cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Transmission Mapping of Healthcare Infection Clusters: A Scoping Review
Creators: name: Raabe, Nathan
name: Brady, Mya
name: Slaughter, Julie
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Clinical Epidemiology
subject: Public Health
subject: Medicine and Health Sciences
subject: COVID-19
subject: HAI
subject: Infection Prevention and Control
subject: Nosocomial
subject: Scoping Review
subject: Transmission Visualization

description: This project is a scoping review that is critically analyzing the current literature containing data visualizations for healthcare cluster investigations. This work is being conducted by individuals from the University of Pittsburgh Graduate School of Public Health and the University of Pittsburgh Medical Center (UPMC Presbyterian) Infection Prevention and Control Department. The overall aim of this project is to evaluate infectious disease transmission visualizations typically used within healthcare settings and to determine the most effective methods for mapping the transmission of infectious diseases in a healthcare setting, to inform interventions to interrupt transmission.
Polyphenol oxidase genes as integral part of the evolutionary history of domesticated tetraploid wheat
Creators: name: Miazzi, Monica Marilena
Publisher: name: figshare
Year: 2022
Subjects: subject: 70108 Sustainable Agricultural Development
subject: FOS: Other agricultural sciences
subject: Plant Biology
subject: FOS: Biological sciences

description: Studying and understanding the genetic basis of polyphenol oxidases (PPO)-related traits plays a crucial role in genetic improvement of crops. A tetraploid wheat collection (T. turgidum ssp., TWC) was analyzed using the 90K wheat SNP iSelect assay and phenotyped for PPO activity. A total of 21,347 polymorphic SNPs were used to perform genome-wide association analysis (GWA) in TWC and durum wheat sub-groups, detecting 23 and 85 marker-trait associations (MTA). In addition, candidate genes responsible for PPO activity were predicted. Based on the 23 MTAs detected in TWC, two haplotypes associated with low and high PPO activity were identified. Four SNPs were developed and validated providing one reliable marker (IWB75732) for marker assisted selection. The 23 MTAs were used to evaluate the genetic divergence (FST > 0.25) between the T. turgidum subspecies, providing new information important for understanding the domestication process of Triticum turgidum ssp. and in particular of ssp. carthlicum.
Energy and system size dependence of strongly intensive fluctuation measures in heavy-ion collisions at FAIR energies
Creators: name: Ali, Bushra
name: Ahmad, Shakeel
name: Ahmad, A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Event-by-event fluctuations of multiplicity and transverse momentum of charged hadrons produced in heavy-ion collisions at FAIR energies, 10A, 20A, 30A and 40A GeV are studied in the framework of relativistic transport model, URQMD. Dependence of two families of strongly intensive measures of multiplicity($N$) and transverse momentum($p_{\rm T}$) fluctuations, $Δ[p_{\rm T},N]$ and $Σ[p_{\rm T},N]$, on collision centrality, centrality bin-widths and pseudorapidity windows are examined. Attempts are also made to study $NN$, $N$$p_{\rm T}$ and $p_{\rm T}$$p_{\rm T}$ fluctuations using two window analysis method. The findings suggest that the measure, $Δ[p_{\rm T},N]$ be dealt with proper selection of centrality intervals. This measure also exhibits a strong dependence on the widths of $η$ windows. The variable $Σ[p_{\rm T},N]$, however, is observed to be insensitive to the centrality bin-widths and shows a variation of $< 5\%$ with the widths of $η$ windows. The analysis of data after event mixing gives $Δ[p_{\rm T},N]$ and $Σ[p_{\rm T},N]$ values as $\sim 1$ irrespective of the widths of $η$ windows and collision centrality, as predicted by model of independent particle emission, IPM. The study of joint fluctuations of the two quantities on two $η$ windows separated in $η$ space, reveals that $Σ[N_{\rm F},N_{\rm B}]$ values are $\sim 1$ irrespective of the position of $η$ windows whereas, the values of $Σ[N_{\rm F},p_{\rm T_B}]$ and $Σ[p_{\rm T_F},p_{\rm T_B}]$ firstly increase with $η_{sep}$ and later acquire saturations. The observed trend of centrality dependence of $Σ[N_{\rm F},N_{\rm B}], Σ[N_{\rm F},p_{\rm T_B}]$ and $Σ[p_{\rm T_F},p_{\rm T_B}]$ agrees fairly well with those observed in MC simulated studies carried out for AA collisions at LHC energies in the framework model of string fusion.
