The electronic contribution to the magnetically induced polarization in orthorhombic TbMnO3 is studied from first principles. We compare the cases in which the spin cycloid, which induces the electric polarization via the spin-orbit interaction, is in either the b-c or a-b plane. We find that the electronic contribution is negligible in the first case, but much larger, and comparable to the lat...

Using first principles, it is demonstrated that radiative damping alone cannot lead to a nonvanishing linear electro-optic effect in a chiral isotropic medium. This conclusion is in contrast with that obtained by a calculation in which damping effects are included using the standard phenomenological model. We show that these predictions differ because the phenomenological damping equations are ...

We selected a sample of 33 Gamma–Ray Bursts (GRBs) detected by Swift, with known redshift and optical extinction at the host frame. For these, we constructed the de–absorbed and K–corrected X–ray and optical rest frame light curves. These are modelled as the sum of two components: emission from the forward shock due to the interaction of a fireball with the circum–burst medium and an additional...

Inclusive spectra of different ejectiles and coincidence spectra of a particles with various nuclides emerging from the collisions of C ions of energy 344.5 MeV with a C target have been measured. A large fraction of the observed cross section is contained in the continuous part of the inclusive spectra. In the coincidence data the excitation of states of intermediate nuclei is observed which i...

Many biological systems are composed of unreliable components which self-organize efficiently into systems that can tackle complex problems.One such example is the true slimemoldPhysarum polycephalum which is an amoeba-like organism that seeks food sources and efficiently distributes nutrients throughout its cell body. The distribution of nutrients is accomplished by a self-assembled resource d...

In this work, some phenomenological models, those that are based only on the population information (macroscopic level), are deduced in an intuitive way. These models, as for instance Verhulst, Gompertz and Bertalanffy models, are posted in such a manner that all the parameters involved have physical interpretation. A model based on the interaction (distance dependent) between the individuals (...

Phenomenological parameterizations of proton and neutron polarized structure functions , g p 1 and g n 1 , are developed for x ∼ > 0.02 using deep inelastic data up to ∼ 50 (GeV /c) 2 as well as available experimental results on photo-and electro-production of nucleon resonances. The generalized Drell-Hearn-Gerasimov sum rules are predicted from low to high values of Q 2 and compared with proto...

The causal set approach to quantum gravity states that spacetime is not a continuous Lorenztian manifold but a causal set composed of discrete spacetime elements together with their causal relations. It is argued that using only causality and discreteness, one can recover a more fundamental theory of gravitation with interesting qualities. Though the theory is incomplete, some phenomenological ...

Horgan and Tienson (2002) argue that some intentional content is constitutively determined by phenomenology alone. We argue that this would require a certain kind of covariation of phenomenal states and intentional states which is not established by Horgan and Tienson’s arguments. We make the case that there is inadequate reason to think phenomenology determines perceptual belief, and that ther...