Search results for "CONSISTENCY"
showing 10 items of 316 documents
El yo ejecutivo o la afirmación de lo biográfico
2017
La idea de «naturaleza humana» que Ortega y Gasset defiende es tan novedosa como opuesta a lo que habitualmente se entiende. Estamos en un error si el punto de partida es concebir al hombre como un ser vivo entre otros. Ni la ciencia ni la filosofía, mientras se mantenga en la tradición eleática, pueden dar una explicación clara. La ciencia, porque si contemplamos al hombre, tal y como se nos presenta, es imposible distinguir en él lo material de lo espiritual, su cuerpo y su psique. La filosofía, porque el concepto de «naturaleza humana» es una invención de nuestra razón, una fantasía. No existe tal naturaleza porque el ser del hombre es de tal modo extraño y diferente al resto de seres qu…
Physics-Aware Machine Learning For Geosciences And Remote Sensing
2021
Machine learning models alone are excellent approximators, but very often do not respect the most elementary laws of physics, like mass or energy conservation, so consistency and confidence are compromised. In this paper we describe the main challenges ahead in the field, and introduce several ways to live in the Physics and machine learning interplay: encoding differential equations from data, constraining data-driven models with physics-priors and dependence constraints, improving parameterizations, emulating physical models, and blending data-driven and process-based models. This is a collective long-term AI agenda towards developing and applying algorithms capable of discovering knowled…
Classical form factor for nlm→n′l′m transitions in the hydrogen atom
2000
Abstract The form factor for nlm → n ′ l ′ m transitions in the hydrogen atom is deduced on the basis of kinematics of the classical mechanics. The consistency of this approach is verified by derivation of the known result for the transition probability averaged over m . The classical transition probability as a function of the final state energy and angular momentum is investigated comprehensively in the case of l = m =0.
Assessment of the accuracy of coupled cluster perturbation theory for open-shell systems. I. Triples expansions
2016
The accuracy at which total energies of open-shell atoms and organic radicals may be calculated is assessed for selected coupled cluster perturbative triples expansions, all of which augment the coupled cluster singles and doubles (CCSD) energy by a non-iterative correction for the effect of triple excitations. Namely, the second- through sixth-order models of the recently proposed CCSD(T-n) triples series [J. Chem. Phys. 140, 064108 (2014)] are compared to the acclaimed CCSD(T) model for both unrestricted as well as restricted open-shell Hartree-Fock (UHF/ROHF) reference determinants. By comparing UHF- and ROHF-based statistical results for a test set of 18 modest-sized open-shell species …
Dipole sum rule enhancement in nuclei
2008
In this work we apply a microscopic many-body approach to photonuclear reactions[1] in order to improve the understanding of the dipole sum rule. At the same time, the sum rule provides us with test of consistency of the underlying theory at low photon energies
A First Assessment of the Corrections for the Consistency of the IAU2000 and IAU2006 Precession-Nutation Models
2020
The Earth precession-nutation model endorsed by resolutions of each the International Astronomical Union and the International Union of Geodesy and Geophysics is composed of two theories developed independently, namely IAU2006 precession and IAU2000A nutation. The IAU2006 precession was adopted to supersede the precession part of the IAU 2000A precession-nutation model and tried to get the new precession theory dynamically consistent with the IAU2000A nutation. However, full consistency was not reached, and slight adjustments of the IAU2000A nutation amplitudes at the micro arcsecond level were required to ensure consistency. The first set of formulae for these corrections derived by Capita…
Self-consistency conditions for localized magnetic moments in a free electron gas
1969
The self-consistent conditions for a localized magnetic moment in a metal are studied in the case where the density of states of the host metal is free electron like. A method is outlined which in principle allows to determine self-consistently in the Hartree-Fock approximation the relevant parameters of the magnetic ground state of the system. A numerical example is approximately worked out to show how the theory gives reasonable answers in spite of the crudeness of some of the approximations used.
MC calculations for the nEDM experiment systematics
2010
International audience; The nEDM experiment hosted at the Paul Scherrer Institute is the flagship project at the new ultracold neutron facility. Estimations of systematic effects for the determination of the neutron electric dipole moment play an important role in this project. Experimental studies are supported by Monte Carlo simulations using the MCUCN code. Here we briefly present first results on the experimental benchmark of the model, and on the evaluation of the storage time dependence of the centre of mass of UCN in the nEDM precession chamber. Such time dependence calculations will serve as consistency tests for future measurements involving field gradient corrections of the Ramsey…
A model study of Hartree-Fock and Linear Response in coordinate space
1979
A fast procedure for spherical Hartree-Fock is obtained by coordinate space representation and a modification of gradient iteration. Along similar lines, the corresponding Linear Response equations are derived and solved, in order to achieve a fully consistent treatment. The Linear Response equations are applied to a change in particle numbers, i.e. to the description of isotopic differences. In a model study we look for their physical and numerical properties, i.e. linearity of the response, numerical stability and consistency requirements for the Hartree-Fock basis.
EFFECTIVE FIELD THEORY APPROACH TO THE NUCLEON–NUCLEON INTERACTION REVISITED
2006
It is argued that Weinberg's approach to the nucleon–nucleon (NN) interaction problem within effective field theory provides a consistent power counting for renormalized diagrams. Within this scheme the NN potential is organized as an expansion in terms of small quantities like small external momenta and the pion mass (divided by the characteristic large scale of the effective theory). Physical observables to any given order in these small quantities are calculated from the solutions of the Lippmann–Schwinger (or Schrödinger) equation.