description: Accepted in Journal of Physics G
General Relativistic Ray-Tracing Method for Estimating the Energy and Momentum Deposition by Neutrino Pair Annihilation in Collapsars
Creators: name: Harikae, Seiji
name: Kotake, Kei
name: Takiwaki, Tomoya
name: Sekiguchi, Yu-ichiro
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Bearing in mind the application to the collapsar models of gamma-ray bursts (GRBs), we develop a numerical scheme and code for estimating the deposition of energy and momentum due to the neutrino pair annihilation ($ν+ {\bar ν} \rightarrow e^{-} + e^{+}$) in the vicinity of accretion tori around a Kerr black hole. Our code is designed to solve the general relativistic neutrino transfer by a ray-tracing method. To solve the collisional Boltzmann equation in curved spacetime, we numerically integrate the so-called rendering equation along the null geodesics. For the neutrino opacity, the charged-current $β$-processes are taken into account, which are dominant in the vicinity of the accretion tori. The numerical accuracy of the developed code is certificated by several tests, in which we show comparisons with the corresponding analytic solutions. Based on the hydrodynamical data in our collapsar simulation, we estimate the annihilation rates in a post-processing manner. Increasing the Kerr parameter from 0 to 1, it is found that the general relativistic effect can increase the local energy deposition rate by about one order of magnitude, and the net energy deposition rate by several tens of percents. After the accretion disk settles into a stationary state (typically later than $\sim 9$ s from the onset of gravitational collapse), we point out that the neutrino-heating timescale in the vicinity of the polar funnel region can be shorter than the dynamical timescale. Our results suggest the neutrino pair annihilation has a potential importance equal to the conventional magnetohydrodynamic mechanism for igniting the GRB fireballs.
description: 33 pages, 15 figures, accepted to the ApJ
Estimation of the Galactocentric Distance of the Sun from Cepheids Close to the Solar Circle
Creators: name: Bobylev, Vadim V.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Based on Cepheids located near the solar circle, we have determined the Galactocentric distance of the Sun $R_0$ and the Galactic rotation velocity at the solar distance $V_0$. For our analysis we used a sample of $\sim$200 classical Cepheids from the catalogue by Skowron et al. (2019), where the distances to them were determined from the period-luminosity relation. For these stars the proper motions and line-of-sight velocities were taken from the Gaia DR3 catalogue. The values of $R_0$ found lie within the range [7.8-8.3] kpc, depending on the heliocentric distance of the sample stars, on the adopted solar velocity relative to the local standard of rest, and on whether or not the perturbations caused by the Galactic spiral density wave are taken into account. The dispersion of the $R_0$ estimates is $\sim$2 kpc. Similarly, the values of $V_0$ lie within the range [240-270] km s$^{-1}$ with a dispersion of the estimates of 70-90 km s$^{-1}$. We consider the following estimates to be the final ones: $R_0=8.24\pm0.20$ kpc and $V_0=268\pm8$ km s$^{-1}$ found by taking into account the perturbations from the Galactic spiral density wave.
description: 10 pages, 3 figures, 5 tables
Repeating FRBs reveal the secret of pulsar magnetospheric activity
Creators: name: Xu, Renxin
name: Wang, Weiyang
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The puzzling mechanism of coherent radio emission remains unknown, but fortunately, repeating fast radio bursts (FRBs) provide a precious opportunity, with extremely bright subpulses created in a clear and vacuum-like pulsar magnetosphere. FRBs are millisecond-duration signals that are highly dispersed at distant galaxies but with uncertain physical origin(s). Coherent curvature radiation by bunches has already been proposed for repeating FRBs. The charged particles are created during central star's quakes, which can form bunches streaming out along curved magnetic field lines, so as to trigger FRBs. The nature of narrow-band radiation with time-frequency drifting can be a natural consequence that bunches could be observed at different times with different curvatures. Additionally, high linear-polarization can be seen if the line of sight is confined to the beam angle, whereas the emission could be highly circular-polarized if off-beam. It is also discussed that pulsar surface may be full of small hills (i.e., zits) which would help producing bulk of energetic bunches for repeating FRBs as well as for rotation-powered pulsars.
description: 7 pages, 2 figures, published in AN
The Motion of a Body in Newtonian Theories
Creators: name: Weatherall, James Owen
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: A theorem due to Bob Geroch and Pong Soo Jang ["Motion of a Body in General Relativity." Journal of Mathematical Physics 16(1), (1975)] provides the sense in which the geodesic principle has the status of a theorem in General Relativity (GR). Here we show that a similar theorem holds in the context of geometrized Newtonian gravitation (often called Newton-Cartan theory). It follows that in Newtonian gravitation, as in GR, inertial motion can be derived from other central principles of the theory.
description: 12 pages, 1 figure. This is the version that appeared in JMP; it is only slightly changed from the previous version, to reflect small issue caught in proof
MOESM1 of Complications of enterostomy and related risk factor analysis of very early onset inflammatory bowel disease with interleukin-10 signalling deficiency: a single-centre retrospective analysis
Creators: name: Tang, Zifei
name: Huang, Zhiheng
name: Yan, Weili
name: Zhang, Yi
name: Shi, Peng
name: Dong, Kuiran
name: Gong, Ying
name: Ji, Min
name: Wang, Yuhuan
name: Yu, Zhuowe
name: Huang, Ying
Publisher: name: figshare
Year: 2020
Subjects: subject: Medicine
subject: Molecular Biology
subject: Immunology
subject: FOS: Clinical medicine
subject: Mathematical Sciences not elsewhere classified
subject: Developmental Biology

description: Additional file 1: Table S1. The pathogenic/likely pathogenic variants in VEOIBD patients with IL10R gene mutation.
