Review on possible gravitational anomalies

This is an updated introductory review of 2 possible gravitational anomalies that has attracted part of the Scientific community: the Allais effect that occur during solar eclipses, and the Pioneer 10 spacecraft anomaly, experimented also by Pioneer 11 and Ulysses spacecrafts. It seems that, to date, no satisfactory conventional explanation exist to these phenomena, and this suggests that possible new physics will be needed to account for them. The main purpose of this review is to announce 3 other new measurements that will be carried on during the 2005 solar eclipses in Panama and Colombia (Apr. 8) and in Portugal (Oct.15).Comment: Published in 'Journal of Physics: Conferences Series of the American Institute of Physics'. Contribution for the VI Mexican School on Gravitation and Mathematical Physics "Approaches to Quantum Gravity" (Playa del Carmen, Quintana Roo, Mexico, Nov. 21-27, 2004). Updates to this information will be posted in http://www.lsc-group.phys.uwm.edu/~xavier.amador/anomalies.htm

Should HIV be a notifiable disease? Old questions with some new arguments

KMHIV notification enters national debate regularly, often introduced by politicians and supported by many individual healthcare workers. We argue that its proponents advance confused or poorly informed rationales for making HIV notifiable. We present reasons why making HIV notifiable would be inappropriate in South Africa, why the public health benefits of a notification programme are not even likely, and why there are risks of public health and human rights harms

On the linear increase of the flux tube thickness near the deconfinement transition

We study the flux tube thickness of a generic Lattice Gauge Theory near the deconfining phase transition. It is well known that the effective string model predicts a logarithmic increase of the flux tube thickness as a function of the interquark distance for any confining LGT at zero temperature. It is perhaps less known that this same model predicts a linear increase in the vicinity of the deconfinement transition. We present a precise derivation of this result and compare it with a set of high precision simulations in the case of the 3d gauge Ising model.Comment: 20 pages, 4 figures, minor changes. Accepted for publication in JHE

A system for PEA space charge measurement on HVDC mini-cables under different isothermal temperatures: Influence of cable clamping force on PEA measurements on HVDC mini-cables

A Pulsed Electro-Acoustic (PEA) apparatus has been developed to measure the space charge distribution inside cable insulation. The technique relies on acoustic contact between the cylindrical cable surface and a flat aluminium plate to couple the acoustic waves to the sensor. This work addresses the practical issue of the clamping force required to maintain good contact and how this may alter the measured space charge distribution. Space charge measurements on mini-cables (model cables)were carried out over a wide range of clamping force and additionally a finite-element simulation model has been developed to model mechanical deformation of mini-cables and provide data that cannot be easily obtained from experiments. A clamping force range for reproducible measurements at room temperature has been determined by comparing results from a group test on a mini-cable

Feasibility of using a flat bottom electrode for PEA space charge measurement on mini-cables under high temperatures

Pulsed Electro-Acoustic (PEA) apparatus has been developed to measure the space charge distribution inside XLPE based mini-cable insulation. The technique relies on the acoustic contact between the cylindrical cable surface and a flat aluminium plate to couple the acoustic waves to the sensor. This work addresses the feasibility of using this technique over a temperature range of 25°C to 70°C. The results demonstrate that increasing the temperature under constant clamping force causes the cable insulation to soften and distort increasing the contact area and signal from the PEA apparatus. However on subsequent cooling to 25°C the mechanical distortion remains frozen-in with little change to the contact area. For reproducible space charge measurements it is necessary to first condition the cable sample by taking the cable and PEA through a temperature cycle before application of the applied voltage

POPLMark reloaded: Mechanizing proofs by logical relations

We propose a new collection of benchmark problems in mechanizing the metatheory of programming languages, in order to compare and push the state of the art of proof assistants. In particular, we focus on proofs using logical relations (LRs) and propose establishing strong normalization of a simply typed calculus with a proof by Kripke-style LRs as a benchmark. We give a modern view of this well-understood problem by formulating our LR on well-typed terms. Using this case study, we share some of the lessons learned tackling this problem in different dependently typed proof environments. In particular, we consider the mechanization in Beluga, a proof environment that supports higher-order abstract syntax encodings and contrast it to the development and strategies used in general-purpose proof assistants such as Coq and Agda. The goal of this paper is to engage the community in discussions on what support in proof environments is needed to truly bring mechanized metatheory to the masses and engage said community in the crafting of future benchmarks

Via Hexagons to Squares in Ferrofluids: Experiments on Hysteretic Surface Transformations under Variation of the Normal Magnetic Field

We report on different surface patterns on magnetic liquids following the Rosensweig instability. We compare the bifurcation from the flat surface to a hexagonal array of spikes with the transition to squares at higher fields. From a radioscopic mapping of the surface topography we extract amplitudes and wavelengths. For the hexagon--square transition, which is complex because of coexisting domains, we tailor a set of order parameters like peak--to--peak distance, circularity, angular correlation function and pattern specific amplitudes from Fourier space. These measures enable us to quantify the smooth hysteretic transition. Voronoi diagrams indicate a pinning of the domains. Thus the smoothness of the transition is roughness on a small scale.Comment: 17 pages, 14 figure

A Quantum-Conceptual Explanation of Violations of Expected Utility in Economics

The expected utility hypothesis is one of the building blocks of classical economic theory and founded on Savage's Sure-Thing Principle. It has been put forward, e.g. by situations such as the Allais and Ellsberg paradoxes, that real-life situations can violate Savage's Sure-Thing Principle and hence also expected utility. We analyze how this violation is connected to the presence of the 'disjunction effect' of decision theory and use our earlier study of this effect in concept theory to put forward an explanation of the violation of Savage's Sure-Thing Principle, namely the presence of 'quantum conceptual thought' next to 'classical logical thought' within a double layer structure of human thought during the decision process. Quantum conceptual thought can be modeled mathematically by the quantum mechanical formalism, which we illustrate by modeling the Hawaii problem situation, a well-known example of the disjunction effect, and we show how the dynamics in the Hawaii problem situation is generated by the whole conceptual landscape surrounding the decision situation.Comment: 9 pages, no figure

Flux tube delocalization at the deconfinement point

We study the behaviour of the flux tube thickness in the vicinity of the deconfinement transition. We show, using effective string methods, that in this regime the square width increases linearly and not logarithmically with the interquark distance. The amplitude of this linear growth is an increasing function of the temperature and diverges as the deconfinement transition is approached from below. These predictions are in good agreement with a set of simulations performed in the 3d gauge Ising model.Comment: 16 pages, 1 figure. Revised version, with an improved discussion of the dimensional reduction approach. Accepted for publication in JHE