Gluon production and diffraction in the dipole picture

Using the eikonal approximation, we show that inclusive gluon production is related to the scattering of a gluon-gluon dipole while diffractive gluon production in DIS is related to a two-$q\bar q$ dipole scattering amplitude. Hence diffractive photon dissociation cross-sections are observables that provide potential information on dipole correlations, which represent an open issue in high-energy QCD.Comment: 4 pages, 2 figures, Proceedings of the 10th International Baryons Conference (Baryons04), Ecole Polytechnique, Palaiseau, France, October 25-29 200

Asymptotic perfect fluid dynamics as a consequence of AdS/CFT

We study the dynamics of strongly interacting gauge-theory matter (modelling quark-gluon plasma) in a boost-invariant setting using the AdS/CFT correspondence. Using Fefferman-Graham coordinates and with the help of holographic renormalization, we show that perfect fluid hydrodynamics emerges at large times as the unique nonsingular asymptotic solution of the nonlinear Einstein equations in the bulk. The gravity dual can be interpreted as a black hole moving off in the fifth dimension. Asymptotic solutions different from perfect fluid behaviour can be ruled out by the appearance of curvature singularities in the dual bulk geometry. Subasymptotic deviations from perfect fluid behaviour remain possible within the same framework.Comment: 19 pages, 1 figure; v2: free streaming example changed to s=1; conclusions unchange

A numerical relativity approach to the initial value problem in asymptotically Anti-de Sitter spacetime for plasma thermalization - an ADM formulation

This article studies a numerical relativity approach to the initial value problem in Anti-de Sitter spacetime relevant for dual non-equilibrium evolution of strongly coupled non-Abelian plasma undergoing Bjorken expansion. In order to use initial conditions for the metric obtained in arXiv:0906.4423 we introduce new, ADM formalism-based scheme for numerical integration of Einstein's equations with negative cosmological constant. The key novel element of this approach is the choice of lapse function vanishing at fixed radial position, enabling, if needed, efficient horizon excision. Various physical aspects of the gauge theory thermalization process in this setup have been outlined in our companion article arXiv:1103.3452. In this work we focus on the gravitational side of the problem and present full technical details of our setup. We discuss in particular the ADM formalism, the explicit form of initial states, the boundary conditions for the metric on the inner and outer edges of the simulation domain, the relation between boundary and bulk notions of time, the procedure to extract the gauge theory energy-momentum tensor and non-equilibrium apparent horizon entropy, as well as the choice of point for freezing the lapse. Finally, we comment on various features of the initial profiles we consider.Comment: 25 pages, 9 figures, 1 table; see also the companion article arXiv:1103.3452; v2: typos fixed; v3: references added and updated, publishe

The importance of unknows in Epidemiologic studies

Journal Article1. Epidemiologic study data often include omitted/unobtainable responses (unknowns). In most cases, unknowns are eliminated during data-reduction to facilitate analysis. We examined the effect that elimination of unknowns would have on mortality calculations using data on newborns admitted to a newborn intensive care unit (NICU). 2. Data were divided into unknown (omitted/unobtainable), abnormal and normal response groups. Forty-three factors with at least four unknown responses recorded during 1984 were selected for analysis. NICU mortality (number of NICU deaths per 100 NICU admissions) was selected as the outcome indicator. In order to quantify the effects of eliminating unknowns, NICU mortality rate ratios (NMRR) were calculated, by factor, for abnormals, normals and knowns (abnormals and normals) both without and with knowns

Cervical cancer mortality in young adult European women

Background: The process of social, political and economic transformation, which took place in Central and Eastern Europe in the early 90's, has affected many spheres of Europeans' lives, including health-associated issues. These changes also had an impact on mortality rates due to cervical cancer (CC). Therefore, the aim of this study was to analyse CC mortality trends in Europe after 1990. Methods: Data on death due to CC, uterine cancers and unspecified uterine cancers, in women aged 20\u201344, were taken from the WHO Mortality Database. Trends in European countries between 1990 and 2017 were assessed using the Joinpoint Regression Program. Results: Most of the countries experienced a decrease in CC mortality. Although the lowest rates were observed in EU15 Member States, the highest decreases were observed in Central and Eastern Europe. However, there are still differences in mortality in these countries. There are also a few countries like Belarus, Latvia and Ukraine, which experienced an increase in mortality. The range of mortality across Europe in 2017 was between 0.6 and 5.2/100,000 women. Conclusions: It is essential to introduce well-organised screening programmes for early detection of CC with coverage of a correspondingly high percentage of the population, particularly in East-Central Europe, as well as to introduce high-coverage HPV vaccination in all European countries

Relaxation mechanisms of the persistent spin helix

We study the lifetime of the persistent spin helix in semiconductor quantum wells with equal Rashba- and linear Dresselhaus spin-orbit interactions. In order to address the temperature dependence of the relevant spin relaxation mechanisms we derive and solve semiclassical spin diffusion equations taking into account spin-dependent impurity scattering, cubic Dresselhaus spin-orbit interactions and the effect of electron-electron interactions. For the experimentally relevant regime we find that the lifetime of the persistent spin helix is mainly determined by the interplay of cubic Dresselhaus spin-orbit interaction and electron-electron interactions. We propose that even longer lifetimes can be achieved by generating a spatially damped spin profile instead of the persistent spin helix state.Comment: 12 pages, 2 figure

Viscous hydrodynamics relaxation time from AdS/CFT

We consider an expanding boost-invariant plasma at strong coupling using the AdS/CFT correspondence for N=4 SYM. We determine the relaxation time in second order viscous hydrodynamics and find that it is around thirty times shorter than weak coupling expectations. We find that the nonsingularity of the dual geometry in the string frame necessitates turning on the dilaton which leads to a nonvanishing expectation value for tr F^2 behaving like tau^(-10/3).Comment: 10 pages, Mathematica script included in the source; v2: typo in (28) fixed, statement about electric/magnetic modes correcte

Dynamical tachyons on fuzzy spheres

We study the spectrum of off-diagonal fluctuations between displaced fuzzy spheres in the BMN plane wave matrix model. The displacement is along the plane of the fuzzy spheres. We find that when two fuzzy spheres intersect at angles classical tachyons develop and that the spectrum of these modes can be computed analytically. These tachyons can be related to the familiar Nielsen-Olesen instabilities in Yang-Mills theory on a constant magnetic background. Many features of the problem become more apparent when we compare with maximally supersymmetric Yang-Mills on a sphere, of which this system is a truncation. We also set up a simple oscillatory trajectory on the displacement between the fuzzy spheres and study the dynamics of the modes as they become tachyonic for part of the oscillations. We speculate on their role regarding the possible thermalization of the system.Comment: 34 pages, 4 figures; v2: 35 pages, expanded sec. 4.3, added reference