197479182
Remarks on the representation theory of the Moyal plane
The authors would like to thank the referee for constructive suggestions. J. M. Isidro thanks Max-Planck-Institut fur Gravitationsphysik (Albert-Einstein-Institut) Golm, Germany, for hospitality. This paper has been supported by Universidad Politecnica de Valencia under Grant PAID-06-09, and by Generalitat Valenciana Spain.
15710118
The Ricci flow on Riemann surfaces
We establish a 1-to-1 relation between metrics on compact Riemann surfaces without boundary, and mechanical systems having those surfaces as configuration spaces.
7346735
On the Ricci flow and emergent quantum mechanics
The Ricci flow equation of a conformally flat Riemannian metric on a closed 2–dimensional configuration space is analysed. It turns out to be equivalent to the classical Hamilton–Jacobi equation for a point particle subject to a potential function that is proportional to the Ricci scalar curvature of configuration space. This allows one to obtain Schrodinger quantum mechanics from Perelman's action functional: the quantum–mechanical wavefunction is the exponential of i times the conformal factor of the metric on configuration space. We explore links with the recently discussed emergent quantum mechanics.
122909473
New evidence of dominant processing effects in standard and oxygenated silicon diodes after neutron irradiation
Abstract Silicon diodes processed on standard and oxygenated silicon substrates by three different manufacturers have been irradiated by neutrons in a nuclear reactor. The leakage current density ( J D ) increase is linear with the neutron fluence. J D and its annealing curve at 80°C do not present any sizeable dependence on substrate oxygenation and/or manufacturing process. The acceptor introduction rate ( β ) of the effective substrate doping concentration ( N eff ) is independent from the oxygen concentration when standard and oxygenated devices from the same manufacturer are considered. On the contrary, β significantly varies from one manufacturer to another showing that the β dependence on the particular process can be important, overtaking the small substrate oxygenation effect. Finally, the average saturation value of the N eff reverse annealing is slightly lower for the oxygenated samples, pointing out a positive effect of the substrate oxygenation even for devices irradiated by neutrons.
119273827
A MECHANICS FOR THE RICCI FLOW
We construct the classical mechanics associated with a conformally flat Riemannian metric on a compact, n-dimensional manifold without boundary. The corresponding gradient Ricci flow equation turns out to equal the time-dependent Hamilton–Jacobi equation of the mechanics so defined.
109841263
Bump bonding of pixel systems
Abstract A pixel detector consists of an array of radiation sensing elements which is connected to an electronic read-out unit. Many different ways of making this connection between these two different devices are currently being used or considered to be used in the next future. Bonding techniques such as flip chip technology can present real advantages because they allow very fine pitch and a high number of I / O s. This paper presents a review of the different flip chip technologies available and their suitability for manufacturing pixel detectors. The particular problems concerning testing of pixel detectors and thermal issues related to them are pointed out.
118747333
Quark contribution to the gluon Regge trajectory at NLO from the high energy effective action
The two loop (NLO) diagrams with quark content contributing to the gluon Regge trajectory are computed within the framework of Lipatov’s eective action for QCD, using the regularization procedure for longitudinal divergencies recently proposed by two of us in [1]. Perfect agreement with previous results in the literature is found, providing a robust check of the regularization prescription and showing that the high energy eective action is a very useful computational tool in the quasi-multi-Regge limit.