2,130 research outputs found
Do Eurozone Countries Cheat with Their Budget Deficit Forecasts?
We estimate the political economy determinants of budget deficit forecast errors. Since the adoption of the Stability Pact, Eurozone governments have manipulated forecasts before elections. The political orientation and the institutional design of governments also affects the quality of forecasts.Fiscal policy, Budget deficit, Forecast error, Electoral cycles
Correlations and Counting Statistics of an Atom Laser
We demonstrate time-resolved counting of single atoms extracted from a weakly
interacting Bose-Einstein condensate of Rb atoms. The atoms are detected
with a high-finesse optical cavity and single atom transits are identified. An
atom laser beam is formed by continuously output coupling atoms from the
Bose-Einstein condensate. We investigate the full counting statistics of this
beam and measure its second order correlation function in a
Hanbury Brown and Twiss type experiment. For the monoenergetic atom laser we
observe a constant correlation function and an atom
number distribution close to a Poissonian statistics. A pseudo-thermal atomic
beam shows a bunching behavior and a Bose distributed counting statistics
Fahrdynamikoptimierung mittels Torque Vectoring bei einem bauraumoptimierten Elektrofahrzeug
Durch bauraumoptimierte Anordnung der Antriebskomponenten eines Elektrofahrzeugs können sich unkonventionelle Achslasten ergeben, welche in der Fahrdynamikauslegung berücksichtigt werden müssen. Die BMW Group Forschung und Technik entwickelt zusammen mit dem Deutschen Zentrum für Luft- und Raumfahrt (DLR) und dem Lehrstuhl für Regelungs- und Steuerungssysteme am Karlsruher Institut für Technologie (KIT) ein Torque-Vectoring-Regelungskonzept. Trotz der fahrdynamischen Herausforderung hoher Hinterachslasten wird dadurch ein ansprechendes und sicheres Fahrverhalten erzielt
6th Data Science Symposium Abstracts
The Data Science Symposium at Haus der Wissenschaft on 8/9 November 2021 in Bremen was the 6th Symposium in this series since 2017
Triplet superconductivity from non-local Coulomb repulsion in Sn/Si(111)
Atomic layers deposited on semiconductor substrates introduce a platform for
the realization of the extended electronic Hubbard model, where the
consideration of electronic repulsion beyond the onsite term is paramount.
Recently, the onset of superconductivity at 4.7K has been reported in the
hole-doped triangular lattice of tin atoms on a silicon substrate. Through
renormalization group methods designed for weak and intermediate coupling, we
investigate the nature of the superconducting instability in hole-doped
Sn/Si(111). We find that the extended Hubbard nature of interactions is crucial
to yield triplet pairing, which is f-wave (p-wave) for moderate (higher) hole
doping. In light of persisting challenges to tailor triplet pairing in an
electronic material, our finding promises to pave unprecedented ways for
engineering unconventional triplet superconductivity.Comment: 4 pages, 3 figures (supplement: 3 pages, 2 figures
Observing the Formation of Long-range Order during Bose-Einstein Condensation
We have experimentally investigated the formation of off-diagonal long-range
order in a gas of ultracold atoms. A magnetically trapped atomic cloud prepared
in a highly nonequilibrium state thermalizes and thereby crosses the
Bose-Einstein condensation phase transition. The evolution of phase coherence
between different regions of the sample is constantly monitored and information
on the spatial first-order correlation function is obtained. We observe the
growth of the spatial coherence and the formation of long-range order in real
time and compare it to the growth of the atomic density. Moreover, we study the
evolution of the momentum distribution during the nonequilibrium formation of
the condensate.Comment: 4 pages, 4 figure
Hybrid apparatus for Bose-Einstein condensation and cavity quantum electrodynamics: Single atom detection in quantum degenerate gases
We present and characterize an experimental system in which we achieve the
integration of an ultrahigh finesse optical cavity with a Bose-Einstein
condensate (BEC). The conceptually novel design of the apparatus for the
production of BECs features nested vacuum chambers and an in-vacuo magnetic
transport configuration. It grants large scale spatial access to the BEC for
samples and probes via a modular and exchangeable "science platform". We are
able to produce \87Rb condensates of five million atoms and to output couple
continuous atom lasers. The cavity is mounted on the science platform on top of
a vibration isolation system. The optical cavity works in the strong coupling
regime of cavity quantum electrodynamics and serves as a quantum optical
detector for single atoms. This system enables us to study atom optics on a
single particle level and to further develop the field of quantum atom optics.
