Dynamical generation and detection of entanglement in neutral leviton pairs

The entanglement of coherently split electron-hole pairs in an electronic conductor is typically not considered accessible due to particle number conservation and fermionic super-selection rules. We demonstrate here that current cross-correlation measurements at the outputs of an electronic Mach-Zehnder interferometer can nevertheless provide a robust witness of electron-hole entanglement. Specifically, we consider neutral excitations generated by modulating the transmission of an unbiased quantum point contact periodically in time. For an optimized modulation profile, an entangled state with one positively-charged leviton (a hole) and one negatively-charged leviton (an electron) gets delocalized over the two paths of the interferometer and is detected at the output arms. We evaluate the influence of finite electronic temperatures and dephasing corresponding to recent experiments.Comment: 5 pages, 3 figures, 1 page of Supplemental Materia

First European interception of the brown fir longhorn beetle, Callidiellum villosulum (Fairmaire, 1900) (Coleoptera, Cerambycidae)

A specimen of the brown fir longhorn beetle, Callidiellum villosulum villosulum found in Malta represents the first record of this invasive species for Europe. Historical details on world invasion of this species are provided as well as a short description, origin and biology. A brief pest risk analysis of this species is also presented.peer-reviewe

Coalescence of Euclidean geodesics on the Poisson-Delaunay triangulation

Let us consider Euclidean first-passage percolation on the Poisson-Delaunay triangulation. We prove almost sure coalescence of any two semi-infinite geodesics with the same asymptotic direction. The proof is based on an adapted Burton-Keane argument and makes use of the concentration property for shortest-path lengths in the considered graphs. Moreover, by considering the specific example of the relative neighborhood graph, we illustrate that our approach extends to further well-known graphs in computational geometry. As an application, we show that the expected number of semi-infinite geodesics starting at a given vertex and leaving a disk of a certain radius grows at most sublinearly in the radius.Comment: 21 pages, 7 figure

Information-not-thing: further problems with and alternatives to the belief that information is physical

In this short paper, we show that a popular view in information science, information-as-thing, fails to account for a common example of information that seems physical. We then demonstrate how the distinction between types and tokens, recently used to analyse Shannon information, can account for this same example by viewing information as abstract, and discuss existing definitions of information that are consistent with this approach. Dans ce court article nous montrons qu'une vision populaire en sciences de l'information, l'information en tant qu’une chose, échoue à rendre compte d'un exemple commun d'information qui semble physique. Nous démontrons ensuite comment la distinction type/token, utilisée récemment pour analyser l'information de Shannon, peut rendre compte de ce même exemple en considérant l'information comme abstraite, et nous discutons des définitions existantes de l’information qui sont compatibles avec cette approche

Maty's Biography of Abraham De Moivre, Translated, Annotated and Augmented

November 27, 2004, marked the 250th anniversary of the death of Abraham De Moivre, best known in statistical circles for his famous large-sample approximation to the binomial distribution, whose generalization is now referred to as the Central Limit Theorem. De Moivre was one of the great pioneers of classical probability theory. He also made seminal contributions in analytic geometry, complex analysis and the theory of annuities. The first biography of De Moivre, on which almost all subsequent ones have since relied, was written in French by Matthew Maty. It was published in 1755 in the Journal britannique. The authors provide here, for the first time, a complete translation into English of Maty's biography of De Moivre. New material, much of it taken from modern sources, is given in footnotes, along with numerous annotations designed to provide additional clarity to Maty's biography for contemporary readers.Comment: Published at http://dx.doi.org/10.1214/088342306000000268 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Exporting deflation? Chinese exports and Japanese prices

Between 1992 and 2002, the Japanese Import Price Index (IPI) registered a decline of almost 9 percent and Japan entered a period of deflation. We show that much of the correlation between import prices and domestic prices was due to formula biases. Had the IPI been computed using a pure Laspeyres index like the CPI, the IPI would have hardly moved at all. A Laspeyres version of the IPI would have risen 1 percentage point per year faster than the official index. Second we show that Chinese prices did not behave differently from the prices of other importers. Although Chinese prices are substantially lower than the prices of other exporters, they do not exhibit a differential trend. However, we estimate that the typical price per unit quality of a Chinese exporter fell by half between 1992 and 2005. Thus the explosive growth in Chinese exports is attributable to growth in the quality of Chinese exports and the increase in new products being exported by China.