cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A Note on the Kaluza-Klein Theory
Creators: name: Li, Li-Xin
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: We show that the Kaluza-Klein theory contains a fundamental problem: The four-dimensional metric tensor and the electromagnetic potential vector assumed in the Kaluza-Klein theory belong to four-dimensional vector spaces that are not integrable in general, resulting that the four-dimensional physical variables and the corresponding field equations derived from the five-dimensional Einstein field equation (i.e., the four-dimensional Einstein field equation and the Maxwell equations) are not defined on a four-dimensional submanifold. That is, the four-dimensional spacetime assumed in the Kaluza-Klein theory does not exist. No satisfactory solutions are found within the Kaluza-Klein formalism. Perhaps the best approach to fix the problem is giving up the Kaluza-Klein theory and looking for a new unified scheme for gravitational and electromagnetic interactions in the framework of a spacetime with extra dimensions, as having already been explored in some literature.
description: 8 pages, 2 figures. Class. Quantum Grav. published online 2023
On the possible observational signatures of white dwarf dynamical interactions
Creators: name: Aznar-Siguán, G.
name: García-Berro, E.
name: Magnien, M.
name: Lorén-Aguilar, P.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We compute the possible observational signatures of white dwarf dynamical interactions in dense stellar environments. Specifically, we compute the emission of gravitational waves, and we compare it with the sensitivity curves of planned space-borne gravitational wave detectors. We also compute the light curves for those interactions in which a detonation occurs, and one of the stars is destroyed, as well as the corresponding neutrino luminosities. We find that for the three possible outcomes of these interactions - which are the formation of an eccentric binary system, a lateral collision in which several mass transfer episodes occur, and a direct one in which just a single mass transfer episode takes place - only those in which an eccentric binary are formed are likely to be detected by the planned gravitational wave mission eLISA, while more sensitive detectors would be able to detect the signals emitted in lateral collisions. On the other hand, the light curves (and the thermal neutrino emission) of these interactions are considerably different, producing both very powerful outbursts and low luminosity events. Finally, we also calculate the X-ray signature produced in the aftermath of those interactions for which a merger occurs. We find that the temporal evolution follows a power law with the same exponent found in the case of the mergers of two neutron stars, although the total energy released is smaller.
description: 14 pages, 11 figures. Accepted for publication in MNRAS
Forecasting for Social Good
Creators: name: Rostami-Tabar, Bahman
name: Ali, Mohammad M
name: Hong, Tao
name: Hyndman, Rob J
name: Porter, Michael D
name: Syntetos, Aris
Publisher: name: Monash University
Year: 2022
Subjects: Econometric and statistical methods
Econometrics not elsewhere classified

description: Forecasting plays a critical role in the development of organisational business strategies. Despite a considerable body of research in the area of forecasting, the focus has largely been on the financial and economic outcomes of the forecasting process as opposed to societal benefits. Our motivation in this study is to promote the latter, with a view to using the forecasting process to advance social and environmental objectives such as equality, social justice and sustainability. We refer to such forecasting practices as Forecasting for Social Good (FSG) where the benefits to society and the environment take precedence over economic and financial outcomes. We conceptualise FSG and discuss its scope and boundaries in the context of the "Doughnut theory". We present some key attributes that qualify a forecasting process as FSG: it is concerned with a real problem, it is focused on advancing social and environmental goals and prioritises these over conventional measures of economic success, and it has a broad societal impact. We also position FSG in the wider literature on forecasting and social good practices. We propose an FSG maturity framework as the means to engage academics and practitioners with research in this area. Finally, we highlight that FSG: (i) cannot be distilled to a prescriptive set of guidelines, (ii) is scalable, and (iii) has the potential to make significant contributions to advancing social objectives.
Computationally Efficient Prediction of Area per Lipid
Creators: name: Chaban, Vitaly
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Area per lipid (APL) is an important property of biological and artificial membranes. Newly constructed bilayers are characterized by their APL and newly elaborated force fields must reproduce APL. Computer simulations of APL are very expensive due to slow conformational dynamics. The simulated dynamics increases exponentially with respect to temperature. APL dependence on temperature is linear over an entire temperature range. I provide numerical evidence that thermal expansion coefficient of a lipid bilayer can be computed at elevated temperatures and extrapolated to the temperature of interest. Thus, sampling times to predict accurate APL are reduced by a factor of ~10.
