A5020756560- Geophysics and Gravity Measurements
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Spacecraft Dynamics and Control
- Planetary Science and Exploration
- Physics of Superconductivity and Magnetism
- High-pressure geophysics and materials
- GNSS positioning and interference
- Aerospace Engineering and Control Systems
- Relativity and Gravitational Theory
- Methane Hydrates and Related Phenomena
- Scientific Research and Discoveries
- Inertial Sensor and Navigation
- Stellar, planetary, and galactic studies
- Cold Atom Physics and Bose-Einstein Condensates
- Mathematics and Applications
- Geophysics and Sensor Technology
- Quantum and electron transport phenomena
- Space Satellite Systems and Control
- earthquake and tectonic studies
- Quantum, superfluid, helium dynamics
- Statistical and numerical algorithms
- Superconductivity in MgB2 and Alloys
- Advanced Chemical Physics Studies
Universidad de Valladolid
2006-2021
Royal Observatory of Belgium
1998
Universidad de Oviedo
1991-1995
National Astronomical Observatory of Japan
1995
Universidad Complutense de Madrid
1991-1993
An exact transition-temperature (${\mathit{T}}_{\mathit{c}}$) formula is derived within the van Hove scenario of BCS phonon-mediated pairing theory consisting a logarithmic singularity in density states (DOS) at Fermi energy. Also evaluated are near-exact zero-temperature gap-energy expression along with an (numerical) temperature-dependent gap Though ${\mathit{T}}_{\mathit{c}}$ greatly enhanced over conventional (constant DOS) value for given (weak) coupling,...
The canonical formalism for the rotation of an earth model composed a rigid mantle and liquid core, established in Getino (1995b), starting from Sevilla & Romero (1987), is applied here to study forced nutations caused by perturbing lunisolar potential. main purpose this paper not get accurate values nutation terms, since considered does include effect elasticity. This approach should be understood as generalization Kinoshita's (1977) theory earth. Under formulation, using Andoyer-like...
Analytic expressions are derived for the root-mean-square (rms) radius of a pair fermions in BCS many-fermion state one, two, and three dimensions, terms gap energy associated chemical potential. These valid any coupling strength interaction model implying momentum-independent energy. The latter holds, e.g., an attractive \ensuremath{\delta} potential examined one-dimensional (1D) case (whose N-fermion ground can be determined exactly) or (electron-phonon) dimension. Weak-coupling and/or...
In this paper we present a theory of the Earth rotation for model composed an inelastic mantle and liquid core, including dissipation in core—mantle boundary (CMB). The main features are: (i) to be Hamiltonian, therefore computation some complex inner torques can avoided; (ii) self-consistent non-dependent on previous rigid theory, so there is no need use transfer functions; (iii) analytical, solution being derived by perturbation methods. Numerical nutation series deduced from are compared...
Following an approach similar to that of Miyake or Randeria, Duan, and Shieh in two dimensions, we study a three-dimensional many-fermion gas at zero temperature interacting via some short-ranged two-body potential. To accommodate possible singularity (e.g., the Coulomb repulsion) interaction, potential is eliminated favor scattering t-matrix, low-energy form which expressible terms s-wave length ${\mathit{a}}_{\mathit{s}}$. The BCS gap equation for pairing then solved simultaneously with...
This paper deals with the canonical formulation of rotation a non-rigid earth heterogeneous stratified liquid core. The treatment Kubo (1979) for rigid core-rigid mantle model is extended by considering core as instead rigid. We show that tensional torque introduced to explain core-mantle interaction due hypothesis rigidity core, this now being included in new expression kinetic energy. More precisely, kind variation or deformation inertia tensor which we have named inertial deformation,...
The Hamiltonian formalism was recently applied by Getino (1995a,b) for the study of rotation a non-rigid earth with heterogeneous and stratified liquid core. That model is generalized here including effect dissipation arising from mantle-core interaction, using similar to that Sasao, Okubo & Saito (1980), which includes both viscous electromagnetic coupling. First, solution free nutations obtained following classical approach, in our opinion more familiar most readers than treatment. This...
The adoption of International Astronomical Union (IAU) 2006 precession model, IAU precession, requires 2000A nutation to be adjusted ensure compatibility between both theories. This consists adding small terms some amplitudes relevant at the microarcsecond level. Those contributions were derived in previously published articles and are incorporated into current astronomical standards. They due estimation process by Very Long Baseline Interferometry (VLBI) changes induced J2 rate present...
We show that, unlike commonly believed, the presence of a fluid core does affect precessional motion Earth by nonnegligible amount, equivalent to variation several parts per million in value precession constant or, correspondingly, dynamical ellipticity Earth. This contribution arises from second-order terms averaged Hamiltonian after application perturbation methods remove periodic terms, some former being amplified as consequence resonance induced core. Our evaluation corresponds...
This paper is the first part of an investigation where we will present analytical general theory rotation non-rigid Earth at second order, which considers effects interaction with itself, also named as spin–spin coupling. Here, and a necessary step in development that theory, derive complete, explicit, formulae rigid account for second-order rotation–rotation interaction. These expressions are not provided this form by any current model. Working within Hamiltonian framework established...
A suitable knowledge of the orientation and motion Earth in space is a common need various fields. That has been ever necessary to carry out astronomical observations, but with advent age, it became essential for making observations satellites predicting determining their orbits, observing from as well. Given relevant role plays Space Geodesy, rotation considered one three pillars other two being geometry gravity. Besides, research on fostered advances many fields, such Mathematics,...
The Hamiltonian formalism is applied to a three‐layer Earth model composed of rigid mantle, fluid outer core and inner core, with no dissipation frictional or electromagnetic origin. Analytical expressions for the free nutations are derived in set nonsingular canonical variables that allow much simpler mathematical treatment. They checked versus numerical solutions compared previous results by Mathews et al . [1991a] Getino Ferrándiz [1996, 1998a] complete agreement up first order ellipticities.
In a previous paper, the authors considered free rotation of an earth model composed rigid mantle and liquid core in presence dissipation under Hamiltonian formalism, obtaining analytical expressions for nutation modes. this paper we treat forced motion. Approximate solutions are worked out by means Hori's perturbation method, obtained former playing role unperturbed required application method. These consistent sense that, with usual terminology, body complex transfer functions calculated...
In this investigation we determine a new contribution to the nutation series due an indirect effect of triaxiality rigid Earth. We undertake work in context Hamiltonian theory for Earth, developed by Kinoshita ([CITE]) and recently updated Souchay et al. ([CITE]). To do this, express potential energy terms action–angle variables triaxial Then, out analytical formulae contributions, showing that their numerical values are within truncation level adopted REN–2000 (Souchay [CITE]), which was fixed as.
Lunar laser ranging (LLR) measurements are crucial for advanced exploration of the laws fundamental gravitational physics and geophysics as well future human robotic missions to Moon. The corner-cube reflectors (CCR) currently on Moon require no power still work perfectly since their installation during project Apollo era. Current LLR technology allows its measure distances with a precision approaching I mm. As NASA pursues vision taking humans back Moon, new, more precise applications will...
The dynamical similarities between the three-dimensional (3D) electron fluid ``jellium'' model and exactly soluble 1D fermion with attractive \ensuremath{\delta}-function pairwise potentials motivates solving Cooper-pair problem in this for all couplings and/or densities. This is accomplished graphical form. For weak coupling, essential singularity characteristic of standard 3D low-temperature superconductivity reemerges, infinite BCS theory reproduces exact ground-state system energy.