4,432 research outputs found
Impacts of gravitational-wave standard siren observation of the Einstein Telescope on weighing neutrinos in cosmology
We investigate the impacts of the gravitational-wave (GW) standard siren
observation of the Einstein Telescope (ET) on constraining the total neutrino
mass. We simulate 1000 GW events that would be observed by the ET in its
10-year observation by taking the standard CDM cosmology as a fiducial
model. We combine the simulated GW data with other cosmological observations
including cosmic microwave background (CMB), baryon acoustic oscillations
(BAO), and type Ia supernovae (SN). We consider three mass hierarchy cases for
the neutrino mass, i.e., normal hierarchy (NH), inverted hierarchy (IH), and
degenerate hierarchy (DH). Using Planck+BAO+SN, we obtain eV
for the NH case, eV for the IH case, and
eV for the DH case. After considering the GW data, i.e., using
Planck+BAO+SN+GW, the constraint results become eV for the
NH case, eV for the IH case, and eV for
the DH case. We find that the GW data can help reduce the upper limits of by 13.7%, 7.5%, and 10.3% for the NH, IH, and DH cases, respectively. In
addition, we find that the GW data can also help break the degeneracies between
and other parameters. We show that the GW data of the ET could
greatly improve the constraint accuracies of cosmological parameters.Comment: 8 pages, 4 figure
A closer look at interacting dark energy with statefinder hierarchy and growth rate of structure
We investigate the interacting dark energy models by using the diagnostics of
statefinder hierarchy and growth rate of structure. We wish to explore the
deviations from CDM and to differentiate possible degeneracies in the
interacting dark energy models with the geometrical and structure growth
diagnostics. We consider two interacting forms for the models, i.e., and , with being the dimensionless
coupling parameter. Our focus is the ICDM model that is a
one-parameter extension to CDM by considering a direct coupling
between the vacuum energy () and cold dark matter (CDM), with the only
additional parameter . But we begin with a more general case by
considering the ICDM model in which dark energy has a constant
(equation-of-state parameter). For calculating the growth rate of structure, we
employ the "parametrized post-Friedmann" theoretical framework for interacting
dark energy to numerically obtain the values for the models. We
show that in both geometrical and structural diagnostics the impact of is
much stronger than that of in the ICDM model. We thus wish to have a
closer look at the ICDM model by combining the geometrical and
structural diagnostics. We find that the evolutionary trajectories in the
-- plane exhibit distinctive features and the departures
from CDM could be well evaluated, theoretically, indicating that the
composite null diagnostic is a promising tool for
investigating the interacting dark energy models.Comment: 17 pages, 4 figures; accepted for publication in JCA
Review on Pulling Force of Agricultural Labor and Its Effectiveness in China
This essay details a 3D simulation of a number of control methods used for maneuvering of teleoperated USAR robots. The implementation was produced in the Unity3D engine. The simulation implemented different variations on field-ofview angle, turning algorithms, and camera view perspectives. An evaluation using volunteer test operators was conducted and discussed. The sample size was too small to draw any definitive conclusions. Further testing is advised.Denna uppsats behandlar en 3D-simulering samt användartester av flera olika kontrollmetoder som används vid fjärrstyrning av obemannade räddningsrobotar. Implementationen skapades med Unity3D-plattformen. De styrmetoder som testades var olika stora synfältsvinklar på kameran, olika algoritmer för att styra robotens svängning, samt olika kameraperspektiv. Användartester med frivilliga testförare genomfördes och diskuteras. Provstorleken var för liten för att kunna dra några definitiva slutsatser. Ytterligare tester rekommenderas
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Review on Pulling Force of Agricultural Labor and Its Effectiveness in China
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