The Not-So-Sterile 4th Neutrino: Constraints on New Gauge Interactions from Neutrino Oscillation Experiments
Creators: name: Kopp, Joachim
name: Welter, Johannes
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Sterile neutrino models with new gauge interactions in the sterile sector are phenomenologically interesting since they can lead to novel effects in neutrino oscillation experiments, in cosmology and in dark matter detectors, possibly even explaining some of the observed anomalies in these experiments. Here, we use data from neutrino oscillation experiments, in particular from MiniBooNE, MINOS and solar neutrino experiments, to constrain such models. We focus in particular on the case where the sterile sector gauge boson $A'$ couples also to Standard Model particles (for instance to the baryon number current) and thus induces a large Mikheyev-Smirnov-Wolfenstein potential. For eV-scale sterile neutrinos, we obtain strong constraints especially from MINOS, which restricts the strength of the new interaction to be less than $\sim 10$ times that of the Standard Model weak interaction unless active-sterile neutrino mixing is very small ($\sin^2 θ_{24} \lesssim 10^{-3}$). This rules out gauge forces large enough to affect short baseline experiments like MiniBooNE and it imposes nontrivial constraints on signals from sterile neutrino scattering in dark matter experiments.
description: 19 pages, 9 figures
Robust Luttinger liquid state of 1D Dirac fermions in a van der Waals system Nb$_9$Si$_4$Te$_{18}$
Creators: name: Yao, Qirong
name: Jung, Hyunjin
name: Kong, Kijeong
name: De, Chandan
name: Kim, Jaeyoung
name: Denlinger, Jonathan D.
name: Yeom, Han Woong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report on the Tomonaga-Luttinger liquid (TLL) behavior in fully degenerate 1D Dirac fermions. A ternary van der Waals material Nb$_9$Si$_4$Te$_{18}$ incorporates in-plane NbTe$_2$ chains, which produce a 1D Dirac band crossing Fermi energy. Tunneling conductance of electrons confined within NbTe2 chains is found to be substantially suppressed at Fermi energy, which follows a power law with a universal temperature scaling, hallmarking a TLL state. The obtained Luttinger parameter of ~0.15 indicates strong electron-electron interaction. The TLL behavior is found to be robust against atomic-scale defects, which might be related to the Dirac electron nature. These findings, as combined with the tunability of the compound and the merit of a van der Waals material, offer a robust, tunable, and integrable platform to exploit non-Fermi liquid physics.
Large area LaBr3:Ce crystals read by SiPM arrays with improved timing and temperature gain drift control
Creators: name: Bonesini, M.
name: Benocci, R.
name: Bertoni, R.
name: Menegolli, A.
name: Prata, M.
name: Rossella, M.
name: Rossini, R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Compact X-rays detectors made of 1/2" or 1" :LaBr3:Ce crystals of cubic shape with SiPM array readout have been developed for the FAMU experiment at RIKEN-RAL. The aim is a precise measurement of the proton Zemach radius with incoming muons. Additional applications may be found in medical physics, such as PET, homeland security and gamma-ray astronomy. Due to the high photon yield of LaBr3:Ce it was possible to use a simple readout scheme based on CAEN V1730 digitizers. Detectors, using Hamamatsu S13361 or S14161 arrays, have good FWHM energy resolutions up to 3 % (8 %) at the Cs137 Co57) peak, comparing well with the best results obtained with a photomultiplier's readout. Detailed studies were performed to correct online the drift with temperature of SiPM gain and to reduce the risetime/falltime of detectors' signals, that increased going from 1/2" to 1" detectors, due to the larger capacity of the used SiPM arrays.
description: arXiv admin note: text overlap with arXiv:2210.02258
Clinical Contrastive Learning for Biomarker Detection
Creators: name: Kokilepersaud, Kiran
name: Prabhushankar, Mohit
name: AlRegib, Ghassan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper presents a novel positive and negative set selection strategy for contrastive learning of medical images based on labels that can be extracted from clinical data. In the medical field, there exists a variety of labels for data that serve different purposes at different stages of a diagnostic and treatment process. Clinical labels and biomarker labels are two examples. In general, clinical labels are easier to obtain in larger quantities because they are regularly collected during routine clinical care, while biomarker labels require expert analysis and interpretation to obtain. Within the field of ophthalmology, previous work has shown that clinical values exhibit correlations with biomarker structures that manifest within optical coherence tomography (OCT) scans. We exploit this relationship between clinical and biomarker data to improve performance for biomarker classification. This is accomplished by leveraging the larger amount of clinical data as pseudo-labels for our data without biomarker labels in order to choose positive and negative instances for training a backbone network with a supervised contrastive loss. In this way, a backbone network learns a representation space that aligns with the clinical data distribution available. Afterwards, we fine-tune the network trained in this manner with the smaller amount of biomarker labeled data with a cross-entropy loss in order to classify these key indicators of disease directly from OCT scans. Our method is shown to outperform state of the art self-supervised methods by as much as 5% in terms of accuracy on individual biomarker detection.
