Noise in strong lensing cosmography

Giant arcs in strong lensing galaxy clusters can provide a purely geometric determination of cosmological parameters, such as the dark energy density and equation of state. We investigate sources of noise in cosmography with giant arcs, focusing in particular on errors induced by density fluctuations along the line-of-sight, and errors caused by modeling uncertainties. We estimate parameter errors in two independent ways, first by developing a Fisher matrix formalism for strong lensing parameters, and next by directly ray-tracing through N-body simulations using a multi-plane lensing code. We show that for reasonable power spectra, density fluctuations from large-scale structure produce > 100% errors in cosmological parameters derived from any single sightline, precluding the use of individual clusters or golden lenses to derive accurate cosmological constraints. Modeling uncertainties similarly can lead to large errors, and we show that the use of parametrized mass models in fitting strong lensing clusters can significantly bias the inferred cosmological parameters. We lastly speculate on means by which these errors may be corrected.Comment: 7 pages, submitted to Ap

Intrahepatisches Sarkom der follikulär-dendritischen Zellen

Zusammenfassung: Wir berichten über ein primär intrahepatisches Sarkom der follikulär-dendritischen Zellen, das bei einer 76-jährigen Patientin auf dem Boden eines Morbus Castleman vom hyalin-vaskulären Typ auftrat. Wir diskutieren die klinisch-pathologischen Befunde, die Pathogenese und das differenzialdiagnostische Vorgehen bei diesem seltenen Tumorty

Double radio peak and non-thermal collimated ejecta in RS Ophiuchi following the 2006 outburst

We report Multi-Element Radio-Linked Interferometer Network, Very Large Array, One-Centimetre Radio Array, Very Long Baseline Array (VLBA), Effelsberg and Giant Metrewave Radio Telescope observations beginning 4.5 days after the discovery of RS Ophiuchi undergoing its 2006 recurrent nova outburst. Observations over the first 9 weeks are included, enabling us to follow spectral development throughout the three phases of the remnant development. We see dramatic brightening on days 4 to 7 at 6 GHz and an accompanying increase in other bands, particularly 1.46 GHz, consistent with transition from the initial ‘free expansion’ phase to the adiabatic expansion phase. This is complete by day 13 when the flux density at 5 GHz is apparently declining from an unexpectedly early maximum (compared with expectations from observations of the 1985 outburst). The flux density recovered to a second peak by approximately day 40, consistent with behaviour observed in 1985. At all times the spectral index is consistent with mixed non-thermal and thermal emission. The spectral indices are consistent with a non-thermal component at lower frequencies on all dates, and the spectral index changes show that the two components are clearly variable. The estimated extent of the emission at 22 GHz on day 59 is consistent with the extended east and west features seen at 1.7 GHz with the VLBA on day 63 being entirely non-thermal. We suggest a two-component model, consisting of a decelerating shell seen in mixed thermal and non-thermal emission plus faster bipolar ejecta generating the non-thermal emission, as seen in contemporaneous VLBA observations. Our estimated ejecta mass of 4 ± 2 × 10−7 M⊙ is consistent with a white dwarf (WD) mass of 1.4 M⊙. It may be that this ejecta mass estimate is a lower limit, in which case a lower WD mass would be consistent with the data

Phase structure and monopoles in U(1) gauge theory

We investigate the phase structure of pure compact U(1) lattice gauge theory in 4 dimensions with the Wilson action supplemented by a monopole term. To overcome the suppression of transitions between the phases in the simulations we make the monopole coupling a dynamical variable. We determine the phase diagram and find that the strength of the first order transition decreases with increasing weight of the monopole term, the transition thus ultimately getting of second order. After outlining the appropriate topological characterization of networks of currents lines, we present an analysis of the occurring monopole currents which shows that the phases are related to topological properties.Comment: 22 pages (latex), 14 figures (available upon request), BU-HEP 94-

Kualitas Produk, Harga, dan Kualitas Layanan, Pengaruhnya terhadap Kepuasan Pelanggan Kartu Prabayar Tri di Kelurahan Wawalintouan Tondano Barat

