2,596 research outputs found
Influence of a magnetic fluxon on the vacuum energy of quantum fields confined by a bag
We study the simultaneous influence of boundary conditions and external
fields on quantum fluctuations by considering vacuum zero-point energies for
quantum fields in the presence of a magnetic fluxon confined by a bag, circular
and spherical for bosons and circular for fermions. The Casimir effect is
calculated in a generalized cut-off regularization after applying zeta-function
techniques to eigenmode sums and using recent techniques about Bessel zeta
functions at negative arguments
Precision tunable resonant microwave cavity
A tunable microwave cavity containing ionizable metallic vapor or gases and an apparatus for precisely positioning a microwave coupling tip in the cavity and for precisely adjusting at least one dimension of the cavity are disclosed. With this combined structure, resonance may be achieved with various types of ionizable gases. A coaxial probe extends into a microwave cavity through a tube. One end of the tube is retained in a spherical joint attached in the cavity wall. This allows the coaxial probe to be pivotally rotated. The coaxial probe is slideable within the tube thus allowing the probe to be extended toward or retracted from the center of the cavity
Galaxy Cluster Mass Estimation from Stacked Spectroscopic Analysis
We use simulated galaxy surveys to study: i) how galaxy membership in
redMaPPer clusters maps to the underlying halo population, and ii) the accuracy
of a mean dynamical cluster mass, , derived from stacked
pairwise spectroscopy of clusters with richness . Using galaxy pairs patterned after the SDSS redMaPPer cluster sample study
of Rozo et al. (2015 RMIV), we show that the pairwise velocity PDF of
central--satellite pairs with in the simulation matches the form
seen in RMIV. Through joint membership matching, we deconstruct the main
Gaussian velocity component into its halo contributions, finding that the
top-ranked halo contributes of the stacked signal. The halo mass
scale inferred by applying the virial scaling of Evrard et al. (2008) to the
velocity normalization matches, to within a few percent, the log-mean halo mass
derived through galaxy membership matching. We apply this approach, along with
mis-centering and galaxy velocity bias corrections, to estimate the log-mean
matched halo mass at of SDSS redMaPPer clusters. Employing the velocity
bias constraints of Guo et al. (2015), we find with and .
Systematic uncertainty in the velocity bias of satellite galaxies
overwhelmingly dominates the error budget.Comment: 14 pages, 7 figure
The influence of local field corrections on Thomson scattering in non-ideal two-component plasmas
Thomson scattering in non-ideal (collision-dominated) two-component plasmas
is calculated accounting for electron-ion collisions as well as
electron-electron correlations. This is achieved by using a novel interpolation
scheme for the electron-electron response function generalizing the traditional
Mermin approach. Also, ions are treated as randomly distributed inert
scattering centers. The collision frequency is taken as a dynamic and complex
quantity and is calculated from a microscopic quantum-statistical approach.
Implications due to different approximations for the electron-electron
correlation, i.e. different forms of the OCP local field correction, are
discussed
The Effect of M&A on Employee Performance : An empirical study on post-MBA employee performance in private Norwegian target companies
This paper analyses post-M&A employee performance for private Norwegian target
companies using accounting data between 2007 and 2016. We have created an algorithm
which identifies ownership changes in firms from accounting data. Our model is based
on the Cobb-Douglas productivity function to measure firm productivity, and utilizes
Propensity Score Matching (PSM) to control for confounding variables. Additionally, we
research if the effect of M&A are different based on labor size or sector. As a robustness
test we use Nearest Neighbour matching combined with a Difference-In-Difference (DD)
analysis to control for possible bias in the PSM analyses. Our results conclude that
M&As do not have an effect on employee performance in Norwegian private companies.
Furthermore, results indicate a negative effect on firm performance post-M&A. We neither
find any reliable differences on employee performance from labor size nor sector. However,
we find that the firm performance for the companies with the largest labor force, in the
retail industry, and in the remaining sectors are negatively affected post-M&A. The DD
analysis mostly support the PSM findings on employee performance and strengthens the
validity of our findings. However, we cannot exclude potential confounding of the firm
performance outcome variable.nhhma
August Stramm – YOU. Lovepoems & posthumous love poems:a centenary commemoration ; translation and essay by Susanne Fiessler
August Stramm was among the most innovative poets of his time, creating a style of extreme intensity and concentration. His small legacy stands comparison with the international avant-garde. You. Lovepoems celebrates his poetic achievements in memory of his passing in September 1915. The translations bring out the erotic tone of the originals while keeping their flow alive. You aims to convey the “inner experience” captured in the poems, to transfer their “heart” to the listener
- …