Heralded single photon absorption by a single atom
Creators: name: Piro, Nicolas
name: Rohde, Felix
name: Schuck, Carsten
name: Almendros, Marc
name: Huwer, Jan
name: Ghosh, Joyee
name: Haase, Albrecht
name: Hennrich, Markus
name: Dubin, Francois
name: Eschner, Jürgen
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The emission and absorption of single photons by single atomic particles is a fundamental limit of matter-light interaction, manifesting its quantum mechanical nature. At the same time, as a controlled process it is a key enabling tool for quantum technologies, such as quantum optical information technology [1, 2] and quantum metrology [3, 4, 5, 6]. Controlling both emission and absorption will allow implementing quantum networking scenarios [1, 7, 8, 9], where photonic communication of quantum information is interfaced with its local processing in atoms. In studies of single-photon emission, recent progress includes control of the shape, bandwidth, frequency, and polarization of single-photon sources [10, 11, 12, 13, 14, 15, 16, 17], and the demonstration of atom-photon entanglement [18, 19, 20]. Controlled absorption of a single photon by a single atom is much less investigated; proposals exist but only very preliminary steps have been taken experimentally such as detecting the attenuation and phase shift of a weak laser beam by a single atom [21, 22], and designing an optical system that covers a large fraction of the full solid angle [23, 24, 25]. Here we report the interaction of single heralded photons with a single trapped atom. We find strong correlations of the detection of a heralding photon with a change in the quantum state of the atom marking absorption of the quantum-correlated heralded photon. In coupling a single absorber with a quantum light source, our experiment demonstrates previously unexplored matter-light interaction, while opening up new avenues towards photon-atom entanglement conversion in quantum technology.
description: 10 pages, 4 figures
Full-scale implementation of passive gravity driven membrane filtration for drinking water treatment
Creators: name: Wei, Yixin
Publisher: name: University of British Columbia
Year: 2023

description: Passive gravity driven membrane filtration (PGDMF) uses a low hydrostatic pressure for filtration and fouling control, without mechanical pumps and chemical systems. In PGDMF, fouling controls are also achieved with hydrostatic pressure, referred to as Passive Fouling Controls. With promising results from laboratory and pilot-scale studies, a full-scale PGDMF drinking water treatment plant including four membrane systems, was implemented for a small First Nation community in British Columbia, Canada. The present study investigated the operational performance of PGDMF systems which could also be operated as GDMF systems (i.e., no passive fouling controls). The performance was assessed based on the permeability and treated water quality. At present, over 2 years of operational data has been collected. The present study focuses on the data of the first 16 months. In Stage 1 and Stage 2 of the performance monitoring, both GDMF and PGDMF operation were considered, respectively. Stage 1 and Stage 2a confirmed the effectiveness of passive fouling controls. Stage 2b considered the impact of variations in feed water characteristics on PGDMF systems. Increases in feed water temperature (i.e., above 16.5 degrees threshold) resulted in a significantly higher rate of decline in permeability. Increases in organic carbon content (i.e., from 1.10±0.12 to 2.20±0.32 mg.L⁻¹) did not impact the permeability. Stage 2b also considered the impact of the operational set-points. Changing one operational set-point (i.e., higher frequency of passive fouling controls, or lower hydrostatic pressure) did not have a significant impact on the permeability. However, changing both operational set-points simultaneously (i.e., higher frequency of passive fouling controls and lower hydrostatic pressure), resulted in a greater rate of decline in permeability. It was hypothesized that microbial communities in the biofilm could not readily adapt to the added stress induced by the simultaneous change in both operational set-points, which requires further research. The results demonstrated the long-term feasibility (beyond 1 year) of PGDMF systems. The treated water quality met all regulatory requirements. Flow throughput declined slowly over 13 months of operation. Positive feedback was also obtained from the operator and the support staff. Moreover, an unexpected 10-day no flow period did not impact the permeability.
Machine Learning applications for Cataclysmic Variable discovery in the ZTF alert stream
Creators: name: Mistry, D.
name: Copperwheat, C. M.
name: Olier, I.
name: Darnley, M. J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Cataclysmic variables (CV) encompass a diverse array of accreting white dwarf binary systems. Each class of CV represents a snapshot along an evolutionary journey, one with the potential to trigger a type Ia supernova event. The study of CVs offers valuable insights into binary evolution and accretion physics, with the rarest examples potentially providing the deepest insights. However, the escalating number of detected transients, coupled with our limited capacity to investigate them all, poses challenges in identifying such rarities. Machine Learning (ML) plays a pivotal role in addressing this issue by facilitating the categorisation of each detected transient into its respective transient class. Leveraging these techniques, we have developed a two-stage pipeline tailored to the ZTF transient alert stream. The first stage is an alerts filter aimed at removing non-CVs, while the latter is an ML classifier produced using XGBoost, achieving a macro average AUC score of 0.92 for distinguishing between CV classes. By utilising the Generative Topographic Mapping algorithm with classifier posterior probabilities as input, we obtain representations indicating that CV evolutionary factors play a role in classifier performance, while the associated feature maps present a potent tool for identifying the features deemed most relevant for distinguishing between classes. Implementation of the pipeline in June 2023 yielded 51 intriguing candidates that are yet to be reported as CVs or classified with further granularity. Our classifier represents a significant step in the discovery and classification of different CV classes, a domain of research still in its infancy.