description: arXiv admin note: text overlap with arXiv:2209.11195
Edge modes in a frustrated quantum Ising chain
Creators: name: Jalal, Somenath
name: Kumar, Brijesh
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The ground state properties of an Ising chain with nearest ($J_{1}$) and next-nearest neighbor ($J_{2}$) interactions in a transverse field are investigated using the density matrix renormalization group and cluster mean-field theory methods. Its quantum phase diagram has two ordered regions (separated by a quantum disordered phase), one of which has simple ferromagnetic or Néel order depending upon the sign of $J_{1}$, and the other is the double-staggered antiferromagnetic phase. The presence of the Majorana-like edge-modes in these ordered phases is inferred by calculating the end-to-end spin-spin correlations on open chains. It is found that there occur four edge modes in the double-staggered phase, while the ferromagnetic and Néel phases support two edge modes, except very near $J_{1}=0$ where it seems they have four edge modes like the exact case at $J_{1}=0$ itself.
description: 8 pages, 13 figures
Time of Day, Cognitive Tasks and Efficiency Gains
Creators: name: Gaggero, Alessio
name: Tommasi, Denni
Publisher: name: Monash University
Year: 2022
Subjects: Econometric and statistical methods
Econometrics not elsewhere classified

description: The link between time-of-day and productivity on cognitive tasks is crucial to understand workplace efficiency and welfare. We study the performance of University students taking at most one exam per day in the final two weeks of the semester. Exams are scheduled at different time-of-day in a quasirandom fashion. We find that peak performance occurs around lunchtime (1.30pm), as compared to morning (9am) or late afternoon (4.30pm). This inverse-U shape relationship between time-of-day and performance (i) is not driven by stress or fatigue, (ii) is consistent with the idea that cognitive functioning is an important determinant of productivity and (iii) implies that efficiency gains of up to 0.14 standard deviations can be achieved through simple re-arrangements of the time of exams. While researchers have shown that biological factors influence changes in productivity between day and night shifts, we establish that such relationship is also important within a standard day-light shift. A simple back of the envelope calculation applied to an external context that is likely to benefit from our results, elective surgeries, suggests that a different sorting of the cognitive tasks performed by surgeons may lead to an increase in the number of patients saved.
Tightly-bound and room-temperature-stable excitons in van der Waals degenerate-semiconductor Bi4O4SeCl2 with high charge-carrier density
Creators: name: Xu, Yueshan
name: Wang, Junjie
name: Su, Bo
name: Deng, Jun
name: Peng, Cao
name: Wu, Chunlong
name: Zhang, Qinghua
name: Gu, Lin
name: Luo, Jianlin
name: Xu, Nan
name: Guo, Jian-gang
name: Chen, Zhi-Guo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Excitons, which represent a type of quasi-particles consisting of electron-hole pairs bound by the mutual Coulomb interaction, were often observed in lowly-doped semiconductors or insulators. However, realizing excitons in the semiconductors or insulators with high charge carrier densities is a challenging task. Here, we perform infrared spectroscopy, electrical transport, ab initio calculation, and angle-resolved-photoemission spectroscopy studies of a van der Waals degenerate-semiconductor Bi4O4SeCl2. A peak-like feature (i.e., alpha peak) is present around ~ 125 meV in the optical conductivity spectra at low temperature T = 8 K and room temperature. After being excluded from the optical excitations of free carriers, interband transitions, localized states and polarons, the alpha peak is assigned as the exciton absorption. Moreover, assuming the existence of weakly-bound excitons--Wannier-type excitons in this material violates the Lyddane-Sachs-Teller relation. Besides, the exciton binding energy of ~ 375 meV, which is about an order of magnitude larger than those of conventional semiconductors, and the charge-carrier concentration of ~ 1.25 * 10^19 cm^-3, which is higher than the Mott density, further indicate that the excitons in this highly-doped system should be tightly bound. Our results pave the way for developing the optoelectronic devices based on the tightly-bound and room-temperature-stable excitons in highly-doped van der Waals degenerate semiconductors.
