Reply to Comment on "Quantum dense key distribution"

In this Reply we propose a modified security proof of the Quantum Dense Key Distribution protocol detecting also the eavesdropping attack proposed by Wojcik in his Comment.Comment: To appear on PRA with minor change

Massive stellar systems: observational challenges and perspectives in the E-ELT era

We introduce the empirical framework concerning optical and near-infrared (NIR) photometry of crowded stellar fields. In particular, we address the impact that linear detectors and analytical PSF played in improving the accuracy and the precision of multi-band color-magnitude diagrams (CMDs). We focus our attention on recent findings based on deep NIR images collected with Adaptive Optics (AO) systems at the 8-10m class telescopes and discuss pros and cons of the different approaches. We also discuss the estimate of the absolute age of globular clusters using a well defined knee along the lower main sequence. We mention the role which the current AO-assisted instruments will have in addressing longstanding astrophysical problems of the Galactic center. Finally, we outline the role of first generation of E-ELT instruments upon photometry and spectroscopy of crowded stellar fields

Recent experiments performed at "Carlo Novero" lab at INRIM on Quantum Information and Foundations of Quantum Mechanics

In this paper we present some recent work performed at "Carlo Novero" lab on Quantum Information and Foundations of Quantum Mechanics.Comment: Contribution to III international workshop "Recent advances in Foundations of Quantum Mechanics and Quantum Information. In memory of Carlo Novero

Two-fluid barotropic models for powder-snow avalanche flows

14 pages, 1 figure. Accepted to Springer series "Notes on Numerical Fluid Mechanics and Multidisciplinary Design". Other authors papers can be downloaded at http://www.lama.univ-savoie.fr/~dutykh/International audienceIn the present study we discuss several modeling issues of powder-snow avalanche flows. We take a two-fluid modeling paradigm. For the sake of simplicity, we will restrict our attention to barotropic equations. We begin the exposition by a compressible model with two velocities for each fluid. However, this model may become non-hyperbolic and thus, represents serious challenges for numerical methods. To overcome these issues, we derive a single velocity model as a result of a relaxation process. This model can be easily shown to be hyperbolic for any reasonable equation of state. Finally, an incompressible limit of this model is derived

Dynamics of black hole-neutron star binaries in young star clusters

Young star clusters are likely the most common birthplace of massive stars across cosmic time and influence the formation of compact binaries in several ways. Here, we simulate the formation of black hole-neutron star binaries (BHNSs) in young star clusters, by means of the binary population synthesis code MOBSE interfaced with the N-body code NBODY6++GPU. BHNSs formed in young star clusters (dynamical BHNSs) are significantly more massive than BHNSs formed from isolated binaries (isolated BHNSs): ~40 per cent of the dynamical BHNS mergers have a total mass of > 15 M0, while only ~0.01 per cent of the isolated BHNS mergers have mass in excess of this value. Hence, our models strongly support a dynamical formation scenario for GW190814, given its total mass of ~26 M0, if this event is a BHNS merger. All our dynamical BHNSs are ejected from their parent star cluster before they reach coalescence. Thus, a significant fraction of BHNS mergers occurring in the field might have originated in a young star cluster. The mass spectrum of BHNS mergers from gravitational-wave detections will provide a clue to differentiate between dynamical and isolated formation of BHNSs

Taille des particules de neige dans une avalanche de neige poudreuse

International audienceLittle quantitative information is available concerning the size of ice particles in the turbulent clouds of powder-snow avalanches. To quantify particle size distributions, we have developed an experimental device that collects particles in real-scale powder avalanches. The device was placed on the concrete bunker of the Swiss Vall´ee de la Sionne avalanche dynamics test site. On 31 January 2003, a large powder-snow avalanche struck the bunker and we were able to collect particle samples. The collected particles have been photographed and the pictures digitized. An image analysis tool allows us to determine an equivalent particle radius. The captured particles have a geometric mean of 0.16mm; the largest particles were 0.8mm in size and the smallest particles 0.03mm

Determining the idle time of a tiling: new results

In the framework of fully permutable loops, tiling has been studied extensively as a sourceto-source program transformation. We build upon recent results by Hogsted, Carter, and Ferrante [12], who aim at determining the cumulated idle time spent by all processors while executing the partitioned (tiled) computation domain. We propose new, much shorter proofs of all their results and extend these in several important directions. More precisely, weprovide an accurate solution for all values of the rise parameter that relates the shape of the iteration space to that of the tiles, and for all possible distributions of the tiles to processors. In contrast, the authors in [12] deal only with a limited number of cases and provide upper bounds rather than exact formulas