description: 27 pages, 11 figures, 7 tables
Exploration of Superposition Theorem in Spectrum Space for Composite Event Analysis in an ADN
Creators: name: He, Xing
name: Ai, Qian
name: Tang, Yuezhong
name: Qiu, Robert
name: Li, Canbing
Publisher: name: arXiv
Year: 2023
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: This study presents a formulation of the Superposition Theorem (ST) in the spectrum space, tailored for the analysis of composite events in an active distribution network (ADN). Our formulated ST enables a quantitative analysis on a composite event, uncovering the property of additivity among independent atom events in the spectrum space. This contribution is a significant addition to the existing literature and has profound implications in various application scenarios. To accomplish this, we leverage random matrix theory (RMT), specifically the asymptotic empirical spectral distribution, Stieltjes transform, and R transform. These mathematical tools establish a nonlinear, model-free, and unsupervised addition operation in the spectrum space. Comprehensive details, including a related roadmap,theorems, deductions, and proofs, are provided in this work. Case studies, utilizing field data, validate our newly derived ST formulation by demonstrating a remarkable performance. Our ST formulation is model-free, non-linear, non-supervised, theory-guided, and uncertainty-insensitive, making it a valuable asset in the realm of composite event analysis in ADN.
description: 12 pages. Accepted by IEEE TPWRS
Compression of Deep Neural Networks for Space Autonomous Systems
Creators: name: Shneider, Carl
name: Sinha, Nilotpal
name: Jamrozik, Michele
name: Astrid, Marcella
name: Rostami, Peyman
name: Kacem, Anis
name: Shabayek, Abdelrahman
name: Aouada, Djamila
Publisher: name: Zenodo
Year: 2023
Subjects: Deep learning
Edge computing
Neural network compression
Neural network pruning
Neural Architecture Search
Disentangled latent representation
Artificial Intelligence
Space autonomous systems
Space resource utilization

description: Efficient compression techniques are required to deploy deep neural networks (DNNs) on edge devices for space resource utilization tasks. Two approaches are investigated.

 Poster from the Computer Vision, Imaging, and Machine Intelligence Research Group (CVI2) at SnT, University of Luxembourg. Selected for poster presentation during the Space Resources Week 2023 conference that took place at the LuxExpo the Box in Luxembourg. Conference organized by the Luxembourg Space Agency (LSA), European Space Agency (ESA), Luxembourg Institute of Science and Technology (LIST), and the European Space Resources Innovation Centre (ESRIC).
description: This work was funded by the Luxembourg National Research Fund (FNR) under the project reference C21/IS/15965298/ELITE.
Cosmography with cluster strong lenses: the influence of substructure and line-of-sight halos
Creators: name: D'Aloisio, Anson
name: Natarajan, Priyamvada
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We explore the use of strong lensing by galaxy clusters to constrain the dark energy equation of state and its possible time variation. The cores of massive clusters often contain several multiply imaged systems of background galaxies at different redshifts. The locations of lensed images can be used to constrain cosmological parameters due to their dependence on the ratio of angular diameter distances. We employ Monte-Carlo simulations of cluster lenses, including the contribution from substructures, to assess the feasibility of this potentially powerful technique. At the present, parametric lens models use well motivated scaling relations between mass and light to incorporate cluster member galaxies, and do not explicitly model line-of-sight structure. Here, we quantify modeling errors due to scatter in the cluster galaxy scaling relations and un-modeled line-of-sight halos. These errors are of the order of a few arcseconds on average for clusters located at typical redshifts (z ~ 0.2 - 0.3). Using Bayesian Markov Chain Monte-Carlo techniques, we show that the inclusion of these modeling errors is critical to deriving unbiased constraints on dark energy. However, when the uncertainties are properly quantified, we show that constraints competitive with other methods may be obtained by combining results from a sample of just 10 simulated clusters with 20 families each. Cosmography with a set of well studied cluster lenses may provide a powerful complementary probe of the dark energy equation of state. Our simulations provide a convenient method of quantifying modeling errors and assessing future strong lensing survey strategies.
description: 14 pages, 11 figures, 2 tables
Superconducting Nanowires as Nonlinear Inductive Elements for Qubits
Creators: name: Ku, Jaseung
name: Manucharyan, Vladimir
name: Bezryadin, Alexey
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We report microwave transmission measurements of superconducting Fabry-Perot resonators (SFPR), having a superconducting nanowire placed at a supercurrent antinode. As the plasma oscillation is excited, the supercurrent is forced to flow through the nanowire. The microwave transmission of the resonator-nanowire device shows a nonlinear resonance behavior, significantly dependent on the amplitude of the supercurrent oscillation. We show that such amplitude-dependent response is due to the nonlinearity of the current-phase relationship (CPR) of the nanowire. The results are explained within a nonlinear oscillator model of the Duffing oscillator, in which the nanowire acts as a purely inductive element, in the limit of low temperatures and low amplitudes. The low quality factor sample exhibits a "crater" at the resonance peak at higher driving power, which is due to dissipation. We observe a hysteretic bifurcation behavior of the transmission response to frequency sweep in a sample with a higher quality factor. The Duffing model is used to explain the Duffing bistability diagram. We also propose a concept of a nanowire-based qubit that relies on the current dependence of the kinetic inductance of a superconducting nanowire.
description: 28 pages, 7 figures
The First Direct Images of an Exoplanet with JWST
Creators: name: Carter, Aarynn L.
