551 research outputs found
Pointwise estimates for the Bergman kernel of the weighted Fock space
We prove upper pointwise estimates for the Bergman kernel of the weighted
Fock space of entire functions in where is a
subharmonic function with a doubling measure. We derive estimates
for the canonical solution operator to the inhomogeneous Cauchy-Riemann
equation and we characterize the compactness of this operator in terms of
Testing spontaneous localization theories with matter-wave interferometry
We propose to test the theory of continuous spontaneous localization (CSL) in
an all-optical time-domain Talbot-Lau interferometer for clusters with masses
exceeding 1000000 amu. By assessing the relevant environmental decoherence
mechanisms, as well as the growing size of the particles relative to the
grating fringes, we argue that it will be feasible to test the quantum
superposition principle in a mass range excluded by recent estimates of the CSL
effect.Comment: 4 pages, 3 figures; corresponds to published versio
Anomalous specific heat jump in the heavy fermion superconductor CeCoIn
We study the anomalously large specific heat jump and its systematic change
with pressure in CeCoIn superconductor. Starting with the general free
energy functional of the superconductor for a coupled electron boson system, we
derived the analytic result of the specific heat jump of the strong coupling
superconductivity occurring in the coupled electron boson system. Then using
the two component spin-fermion model we calculate the specific heat coefficient
both for the normal and superconducting states and show a good
agreement with the experiment of CeCoIn. Our result also clearly
demonstrated that the specific heat coefficient of a coupled electron
boson system can be freely interpreted as a renormalization either of the
electronic or of the bosonic degrees of freedom.Comment: 5 pages, 2 figure
Concept of an ionizing time-domain matter-wave interferometer
We discuss the concept of an all-optical and ionizing matter-wave
interferometer in the time domain. The proposed setup aims at testing the wave
nature of highly massive clusters and molecules, and it will enable new
precision experiments with a broad class of atoms, using the same laser system.
The propagating particles are illuminated by three pulses of a standing
ultraviolet laser beam, which detaches an electron via efficient single
photon-absorption. Optical gratings may have periods as small as 80 nm, leading
to wide diffraction angles for cold atoms and to compact setups even for very
massive clusters. Accounting for the coherent and the incoherent parts of the
particle-light interaction, we show that the combined effect of phase and
amplitude modulation of the matter waves gives rise to a Talbot-Lau-like
interference effect with a characteristic dependence on the pulse delay time.Comment: 25 pages, 5 figure
Colloquium: Quantum interference of clusters and molecules
We review recent progress and future prospects of matter wave interferometry
with complex organic molecules and inorganic clusters. Three variants of a
near-field interference effect, based on diffraction by material
nanostructures, at optical phase gratings, and at ionizing laser fields are
considered. We discuss the theoretical concepts underlying these experiments
and the experimental challenges. This includes optimizing interferometer
designs as well as understanding the role of decoherence. The high sensitivity
of matter wave interference experiments to external perturbations is
demonstrated to be useful for accurately measuring internal properties of
delocalized nanoparticles. We conclude by investigating the prospects for
probing the quantum superposition principle in the limit of high particle mass
and complexity.Comment: 19 pages, 13 figures; v2: corresponds to published versio
Uncertainty contributions to low-flow projections in Austria
The main objective of the paper is to understand the
contributions to the uncertainty in low-flow projections resulting from
hydrological model uncertainty and climate projection uncertainty. Model
uncertainty is quantified by different parameterisations of a conceptual
semi-distributed hydrologic model (TUWmodel) using 11 objective functions in
three different decades (1976–1986, 1987–1997, 1998–2008), which allows for disentangling the effect of the objective function-related uncertainty and temporal stability of model parameters. Climate projection uncertainty is
quantified by four future climate scenarios (ECHAM5-A1B, A2, B1 and
HADCM3-A1B) using a delta change approach. The approach is tested for 262
basins in Austria.
The results indicate that the seasonality of the low-flow regime is an
important factor affecting the performance of model calibration in the
reference period and the uncertainty of Q95 low-flow projections in the
future period. In Austria, the range of simulated Q95 in the reference
period is larger in basins with a summer low-flow regime than in basins with
a winter low-flow regime. The accuracy of simulated Q95 may result in a
range of up to 60 % depending on the decade used for calibration.
