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In meteorology the analysis of motions of the atmosphere on the Earth has been done using various mathematical models and using various approximations. In this article as the simplest model the compressible Euler equations with barotropic…

Analysis of PDEs · Mathematics 2023-02-21 Tetu Makino

We examine the constraints of spherically symmetric general relativity with one asymptotically flat region, exploiting both the traditional metric variables and variables constructed from the optical scalars. With respect to the latter…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Jemal Guven , Niall Ó Murchadha

The problem of the long-period gravity modes of the Earth outer fluid core is investigated using either the subseismic or the anelastic approximation These two approximations aim at filtering out the uninteresting short-period seismic or…

Astrophysics · Physics 2007-05-23 Boris Dintrans

It is shown that the generalized geometries may be obtained as a deformation of the proper Euclidean geometry. Algorithm of construction of any proposition S of the proper Euclidean geometry E may be described in terms of the Euclidean…

General Mathematics · Mathematics 2007-05-23 Yuri A. Rylov

Historically, there have been many attempts to produce an appropriate mathematical formalism for modeling the nature of physical space, such as Euclid's geometry, Descartes' system of Cartesian coordinates, the Argand plane, Hamilton's…

History and Philosophy of Physics · Physics 2016-02-23 James M. Chappell , Azhar Iqbal , Derek Abbott

Numerical simulations of turbulent Rayleigh-B\'enard convection in an ideal gas, using either the anelastic approximation or the fully compressible equations, are compared. Theoretically, the anelastic approximation is expected to hold in…

Solar and Stellar Astrophysics · Physics 2015-05-27 Jan Verhoeven , Thomas Wiesehöfer , Stephan Stellmach

Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations, and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive…

Solar and Stellar Astrophysics · Physics 2015-06-15 Regner Trampedach , Martin Asplund , Remo Collet , Åke Nordlund , Robert F. Stein

In this paper, we deal with a generalization of the geometry of parallelizable manifolds, or the absolute parallelism (AP-) geometry, in the context of generalized Lagrange spaces. All geometric objects defined in this geometry are not only…

General Relativity and Quantum Cosmology · Physics 2008-05-02 M. I. Wanas , N. L. Youssef , A. M. Sid-Ahmed

The present work represents a step to deal with stellar structure using a pure geometric approach. A geometric field theory is used to construct a model for a spherically symmetric configuration. The model obtained can be considered as a…

General Relativity and Quantum Cosmology · Physics 2011-09-27 M. I. Wanas , Samah A. Ammar

We report a search for new gravitational physics phenomena based on Einstein-Cartan theory of General Relativity including spacetime torsion. Starting from the parametrized torsion framework of Mao, Tegmark, Guth and Cabi, we analyze the…

General Relativity and Quantum Cosmology · Physics 2011-05-13 Riccardo March , Giovanni Bellettini , Roberto Tauraso , Simone Dell'Agnello

While geostrophy remains the simplest and most practical balance to extract velocity information from sea-surface height anomaly (SSHa), confusions remain within the oceanographic community to what extent this balance can be applied to…

Atmospheric and Oceanic Physics · Physics 2026-01-27 Takaya Uchida , Badarvada Yadidya , Vadim Bertrand , Jia-Xian Chang , Brian Arbic , Jay Shriver , Julien Le Sommer

We propose a class of spherical wavelet bases for the analysis of geophysical models and forthe tomographic inversion of global seismic data. Its multiresolution character allows for modeling with an effective spatial resolution that varies…

In this work, we investigate the construction of spherically symmetric solutions within the framework of modified teleparallel gravity, focusing in particular on $f({\cal T})$ theory, where ${\cal T}$ represents the torsion scalar.…

General Relativity and Quantum Cosmology · Physics 2025-08-08 G. G. L. Nashed , A. Eid

Spatial approximations have been traditionally used in spatial databases to accelerate the processing of complex geometric operations. However, approximations are typically only used in a first filtering step to determine a set of candidate…

Classical field forecast evaluation relies mainly on local scores such as RMSE or MAE. These metrics severely over-penalize small spatial or temporal displacements of coherent structures, a limitation known as the double-penalty issue and…

Atmospheric and Oceanic Physics · Physics 2026-04-20 Cyril Voyant

The adhesion approximation is a simple analytical model suggested for explanation of the major geometrical features of the observed structure in the galaxy distribution on scales from 1 to (a few)x100/h Mpc. It is based on Burgers' equation…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-24 Sergei F. Shandarin

The dynamics of any spherical cosmology with a scalar field (`scalaron') coupling to gravity is described by the nonlinear second-order differential equations for two metric functions and the scalaron depending on the `time' parameter. The…

High Energy Physics - Theory · Physics 2017-04-05 A. T. Filippov

Starting from a general transformation for spherically symmetric metrics where g\_11=-1/g\_00, we analyze coordinates with the common property of conformal flatness at constant solid angle element. Three general possibilities arise: one…

General Relativity and Quantum Cosmology · Physics 2024-05-29 E. A. León , J. A. Nieto , A. Sandoval-Rodríguez , B. Martínez-Olivas

We present the Bayesian Global Sky Model (B-GSM), a new absolutely calibrated model of the diffuse Galactic foreground at frequencies below 408 MHz. We assemble a dataset of publicly available diffuse emission maps at frequencies between 45…

Instrumentation and Methods for Astrophysics · Physics 2025-04-08 George Carter , Will Handley , Mark Ashdown , Nima Razavi-Ghods

The gravitational field exterior respectively interior to an axially symmetric, metrically stationary, isolated spinning source made of perfect fluid is examined within the quasi-metric framework. (A metrically stationary system is defined…

General Relativity and Quantum Cosmology · Physics 2024-03-25 Dag Østvang