Publisher: name: Zenodo
Year: 2023

description: We present JWST Early Release Science (ERS) coronagraphic observations of the super-Jupiter exoplanet, HIP 65426b, with the Near-Infrared Camera (NIRCam) from 2-5 μm, and with the Mid-Infrared Instrument (MIRI) from 11-16 μm. At a separation of ~0.82” (87+108-31 au), HIP 65426b is clearly detected in all seven of our observational filters, representing the first images of an exoplanet to be obtained by JWST, and the first ever direct detection of an exoplanet beyond 5 μm. These observations demonstrate that JWST is exceeding its nominal predicted performance by up to a factor of 10, depending on separation and subtraction method, with measured 5σ contrast limits of ~1x10-5 and ~2x10-4 at 1” for NIRCam at 4.4 μm and MIRI at 11.3 μm, respectively. These contrast limits provide sensitivity to sub-Jupiter companions with masses as low as 0.3 beyond separations of ~100 au. Together with existing ground-based near-infrared data, the JWST photometry are well fit by a BT-SETTL atmospheric model from 1-16 μm, and span ~97% of HIP 65426b's luminous range. Independent of the choice of model atmosphere we measure an empirical bolometric luminosity that is tightly constrained between log(Lbol/LSun)=-4.31 to -4.14, which in turn provides a robust mass constraint of 7.1±1.2 MJup. In totality, these observations confirm that JWST presents a powerful and exciting opportunity to characterise the population of exoplanets amenable to high-contrast imaging in greater detail.
description: On behalf of the ERS 1386 team.
CMB (Cosmic Microwave Background)
Creators: name: Ducharme, Michael James Jeffery
Publisher: name: University of British Columbia
Year: 2023

description: This thesis, titled CMB (Cosmic Microwave Background), is a 15-minute musical work for a chamber sextet with live electronics and interactive video. It is a quasi-spectral work that utilizes sonifications and data from the Cosmic Microwave Background radiation of the Universe to generate harmonic spectra from which the various subsections draw. The Cosmic Microwave Background (CMB) radiation is an echo of the Big Bang that marked the beginning of the Universe. Using CMB data provided by the University of British Columbia Department of Physics and Astronomy, I have created an innovative multimedia work using acoustic instruments, live electronics, and interactive video that depicts the evolution of the Universe from its beginnings to its eventual end.
The role of positronium decoherence in the studies of positron annihilation in matter
Creators: name: Pietrow, Marek
name: Slomski, Piotr
Publisher: name: arXiv
Year: 2010
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A small difference between the energy of the para-positronium (p-Ps) and ortho-positronium (o-Ps) states suggests the possibility of superposition of p-Ps and o-Ps during the formation of positronium (Ps) from pre-Ps terminating its migration in the matter in a void ('free volume'). It is shown that such a superposition decohere in the basis of p-Ps and o-Ps and the decoherence time is estimated. The time scale of the decoherence estimated here motivates respective correction in decomposition of the positron annihilation lifetime spectra. The way of the correction is sketched. The timescale of the decoherence suggests a need of awareness when experimental data from positron annihilation techniques are processed. More generally, the superposited state of Ps should contribute to the evolution theory of positronium in matter.
description: 15 pages, 6 figures
Direct Imaging with MIRI-MRS: A key ingredient to solve gas giant exoplanet formation
Creators: name: Patapis, Polychronis
Publisher: name: Zenodo
Year: 2023

description: The MIRI MRS on board JWST opens up new windows into the atmospheres of young, directly imaged gas giant exoplanets. We show how the mid-infrared can complement near-infrared observations to unlock the mysteries of planet formation.
Lectures on neutrino phenomenology
Creators: name: Winter, Walter
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The fundamental properties of the lepton sector include the neutrino masses and flavor mixings. Both are difficult to observe because of the extremely small neutrino masses and neutrino-matter cross sections. In these lectures, we focus on the basic concepts for the determination of neutrino properties. We introduce neutrino oscillations as standard mechanism for neutrino flavor changes, and we discuss methods to measure the neutrino mass. Furthermore, we illustrate how precision measurements in neutrino oscillations will be performed in the future, and may even open a window to new physics properties, such as motivated by LHC physics. Finally, we discuss some applications of neutrinos in astrophysics, such as neutrino oscillations in the Sun. We also illustrate how neutrinos from extragalactic cosmic accelerators may be used for the determination of neutrino properties.
description: 37 pages, 13 figures, 1 table. Lectures given at the Schladming Winter School 2010 "Masses and Constants".
