9,365 research outputs found
A continuous movement version of the Banach—Tarski paradox: A solution to de Groot's Problem
In 1924 Banach and Tarski demonstrated the existence of a paradoxical decomposition of the 3-ball B, i.e., a piecewise isometry from B onto two copies of B. This article answers a question of de Groot from 1958 by showing that there is a paradoxical decomposition of B in which the pieces move continuously while remaining disjoint to yield two copies of B. More generally, we show that if n ≥ 2, any two bounded sets i
The Effects of Departmental and Positional Power on Job Evaluation Outcomes: A Dual-Level Analysis of Power and Resource Allocation
We replicate research from two separate power and resource allocation research streams to test whether job evaluation outcomes at a university are simultaneously susceptible to effects of power held at both the group (i.e., academic department) and individual (i.e., a job\u27s hierarchical position) levels. In doing so, we illustrate limitations of the dominant rational model of research in job evaluation and, more generally, how dual levels of analysis can illuminate the relationship between power and resource allocation. We then investigate whether departmental and positional power interact in the allocation of resources at both levels. Results from six years of job evaluation data indicate that job evaluation outcomes are highly susceptible to both departmental and positional power. Moreover, our results suggest that positional power moderated the effect of departmental power on group level job evaluation successes. Drawing on our dual-level analysis, we propose a new model of power, resource allocation, and the perpetuation of power
Rational and Coalition Models of Job Evaluation: Do More Powerful University Departments Have an Advantage?
Job evaluation research has, to date, focused on the individual as the unit of analysis. After approximately 50 years of study, evidence on the basic assumptions supporting job evaluation is still inconclusive. This study expands the research by employing organizational theory to the topic and studying job evaluation at the group level. Prior work on rational and coalition models of resource allocation is used to develop hypotheses that are tested with six years of job evaluation data from a university. The results support the coalition model and the conclusion that departmental power can affect job evaluation outcomes
The effect of small inter-pulsar distance variations in stochastic gravitational wave background searches with Pulsar Timing Arrays
One of the primary objectives for Pulsar Timing Arrays (PTAs) is to detect a
stochastic background generated by the incoherent superposition of
gravitational waves (GWs), in particular from the cosmic population of
supermassive black hole binaries. Current stochastic background searches assume
that pulsars in a PTA are separated from each other and the Earth by many GW
wavelengths. As more millisecond pulsars are discovered and added to PTAs, some
may be separated by only a few radiation wavelengths or less, resulting in
correlated GW phase changes between close pulsars in the array. Here we
investigate how PTA overlap reduction functions (ORFs), up to quadrupole order,
are affected by these additional correlated phase changes, and how they are in
turn affected by relaxing the assumption that all pulsars are equidistant from
the solar system barycenter. We find that in the low frequency GW background
limit of ~Hz, and for pulsars at varying distances from the
Earth, that these additional correlations only affect the ORFs by a few percent
for pulsar pairs at large angular separations, as expected. However when nearby
(order 100 pc) pulsars are separated by less than a few degrees, the correlated
phase changes can introduce variations of a few tens of percent in the
magnitude of the isotropic ORF, and much larger fractional differences in the
anisotropic ORFs-- up to 188 in the , ORF for equidistant pulsars
separated by 3 degrees. In fact, the magnitude of most of the anisotropic ORFs
is largest at small, but non-zero, pulsar separations. Finally, we write down a
small angle approximation for the correlated phase changes which can easily be
implemented in search pipelines, and for completeness, examine the behavior of
the ORFs for pulsars which lie at a radiation wavelength from the Earth.Comment: 16 pages, 8 figures, submitted to PR
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