N=2 Einstein-Yang-Mills' static two-center solutions

We construct bona fide one- and two-center supersymmetric solutions to N=2, d=4 supergravity coupled to SU(2) non-Abelian vector multiplets. The solutions describe black holes and global monopoles alone or in equilibrium with each other and exhibit non-Abelian hairs of different kinds.Comment: 46 pages, 1 figure; v2 references adde

Resolution of SU(2) monopole singularities by oxidation

We show how "colored" SU(2) BPS monopoles (that is: SU(2) monopoles satisfying the Bogomol'nyi equation whose Higgs field and magnetic charge vanish at infinity and which are singular at the origin) can be obtained from the BPST instanton by a singular dimensional reduction, explaining the origin of the singularity and implying that the singularity can be cured by the oxidation of the solution. We study the oxidation of other monopole solutions in this scheme.Comment: 13 pages, LaTeX file, no figure

PROBING ATMOSPHERIC AEROSOL AND GAS PROPERTIES WITH PHOTOACOUSTIC SPECTROSCOPY

Absorption by atmospheric aerosols is the wild card for global climate change. Issues regarding atmospheric gases and aerosols have been at the forefront and the work presented within is directed at those issues. Specifically, work has been performed in order to help understand the issue of absorption in the atmosphere and whether this contributes towards positive forcing or warming of the atmosphere. In the process of conducting this research a custom, first-principles photoacoustic spectrometer was improved, calibrated and used extensively in order to obtain knowledge of the interaction of light with atmospherically relevant gases and make the first measurements of absorbing aerosols. The absorption cross-section of uncoated and coated soot was measured and quantified and found to be consistent with other work where amplifications on the order of nearly 100% were observed with uncertainty levels much lower than previously reported. Soot was also found to be optically thin where the total mass of the soot contributes to the absorption. Consequential to the soot work, the photoacoustic spectrometer developed to measure the absorption was utilized as a high precision greenhouse gas sensor. The photoacoustic spectrometer was found to produce results on the absorption of CO2 to within 3% of the theoretically predicted line profile Moreover, the photoacoustic spectrometer was used to determine measurable coating thicknesses of less than 10 nanometers on 100 nm soot particles

Testigos de piedra: estelas armadas entre el Tajo internacional y el Duero, Península Ibérica

Pocos territorios en Europa reúnen la concentración de estelas en piedra que se documentan entre el Tajo y el Duero. La arqueología asegura amplias posibilidades extractivas, con un claro centro neurálgico en el actual distrito de Castelo Branco. Desde los primeros descubrimientos de piezas tan singulares como las de São Martinho, hasta el registro actual, la variedad y diacronía de estelas y menhires en piedra resulta excepcional en el contexto ibérico y europeo. La tradicional lectura, que alejaba los viejos menhires de las estelas del Bronce Final, queda muy matizada ante el uso de referencias temáticas y técnicas semejantes. En este texto aportamos otro argumento a sumar a esas similitudes, con la reutilización de los antiguos soportes como base material para la generación de las estelas del Bronce Final. Las imágenes humanas que se grabaron en estas memorias en piedra expresan narrativas sociales elaboradas. Las secuencias gráficas que argumentamos aseguran el papel político de estas piezas como justificaciones materiales de pasados ancestrales. Indudablemente albergan relatos orales sobre la relación entre los viejos ancestros y los nuevos líderes, justificando el orden del entramado económico asociado al control de la extracción y comercio del metal.Few places in Europe concentrate as many stone stelae as the area between the Tagus and the Douro. Archaeology has shown the ample possibilities for metal mining, the modern region of Castelo Branco being the epicentre in the area. From the first discoveries of such unique objects as the São Martinho stelae to the current record, the variety and diachronicity of stone stelae and menhirs is exceptional on the Iberian and European scales. The traditional interpretation that differentiated between the old menhirs and Late Bronze Age stelae has been nuanced by the evidence of similar themes and techniques. Another argument presented here is the use of the old stones as the basic material to produce the Late Bronze Age stelae. Human images carved on these memorial stones express elaborate social narratives. The graphic sequences described here demonstrate the ‘political’ role of these stones and material justification of ancestral pasts. They were undoubtedly imbued with oral tales about old ancestors and new leaders, to justify the order of the economic system associated with mining and metal trade.Ministerio de Ciencia, Innovación y Universidades 2018-099405-BI0

Macroecology of parental care in arthropods: higher mortality risk leads to higher benefits of offspring protection in tropical climates

The intensity of biotic interactions varies around the world, in such a way that mortality risk imposed by natural enemies is usually higher in the tropics. A major role of offspring attendance is protection against natural enemies, so the benefits of this behaviour should be higher in tropical regions. We tested this macroecological prediction with a meta-regression of field experiments in which the mortality of guarded and unguarded broods was compared in arthropods. Mortality of unguarded broods was higher, and parental care was more beneficial, in warmer, less seasonal environments. Moreover, in these same environments, additional lines of defence further reduced offspring mortality, implying that offspring attendance alone is not enough to deter natural enemies in tropical regions. These results help to explain the high frequency of parental care among tropical species and how biotic interactions influence the occurrence of parental care over large geographic scales. Finally, our findings reveal that additional lines of defences – an oftentimes neglected component of parental care – have an important effect on the covariation between the benefits of parental care and the climate-mediated mortality risk imposed by natural enemies

Program development using abstract interpretation (and the ciao system preprocessor)

The technique of Abstract Interpretation has allowed the development of very sophisticated global program analyses which are at the same time provably correct and practical. We present in a tutorial fashion a novel program development framework which uses abstract interpretation as a fundamental tool. The framework uses modular, incremental abstract interpretation to obtain information about the program. This information is used to validate programs, to detect bugs with respect to partial specifications written using assertions (in the program itself and/or in system librarles), to genérate and simplify run-time tests, and to perform high-level program transformations such as múltiple abstract specialization, parallelization, and resource usage control, all in a provably correct way. In the case of validation and debugging, the assertions can refer to a variety of program points such as procedure entry, procedure exit, points within procedures, or global computations. The system can reason with much richer information than, for example, traditional types. This includes data structure shape (including pointer sharing), bounds on data structure sizes, and other operational variable instantiation properties, as well as procedure-level properties such as determinacy, termination, non-failure, and bounds on resource consumption (time or space cost). CiaoPP, the preprocessor of the Ciao multi-paradigm programming system, which implements the described functionality, will be used to illustrate the fundamental ideas