We describe the technological modules and the operation of the combined BEC
cavity apparatus. Its performance is characterized by single atom detection
measurements for thermal and quantum degenerate atomic beams. The atom laser
provides a fast and controllable supply of atoms coupling with the cavity mode
and allows for an efficient study of atom field interactions in the strong
coupling regime. Moreover, the high detection efficiency for quantum degenerate
atoms distinguishes the cavity as a sensitive and weakly invasive probe for
cold atomic clouds
Intercepting second-messenger signaling by rationally designed peptides sequestering c-di-GMP
The bacterial second messenger cyclic diguanylate (c-di-GMP) regulates a wide range of cellular functions from biofilm formation to growth and survival. Targeting a second-messenger network is challenging because the system involves a multitude of components with often overlapping functions. Here, we present a strategy to intercept c-di-GMP signaling pathways by directly targeting the second messenger. For this, we developed a c-di-GMP-sequestering peptide (CSP) that was derived from a CheY-like c-di-GMP effector protein. CSP binds c-di-GMP with submicromolar affinity. The elucidation of the CSP⋅c-di-GMP complex structure by NMR identified a linear c-di-GMP-binding motif, in which a self-intercalated c-di-GMP dimer is tightly bound by a network of H bonds and π-stacking interactions involving arginine and aromatic residues. Structure-based mutagenesis yielded a variant with considerably higher, low-nanomolar affinity, which subsequently was shortened to 19 residues with almost uncompromised affinity. We demonstrate that endogenously expressed CSP intercepts c-di-GMP signaling and effectively inhibits biofilm formation in Pseudomonas aeruginosa , the most widely used model for serious biofilm-associated medical implications
Rashba spin-orbit coupling in the square lattice Hubbard model: A truncated-unity functional renormalization group study
The Rashba-Hubbard model on the square lattice is the paradigmatic case for
studying the effect of spin-orbit coupling, which breaks spin and inversion
symmetry, in a correlated electron system. We employ a truncated-unity variant
of the functional renormalization group which allows us to analyze magnetic and
superconducting instabilities on equal footing. We derive phase diagrams
depending on the strengths of Rasbha spin-orbit coupling, real second-neighbor
hopping and electron filling. We find commensurate and incommensurate magnetic
phases which compete with d-wave superconductivity. Due to the breaking of
inversion symmetry, singlet and triplet components mix; we quantify the mixing
of d-wave singlet pairing with f-wave triplet pairing.Comment: 9 pages, 7 figure
Fachplanung Mountainbike-Tourismus des Freistaates Sachsen
Ziel dieser Mountainbike-Fachplanung ist es, den Freistaat zu einem der führenden grenzübergreifenden Mountainbike-Reiseziele in Deutschland zu entwickeln. Dafür beschreibt die Planung konkrete Maßnahmen. Als praxisorientiertes Handbuch soll sie zudem als Orientierung bei der Planung und Entwicklung neuer Mountainbike-Angebote dienen. Die Fachplanung zeigt auf, wie vorhandene Infrastrukturen wie Skiliftanlagen und regionale Sehenswürdigkeiten in die Mountainbike-Projekte eingebunden werden können und dadurch besser ausgelastet werden. Ebenfalls deutlich wird der Wirtschaftsfaktoreffekt für die vorhandenen Gastronomie- und Beherbergungsbetriebe entlang und im Umfeld der Strecken. Natur und Kultur erlebbar zu machen, gleichzeitig aber durch gezielte Besucherlenkung zu schützen und zu erhalten, sind zentrale Ansprüche der Fachplanung.
Redaktionsschluss: 31.05.202
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