L-functions with large analytic rank and abelian varieties with large algebraic rank over function fields

The goal of this paper is to explain how a simple but apparently new fact of linear algebra together with the cohomological interpretation of L-functions allows one to produce many examples of L-functions over function fields vanishing to high order at the center point of their functional equation. The main application is that for every prime p and every integer g>0 there are absolutely simple abelian varieties of dimension g over Fp(t) for which the BSD conjecture holds and which have arbitrarily large rank.Comment: To appear in Inventiones Mathematica

An integrated approach to modelling the fluid-structure interaction of a collapsible tube

The well known collapsible tube experiment was conducted to obtain flow, pressure and materials property data for steady state conditions. These were then used as the boundary conditions for a fully coupled fluid-structure interaction (FSI) model using a propriety computer code, LS-DYNA. The shape profiles for the tube were also recorded. In order to obtain similar collapse modes to the experiment, it was necessary to model the tube flat, and then inflate it into a circular profile, leaving residual stresses in the walls. The profile shape then agreed well with the experimental ones. Two departures from the physical properties were required to reduce computer time to an acceptable level. One of these was the lowering of the speed of sound by two orders of magnitude which, due to the low velocities involved, still left the mach number below 0.2. The other was to increase the thickness of the tube to prevent the numerical collapse of elements. A compensation for this was made by lowering the Young's modulus for the tube material. Overall the results are qualitatively good. They give an indication of the power of the current FSI algorithms and the need to combine experiment and computer models in order to maximise the information that can be extracted both in terms of quantity and quality

On Synchronization in a Lattice Model of Pulse-Coupled Oscillators

We analyze the collective behavior of a lattice model of pulse-coupled oscillators. By means of computer simulations we find the relation between the intrinsic dynamics of each member of the population and their mutual interaction that ensures, in a general context, the existence of a fully synchronized regime. This condition turns out to be the same than the obtained for the globally coupled population. When the condition is not completely satisfied we find different spatial structures. This also gives some hints about self-organized criticality.Comment: 4 pages, RevTex, 1 PostScript available upon request, To appear in Phys. Rev. Let

First-principles extrapolation method for accurate CO adsorption energies on metal surfaces

We show that a simple first-principles correction based on the difference between the singlet-triplet CO excitation energy values obtained by DFT and high-level quantum chemistry methods yields accurate CO adsorption properties on a variety of metal surfaces. We demonstrate a linear relationship between the CO adsorption energy and the CO singlet-triplet splitting, similar to the linear dependence of CO adsorption energy on the energy of the CO 2$\pi$* orbital found recently {[Kresse {\em et al.}, Physical Review B {\bf 68}, 073401 (2003)]}. Converged DFT calculations underestimate the CO singlet-triplet excitation energy $\Delta E_{\rm S-T}$, whereas coupled-cluster and CI calculations reproduce the experimental $\Delta E_{\rm S-T}$. The dependence of $E_{\rm chem}$ on $\Delta E_{\rm S-T}$ is used to extrapolate $E_{\rm chem}$ for the top, bridge and hollow sites for the (100) and (111) surfaces of Pt, Rh, Pd and Cu to the values that correspond to the coupled-cluster and CI $\Delta E_{\rm S-T}$ value. The correction reproduces experimental adsorption site preference for all cases and obtains $E_{\rm chem}$ in excellent agreement with experimental results.Comment: Table sent as table1.eps. 3 figure

The Quality of Legal Dictionaries::An assesment

In this article, the quality of the different bilingual legal dictionaries between the languages of the Member States of the European Union will be assessed. In order to do so, some general remarks will be made first about problems with translating legal terminology. Based on those remarks, criteria for reliable bilingual dictionaries will be formulated in the next section. Finally, these criteria will be applied on the available bilingual dictionaries containing the legal language used by one or more EU Member States. To illustrate this, we have attached an updated bibliography encompassing about 200 recently published bilingual and multilingual legal dictionaries in the European Union. The bibliography in the Annex will be the evidence for our final conclusion that most legal dictionaries must be classified as a word list, which implies here that they are of dubious quality. To date, few legal dictionaries have attempted to meet our criteria. Dictionaries that are based on comparative legal research, on the other hand, offer advantages that render them useful to professional translators

