Antiresonances as precursors of decoherence

We show that, in presence of a complex spectrum, antiresonances act as a precursor for dephasing enabling the crossover to a fully decoherent transport even within a unitary Hamiltonian description. This general scenario is illustrated here by focusing on a quantum dot coupled to a chaotic cavity containing a finite, but large, number of states using a Hamiltonian formulation. For weak coupling to a chaotic cavity with a sufficiently dense spectrum, the ensuing complex structure of resonances and antiresonances leads to phase randomization under coarse graining in energy. Such phase instabilities and coarse graining are the ingredients for a mechanism producing decoherence and thus irreversibility. For the present simple model one finds a conductance that coincides with the one obtained by adding a ficticious voltage probe within the Landauer-Buettiker picture. This sheds new light on how the microscopic mechanisms that produce phase fluctuations induce decoherence.Comment: 7 pages, 2 figures, to appear in Europhys. Let

An initial evaluation of a biohygrothermal model for the purpose of assessing the risk mould growth in UK dwellings

Moulds are organisms that may be found in both the indoor and outdoor environment. Moulds play an important rolebreaking down and digesting organic material, but, if they are significantly present in the indoor environment they mayaffect the health of the occupants. A relative humidity of 80% at wall surfaces is frequently stated as the decisivecriterion for mould growth and methods used to assess the risk of mould growth are often based on steady stateconditions. However, considering the dynamic conditions typically found in the indoor environment, a betterunderstanding of the conditions required for mould to grow would seem desirable. This paper presents initialexploratory work to evaluate and assess ‘WUFI-bio’ - ‘biohygrothermal’ software that predicts the likelihood of mould growth under transient conditions. Model predictions are compared with large monitored data set from 1,388 UKdwellings before and after insulation and new heating systems are installed (‘Warm Front’), the suitability of thissoftware as a tool to predict mould growth will ultimately be assessed. This paper presents some initial, exploratorywork

Religiosidad e Historiografía. La irrupción del pluralismo religioso en América Latina y su elaboración metódica en la historiografía. [Reseña]

Reseña de: Hans-Jürgen PRIEN (ed.), Religiosidad e Historiografía. La irrupción del pluralismo religioso en América Latina y su elaboración metódica en la historiografía, Vervuert-Iberoamericana («Acta Coloniensia», 1), Frankfurt am Main 1998, 284 pp