35,785 research outputs found
Nonminimally coupled topological-defect boson stars: Static solutions
We consider spherically symmetric static composite structures consisting of a
boson star and a global monopole, minimally or non-minimally coupled to the
general relativistic gravitational field. In the non-minimally coupled case,
Marunovic and Murkovic have shown that these objects, so-called boson D-stars,
can be sufficiently gravitationally compact so as to potentially mimic black
holes. Here, we present the results of an extensive numerical parameter space
survey which reveals additional new and unexpected phenomenology in the model.
In particular, focusing on families of boson D-stars which are parameterized by
the central amplitude of the boson field, we find configurations for both the
minimally and non-minimally coupled cases that contain one or more shells of
bosonic matter located far from the origin. In parameter space, each shell
spontaneously appears as one tunes through some critical central amplitude of
the boson field. In some cases the shells apparently materialize at spatial
infinity: in these instances their areal radii are observed to obey a universal
scaling law in the vicinity of the critical amplitude. We derive this law from
the equations of motion and the asymptotic behavior of the fields.Comment: 17 pages, 24 figure
Event Generation from Effective Field Theory
A procedure is developed for using Soft Collinear Effective Theory (SCET) to
generate fully exclusive events, which can then be compared to data from
collider experiments. We show that SCET smoothly interpolates between QCD for
hard emissions, and the parton shower for soft emissions, while resumming all
large logarithms. In SCET, logarithms are resummed using the renormalization
group, instead of classical Sudakov factors, so subleading logarithms can be
resummed as well. In addition, all loop effects of QCD can be reproduced in
SCET, which allows the effective theory to incorporate next-to-leading and
higher-order effects. We also show through SCET that in the soft/collinear
limit, successive branchings factorize, a fact which is essential to parton
showers, and that the splitting functions of QCD are reproduced. Finally,
combining these results, we present a example of an algorithm that incorporates
the SCET results into an event generator which is systematically improvable.Comment: 42 pages, 3 figure
Quality Improvement in Health Care: A Framework for Price and Output Measurement
The durability of health care treatment, the substantial technical change in health care treatment, and the prevalence of third-party payment interact to create substantial difficulty in measuring the price and output of health care. This paper provides a framework for analyzing the demand for health care taking into account these difficulties. It then suggests how this framework might be used to improve measurement of health care prices and output.
Quality Uncertainty and Grain Merchandising Risk: Vomitoxin in Spring Wheat
Marketing, Risk and Uncertainty,
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