Gutzwiller-Correlated Wave Functions: Application to Ferromagnetic Nickel

Ferromagnetic Nickel is the most celebrated iron group metal with pronounced discrepancies between the experimental electronic properties and predictions of density functional theories. In this work, we show in detail that the recently developed multi-band Gutzwiller theory provides a very good description of the quasi-particle band structure of nickel. We obtain the correct exchange splittings and we reproduce the experimental Fermi-surface topology. The correct (111)-direction of the magnetic easy axis and the right order of magnitude of the magnetic anisotropy are found. Our theory also reproduces the experimentally observed change of the Fermi-surface topology when the magnetic moment is oriented along the (001)-axis. In addition to the numerical study, we give an analytical derivation for a much larger class of variational wave-functions than in previous investigations. In particular, we cover cases of superconductivity in multi-band lattice systems.Comment: 35 pages, 3 figure

Governing Boards and Profound Organizational Change in Hospitals

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69047/2/10.1177_107755878904600204.pd

Is basal metabolic rate associated with recruit production and survival in free-living house sparrows?

Life history theory predicts that available energy is limited and needs to be allocated among different processes such as growth, reproduction and self-maintenance. Basal metabolic rate (BMR), a common measure of an animal's maintenance cost, is therefore believed to be a trait of ecological and evolutionary significance. However, although BMR is often assumed to be correlated with fitness, its association with individual variation in fitness in free-living populations is virtually unknown. We examined the relationship between BMR in late winter prior to the breeding season and recruit production (number of offspring recorded the subsequent year), as well as adult survival, in two populations of house sparrow (Passer domesticus) on the islands Leka and Vega in northern Norway. Number of recruits tended to be negatively related to BMR. However, analysing the data for each sex within the two populations revealed that the negative effect of BMR on recruit production was significant only for females in the Vega population. Survival probability was associated with BMR, but the relationship differed both between sexes and populations. In the Leka population, we found evidence for stabilizing selection in the females and disruptive selection in the males. In contrast, there was no effect of BMR on survival in the Vega population. Body mass influenced adult survival, but not recruit production. Furthermore, the relationship between BMR and fitness in females remained significant after controlling for body mass. Thus, the selection on BMR in females was not driven by a BMR-body mass correlation. Basal metabolic rate was significantly related to fitness in both populations. However, the results in the present study show spatial variation as well as sex specific differences in the influence of BMR on fitness in house sparrows

THE SOFT X-RAY LASER PROGRAM AT LI VERMORE

We describe the experiments and supporting theoretical modelling to develop and characterize soft x-ray lasers. The x-ray lasers are created in dense plasmas produced by optical laser irradiation of solid targets with line focussed beams. We use mainly thin foil targets, which upon appropriate illumination, produce rather uniform plasmas. We consider laser schemes pumped by electron collisional excitation and dielectronic recombination in Ne-like and Ni-like ions, and schemes pumped by collisional and radiative recombination foilowing rapid cooling for H-like and Li-like ions. Experimental measurements of the time and space resolved spectra taken both along the lasing axis and at other viewing angles, in addition to data on the angular pattern of x-ray laser radiation and on the absorption and scattering of the optical laser light are presented. These data allow us the determine the characteristics of the plasmas which have been created, as well as the properties of the x-ray lasers, such as the gain coefficients for the inverted transitions, and their spatial and temporal distributions. The modelling includes calculations of the absorption of the optical laser light, the heating and hydrodynamics of the targets and the evolution of the atomic level populations within the plasma. Transfer of the emitted radiation is calculated, including resonance line trapping, amplification for inverted transitions, and refraction of the x-ray laser beam due to electron density gradients. Results are used to optimize x-ray laser designs before the experiments and to interpret the measured spectra. The latest experimental results from the NOVA laser facility on the performance of several laser schemes and on the use of multilayer mirrors to produce x-ray laser cavities are reported. These results are compared to the models to test and improve our understanding of the complex physics involved in making x-ray lasers. Based on current experiments, we show how the modelling can be use to design shorter wavelength and more efficient schemes for use in applications such as x-ray holography