Persaingan dalam bisnis operator seluler saat ini kian meningkat seiring berkembangnya teknologi komunikasi. Hal ini menuntut Perusahaan untuk terus berinovasi dalam meningkatkan kualitas produk serta layanannya dan lebih cermat dalam menentukan harga agar Perusahan dapat bersaing dengan kompetitornya. Tujuan penelitian untuk mengetahui pengaruh kualitas produk, harga serta kualitas layanan terhadap kepuasan pelanggan kartu prabayar Tri di Kelurahan Wawalintouan Tondano Barat. Penelitian ini menggunakan metode penelitian asosiatif dengan teknik analisis regresi berganda. Sampel yang digunakan 100 responden. Hasil penelitian menunjukan kualitas produk, harga serta kualitas layanan secara simultan dan parsial berpengaruh signifikan terhadap kepuasan pelanggan kartu prabayar Tri. Manajemen PT. Hutchison 3, sebaiknya tidak cepat puas dengan pencapaian yang diperoleh, melainkan terus berinovasi agar mampu meningkatkan kualitas produk, dan layanannya sehingga Perusahaan dapat tetap bertahan mengingat persaingan dalam bidang telekomunikasi semakin ketat, juga dikarenakan semakin meningkatnya selera konsumen sebagai dampak dari perkembangan zaman yang semakin modern. . Kata kunci : kualitas produk, harga, kualitas layanan, kepuasan pelangga

Magnetic properties of Quantum Corrals from first principles calculations

We present calculations for electronic and magnetic properties of surface states confined by a circular quantum corral built of magnetic adatoms (Fe) on a Cu(111) surface. We show the oscillations of charge and magnetization densities within the corral and the possibility of the appearance of spin--polarized states. In order to classify the peaks in the calculated density of states with orbital quantum numbers we analyzed the problem in terms of a simple quantum mechanical circular well model. This model is also used to estimate the behaviour of the magnetization and energy with respect to the radius of the circular corral. The calculations are performed fully relativistically using the embedding technique within the Korringa-Kohn-Rostoker method.Comment: 14 pages, 9 figures, submitted to J. Phys. Cond. Matt. special issue on 'Theory and Simulation of Nanostructures

Market Disequilibria and Their Influence on Small Retail Store Pricing

In this paper a quantitative model is developed to explain differences in average store price levels. We assume that stores may operate under different economic regimes, that is, under excess capacity or excess demand. Prices are expected to be higher than average in case of an excess demand regime and lower in an excess capacity situation. Actual information regarding the regime that applies to each individual store is not available. Therefore, we propose to use a so-called 'switching model' with endogenous regime choice to analyse the store price differences. The model developed m the paper is estimated using four largely differing types of stores from the Durch retail trade. These samples consist mainly of small stores

Multicanonical Hybrid Monte Carlo: Boosting Simulations of Compact QED

We demonstrate that substantial progress can be achieved in the study of the phase structure of 4-dimensional compact QED by a joint use of hybrid Monte Carlo and multicanonical algorithms, through an efficient parallel implementation. This is borne out by the observation of considerable speedup of tunnelling between the metastable states, close to the phase transition, on the Wilson line. We estimate that the creation of adequate samples (with order 100 flip-flops) becomes a matter of half a year's runtime at 2 Gflops sustained performance for lattices of size up to 24^4.Comment: 15 pages, 8 figure

Macrospin approximation and quantum effects in models for magnetization reversal

The thermal activation of magnetization reversal in magnetic nanoparticles is controlled by the anisotropy-energy barrier. Using perturbation theory, exact diagonalization and stability analysis of the ferromagnetic spin-s Heisenberg model with coupling or single-site anisotropy, we study the effects of quantum fluctuations on the height of the energy barrier. Opposed to the classical case, there is no critical anisotropy strength discriminating between reversal via coherent rotation and via nucleation/domain-wall propagation. Quantum fluctuations are seen to lower the barrier depending on the anisotropy strength, dimensionality and system size and shape. In the weak-anisotropy limit, a macrospin model is shown to emerge as the effective low-energy theory where the microscopic spins are tightly aligned due to the ferromagnetic exchange. The calculation provides explicit expressions for the anisotropy parameter of the effective macrospin. We find a reduction of the anisotropy-energy barrier as compared to the classical high spin-s limit.Comment: 10 pages, 11 figure