The low-flow projections of Q95 show an increase of low flows in the
Alps, typically in the range of 10–30 % and a decrease in the
south-eastern part of Austria mostly in the range −5 to −20 % for the
climate change projected for the future period 2021–2050, relative the reference
period 1978–2007. The change in seasonality varies between scenarios, but
there is a tendency for earlier low flows in the northern Alps and later low
flows in eastern Austria. The total uncertainty of Q95 projections is
the largest in basins with a winter low-flow regime and, in some basins the
range of Q95 projections exceeds 60 %. In basins with summer low flows, the total uncertainty is mostly less than 20 %. The ANOVA
assessment of the relative contribution of the three main variance components
(i.e. climate scenario, decade used for model calibration and calibration
variant representing different objective function) to the low-flow projection
uncertainty shows that in basins with summer low flows climate scenarios
contribute more than 75 % to the total projection uncertainty. In basins
with a winter low-flow regime, the median contribution of climate scenario,
decade and objective function is 29, 13 and 13 %,
respectively. The implications of the uncertainties identified in this paper
for water resource management are discussed
Automatic Filters for the Detection of Coherent Structure in Spatiotemporal Systems
Most current methods for identifying coherent structures in
spatially-extended systems rely on prior information about the form which those
structures take. Here we present two new approaches to automatically filter the
changing configurations of spatial dynamical systems and extract coherent
structures. One, local sensitivity filtering, is a modification of the local
Lyapunov exponent approach suitable to cellular automata and other discrete
spatial systems. The other, local statistical complexity filtering, calculates
the amount of information needed for optimal prediction of the system's
behavior in the vicinity of a given point. By examining the changing
spatiotemporal distributions of these quantities, we can find the coherent
structures in a variety of pattern-forming cellular automata, without needing
to guess or postulate the form of that structure. We apply both filters to
elementary and cyclical cellular automata (ECA and CCA) and find that they
readily identify particles, domains and other more complicated structures. We
compare the results from ECA with earlier ones based upon the theory of formal
languages, and the results from CCA with a more traditional approach based on
an order parameter and free energy. While sensitivity and statistical
complexity are equally adept at uncovering structure, they are based on
different system properties (dynamical and probabilistic, respectively), and
provide complementary information.Comment: 16 pages, 21 figures. Figures considerably compressed to fit arxiv
requirements; write first author for higher-resolution version
Kinetic Energy, Condensation Energy, Optical Sum Rule and Pairing Mechanism in High-Tc Cuprates
The mechanism of high-Tc superconductivity is investigated with interests on
the microscopic aspects of the condensation energy. The theoretical analysis is
performed on the basis of the FLEX approximation which is a microscopic
description of the spin-fluctuation-induced-superconductivity. Most of phase
transitions in strongly correlated electron system arise from the correlation
energy which is copmetitive to the kinetic energy. However, we show that the
kinetic energy cooperatively induces the superconductivity in the underdoped
region. This unusual decrease of kinetic energy below T_c is induced by the
feedback effect. The feedback effect induces the magnetic resonance mode as
well as the kink in the electronic dispersion, and alters the properties of
quasi-particles, such as mass renormalization and lifetime. The crossover from
BCS behavior to this unusual behavior occurs for hole dopings. On the other
hand, the decrease of kinetic energy below T_c does not occur in the
electron-doped region. We discuss the relation to the recent obserbation of the
violation of optical sum rule
In-depth transcriptomic analysis of human retina reveals molecular mechanisms underlying diabetic retinopathy
Diabetic Retinopathy (DR) is among the major global causes for vision loss. With the rise in diabetes prevalence, an increase in DR incidence is expected. Current understanding of both the molecular etiology and pathways involved in the initiation and progression of DR is limited. Via RNA-Sequencing, we analyzed mRNA and miRNA expression profiles of 80 human post-mortem retinal samples from 43 patients diagnosed with various stages of DR. We found differentially expressed transcripts to be predominantly associated with late stage DR and pathways such as hippo and gap junction signaling. A multivariate regression model identified transcripts with progressive changes throughout disease stages, which in turn displayed significant overlap with sphingolipid and cGMP-PKG signaling. Combined analysis of miRNA and mRNA expression further uncovered disease-relevant miRNA/mRNA associations as potential mechanisms of post-transcriptional regulation. Finally, integrating human retinal single cell RNA-Sequencing data revealed a continuous loss of retinal ganglion cells, and Müller cell mediated changes in histidine and β-alanine signaling. While previously considered primarily a vascular disease, attention in DR has shifted to additional mechanisms and cell-types. Our findings offer an unprecedented and unbiased insight into molecular pathways and cell-specific changes in the development of DR, and provide potential avenues for future therapeutic intervention
Coordinated and Interoperable Seismological Data and Product Services in Europe: the EPOS Thematic Core Service for Seismology
In this article we describe EPOS Seismology, the Thematic Core Service consortium for the seismology domain within the European Plate Observing System infrastructure. EPOS Seismology was developed alongside the build-up of EPOS during the last decade, in close collaboration between the existing pan-European seismological initiatives ORFEUS (Observatories and Research Facilities for European Seismology), EMSC (Euro-Mediterranean Seismological Center) and EFEHR (European Facilities for Earthquake Hazard and Risk) and their respective communities. It provides on one hand a governance framework that allows a well-coordinated interaction of the seismological community services with EPOS and its bodies, and on the other hand it strengthens the coordination among the already existing seismological initiatives with regard to data, products and service provisioning and further development. Within the EPOS Delivery Framework, ORFEUS, EMSC and EFEHR provide a wide range of services that allow open access to a vast amount of seismological data and products, following and implementing the FAIR principles and supporting open science. Services include access to raw seismic waveforms of thousands of stations together with relevant station and data quality information, parametric earthquake information of recent and historical earthquakes together with advanced event-specific products like moment tensors or source models and further ancillary services, and comprehensive seismic hazard and risk information, covering latest European scale models and their underlying data. The services continue to be available on the well-established domain-specific platforms and websites, and are also consecutively integrated with the interoperable central EPOS data infrastructure. EPOS Seismology and its participating organizations provide a consistent framework for the future development of these services and their operation as EPOS services, closely coordinated also with other international seismological initiatives, and is well set to represent the European seismological research infrastructures and their stakeholders withi
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