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Hipparcos observations of double stars, mainly A and F primaries, aremodelled in order to check the statistics of double-star solutions inthe Hipparcos Catalogue and to set quantitative limits on binarydistributions. The number of companions per primary is estimated to 0.25+/-0.05 for semi-major axes from 1 to 10 AU, and to 0.43 +/-0.20 for therange 10--100 AU. The total multiplicity found is betw
The spectroscopic data mercury (Hg) I and Hg II was analyzed from beam-foil spectroscopy. The wavelength was found to be of course fixed and independent of the light source and recording conditions. It was found that if the calculated branching ratio was correct, then the Hg II was an important constituent of fluorescent light tube plasmas. The wavelength region from 40 to 600 nm in overlapping wa
In this paper we consider a general problem of astrophysical lasersoperating with optical pumping by accidental resonance (PAR) with strongspontaneous emission lines of other elements. The origin of populationinversion and the coefficient of amplification due to the opticalexcitation of atoms (ions) by a four-level scheme with PAR are analyzed.We elucidate conclusively the question of the manifest
The motivation for using a zero-dispersion monochromator as a band-pass filter with a Fourier transform spectrometer is discussed, and the design of such an instrument is presented. Benefits in performance over commercial band-pass filters are demonstrated. In addition the advantages of using the second optical output of the spectrometer are discussed, particularly with respect to absorption spect
In this contribution we present some preliminary results on the dynamical evolution of two planet systems around stellar hosts evolving from the main sequence to the white dwarf phase. The aim is to study the instabilities triggered by stellar evolution that may bring planets onto the stellar surface or produce planetary scale collisions (hence debris) that could explain the metallic atmospheric p
Uppsatsen syftar till att ge läsaren en god inblick i den generella rättsliga regleringen av asyl-och sexualbrottsrätten. Därutöver behandlas en rad frågor som korrelerar mellan dessa rättsområden med fokus på den gemensamma beröringspunkten beträffande momentet som vanligen blir avgörande för utgången i målen; tillförlitlighets- samt trovärdighetsbedömningen. En rad nya aspekter på den i praxis f
Bildandet av planeter äger rum i skivor av gas, stoft och is runt nybildade stjärnor. Den här processen är inte helt förstådd men det första steget tros vara växten från mikrometer-stora stoftkorn till mm-cm-stora småstenar genom sammanväxande kollisioner. Vid de här storlekarna studsar stenarna eller går sönder snarare än fastnar i varandra när de kolliderar så tillväxten avstannar. Dessutom kännPlanets form in protoplanetary discs of gas, dust and ice around newborn stars. In the Solar System, not only planets are found as a result from the time of planet formation, but also remnant planetesimals in the form of asteroids, Kuiper belt objects and comets. Recent observations, e.g. by the space mission Rosetta, have found that comets are porous objects barely able to hold themselves togethe
This article is over 5 years old, and the information may therefore be outdated. The Ravensbrück archive at the University Library is unique in the world. Nowhere else is there a collection of 500 testimonies from concentration camp survivors, recorded so soon after their terrible ordeal. Now, their stories from Ravensbrück will be made available in digital form, so that anyone can search the arch
https://www.staff.lu.se/article/important-testimonies-digitised - 2026-05-27
The technological development has provided the art scene with many new opportunities of including the spectator as an active part of an artwork. Moreover, one could argue that some artworks have grown to rely on the spectators participation to function to its full extent. This function includes both a physical function as well as an ability to create emotions and a relatable- meaning within the sp
Here we present a single-cell-based model of cell-cell interactions in a growing yeast colony. We examine the influence of multiple factors on the colony morphology and switch to a foraging growth behavior. We find that the cell-growth inhibition by neighboring cells along with polar division growth patterns are the most significant factors driving the exploratory behavior of a colony.
The Apollonian tiling of the plane into circles is analyzed with respect to its group properties. The relevant group, which is noncompact and discrete, is found to be identical to the symmetry group of a particular geometric tree graph in hyperbolic three-space. A linear recursive method to compute the radii is obtained. Certain modifications of the problem are investigated, and relations to other
The aim of this study is to look at the discourses of European identity from two different angles. The first angle is European identity from an EU perspective which EU seeks to create amongst the European citizens. This is studied in the book European Foreign Policy, consisting of legislations and treaties connected to the Common Foreign and Security Policy. The second angle is the images of Europ
We compare different procedures for combining fixed-order tree-level matrix-element generators with parton showers. We use the case of W-production at the Tevatron and the LHC to compare different implementations of the so-called CKKW and MLM schemes using different matrix-element generators and different parton cascades. We find that although similar results are obtained in all cases, there are i
Event generators play a crucial role in the exploration of LHC physics. This presentation summarizes news and plans for the three general-purpose pp generators HERWIG, PYTHIA and SHERPA, as well as briefer notes on a few other generators. Common themes, such as the matching and merging between matrix elements and parton showers, are highlighted. Other topics include a historical introduction, from
An overview is given of Chiral Perturbation Theory and various applications to eta decays. In particular. the main decay eta --> 3pi is discussed at the one-loop level, and estimates of the higher order corrections are given. The importance of p(6) and higher order effects in double Dalitz and eta --> pi(0)gammagamma decays is pointed out. In all these cases the need for new experimental results i
We discuss some of the effects of twisted boundary conditions in finite volume using continuum SU(3) Chiral Perturbation Theory. We point out how broken cubic symmetry affects the definitions of quantities such as form-factors. Using the π+ as an example, we give one loop results for the mass, decay constants and electromagnetic form-factor and illustrate how the relevant Ward identities are satis
We show that the geometry of the Wilson lines, entering the operator definition of the transverse-momentum dependent parton distributions and that of the soft factor, follows from the kinematics of the underlying physical process in conjunction with the gauge invariance of the QCD Lagrangian. We demonstrate our method in terms of concrete examples and determine the paths of the associated Wilson l
This review contains an overview of strong interaction effects in weak decays starting with a historical introduction. It contains a short overview of semileptonic decays and their relevance for measuring CKM matrix elements. The main part is devoted to the theoretical calculation on nonleptonic matrix elements relevant for K0-K0bar mixing and K to pi pi decays. It concludes