Central limit theorem for multiplicative class functions on the symmetric group
Creators: name: Zeindler, Dirk
Publisher: name: arXiv
Year: 2010
Subjects: subject: Probability (math.PR)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 60F05

description: Hambly, Keevash, O'Connell and Stark have proven a central limit theorem for the characteristic polynomial of a permutation matrix with respect to the uniform measure on the symmetric group. We generalize this result in several ways. We prove here a central limit theorem for multiplicative class functions on symmetric group with respect to the Ewens measure and compute the covariance of the real and the imaginary part in the limit. We also estimate the rate of convergence with the Wasserstein distance.
description: 23 pages; the mathematics is the same as in the previous version, but there are several improvments in the presentation, including a more intuitve name for the considered functions
PICASO: Modeling Exoplanetary Atmospheres Self-Consistently with Photochemistry and Vertical Mixing
Creators: name: Mukherjee, Sagnick
name: Fortney, Jonathan J.
Publisher: name: Zenodo
Year: 2023
Subjects: Exoplanet Atmospheres, Atmospheric Chemistry

description: JWST observations of exoplanetary atmospheres have already shown that processes causing disequilibrium chemistry, such as vertical mixing and photochemistry, are extremely important. Apart from being poorly understood, they are already identified as important pathways to probe the interiors and formation pathways of exoplanets. However, to effectively use these processes as probes of deep exoplanetary atmospheres and interiors in the JWST era, they need to be physically understood first, which requires more sophisticated atmospheric models than what is available today. We have developed PICASO 3.0, an open-sourced atmospheric model coupled with the 1D chemical network code VULCAN, which has allowed us to model the effects of vertical mixing, photochemistry, and molecular diffusion in exoplanetary atmospheres self-consistently. Using this state-of-the-art model, we have explored the impact of these processes on the thermal structure, transmission spectra, and emission spectra of H2-He dominated atmospheres across a range of planet equilibrium temperatures and carbon-to-oxygen ratios. As this model is open-sourced and well-documented, it serves as an important resource for the whole community for modeling JWST observations of transiting exoplanets and brown dwarfs.
Use Cases Definition and Pilot Overview Document v2
Creators: name: Marco, Manso
Publisher: name: Zenodo
Year: 2020
Subjects: Use Cases
Application Scenarios
Pilots
KPIs

description: This document presents the SPHINX use cases that specifically address users' requirements and expectations on the use of new and advanced cybersecurity tools and services for the benefit of healthcare organisations and their patients. In particular, this document provides an overview and the main outcomes of the work performed by the SPHINX Consortium on the SPHINX use cases, as part of Task 2.4 – Reference Scenarios and Pilot Operations Specifications and KPIs for a period of two months (month 23 or November 2020 and month 24 or December 2020). Based on a compound framework of critical assets, threat taxonomy and actors, attack vectors and impact, this document updates deliverable D2.4 with five new use cases (use cases 17 to 21) that enrich the set of SPHINX use cases forming a basis for the three SPHINX pilots, as well as helping with the definition of the SPHINX user requirements (WP2), technical specifications (WP2) and development effort (WPs 3 to 6), while supporting SPHINX testing and validation effort (WP7). Overall, the SPHINX use cases are intended to highlight the greatest possible breadth of the SPHINX’s capabilities, whilst remaining realistic and testable in realistic conditions. They also seek, where possible, to address potential risks and limitations of the SPHINX System and its usage. In addition, this report discloses the relevant work SPHINX partners have been developing to support the SPHINX piloting activities, namely in what concerns the key performance indicators identified as relevant to enable the evaluation of the SPHINX’s impact in cybersecurity systems and healthcare organisations.
Broadband enhancement of light harvesting in luminescent solar concentrator
Creators: name: Xiao, Yun-Feng
name: Zou, Chang-Ling
name: Hu, Yi-Wen
name: Li, Yan
name: Xiao, Lixin
name: Sun, Fang-Wen
name: Gong, Qihuang
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Luminescent solar concentrator (LSC) can absorb large-area incident sunlight, then emit luminescence with high quantum efficiency, which finally be collected by a small photovoltaic (PV) system. The light-harvesting area of the PV system is much smaller than that of the LSC system, potentially improving the efficiency and reducing the cost of solar cells. Here, based on Fermi-golden rule, we present a theoretical description of the luminescent process in nanoscale LSCs where the conventional ray-optics model is no longer applicable. As an example calculated with this new model, we demonstrate that a slot waveguide consisting of a nanometer-sized low-index slot region sandwiched by two high-index regions provides a broadband enhancement of light harvesting by the luminescent centers in the slot region. This is because the slot waveguide can (1) greatly enhance the spontaneous emission due to the Purcell effect, (2) dramatically increase the effective absorption cross-section of luminescent centers, and (3) strongly improve the quantum efficiency of luminescent centers. It is found that about 80% solar photons can be ultimately converted to waveguide-coupled luminescent photons even for a low luminescent quantum efficiency of 0.5. This LSC is potential to construct a tandem structure which can absorb nearly full-spectrum solar photons, and also may be of special interest for building integrated nano-PV applications.
