ober-Blöbaum

Kinetic plasma theory is used to generate synthetic spacecraft data to analyze and interpret the compressible fluctuations in the inertial range of solar wind turbulence. The kinetic counterparts of the three familiar linear MHD wave…

Space Physics · Physics 2015-06-05 K. G. Klein , G. G. Howes , J. M. TenBarge , S. D. Bale , C. H. K. Chen , C. S. Salem

One of the best tools we have in geophysical modelling is the ability to interpolate the horizontal geomagnetic field at the surface of the Earth. This is especially useful in regions, such as southern Africa, where there is a sparse array…

Space Physics · Physics 2019-12-11 M. J. Heyns , S. I. Lotz , C. T. Gaunt

Magnetic reconnection occurring in collisionless environments is a multi-scale process involving both ion and electron kinetic processes. Because of their small mass, the electron scales are difficult to resolve in numerical and satellite…