description: Accepted by Communications Materials
NGC 6522: A typical globular cluster in the Galactic bulge without signatures of rapidly rotating Population III stars
Creators: name: Ness, Melissa
name: Asplund, Martin
name: Casey, Andrew R.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present an abundance analysis of eight potential member stars of the old Galactic bulge globular cluster NGC6522. The same stars have previously been studied by Chiappini et al. (2011), who found very high abundances of the slow neutron capture elements compared with other clusters and field stars of similar metallicity, which they interpreted as reflecting nucleosynthesis in rapidly rotating, massive Population III stars. In contrast to their analysis, we do not find any unusual enhancements of the neutron capture elements Sr, Y, Ba and Eu and conclude that previous claims result mainly from not properly accounting for blending lines. Instead we find NGC6522 to be an unremarkable globular cluster with comparable abundance trends to other Galactic globular clusters at the same metallicity ([Fe/H] = -1.15 +/- 0.16). The stars are also chemically similar to halo and bulge field stars at the same metallicity, spanning a small range in [Y/Ba] and with normal α-element abundances. We thus find no observational evidence for any chemical signatures of rapidly rotating Population III stars in NGC 6522.
description: 5 pages, 4 figures, submitted to MNRAS letters
Адаптация метода флуоресцентной in situ гибридизации для изучения взаимодействия микроорганизмов с эритроцитами
Creators: name: Е. А. Щуплова
Publisher: name: Бюллетень Оренбургского научного центра УрО РАН
Year: 2017
Subjects: эритроциты
микроорганизмы
ДНК-зонды
гибридизация
флуоресцентная микроскопия
erythrocytes
microorganisms
DNA probes
hybridization
fluorescence microscopy

description: Цель. Разработать оптимальный протокол FISH для изучения взаимодействия бактерий с эритроцитами. Материалы и методы. В исследовании использовали кровь от здорового донора, различные штаммы микроорганизмов из рабочей коллекции лаборатории экологии микроорганизмов. В основу разработки оптимального протокола FISH для изучения взаимодействия бактерий с эритроцитами была положена методика ДНК-гибридизации в растворе с олигонуклеотидными зондами, мечеными FITC, описанная в работе Sladjana Malic et аl. Результаты. В данной работе были подобраны условия необходимые при получении качественных образцов крови для выявления бактерий, локализованных на поверхности или внутри эритроцитов, а также подобрано время специфического связывания меченого FITC ДНК-зонда с ДНК исследуемых бактерий и с помощью люминесцентной или конфокальной лазерной сканирующей микроскопии регистрировали результаты исследований. Заключение. Разработан оптимальный протокол FISH для изучения взаимодействия бактерий с эритроцитами. Данный метод позволяет провести быструю дифференциацию и идентификацию микроорганизмов в образцах крови, что является перспективным для диагностики бактериемии и септических состояний. Результаты данного исследования могут быть использованы в клинических лабораториях лечебных учреждений для экспрессдиагностики септических состояний пациентов.
description: Objective. Develop an optimal FISH protocol for studying the interaction of bacteria with erythrocytes. Materials and methods. The study used blood from a healthy donor, various strains of microorganisms from the working collection of the laboratory of ecology of microorganisms. The basis for the development of the optimal FISH protocol for the study of the interaction of bacteria with erythrocytes was the DNA hybridization technique in solution with oligonucleotide probes labeled with FITC described in Sladjana Malic et аl. Results. In this study, the conditions necessary for obtaining qualitative blood samples for detecting bacteria localized on the surface or inside the red blood cells were selected, and the time for the specific binding of the labeled FITC DNA probe to the DNA of the bacteria was determined and the results of the studies were recorded with luminescent or confocal laser scanning microscopy. Conclusion. An optimal FISH protocol has been developed to study the interaction of bacteria with erythrocytes. This method allows rapid differentiation and identification of microorganisms in blood samples, which is promising for the diagnosis of bacteremia and septic states. The results of this study can be used in clinical laboratories of medical institutions for the rapid diagnosis of septic states of patients.
