Self-induced flavor instabilities of a dense neutrino stream in a two-dimensional model

We consider a simplifed model for self-induced flavor

Proceedings Ninth Workshop on Model-Based Testing

This volume contains the proceedings of the Ninth Workshop on Model-Based Testing (MBT 2014), which was held in Grenoble, France on April 6, 2014 as a satellite workshop of the European Joint Conferences on Theory and Practice of Software (ETAPS 2014).

Higher-Order Process Modeling: Product-Lining, Variability Modeling and Beyond

We present a graphical and dynamic framework for binding and execution of business) process models. It is tailored to integrate 1) ad hoc processes modeled graphically, 2) third party services discovered in the (Inter)net, and 3) (dynamically) synthesized process chains that solve situation-specific tasks, with the synthesis taking place not only at design time, but also at runtime. Key to our approach is the introduction of type-safe stacked second-order execution contexts that allow for higher-order process modeling. Tamed by our underlying strict service-oriented notion of abstraction, this approach is tailored also to be used by application experts with little technical knowledge: users can select, modify, construct and then pass (component) processes during process execution as if they were data. We illustrate the impact and essence of our framework along a concrete, realistic (business) process modeling scenario: the development of Springers browser-based Online Conference Service (OCS). The most advanced feature of our new framework allows one to combine online synthesis with the integration of the synthesized process into the running application. This ability leads to a particularly flexible way of implementing self-adaption, and to a particularly concise and powerful way of achieving variability not only at design time, but also at runtime.

On The {it Fermi} -Lat Surplus of the Diffuse Galactic Gamma-Ray Emission

Recent observations of the diffuse Galactic gr emission (DGE) by the {it Fermi} Large Area Telescope ({it Fermi}-LAT) have shown significant deviations, above a few GeV until about 100 GeV, from DGE models that use the GALPROP code for the propagation of cosmic ray (CR) particles outside their sources in the Galaxy and their interaction with the target distributions of the interstellar gas and radiation fields. The surplus of radiation observed is most pronounced in the inner Galaxy, where the concentration of CR sources is strongest. The present study investigates this {it Fermi}-LAT Galactic Plane Surplus by estimating the gr emission from the sources themselves, which is disregarded in the above DGE models. It is shown that indeed the expected hard spectrum of CRs, still confined in their sources (SCRs), can explain this surplus. The method is based on earlier studies regarding the so-called EGRET GeV excess which by now is generally interpreted as an instrumental effect. The contribution from SCRs is predicted to increasingly exceed the DGE models also above 100 GeV, up to gr energies of about ten TeV, where the corresponding surplus exceeds the hadronic part of the DGE by about one order of magnitude. Above such energies the emission surplus should decrease again with energy due to the finite life-time of the assumed supernova remnant sources. Observations of the DGE in the inner Galaxy at 15 TeV with the Milagro gr detector and, at TeV energies, with the ARGO-YBJ detector are interpreted to provide confirmation of a significant SCR contribution to the DGE.

Planetary transit timing variations induced by stellar binarity. The light travel time effect

[ABRIDGED] Since the discovery of the first transiting extrasolar planet, transit timing has been recognized as a powerful method to discover and characterize additional planets in these systems. However, the gravitational influence of additional planets is not the only expected source of transit timing variations. In this work, we derive the expected detection frequency of stellar companions of hot-jupiter transiting planets host-stars, detectable by means of transit timing analysis. Since roughly half of the stars in the solar neighborhood belong to binary or multiple stellar systems, the same fraction of binary systems may be expected to be present among transiting planet-host stars, unless planet formation is significantly influenced by the presence of a stellar companion. Transit searches are less affected by the selection biases against long-period binaries that plague radial velocity surveys. If the frequency of binaries among hot-jupiter planets host stars is the same as determined in the solar neighborhood, after 5 years since the discovery of a sample of transiting planets 1.0%+/-0.2% of them have a probability >99% to present transit timing variations >50 sec induced by stellar binarity, and 2.8%+/-0.3% after 10 years, if the planetary and binary orbits are coplanar. Considering the case of random inclinations the probabilities are 0.6%+/-0.1% and 1.7%+/-0.2% after 5 and 10 years respectively. Our estimates can be considered conservative lower limits, since we have taken into account only binaries with periods P>5x10^3 days (a>=6 AU). Our simulations indicate that transit timing variations due to the light travel time effect allow discovery of stellar companions up to maximum separations equal to asim36 AU after 5 years since the discovery of the planet (asim75 AU after 10 years).

The X-Ray Point-Source Population of NGC 1365: The Puzzle of Two Highly-Variable Ultraluminous X-ray Sources

We present 26 point-sources discovered with Chandra within 200 (~20kpc) of the center of the barred supergiant galaxy NGC 1365. The majority of these sources are high-mass X-ray binaries, containing a neutron star or a black hole accreting from a luminous companion at a sub-Eddington rate. Using repeat Chandra and XMM-Newton as well as optical observations, we discuss in detail the natures of two highly-variable ultraluminous X-ray sources (ULXs): NGC 1365 X1, one of the most luminous ULXs known since the ROSAT era, which is X-ray variable by a factor of 30, and NGC 1365 X2, a newly discovered transient ULX, variable by a factor of >90. Their maximum X-ray luminosities (3-5 x 10^40 erg/s, measured with Chandra) and multiwavelength properties suggest the presence of more exotic objects and accretion modes: accretion onto intermediate mass black holes (IMBHs) and beamed/super-Eddington accretion onto solar-mass compact remnants. We argue that these two sources have black-hole masses higher than those of the typical primaries found in X-ray binaries in our Galaxy (which have masses of <20 Msolar), with a likely black-hole mass of 40-60 Msolar in the case of NGC 1365 X1 with a beamed/super-Eddington accretion mode, and a possible IMBH in the case of NGC 1365 X2 with M=80-500Msolar.