Secular variations of the geomagnetic field have been measured with a continuously improving accuracy during the last few hundred years, culminating nowadays with satellite data. It is however well known that the dynamics of the magnetic field is linked to that of the velocity field in the core and any attempt to model secular variations will involve a coupled dynamical system for magnetic fiel...

Abstract In December 2019, the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group (V-MOD) adopted thirteenth generation Geomagnetic Reference Field (IGRF). This IGRF updates previous with a definitive main field model for epoch 2015.0, 2020.0, predictive linear secular variation 2020.0 to 2025.0. letter provides equations defining IGRF, spherical harmonic coe...

Random Phase Approximation (RPA) is the theory most commonly used to describe excitations of many-body systems. In this article, secular equations are obtained by using three different approaches: equation motion method, Green function perturbation and time-dependent Hartree–Fock theory. Each approach emphasizes specific aspects overlooked other methods. Extensions RPA treat continuum part exci...

We calculate the classical and general relativistic effects induced by an isotropic mass loss Ṁ/M of a body on the orbital motion of a test particle around it; the present analysis is valid also for a variation Ġ/G of the Newtonian constant of gravitation. Concerning the Newtonian case, we perturbatively obtain negative secular rates for the osculating semimajor axis a, the eccentricity e and t...

though muslims have been living in nepal from the 15th century, they have started practicingtheir religious activities freely only after enactment of new civil code in 1963. this paper aims to explore the potentials and problems on the existing mosques, perception of the religious structures by muslim community and analysing of existing legal and institutional framework before drawing a conclus...

Research by economists suggests that recent Mexican migrants are better educated and have higher socioeconomic status (SES) than previous migrants. Because factors associated with higher SES and improved education can lead to positive secular changes in overall body form, secular changes in the craniofacial complex were analyzed within a recent migrant group from Mexico. The Mexican group repre...

The eccentricity evolution of multiple planet systems can provide valuable constraints on planet formation models. Unfortunately, the inevitable uncertainties in the current orbital elements can lead to significant ambiguities in the nature of the secular evolution. Integrating any single set of orbital elements inadequately describes the full range of secular evolutions consistent with current...