Distinct neural profiles during aversive learning mediate the longitudinal association of childhood trauma and symptoms of internalizing and externalizing psychopathology in youth
Creators: name: DeCross, Stephanie N.
name: McLaughlin, Katie A.
Publisher: name: Zenodo
Year: 2020
Subjects: fear conditioning
aversive learning
childhood trauma
psychopathology
mechanisms
affective neuroscience
developmental neuroimaging
temporal dynamics
salience network
default mode network
functional connectivity
mediation

description: Oral presentation at the Association for Behavioral and Cognitive Therapies (ABCT) 2020 virtual conference as part of the symposium "Remembering (not) to fear: Understanding the development and treatment of anxiety and PTSD through translational research on fear memory and learning." Abstract One potential mechanism linking childhood trauma (CT) exposure with psychopathology is aversive learning. This study aims to describe the temporal dynamics of neural activation during aversive learning and patterns of task-based functional connectivity, as well as how CT may influence these neural correlates in ways that contribute to psychopathology. 147 children (aged 8-16 years) with and without exposure to CT completed a fear conditioning procedure during an fMRI scan, and measures of clinical symptoms were collected at baseline and two-year follow-up. Whole-brain and region-of-interest analyses were conducted to examine dynamic patterns of learning and connectivity, and nonparametric mediation models were run to test whether these neural measures mediated the relationship between CT and psychopathology at baseline and follow-up. In children, canonical salience network regions were active to the threat vs. safety cue, and exhibited habituation across blocks. Default mode network regions were active to the safety vs. threat cue, with activation increasing across blocks. Moreover, children with CT displayed blunted learning slopes over time in right amygdala, right hippocampus, and frontal pole, as well as elevated connectivity of amygdala with regions associated with attention direction and initiation of defensive responses and reduced amygdala-hippocampal connectivity. Patterns of neural response across blocks and task-based connectivity were associated with transdiagnostic psychopathology (depression, panic, generalized anxiety, externalizing, and PTSD) at baseline and follow-up. Critically, blunted learning slopes in right amygdala and insula mediated the pathway between CT and externalizing at two-year follow-up, controlling for baseline symptoms, and reduced amygdala-hippocampal connectivity mediated the pathway between CT and panic and generalized anxiety. This study provides evidence that alterations in aversive learning processes and the dynamic communication between salience network and default mode network regions may be a key mechanism underlying the link between CT and psychopathology. Disruptions in neural activation versus connectivity during learning may set some children on trajectories towards differentiable clinical symptom profiles.
Pinning, Ordering, and Dynamics of Vortices in Conformal Crystal and Gradient Pinning Arrays
Creators: name: Ray, D.
name: Reichhardt, C.
name: Reichhardt, C. J. Olson
Publisher: name: arXiv
Year: 2014
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We numerically investigate magnetization, pinning, ordering, and dynamics of vortices interacting with pinning arrangements which have a density gradient. We focus on conformal crystal structures obtained by conformally transforming a spatially uniform periodic array, as well as non-conformal gradient structures and structures with quasiperiodic order. The conformal structures feature a density gradient and local ordering. Using magnetization simulations we find that conformal pinning arrays exhibit enhanced pinning compared to non-conformal gradient arrays as well as compared to random, periodic, and quasiperiodic arrays, for a broad range of fields. The effectiveness of conformal arrays arises from the continuum of length scales introduced into the arrays by the conformal transformation, allowing for a broad range of local commensuration effects. At higher vortex fillings above the range of conformal effectiveness, we show that a non-conformal rectangular gradient array exhibits strong pinning due to a novel commensuration effect and vortex ordering. Using transport simulations where vortices are driven along the gradient and at an angle to the gradient, we confirm the effectiveness of conformal pinning at increasing the critical current. For a rotated drive, the gradient arrays produce a strong vortex guidance effect in the direction perpendicular to the gradient.
description: 17 pages, 19 postscript figures
A Class of Time-Varying Vector Moving Average (infinity) Models
Creators: name: Yan, Yayi
name: Gao, Jiti
name: peng, Bin
Publisher: name: Monash University
Year: 2022
Subjects: Econometric and statistical methods
Econometrics not elsewhere classified

description: Multivariate time series analyses are widely encountered in practical studies, e.g., modelling policy transmission mechanism and measuring connectedness between economic agents. To better capture the dynamics, this paper proposes a class of multivariate dynamic models with time-varying coefficients, which have a general time-varying vector moving average (VMA) representation, and nest, for instance, time-varying vector autoregression (VAR), time-varying vector autoregression moving-average (VARMA), and so forth as special cases. The paper then develops a unified estimation method for the unknown quantities before an asymptotic theory for the proposed estimators is established. In the empirical study, we investigate the transmission mechanism of monetary policy using U.S. data, and uncover a fall in the volatilities of exogenous shocks. In addition, we find that (i) monetary policy shocks have less influence on inflation before and during the so-called Great Moderation, (ii) inflation is more anchored recently, and (iii) the long-run level of inflation is below, but quite close to the Federal Reserve's target of two percent after the beginning of the Great Moderation period.
