M-theory from the superpoint

The “brane scan” classifies consistent Green–Schwarz strings and membranes in terms of the invariant cocycles on super Minkowski spacetimes. The “brane bouquet” generalizes this by consecutively forming the invariant higher central extensions induced by these cocycles, which yields the complete fundamental brane content of string/M-theory, including the D-branes and the M5-brane, as well as the various duality relations between these. This raises the question whether the super Minkowski spacetimes themselves arise as maximal invariant central extensions. Here, we prove that they do. Starting from the simplest possible super Minkowski spacetime, the superpoint, which has no Lorentz structure and no spinorial structure, we give a systematic process of consecutive “maximal invariant central extensions” and show that it discovers the super Minkowski spacetimes that contain superstrings, culminating in the 10- and 11-dimensional super Minkowski spacetimes of string/M-theory and leading directly to the brane bouquet

Forbidden Line Emission in the Eccentric Spectroscopic Binaries DQ Tauri and UZ Tauri E Monitored over an Orbital Period

We present echelle spectroscopy of the close pre-main-sequence binary star systems DQ Tau and UZ Tau-E. Over a 16 day time interval we acquired 14 nights of spectra for DQ Tau and 12 nights of spectra for UZ Tau-E. This represents the entire phase of DQ Tau, and 63 percent of the phase of UZ Tau-E. As expected, photospheric lines such as Li I 6707 clearly split into two components as the primary and secondary orbit one another, as did the permitted line He I 5876. Unlike the photospheric features, the forbidden lines of [O I] 6300 and [O I] 5577, retain the same shape throughout the orbit. Therefore these lines must originate outside of the immediate vicinity of the two stars and any circumstellar disks that participate in the orbital motion of the stars.Comment: 14 pages including 6 figures, aastex preprint, accepted to Astronomical Journa

El Paleozoico inferior del SE del Montseny

The Southeastern part of the Montseny massif and the Guilleries are the areas where the oldest rocks of the Catalonian Coastal Ranges are exposed. These are also the only areas where a high grade metamorphism is found. The sequence consists from bottom to top of the following three complexes: I) fine grained leucocratic gneisses, 2) micaschists with some interlayered quartzite beds and with marbles and gneiss lenses in the lower part, 3) lower-grade metapelites and metarenites. The age has been traditionally assigned to the Cambrian-Early Ordovician. The high grade rocks are affected by an schistosy trending east-west and dipping south about 30-60'. In some instances this schistosity shows evidences of its origin from the crenulation of an older foliation. The lower grade rocks are affected by a slaty cleavage and show in addition a crenulation cleavage dipping to the south-east about 70% Three different metamorphisms can be observed in the area: 1) prograde regional metamorphism, 2) contact metamorphism and 3) retrograde metamorphism. The prograde sequence is biotite-andalucite/cordierite-sillimanite. The climax postdates the main deformation. Inside andalucite porfiroblasts staurolite relics can be sometimes observed, indicating a variation in the PD trajectory. The contact metamorphism is induced by the late granitoids and reaches the hornblende facies conditions

Cyanide-modified Pt(111) : structure, stability and hydrogen adsorption

A.C. acknowledges the support of the DGI (Spanish Ministry of Science and Innovation) through Project CTQ2009-07017. W.S. acknowledges financial support by the Deutsche Forschungsgemeinschaft under Schm 344/40-1, Schm 344/34-1.2 and FOR 1376. W.S. and P.Q. thank DFG-CONICET International Cooperation and CONICET for continued support. E.P.M.L. and M.Z.-M. wish to acknowledge CONICET PIP: 112-200801-000983, Secyt UNC, Program BID (PICT 2006N 946), and PME: 2006-01581 for financial support. P.Q. acknowledges PICT 0737-2008. A generous grant of computing time from the Baden-Wuerttemberg grid is gratefully acknowledged. M.E.-E. acknowledges an FPI fellowship from the Spanish Ministry of Science and Innovation and an accommodation grant at the Residencia de Estudiantes from the Madrid City Council.Peer reviewedPostprin

El Paleozoico inferior del SE del Montseny

The Southeastern part of the Montseny massif and the Guilleries are the areas where the oldest rocks of the Catalonian Coastal Ranges are exposed. These are also the only areas where a high grade metamorphism is found. The sequence consists from bottom to top of the following three complexes: I) fine grained leucocratic gneisses, 2) micaschists with some interlayered quartzite beds and with marbles and gneiss lenses in the lower part, 3) lower-grade metapelites and metarenites. The age has been traditionally assigned to the Cambrian-Early Ordovician. The high grade rocks are affected by an schistosy trending east-west and dipping south about 30-60'. In some instances this schistosity shows evidences of its origin from the crenulation of an older foliation. The lower grade rocks are affected by a slaty cleavage and show in addition a crenulation cleavage dipping to the south-east about 70% Three different metamorphisms can be observed in the area: 1) prograde regional metamorphism, 2) contact metamorphism and 3) retrograde metamorphism. The prograde sequence is biotite-andalucite/cordierite-sillimanite. The climax postdates the main deformation. Inside andalucite porfiroblasts staurolite relics can be sometimes observed, indicating a variation in the PD trajectory. The contact metamorphism is induced by the late granitoids and reaches the hornblende facies conditions

Revisiting the optical PTPT-symmetric dimer

Optics has proved a fertile ground for the experimental simulation of quantum mechanics. Most recently, optical realizations of $\mathcal{PT}$-symmetric quantum mechanics have been shown, both theoretically and experimentally, opening the door to international efforts aiming at the design of practical optical devices exploiting this symmetry. Here, we focus on the optical $\mathcal{PT}$-symmetric dimer, a two-waveguide coupler were the materials show symmetric effective gain and loss, and provide a review of the linear and nonlinear optical realizations from a symmetry based point of view. We go beyond a simple review of the literature and show that the dimer is just the smallest of a class of planar $N$-waveguide couplers that are the optical realization of Lorentz group in 2+1 dimensions. Furthermore, we provide a formulation to describe light propagation through waveguide couplers described by non-Hermitian mode coupling matrices based on a non-Hermitian generalization of Ehrenfest theorem.Comment: 25 pages, 12 figure

On Coupled Reaction Diffusion Equations and Their Applications

Reaction-diffusion equations are nonlinear partial differential equations that have been used extensively in mathematical modeling. An interesting case in this type of equation is the Fisher-Kolmogorov system, which has been used to study a low-grade glioma, a group of primary brain tumors. In the first part of this thesis, a stochastic version of the Fisher-Kolmogorov system will be studied, and exact and numerical solutions will be presented. The second part of this thesis will show how the speed of information propagation affects disease spread and vaccination uptake through networks in epidemics. In this model, the information reaches different people at different distances from the center of information containing the health data. The Fisher-Kolmogorov equations are used to depict the vaccine and disease information propagation on a network embedded into a straight line. The Fisher-Kolmogorov equations are coupled equations with the SIR (Susceptible-Infected-Recovered) model to examine the anticipated mutual influence. Numerical simulations of the model are presented. It is shown how the propagation of information about the disease impacts the probability of vaccination and, consequently, the vaccination rate