Probing the nature of Dark Matter with the SKA

Dark Matter (DM) is a fundamental ingredient of our Universe and of structure formation, and yet its nature is elusive to astrophysical probes. Information on the nature and physical properties of the WIMP (neutralino) DM (the leading candidate for a cosmologically relevant DM) can be obtained by studying the astrophysical signals of their annihilation/decay. Among the various e.m. signals, secondary electrons produced by neutralino annihilation generate synchrotron emission in the magnetized atmosphere of galaxy clusters and galaxies which could be observed as a diffuse radio emission (halo or haze) centered on the DM halo. A deep search for DM radio emission with SKA in local dwarf galaxies, galaxy regions with low star formation and galaxy clusters (with offset DM-baryonic distribution, like e.g. the Bullet cluster) can be very effective in constraining the neutralino mass, composition and annihilation cross-section. For the case of a dwarf galaxy, like e.g. Draco, the constraints on the DM annihilation cross-section obtainable with SKA1-MID will be at least a factor $\sim 10^3$ more stringent than the limits obtained by Fermi-LAT in the $\gamma$-rays. These limits scale with the value of the B field, and the SKA will have the capability to determine simultaneously both the magnetic field in the DM-dominated structures and the DM particle properties. The optimal frequency band for detecting the DM-induced radio emission is around $\sim 1$ GHz, with the SKA1-MID Band 1 and 4 important to probe the synchrotron spectral curvature at low-$\nu$ (sensitive to DM composition) and at high-$\nu$ (sensitive to DM mass).Comment: 10 pages, 5 figures, to appear as part of 'Cosmic Magnetism' in proceedings of 'Advancing Astrophysics with the Square Kilometre Array' PoS(AASKA14)10

Nonlinear Dynamical Equation for Irreversible, Steepest-Entropy-Ascent Relaxation to Stable Equilibrium

We discuss the structure and main features of the nonlinear evolution equation proposed by this author as the fundamental dynamical law within the framework of Quantum Thermodynamics. The nonlinear equation generates a dynamical group providing a unique deterministic description of irreversible, conservative relaxation towards equilibrium from any non-equilibrium state, and satisfies a very restrictive stability requirement equivalent to Hatsopoulos-Keenan statement of the second law of thermodynamics. Here, we emphasize its mathematical structure and its applicability also within other contexts, such as Classical and Quantum Statistical Mechanics, and Information Theory.Comment: Proceedings of the Conference "Quantum Theory: Reconsideration of Foundations - 4", Vaxjo, Sweden, June 11-16, 200

Acquisition of Information is Achieved by the Measurement Process in Classical and Quantum Physics

No consensus seems to exist as to what constitutes a measurement which is still considered somewhat mysterious in many respects in quantum mechanics. At successive stages mathematical theory of measure, metrology and measurement theory tried to systematize this field but significant questions remain open about the nature of measurement, about the characterization of the observer, about the reliability of measurement processes etc. The present paper attempts to talk about these questions through the information science. We start from the idea, rather common and intuitive, that the measurement process basically acquires information. Next we expand this idea through four formal definitions and infer some corollaries regarding the measurement process from those definitions. Relativity emerges as the basic property of measurement from the present logical framework and this rather surprising result collides with the feeling of physicists who take measurement as a myth. In the closing this paper shows how the measurement relativity wholly consists with some effects calculated in QM and in Einstein's theory.Comment: Prepared for : Quantum Theory: Reconsideration of Foundations - 4 (QTFR-4), Vaxjo, Sweden, 6-11 June 2007. To be published by the American Institute of Physics in the AIP Conference Proceedings series. Talk presented by Paolo Rocch

Advanced Circuital Model for e-Drive Simulation, Including Harmonic Effects and Fault Scenarios

The paper presents an advanced circuital model of e-drive for control frmware development and real-time simulation purposes, compatible with Simulink and PLECS environments. The model accounts for PWM voltage supply, magnetic saturation, iron losses and space harmonic felds in the e-motor, and covers both healthy and faulty scenarios. The use of advanced dqθ fux maps allows for accurate simulation of torque ripple and back-EMF undulation. The proposed model is experimentally validated on a traction PMSM and can be automatically generated within the SyR-e open-source design platform

Direct Instanton Effects in Current-Current Correlators

We compute the effect of small-size instantons on the coefficient function of the chiral condensate in the operator product expansion of current-current correlators. Furthermore, we also compute the instanton corrections associated with four-quark and six-quark operators in the factorization approximation. We discuss the phenomenological implications of our result.Comment: 24 pages, Late

Soil-Structure Interaction for Integrated Design of Weakened and Damped Structures

Previous research has shown the effectiveness of the integrated design of weakening and damping techniques (WeD) for the seismic retrofitting of structures. Indeed, WeD techniques are able to reduce inter-story drifts and total accelerations, the two major performance measures to evaluate the seismic behavior of structures. Past research has been applied to fixed-based structures considering relatively stiff soil conditions. It has been suspected, though, that using such techniques in soft soil sites while considering soil structure interaction, may diminish some of the advantages observed in past research. This paper examines the effect of site conditions and soil-structure interaction on the seismic performance of Weakening and Damping techniques. An established rheological soil-shallow foundation-structure model with equivalent linear soil behavior and nonlinear behavior of the superstructure has been used. A large number of models incorporating wide range of soil, foundation and structural parameters were generated using robust Monte-Carlo simulation. The various structural models, along with the various site conditions, have been used for the comparative study. The design methodologies previously developed by the authors have been applied to each model considering different site conditions leading to the optimal weakening and damping. The results of the comparative study are used to quantify the effects of site conditions and foundation °exibility on the performance of the retrofitted structures

Unsupervised semantic frame induction using triclustering

We use dependency triples automatically extracted from a Web-scale corpus to perform unsupervised semantic frame induction. We cast the frame induction problem as a triclustering problem that is a generalization of clustering for triadic data. Our replicable benchmarks demonstrate that the proposed graph-based approach, Triframes, shows state-of-the art results on this task on a FrameNet-derived dataset and performing on par with competitive methods on a verb class clustering task