New algorithms to obtain analytical solutions of Einstein's equations in isotropic coordinates

The main objective of this work, is to show two inequivalent methods to obtain new spherical symmetric solutions of Einstein's Equations with anisotropy in the pressures in isotropic coordinates. This was done inspired by the MGD method, which is known to be valid for line elements in Schwarzschild coordinates. As example, we obtained four analytical solutions using Gold III as seed solution. Two solutions, out of four, (one for each algorithm), satisfy the physical acceptability conditions.Comment: 14 pages, 24 figures, results were improve

Hamilton-Jacobi Theory in k-Symplectic Field Theories

In this paper we extend the geometric formalism of Hamilton-Jacobi theory for Mechanics to the case of classical field theories in the k-symplectic framework

Entanglement swapping between spacelike separated atoms

We show a mechanism that projects a pair of neutral two-level atoms from an initially uncorrelated state to a maximally entangled state while they remain spacelike separated. The atoms begin both excited in a common electromagnetic vacuum, and the radiation is collected with a partial Bell-state analyzer. If the interaction time is short enough and a certain two-photon Bell state is detected after the interaction, a high degree of entanglement, even maximal, can be generated while one atom is outside the light cone of the other, for arbitrary large interatomic distances.Comment: v2: version accepted in Phys. Rev.

Generation of atom-atom correlations inside and outside the mutual light cone

We analyze whether a pair of neutral two level atoms can become entangled in a finite time while they remain causally disconnected. The interaction with the e. m. field is treated perturbatively in the electric dipole approximation. We start from an initial vacuum state and obtain the final atomic correlations for the cases where n = 0, 1, or 2 photons are produced in a time t, and also when the final field state is unknown. Our results show that correlations are sizable inside and outside the mutual light cone for n= 1 and 2, and also that quantum correlations become classical by tracing over the field state. For n = 0 we obtain entanglement generation by photon propagation between the atoms, the correlations come from the indistinguishability of the source for n = 1, and may give rise to entanglement swapping for n = 2.Comment: v2: Minor changes, references added. v3: full revision, appendix added. v4: Minor changes. Accepted in Phys. Rev.

Photoluminiscence of a quantum dot hybridized with a continuum

We calculate the intensity of photon emission from a trion in a single quantum dot, as a function of energy and gate voltage, using the impurity Anderson model and variational wave functions. Assuming a flat density of conduction states and constant hybridization energy, the results agree with the main features observed in recent experiments: non-monotonic dependence of the energy on gate voltage, non-Lorentzian line shapes, and a line width that increases near the regions of instability of the single electron final state to occupations zero or two.Comment: 4 pages, 3 figures, Journal-ref adde

Time-dependent Mechanics and Lagrangian submanifolds of Dirac manifolds

A description of time-dependent Mechanics in terms of Lagrangian submanifolds of Dirac manifolds (in particular, presymplectic and Poisson manifolds) is presented. Two new Tulczyjew triples are discussed. The first one is adapted to the restricted Hamiltonian formalism and the second one is adapted to the extended Hamiltonian formalism