Anisotropy of the in-plane angular magnetoresistance of electron-doed Sr1-xLaxCuO2 thin films
Creators: name: Jovanović, V. P.
name: Fruchter, L.
name: Li, Z. Z.
name: Raffy, H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Signatures of antiferromagnetism (AF) in the underdoped Ln2-xCexCuO4 (Ln = Nd, Pr,...) family are observed even for doping levels for which superconductivity exists. We have looked for a similar property in a different electron-doped cuprate family, Sr1-xLaxCuO2, which consists of CuO2 planes separated by Sr/La atoms, and is exempt of the possible influence of magnetic rare earth ions. We report in-plane magnetoresistance measurements in the normal state of underdoped, superconducting, c-axis oriented, epitaxial Sr1-xLaxCuO2 thin films. This probe is sensitive to spin arrangement and we find that the in-plane magnetoresistance, which is negative and does not saturate for T, exhibits an angular dependence when measured upon rotating a magnetic field within the CuO2 planes. The analysis reveals a superposition of fourfold and twofold angular oscillations. Both of these increase in amplitude with increasing field and decreasing and appear below a temperature, which gets higher with decreasing doping levels. Our results demonstrate that these magnetoresistance oscillations, also observed for the Ln2-xCexCuO4 (Ln = Nd, Pr,...) family and attributed to an AF signature, are, without ambiguity, a property of CuO2 planes. Besides, these oscillations vary with doping in an unusual way compared to previous results: fourfold oscillations are essentially present in the more underdoped samples while only twofold oscillations are visible in the less underdoped ones. This intriguing observation appears to be a consequence of spin dilution with increasing doping level.
description: 25 pages, 6 figures
Eagle Strategy Using Lévy Walk and Firefly Algorithms For Stochastic Optimization
Creators: name: Yang, Xin-She
name: Deb, Suash
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: Most global optimization problems are nonlinear and thus difficult to solve, and they become even more challenging when uncertainties are present in objective functions and constraints. This paper provides a new two-stage hybrid search method, called Eagle Strategy, for stochastic optimization. This strategy intends to combine the random search using Lévy walk with the firefly algorithm in an iterative manner. Numerical studies and results suggest that the proposed Eagle Strategy is very efficient for stochastic optimization. Finally practical implications and potential topics for further research will be discussed.
description: 10 pages, 3 figures
From permanence to total availability: a quantum conceptual upgrade
Creators: name: de Bianchi, Massimiliano Sassoli
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Physics (physics.gen-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the classical concept of time of permanence and observe that its quantum equivalent is described by a bona fide self-adjoint operator. Its interpretation, by means of the spectral theorem, reveals that we have to abandon not only the idea that quantum entities would be characterizable in terms of spatial trajectories but, more generally, that they would possess the very attribute of spatiality. Consequently, a permanence time shouldn't be interpreted as a "time" in quantum mechanics, but as a measure of the total availability of a quantum entity in participating to a process of creation of a spatial localization.
Multiple Populations in Globular Clusters: The Possible Contributions of Stellar Collisions
Creators: name: Sills, Alison
name: Glebbeek, Evert
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Globular clusters were thought to be simple stellar populations, but recent photometric and spectroscopic evidence suggests that the clusters' early formation history was more complicated. In particular, clusters show star-to-star abundance variations, and multiple sequences in their colour-magnitude diagrams. These effects seem to be restricted to globular clusters, and are not found in open clusters or the field. In this paper, we combine the two competing models for these multiple populations and include a consideration of the effects of stellar collisions. Collisions are one of the few phenomena which occur solely in dense stellar environments like (proto-)globular clusters. We find that runaway collisions between massive stars can produce material which has abundances comparable to the observed second generations, but that very little total mass is produced by this channel. We then add the contributions of rapidly-rotating massive stars (under the assumption that massive stars are spun up by collisions and interactions), and the contribution of asymptotic giant branch stars. We find that collisions can help produce the extreme abundances which are seen in some clusters. However, the total amount of material produced in these generations is still too small (by at least a factor of 10) to match the observations. We conclude with a discussion of the additional effects which probably need to be considered to solve this particular problem.
description: 9 pages, 3 figures. Accepted by MNRAS
The XMM Cluster Survey: X-ray analysis methodology
Creators: name: Lloyd-Davies, E. J.
name: Romer, A. Kathy
name: Mehrtens, Nicola
name: Hosmer, Mark
name: Davidson, Michael
name: Sabirli, Kivanc
name: Mann, Robert G.
name: Hilton, Matt
name: Liddle, Andrew R.
name: Viana, Pedro T. P.
name: Campbell, Heather C.
name: Collins, Chris A.
name: Dubois, E. Naomi
name: Freeman, Peter
name: Harrison, Craig D.