The Dubious Quality of Legal Dictionaries

As a consequence of the still increasing transnational commercial and scholarly cooperation and exchange, more and more often legal information has to be translated. Sometimes the content of legal documents (contracts, statutory provisions, books and articles on legal topics and so on) has to be translated into another language. But even more frequently, information on rules from one legal system has to be provided in the legal language of another legal system. In both cases the translator or the lawyer involved is confronted with difficulties of legal translation. In both cases bilingual legal dictionaries could play an important role in the translating process by providing translation suggestions and information on the linguistic context of terms in the target language, such as specific noun-verb combinations, or typical collocations. It is, therefore, not really surprising that publishing houses are offering numerous bilingual legal dictionaries to translators and lawyers. To translate between the different languages of the Member States of the European Union (EU) about one hundred seventy bilingual legal dictionaries are available. Regrettably, the quality of most of these dictionaries is poor to extremely bad. Only a few dictionaries are of good quality. It seems to us that many authors or compilers of bilingual legal dictionaries do not understand how legal translations should be made. They simply make a list of legal terms in the source language and give for each term one or more words from the target language as translation without any further information on the legal context. Because of the system-specificity of legal terminology, this kind of dictionaries is practically useless. In this article, the quality of the different bilingual legal dictionaries between the languages of the Member States of the European Union will be assessed. In order to do so, some general remarks will be made first about problems with translating legal terminology. Based on those remarks, criteria for reliable bilingual dictionaries will be formulated in the next section. Finally, these criteria will be applied on the available bilingual dictionaries containing the legal language used by one or more EU Member States. In addition, statistics are presented in order to give an impression between which legal languages of the Member States of the EU bilingual legal dictionaries are available

Good Gottesman Kitaev Preskill codes from the NTRU cryptosystem

We introduce a new class of random Gottesman Kitaev Preskill GKP codes derived from the cryptanalysis of the so called NTRU cryptosystem. The derived codes are good in that they exhibit constant rate and average distance scaling amp; 916; amp; 8733; amp; 8730;n with high probability, where n is the number of bosonic modes, which is a distance scaling equivalent to that of a GKP code obtained by concatenating single mode GKP codes into a qubit quantum error correcting code with linear distance. The derived class of NTRU GKP codes has the additional property that decoding for a stochastic displacement noise model is equivalent to decrypting the NTRU cryptosystem, such that every random instance of the code naturally comes with an efficient decoder. This construction highlights how the GKP code bridges aspects of classical error correction, quantum error correction as well as post quantum cryptography. We underscore this connection by discussing the computational hardness of decoding GKP codes and propose, as a new application, a simple public key quantum communication protocol with security inherited from the NTRU cryptosyste

Constraints on Dark Matter Annihilation in Clusters of Galaxies with the Fermi Large Area Telescope

Nearby clusters and groups of galaxies are potentially bright sources of high-energy gamma-ray emission resulting from the pair-annihilation of dark matter particles. However, no significant gamma-ray emission has been detected so far from clusters in the first 11 months of observations with the Fermi Large Area Telescope. We interpret this non-detection in terms of constraints on dark matter particle properties. In particular for leptonic annihilation final states and particle masses greater than ~200 GeV, gamma-ray emission from inverse Compton scattering of CMB photons is expected to dominate the dark matter annihilation signal from clusters, and our gamma-ray limits exclude large regions of the parameter space that would give a good fit to the recent anomalous Pamela and Fermi-LAT electron-positron measurements. We also present constraints on the annihilation of more standard dark matter candidates, such as the lightest neutralino of supersymmetric models. The constraints are particularly strong when including the fact that clusters are known to contain substructure at least on galaxy scales, increasing the expected gamma-ray flux by a factor of ~5 over a smooth-halo assumption. We also explore the effect of uncertainties in cluster dark matter density profiles, finding a systematic uncertainty in the constraints of roughly a factor of two, but similar overall conclusions. In this work, we focus on deriving limits on dark matter models; a more general consideration of the Fermi-LAT data on clusters and clusters as gamma-ray sources is forthcoming.Comment: accepted to JCAP, Corresponding authors: T.E. Jeltema and S. Profumo, minor revisions to be consistent with accepted versio

Observation of the decay \psip\rar\kstark

Using 14 million $\psi(2S)$ events collected with the BESII detector, branching fractions of \psip\rar\kstarkpm and \kstarknn are determined to be: \calB(\psip\rar\kstarkpm)=(2.9^{+1.3}_{-1.7}\pm0.4)\times 10^{-5} and \calB(\psip\rar\kstarknn)=(13.3^{+2.4}_{-2.7}\pm1.9)\times 10^{-5}. The results confirm the violation of the "12%" rule for these two decay channels with higher precision. A large isospin violation between the charged and neutral modes is observed.Comment: 5 pages, 3 figure