Parameterizing Quasiperiodicity: Generalized Poisson Summation and Its Application to Modified-Fibonacci Antenna Arrays

The fairly recent discovery of "quasicrystals", whose X-ray diffraction patterns reveal certain peculiar features which do not conform with spatial periodicity, has motivated studies of the wave-dynamical implications of "aperiodic order". Within the context of the radiation properties of antenna arrays, an instructive novel (canonical) example of wave interactions with quasiperiodic order is illustrated here for one-dimensional (1-D) array configurations based on the "modified-Fibonacci" sequence, with utilization of a two-scale generalization of the standard Poisson summation formula for periodic arrays. This allows for a "quasi-Floquet" analytic parameterization of the radiated field, which provides instructive insights into some of the basic wave mechanisms associated with quasiperiodic order, highlighting similarities and differences with the periodic case. Examples are shown for quasiperiodic infinite and spatially-truncated arrays, with brief discussion of computational issues and potential applications.Comment: 29 pages, 10 figures. To be published in IEEE Trans. Antennas Propagat., vol. 53, No. 6, June 200

The effect of placebo and neurophysiological involvements

Placebo and placebo effect are important issues related to the drug therapy for clinical and scientific meanings. The rates of placebo may get as many as 50% for analgesic drugs in headache. The high answer to placebo brings questions on pathophysiology of headache. Answers may offer a new strategy in the implementation of trials and new insight in neurophysiology of headache. Current knowledge on placebo and placebo effect will be analysed and dicussed looking for new direction in headache field

Ferromagnetism and orbital order in a topological ferroelectric

We explore via density functional calculations the magnetic doping of a topological ferroelectric as an unconventional route to multiferroicity. Vanadium doping of the layered perovskite La$_{2}$Ti$_{2}$O$_{7}$ largely preserves electric polarization and produces robust ferromagnetic order, hence proper multiferroicity. The marked tendency of dopants to cluster into chains results in an insulating character at generic doping. Ferromagnetism stems from the symmetry breaking of the multi-orbital V system via an unusual "antiferro"-orbital order, and from the host's low-symmetry layered structure.Comment: 4 pages, 3 figures; Physical Review Letters 109, in print (2012

Colored Speech: Cross Burnings, Epistemics, and the Triumph of the Crits?

This Essay examines the Court\u27s recent decision in Virginia v. Black. It argues that Black signifies a different approach to the constitutionality of statutes regulating cross burnings. It shows how the Court\u27s conservatives have essentially accepted the intellectual framework and the mode of analysis suggested previously by the critical race theorists. In particular, this Essay explores the role that Justice Thomas plays in the case. The Essay explains Justice Thomas\u27s active participation as a matter of epistemic authority and epistemic deference

Factorization in exclusive semileptonic radiative B decays

We derive a new factorization relation for the semileptonic radiative decay B -> \pi \ell \nu \gamma in the kinematical region of a slow pion p_\pi ~ \Lambda and an energetic photon E_\gamma >> \Lambda, working at leading order in \Lambda/m_b. In the limit of a soft pion, the nonperturbative matrix element appearing in this relation can be computed using chiral perturbation theory. We present a phenomenological study of this decay, which may be important for a precise determination of the exclusive nonradiative decay.Comment: 10 pages, 3 figures; minor corrections, one reference adde

Experimental observation of impossible-to-beat quantum advantage on a hybrid photonic system

Quantum resources outperform classical ones for certain communication and computational tasks. Remarkably, in some cases, the quantum advantage cannot be improved using hypothetical postquantum resources. A class of tasks with this property can be singled out using graph theory. Here we report the experimental observation of an impossible-to-beat quantum advantage on a four-dimensional quantum system defined by the polarization and orbital angular momentum of a single photon. The results show pristine evidence of the quantum advantage and are compatible with the maximum advantage allowed using postquantum resources.Comment: REVTeX4, 5 pages, 2 figure

Results of the simulations of the petal/lens as part of the LAUE project

In the context of the LAUE project for focusing hard X-/gamma rays, a petal of the complete lens is being assembled at the LARIX facility in the Department of Physics and Earth Science of the University of Ferrara. The lens petal structure is composed of bent Germanium and Gallium Arsenide crystals in transmission geometry. We present the expectations derived from a mathematical model of the lens petal. The extension of the model for the complete LAUE project in the 90 -- 600 keV energy range will be discussed as well. A quantitative analysis of the results of these simulations is also presented.Comment: 12 pages, 26 figures, SPIE optics + Photonics conference 2013, Vol: 886