15,996 research outputs found
Mapping monojet constraints onto Simplified Dark Matter Models
The move towards simplified models for Run II of the LHC will allow for
stronger and more robust constraints on the dark sector. However there already
exists a wealth of Run I data which should not be ignored in the run-up to Run
II. Here we reinterpret public constraints on generic beyond-standard-model
cross sections to place new constraints on a simplified model. We make use of
an ATLAS search in the monojet missing energy channel to constrain a
representative simplified model with the dark matter coupling to an
axial-vector . We scan the entire parameter space of our chosen model to
set the strongest current collider constraints on our model using the full 20.3
fb ATLAS 8 TeV dataset and provide predictions for constraints that can
be set with 20 fb of 14 TeV data. Our technique can also be used for the
interpretation of Run II data and provides a broad benchmark for comparing
future constraints on simplified models.Comment: 19 pages, 6 figures; v2: added references, corrected mistake in
discussion of previous results; v3: major content additions, version accepted
by JHE
The two levels of natural law thinking
Central parts of the natural law theories of Grotius and Pufendorf assume that persons by nature have individual realms of their own (suum), violations of which constitute a wrong. This is the basis for their accounts of promises, ownership and reactions against wrongs. These accounts are significantly independent of any assumption that a superior being imposes obligations: rather, the individuals themselves create obligations by their own acts of will. The translator's introducton draws attention to the author's relation to Hägerström, and remarks briefly on related points in Ames, Köhler and Georges Dav
Universal scaling at non-thermal fixed points of a two-component Bose gas
Quasi-stationary far-from-equilibrium critical states of a two-component Bose
gas are studied in two spatial dimensions. After the system has undergone an
initial dynamical instability it approaches a non-thermal fixed point. At this
critical point the structure of the gas is characterised by ensembles of
(quasi-)topological defects such as vortices, skyrmions and solitons which give
rise to universal power-law behaviour of momentum correlation functions. The
resulting power-law spectra can be interpreted in terms of
strong-wave-turbulence cascades driven by particle transport into
long-wave-length excitations. Scaling exponents are determined on both sides of
the miscible-immiscible transition controlled by the ratio of the intra-species
to inter-species couplings. Making use of quantum turbulence methods, we
explain the specific values of the exponents from the presence of transient
(quasi-)topological defects.Comment: 13 pages, 12 figure
Configuration of Distributed Message Converter Systems using Performance Modeling
To find a configuration of a distributed system satisfying performance goals is a complex search problem that involves many design parameters, like hardware selection, job distribution and process configuration. Performance models are a powerful tools to analyse potential system configurations, however, their evaluation is expensive, such that only a limited number of possible configurations can be evaluated. In this paper we present a systematic method to find a satisfactory configuration with feasible effort, based on a two-step approach. First, using performance estimates a hardware configuration is determined and then the software configuration is incrementally optimized evaluating Layered Queueing Network models. We applied this method to the design of performant EDI converter systems in the financial domain, where increasing message volumes need to be handled due to the increasing importance of B2B interaction
Welfare Theory: History and Modern Results
This paper contains a fairly brief, but self-contained, version of the history of welfare economics, as well as the more modern welfare results. We introduce public goods and asymmetric information, and we hint at some of the modern mechanism design results. The paper also contains a section on welfare measures in a dynamic economy.Welfare Theory;
Loss of Age-Restricted Status and Property Values: Youngtown Arizona
This study finds evidence of a large premium in house prices in Youngtown Arizona attributable to its age-restricted status. The persistence of a premium over long periods of time suggests that age restricted status can be a valuable component of the housing bundle, much like physical characteristics or location. It is likely that age-restricted status acts as a signal that the community provides facilities and services that meet the needs of the elderly and the assurance that those facilities and services will be available in the future. This assurance reduces uncertainty about the future and it is the reduced uncertainty that can be capitalized into house prices. The loss of age-restricted status in Youngtown, which increased uncertainty about the future, resulted in the elimination of the premium over approximately twelve to eighteen months even though essentially the same facilities and services continued to be available. The legal determination that Youngtown?s age restriction ordinance was invalid and could not be enforced had an immediate but temporary negative impact on house prices.
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