A middleware for creating physical mashups of things

Indexación: Scopus.Nowadays, “things” deployed in cities are crucial to gather data to support decision making systems. Unfortunately, there is a low level of reuse of “things” between smart city applications of different organizations because “things” were unknown to developers or because it was harder to reuse them than use new ones due to technical details. In this ongoing work, we propose to convert “things” into active entities capable of discovering and organizing themselves driven by the applications goals’ satisfaction. Moreover, “things” are capable of collaborating between them in order to satisfy or maintain satisfied the published goals of applications. To validate the feasibility of our proposal, we are building mashThings, an Internet of Things (IoT) platform to build smart city applications as physical mashups, where the middleware layer is augmented by a multiagent layer of broker agents representing the available “things” in the city.http://ceur-ws.org/Vol-1950/paper11.pd

Singularity free gravitational collapse in an effective dynamical quantum spacetime

We model the gravitational collapse of heavy massive shells including its main quantum corrections. Among these corrections, quantum improvements coming from Quantum Einstein Gravity are taken into account, which provides us with an effective quantum spacetime. Likewise, we consider dynamical Hawking radiation by modeling its back-reaction once the horizons have been generated. Our results point towards a picture of gravitational collapse in which the collapsing shell reaches a minimum non-zero radius (whose value depends on the shell initial conditions) with its mass only slightly reduced. Then, there is always a rebound after which most (or all) of the mass evaporates in the form of Hawking radiation. Since the mass never concentrates in a single point, no singularity appears.Comment: 19 pages, 5 figure

Peak statistics on COBE maps

We perform the stastistics of temperature maxima and minima in COBE-DMR 2-year maps. For power-law spectra the surface distribution of peaks implies an amplitude consistent with more conventional analyses of COBE data (for instance, we get $Q_{{\rm rms-PS}}=17\pm 3\ \mu$K for a spectral index $n=1),$ but not with the measured quadrupole $Q_{{\rm rms}}=6\pm 3\ \mu$K. This provides further support for the existence an infrared cutoff in the cosmic spectrum.Comment: Latex file, Astronomy & Astrophysics L-aa style. Hardcopy figures available separately, send requests to [email protected]

Modeling Kepler Transit Light Curves as False Positives: Rejection of Blend Scenarios for Kepler-9, and Validation of Kepler-9 d, A Super-earth-size Planet in a Multiple System

Light curves from the Kepler Mission contain valuable information on the nature of the phenomena producing the transit-like signals. To assist in exploring the possibility that they are due to an astrophysical false positive, we describe a procedure (BLENDER) to model the photometry in terms of a "blend" rather than a planet orbiting a star. A blend may consist of a background or foreground eclipsing binary (or star-planet pair) whose eclipses are attenuated by the light of the candidate and possibly other stars within the photometric aperture. We apply BLENDER to the case of Kepler-9 (KIC 3323887), a target harboring two previously confirmed Saturn-size planets (Kepler-9 b and Kepler-9 c) showing transit timing variations, and an additional shallower signal with a 1.59 day period suggesting the presence of a super-Earth-size planet. Using BLENDER together with constraints from other follow-up observations we are able to rule out all blends for the two deeper signals and provide independent validation of their planetary nature. For the shallower signal, we rule out a large fraction of the false positives that might mimic the transits. The false alarm rate for remaining blends depends in part (and inversely) on the unknown frequency of small-size planets. Based on several realistic estimates of this frequency, we conclude with very high confidence that this small signal is due to a super-Earth-size planet (Kepler-9 d) in a multiple system, rather than a false positive. The radius is determined to be 1.64^(+0.19)_(–0.14) R_⊕, and current spectroscopic observations are as yet insufficient to establish its mass

The nuclear contacts and short range correlations in nuclei

Atomic nuclei are complex strongly interacting systems and their exact theoretical description is a long-standing challenge. An approximate description of nuclei can be achieved by separating its short and long range structure. This separation of scales stands at the heart of the nuclear shell model and effective field theories that describe the long-range structure of the nucleus using a mean- field approximation. We present here an effective description of the complementary short-range structure using contact terms and stylized two-body asymptotic wave functions. The possibility to extract the nuclear contacts from experimental data is presented. Regions in the two-body momentum distribution dominated by high-momentum, close-proximity, nucleon pairs are identified and compared to experimental data. The amount of short-range correlated (SRC) nucleon pairs is determined and compared to measurements. Non-combinatorial isospin symmetry for SRC pairs is identified. The obtained one-body momentum distributions indicate dominance of SRC pairs above the nuclear Fermi-momentum.Comment: Accepted for publication in Physics Letters. 6 pages, 2 figure

Quark matter equation of state and stellar properties

In this paper we study strange matter by investigating the stability window within the QMDD model at zero temperature and check that it can explain the very massive pulsar recently detected. We compare our results with the ones obtained from the MIT bag model and see that the QMDD model can explain larger masses, due to the stiffening of the equation of state