In this work it is investigated if fermionic sources could be responsible for accelerated periods during the evolution of a universe where a matter field would answer for the decelerated period. The self-interaction potential of the fermionic field is considered as a function of the scalar and pseudoscalar invariants. Irreversible processes of energy transfer between the matter and gravitationa...

An overview of the recent activity of the laboratory in the determination of the photophysical properties of porphyrinic arrays, with emphasis on the theme of photoinduced charge separation, is presented.

The ac Stark effect was used to induce resonant energy transfer between translationally cold 85Rb Rydberg atoms. When a 28.5 GHz dressing field was set at specific field strengths, the two-atom dipole-dipole process 43d5/2+43d5/2-->45p3/2+41f was dramatically enhanced, due to induced degeneracy of the initial and final states. This method for enhancing interactions is complementary to dc electr...

Short-range interaction can give rise to particle pairing with a short-range correlation, which may be destroyed in the presence of an external field. We study the transition between correlated and uncorrelated particle states in the framework of one- dimensional Hubbard model driven by a field. We show that the long time-scale transfer rate from an initial correlated state to final uncorrelate...

We monitored PCR in volumes of the order of 10 nl in glass microcapillaries using a fluorescence energy transfer assay in which fluorescence increases if product is made due to template-dependent nucleolytic degradation of an internally quenched probe (TaqMan assay). This assay detected single starting template molecules in dilutions of genomic DNA. The results suggest that it may be feasible t...

Asymmetric, heteroleptic dinuclear bis(dipyrrinato)zinc(II) complexes were synthesized and demonstrated to collect a wide range of light across the UV and visible regions (340-655 nm). The complexes also conveyed excitons across their structure from one end to the other, with spectroscopic studies demonstrating quantitative and fast energy transfer.

We demonstrate coherent interactions between spatial gap solitons in optically induced photonic lattices. Because of the "staggered" phase structures, two in-phase (out-of-phase) bright gap solitons can repel (attract) each other at close proximity, in contrast to soliton interaction in homogeneous media. A reversal of energy transfer direction and a transition between attractive and repulsive ...

Experiments and direct numerical simulations reveal the coexistence of two cascades in two-dimensional grid turbulence. Several features of this flow such as the energy density and the scalar spectra are found to be consistent with well known theoretical predictions. The energy transfer function displays the expected up-scale energy transfers. The vorticity correlation function is logarithmic a...

We derive a hierarchy of stochastic evolution equations for pure states (quantum trajectories) for open quantum system dynamics with non-Markovian structured environments. This hierarchy of pure states (HOPS) is generally applicable and provides the exact reduced density operator as an ensemble average over normalized states. The corresponding nonlinear equations are presented. We demonstrate t...