Convenient parameterizations of matrices in terms of vectors

Convenient parameterizations of matrices in terms of vectors transform (certain classes of) matrix equations into covariant (hence rotation-invariant) vector equations. Certain recently introduced such parameterizations are tersely reviewed, and new ones introduced

Asymptotic solitons of the Johnson equation

We prove the existence of non-decaying real solutions of the Johnson equation, vanishing as $x\to+\infty$. We obtain asymptotic formulas as $t\to\infty$ for the solutions in the form of an infinite series of asymptotic solitons with curved lines of constant phase and varying amplitude and width

An Integrated Circuit Compatible Compact Package for Thermal Gas Flowmeters

An original packaging method suitable for integrated thermal mass flow sensors is presented. The method consists in the application of a plastic transparent adapter to the chip surface. The adapter is sealed to the chip surface by means of a thermal procedure. By this approach it is possible to selectively convey the fluid flow to reduced chip areas, avoiding contact with the pads. Fabrication and testing of a very compact flow sensor is described.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Charged Unruh effect on geon spacetimes

A topological geon black hole with gauge charges may have a gauge bundle that necessarily incorporates charge conjugation as a gauge symmetry. This happens for example for the Reissner-Nordstrom geon. We show that gauging the charge conjugation leaves an imprint in the Unruh effect: the geon's exterior region contains non-thermal correlations for particle pairs of the same, rather than opposite, charge. The phenomenon occurs also in topologically similar Rindler spacetimes with a background gauge field.Comment: 3 pages, talk given by David E. Bruschi at the 12th Marcel Grossmann Meetin