Quantum Hamiltonians with Quasi-Ballistic Dynamics and Point Spectrum

Consider the family of Schr\"odinger operators (and also its Dirac version) on $\ell^2(\mathbb{Z})$ or $\ell^2(\mathbb{N})$ $$H^W_{\omega,S}=\Delta + \lambda F(S^n\omega) + W, \quad \omega\in\Omega,$$ where $S$ is a transformation on (compact metric) $\Omega$, $F$ a real Lipschitz function and $W$ a (sufficiently fast) power-decaying perturbation. Under certain conditions it is shown that $H^W_{\omega,S}$ presents quasi-ballistic dynamics for $\omega$ in a dense $G_{\delta}$ set. Applications include potentials generated by rotations of the torus with analytic condition on $F$, doubling map, Axiom A dynamical systems and the Anderson model. If $W$ is a rank one perturbation, examples of $H^W_{\omega,S}$ with quasi-ballistic dynamics and point spectrum are also presented.Comment: 17 pages; to appear in Journal of Differential Equation

Dynamical Delocalization for the 1D Bernoulli Discrete Dirac Operator

An 1D tight-binding version of the Dirac equation is considered; after checking that it recovers the usual discrete Schr?odinger equation in the nonrelativistic limit, it is found that for two-valued Bernoulli potentials the zero mass case presents absence of dynamical localization for specific values of the energy, albeit it has no continuous spectrum. For the other energy values (again excluding some very specific ones) the Bernoulli Dirac system is localized, independently of the mass.Comment: 9 pages, no figures - J. Physics A: Math. Ge

Dynamical Lower Bounds for 1D Dirac Operators

Quantum dynamical lower bounds for continuous and discrete one-dimensional Dirac operators are established in terms of transfer matrices. Then such results are applied to various models, including the Bernoulli-Dirac one and, in contrast to the discrete case, critical energies are also found for the continuous Dirac case with positive mass.Comment: 18 pages; to appear in Math.

Acrocarpus fraxinifolius Wight & Arn.

Seminário realizado em Curitiba, de 6 a 8 de outubro de 1998

Periodic orbit bifurcations and scattering time delay fluctuations

We study fluctuations of the Wigner time delay for open (scattering) systems which exhibit mixed dynamics in the classical limit. It is shown that in the semiclassical limit the time delay fluctuations have a distribution that differs markedly from those which describe fully chaotic (or strongly disordered) systems: their moments have a power law dependence on a semiclassical parameter, with exponents that are rational fractions. These exponents are obtained from bifurcating periodic orbits trapped in the system. They are universal in situations where sufficiently long orbits contribute. We illustrate the influence of bifurcations on the time delay numerically using an open quantum map.Comment: 9 pages, 3 figures, contribution to QMC200

The Iberian town of Ullastret (Catalonia). An Iron Age urban agglomeration reconstructed virtually

The Iberian town of Ullastret (6th-2nd centuries BC), in the NE of the Iberian Peninsula, is one of the most important Iron Age archaeological sites in the north-western Mediterranean. It consists of two residential areas, Puig de Sant Andreu and Illa d’enReixac. Separated by only 300 m, together they make up the capital of the Iberian tribe known as the Indiketes, mentioned by classical authors such as Avienus, Ptolemy and Strabo. Decades of continuous archaeological investigation, and especially the geophysics surveys undertaken in recent years, have given us an overall view of the urban structure of this dipolis and its immediate territory, which was occupied and exploited intensively starting mainly in the 4th century BC. This high degree of theoretical knowledge led us to propose the creation of a virtual reconstruction of the whole complex, as well as its contextualisation in its geomorphologic and landscape surroundings. This 3D modelling is an excellent research tool that permits the formulation-validation of hypotheses for architectural reconstruction. It is also especially useful for the creation of applications that add to our knowledge of this heritage site and aid in its presentation and dissemination

Universal quantum signature of mixed dynamics in antidot lattices

We investigate phase coherent ballistic transport through antidot lattices in the generic case where the classical phase space has both regular and chaotic components. It is shown that the conductivity fluctuations have a non-Gaussian distribution, and that their moments have a power-law dependence on a semiclassical parameter, with fractional exponents. These exponents are obtained from bifurcating periodic orbits in the semiclassical approximation. They are universal in situations where sufficiently long orbits contribute.Comment: 7 page

Managing Uncertain Complex Events in Web of Things Applications

A critical issue in the Web of Things (WoT) is the need to process and analyze the interactions of Web-interconnected real-world objects. Complex Event Processing (CEP) is a powerful technology for analyzing streams of information about real-time distributed events, coming from different sources, and for extracting conclusions from them. However, in many situations these events are not free from uncertainty, due to either unreliable data sources and networks, measurement uncertainty, or to the inability to determine whether an event has actually happened or not. This short research paper discusses how CEP systems can incorporate different kinds of uncertainty, both in the events and in the rules. A case study is used to validate the proposal, and we discuss the benefits and limitations of this CEP extension.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Getting rid of gut microbes: surface sterilization cleans symbionts from the insects'egg masses.

Diverse heteropteran insects that feed on economic important crops, commonly known as stink bugs, are associated with specific gut symbiotic bacteria within their midgut cryptic spaces or the gastric caeca. Recent studies have revealed that the stink bugs Nezara viridula, Acrosternum hilare, Murgantia histrionica, Euschistus heros, Chlorochroa ligata, Chlorochroa sayi, Chlorochroa uhleri, Plautia stali, Thyanta pallidovirens, Dichelops melacanthus, Edessa meditabunda, Loxa deducta, Pellaea stictica, Piezodorus guildinii, Thyanta perditor, (all within Pentatomidae family) carried one major bacterium in their midgut. Phylogenetic tree generated using the 16S rRNA gene sequences obtained from the midgut of these previous species placed all symbionts in a clade with the plant-associated bacteria Erwinia and Pantoea species. In this system, females of stink bug vertically transmit the symbionts by smearing them on the surface of the egg masses. When first instars of nymphs hatch, they probe the egg surface and orally acquire the symbionts. Once ingested, these microbial symbionts will reach the 4th section of the ventriculum (V4), also known as gastric caecum, where they establish. It was hypothesized that nymphs born from surface sterilized eggs do not carry the caeca-associated symbionts. Once ingested these microbial symbionts will reach the 4th section of the ventriculum (V4), also known as gastric caecum, where they establish. It was hypothesized that nymphs born from surface sterilized eggs do not carry the caeca-associated symbionts. Herne, using scanning eletron microscopy (SEM), we are showing that surface sterilized eggs do not carry the surface microbes while eggs from the field of E. heros, D. melacanthus, N. viridula, P. stitica, and Pi. Guildinii carry them. In this unique model of transmission where the symbionts located temporally on the surface of eggs, environment factors may have a great impact on bacterial survival. Additionally, climate change may impact the insect host ecology. This information may lead to design new strategies to control the stink bugs that could used in the integrated pest management