name: Hoyle, Ben
name: Kay, Scott T.
name: Kuwertz, Emma
name: Miller, Christopher J.
name: Nichol, Robert C.
name: Sahlen, Martin
name: Stanford, S. A.
name: Stott, John P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we describe the data processing methodology applied to the 5,776 XMM observations used to construct the current XCS source catalogue. A total of 3,675 > 4-sigma cluster candidates with > 50 background-subtracted X-ray counts are extracted from a total non-overlapping area suitable for cluster searching of 410 deg^2. Of these, 993 candidates are detected with > 300 background-subtracted X-ray photon counts, and we demonstrate that robust temperature measurements can be obtained down to this count limit. We describe in detail the automated pipelines used to perform the spectral and surface brightness fitting for these candidates, as well as to estimate redshifts from the X-ray data alone. A total of 587 (122) X-ray temperatures to a typical accuracy of < 40 (< 10) per cent have been measured to date. We also present the methodology adopted for determining the selection function of the survey, and show that the extended source detection algorithm is robust to a range of cluster morphologies by inserting mock clusters derived from hydrodynamical simulations into real XMM images. These tests show that the simple isothermal beta-profiles is sufficient to capture the essential details of the cluster population detected in the archival XMM observations. The redshift follow-up of the XCS cluster sample is presented in a companion paper, together with a first data release of 503 optically-confirmed clusters.
description: MNRAS accepted, 45 pages, 38 figures. Our companion paper describing our optical analysis methodology and presenting a first set of confirmed clusters has now been submitted to MNRAS
"Maps preserving the spectrum of generalized Jordan product of operators", and its "Addendum"
Creators: name: Hou, Jinchuan
name: Li, Chi-Kwong
name: Wong, Ngai-Ching
Publisher: name: arXiv
Year: 2010
Subjects: subject: Functional Analysis (math.FA)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46, 47

description: In the paper "Maps preserving the spectrum of generalized Jordan product of operators", we define a generalized Jordan products on standard operator algebras $A_1, A_2$ on complex Banach spaces $X_1, X_2$, respectively. This includes the usual Jordan product $A_1 \circ A_2 = A_1 A_2 + A_2 A_1$, and the triple $\{A_1,A_2,A_3\} = A_1 A_2 A_3 + A_3 A_2 A_1$. Let a map $Φ: A_1 \to A_2$ prserving the spectra of the products $$ σ(Φ(A_1) \circ ... \circ Φ(A_k)) = σ(A_1\circ ... \circ A_k) $$ whenever any one of $A_1, ..., A_k$ has rank at most one. It is shown in this paper that if the range of $Φ$ contains all operators of rank at most three, then $Φ$ must be a Jordan isomorphism multiplied by an $m$th root of unity. Similar results for maps between self-adjoint operators acting on Hilbert spaces are also obtained. After our paper "Maps preserving the spectrum of generalized Jordan product of operators" was published in Linear Algebra Appl. 432 (2010), 1049-1069, Jianlian Cui pointed out that some arguments in the proof of Theorem 3.1 are not entirely clear and accurate. Here we supply some details in the "Addendum".
description: 1. 29 pages, the "orginal paper". 2. 5 pages, the "Addendum". 3. Replace the latex file of the "original paper" to avoid the conflict of using an old version of 'natbib' at April 23, 2010. The newer version simply does not use `natbib' at all, and nothing else is changed.
title: Officially Supported Export Credits in Germany and the People‘s Republic of China – A Systematic Literature Review
Creators: name: Albrecht, Justine
name: Raimann, Laura
Year: 2022

description: Germany was considered the world's export champion for a long time, until it was overtaken by China in 2009. Both nations provide officially supported export credits to national exporting organizations, but the two systems operate differently. German export credit guarantees serve as a substitute when the private market is unable to assume the risks of exporting companies. The German Export Credit Agency Euler Hermes is responsible for processing applications on behalf of the Federal Government. China belongs to the largest providers of export finance with the institutions China EXIM and Sinosure. While Germany is bound by the OECD consensus, which defines the level playing field, Chinese export credit agencies have greater flexibility not being bound by international rules or agreements.
description: IfTI Working Paper; 17 (2021)
Comments on Ultra-High-Energy Photons and D-Foam models
Creators: name: Ellis, John
name: Mavromatos, Nick E.
name: Nanopoulos, Dimitri V.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We revisit the constraints that the non-observation of ultra-high-energy photons due to the GZK cutoff can impose on models of Lorentz violation in photon propagation, following recent work by Maccione, Liberati and Sigl [arXiv:1003.5468] that carries further an earlier analysis by the present authors (Phys. Rev. D 63,12402 (2001), [hep-th/0012216]). We argue that the GZK cutoff constraint is naturally evaded in the D-brane model of space-time foam presented recently by the present authors (Phys. Lett. B 665, 412 (2008) [arXiv:0804.3566]), in which Lorentz-violating effects on photon propagation are independent of possible effects during interactions. We also note a novel absorption mechanism that could provide a GZK-like cutoff for photons in low-scale string models.
description: 4 pages LaTeX