Search results

We explore the possibilities of using the complex Langevin equation to Monte Carlo generate configurations of gauge theories with static charges present in the action. Successful results are obtained for systems that possess nontrivial saddle-point (classical) solutions. For that reason the algorithm works impressively for two-dimensional U(1) in the entire β-range whereas for three- and four-dime

By Monte Carlo calculations on a 124 lattice we investigate four-dimensional SU(2) lattice gauge theory with respect to the conjecture that at large distances this theory reduces approximately to two-dimensional SU(2) lattice gauge theory. We find good numerical evidence for this conjecture. As a by-product we also measure the SU(2) string tension and find reasonable agreement with scaling. The "a

A neural network algorithm for finding tracks in high energy physics experiments is presented. The performance of the algorithm is explored on modest size samples with encouraging results. It is inherently parallel and thus suitable for execution on a conventional SIMD architecture. More important, it naturally lends itself to direct implementations in custom made hardware, which would permit real

A F77 package of adaptive artificial neural network algorithms, JETNET 2.0, is presented. Its primary target is the high energy physics community, but it is general enough to be used in any pattern-recognition application area. The basic ingredients are the multilayer perceptron back-propagation algorithm and the topological self-organizing map. The package consists of a set of subroutines, which

We calculate differential cross sections for exclusive double diffractive (EDD) production of open charm in proton-proton and proton-antiproton collisions. Sizeable cross sections are found. The EDD contribution constitutes about 1% of the total inclusive cross section for open charm production. A few differential distributions are shown and discussed. The EDD contribution falls faster both with t

This work presents a way of analysing photographs stored in Canon’s CR2-format in order to analyse the light intensity profile of the area where the photographs were taken. A set of underwater photographs of the habitat of the Cuttlefish, Sepia officinalis, were provided for this thesis. The light intensity profile of the habitat of the cuttlefish is of interest because of the unusual shape of its pupil

Stamcellsforskning har på senare tid lett till förhoppningar om att bota alla möjliga sorters sjukdomar. De stamceller som är mest flexibla och därför mest användbara finns i embryo. Att få tag på mänskliga embryon kan dock både vara dyrt och moraliskt problematiskt. Därför har forskare försökt att istället omprogrammera celler från vuxna individer. En sådan teknik som nyligen tagit fart är direkt

Gener fungerar som instruktioner för vad cellen skall producera. Det är aktiveringen och hämningen av gener som ger upphov till många olika typer av celler i människans kropp som till exempel hudceller, blodceller och nervceller. Dessa celler samarbetar med varandra för att tillsammans skapa den flercelliga organismen: människan. Det finns två huvudkategorier av celler i kroppen, somatiska celler Scientists are now able to directly convert one somatic cell type into another using a procedure known as direct lineage reprogramming or transdifferentiation. In this procedure, transcription factors which are important for initiating a rewriting of the gene expressions are introduced in the cell. One specific type of reprogramming involves generating dopamine producing neurons from human adult f

Dubbel ickebeskattning på grund av tillämpning av skatteavtal kan definieras som den skattemässiga effekt som inträder då varken hemviststaten eller källstaten har något beskattningsanspråk i förhållande till en viss inkomst men där inkomsten skulle ha beskattats av någon stat i frånvaro av skatteavtalet. Hittills har intresset och förståelsen för de bakomliggande orsakerna varit begränsad och det

Owing to their extreme crowding and high and variable extinction, stars in the Galactic Bulge, within ±2° of the Galactic plane, and especially those in the Nuclear Star Cluster, have only rarely been targeted for an analyses of their detailed abundances. There is also some disagreement about the high end of the abundance scale for these stars. It is now possible to obtain high dispersion, high S/

We report on recent new developments around the Astrometric Global Iterative Solution system. This includes the availability of an efficient Conjugate Gradient solver and the Generic Astrometric Calibration scheme that had been proposed a while ago. The number of primary stars to be included in the core solution is now believed to be significantly higher than the 100 Million that served as baselin

Methods of VUV electron beam ion trap (EBIT) spectroscopy are applied to the study of Pm-like tungsten (W13+). These data show that theory appears well capable of dealing with these multi-electron (61) ions, at least for high ionization stages. A comparison of other spectroscopic methods applied to the study of other ions of the Pm I sequence is also given, and finally a search for the Pm-like W l

A systematic study is carried out on the angular distribution and polarization of photons emitted following radiative-recombination of bare and He-like ions of Ne, Ar, Ni and Mo with a unidirectional electron beam. In order to incorporate the screening effect due to inner-shell electrons, a distorted wave method is used. Scaling rules for polarization of the photon following radiative recombinatio

We discuss the tracing of star formation histories with ESAs spaceastrometry mission GAIA, emphasizing the advantages of AGB stars for thepurpose. GAIAs microarcsecond-level astrometry, multi-band photometryand spectroscopy will provide individual distances, motions,T_eff, log g and [M/H for vast numbers of AGB stars in theGalaxy and beyond. Reliable ages of AGB stars can be determined t

Gene expression signatures consisting of tens to hundreds of genes have been found to be informative for different biological states. Recently, many computational methods have been proposed for biological interpretation of such signatures. However, there is a lack of methods for identifying cell signaling pathways whose deregulation result in an observed expression signature. We present a strategy

https://www.sam.lu.se/en/internal/article/new-member-faculty-board - 2026-05-27

Samhällsvården har under de senaste åren blivit hårt kritiserad i media. I synnerhet är det de särskilda ungdomshemmen som legat i fokus där man bl.a. har läst om övergrepp och kränkningar. Men den mediala uppmärksamheten har missat att belysa de systematiska fel som föreligger inom framförallt socialtjänsten när det gäller hanteringen av ungdomarnas rättigheter. Socialtjänsten brister i sin tillä

Optical region spectra for a number of upper main sequence chemically peculiar (CP) stars have been observed to study singly and doubly ionized praseodymium and neodymium lines. In order to improve existing atomic data of these elements, laboratory measurements have been carried out with the Lund VUV Fourier Transform Spectrometer (FTS). From these measurements wavelengths and hyperfine structure

HERA provides a unique possibility to investigate the dependence of multiple interactions on transverse interaction sizes through variation of the photon virtuality Q2. In order to observe effects of multiple interactions at Q2 substantially different from zero we have to look into regions of phase space where resolved processes dominate over direct ones. The forward jet production at small values