30,022 research outputs found
Multi-ion sensing of dipolar noise sources in ion traps
Trapped-ion quantum platforms are subject to `anomalous' heating due to
interactions with electric-field noise sources of nature not yet completely
known. There is ample experimental evidence that this noise originates at the
surfaces of the trap electrodes, and models assuming fluctuating point-like
dipoles are consistent with observations, but the exact microscopic mechanisms
behind anomalous heating remain undetermined. Here we show how a two-ion probe
displays a transition in its dissipation properties, enabling experimental
access to the mean orientation of the dipoles and the spatial extent of
dipole-dipole correlations. This information can be used to test the validity
of candidate microscopic models, which predict correlation lengths spanning
several orders of mag- nitude. Furthermore, we propose an experiment to measure
these effects with currently-available traps and techniques
Studies of the nucler equation of state using numerical calculations of nuclear drop collisions
A numerical calculation for the full thermal dynamics of colliding nuclei was developed. Preliminary results are reported for the thermal fluid dynamics in such processes as Coulomb scattering, fusion, fusion-fission, bulk oscillations, compression with heating, and collisions of heated nuclei
Non-grey dimming events of KIC 8462852 from GTC spectrophotometry
We report ground-based spectrophotometry of KIC 8462852, during its first
dimming events since the end of the Kepler mission. The dimmings show a clear
colour-signature, and are deeper in visual blue wavelengths than in red ones.
The flux loss' wavelength dependency can be described with an \AA ngstr\"om
absorption coefficient of , which is compatible with absorption by
optically thin dust with particle sizes on the order of 0.0015 to 0.15 m.
These particles would be smaller than is required to be resistant against
blow-out by radiation pressure when close to the star. During occultation
events, these particles must be replenished on time-scales of days. If dust is
indeed the source of KIC 8462852's dimming events, deeper dimming events should
show more neutral colours, as is expected from optically thick absorbers.Comment: 5 pages, accepted for A&A letter
The group of strong Galois objects associated to a cocommutative Hopf quasigroup
Let H be a cocommutative faithfully flat Hopf quasigroup in a strict
symmetric monoidal category with equalizers. In this paper we introduce the
notion of (strong) Galois H-object and we prove that the set of isomorphism
classes of (strong) Galois H-objects is a (group) monoid which coincides, in
the Hopf algebra setting, with the Galois group of H-Galois objects introduced
by Chase and Sweedler
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Effects of blood withdrawal and reinfusion on biomarkers of erythropoiesis in humans: Implications for anti-doping strategies
To discriminate autologous blood doping procedures from normal conditions, we examined the hematological response to blood withdrawal and reinfusion. We found that biomarkers of erythropoiesis are primarily affected in the anemic period. Therefore, individual variations in [Hb] exceeding 15% between samples obtained shortly before any major competition would be indicative of autologous blood manipulation
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