Global impacts of a Foreshock Bubble: Magnetosheath, magnetopause and ground-based observations
Creators: name: Archer, Martin
name: Turner, Drew
name: Eastwood, Jonathan
name: Schwartz, Steven
name: Horbury, Timothy
Publisher: name: arXiv
Year: 2014
Subjects: subject: Space Physics (physics.space-ph)
subject: Geophysics (physics.geo-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Using multipoint observations we show, for the first time, that Foreshock Bubbles (FBs) have a global impact on Earth's magnetosphere. We show that an FB, a transient kinetic phenomenon due to the interaction of backstreaming suprathermal ions with a discontinuity, modifies the total pressure upstream of the bow shock showing a decrease within the FB's core and sheath regions. Magnetosheath plasma is accelerated towards the the intersection of the FB's current sheet with the bow shock resulting in fast, sunward, flows as well as outward motion of the magnetopause. Ground-based magnetometers also show signatures of this magnetopause motion simultaneously across at least 7 hours of magnetic local time, corresponding to a distance of 21.5 RE transverse to the Sun-Earth line along the magnetopause. These observed global impacts of the FB are in agreement with previous simulations and in stark contrast to the known localised, smaller scale effects of Hot Flow Anomalies (HFAs).
Fast immersed boundary method based on weighted quadrature
Creators: name: Marussig, Benjamin
name: Hiemstra, René
name: Schillinger, Dominik
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: Combining sum factorization, weighted quadrature, and row-based assembly enables efficient higher-order computations for tensor product splines. We aim to transfer these concepts to immersed boundary methods, which perform simulations on a regular background mesh cut by a boundary representation that defines the domain of interest. Therefore, we present a novel concept to divide the support of cut basis functions to obtain regular parts suited for sum factorization. These regions require special discontinuous weighted quadrature rules, while Gauss-like quadrature rules integrate the remaining support. Two linear elasticity benchmark problems confirm the derived estimate for the computational costs of the different integration routines and their combination. Although the presence of cut elements reduces the speed-up, its contribution to the overall computation time declines with h-refinement.
Annealing Relaxation of Ultrasmall Gold Nanostructures
Creators: name: Chaban, Vitaly
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Except serving as an excellent gift on proper occasions, gold finds applications in life sciences, particularly in diagnostics and therapeutics. These applications were made possible by gold nanoparticles, which differ drastically from macroscopic gold. Versatile surface chemistry of gold nanoparticles allows coating with small molecules, polymers, biological recognition molecules. Theoretical investigation of nanoscale gold is not trivial, because of numerous metastable states in these systems. Unlike elsewhere, this work obtains equilibrium structures using annealing simulations within the recently introduced PM7-MD method. Geometries of the ultrasmall gold nanostructures with chalcogen coverage are described at finite temperature, for the first time.
On GMM Inference: Partial Identification, Identification Strength, and Non-Standard
Creators: name: Poskitt, Don S.
Publisher: name: Monash University
Year: 2022
Subjects: Econometric and statistical methods
Econometrics not elsewhere classified

description: This paper analyses aspects of GMM inference in moment equality models when the moment Jacobian is allowed to be rank deficient. In this setting first order identification may fail, and the singular values of the Jacobian are not constrained, thereby allowing for varying levels of identification strength. No specific structure is imposed on the functional form of the moment conditions, the long-run variance of the moment conditions can be singular, and the GMM criterion function weighting matrix may also be chosen sub-optimally. Explicit analytic formulations for the asymptotic distributions of estimable functions of the resulting GMM estimator and the asymptotic distributions of GMM criterion test statistics are derived under relatively mild assumptions. The distributions can be computed using standard software without recourse to bootstrap or simulation methods. The practical operation of the theoretical results, and the relationship between lack of identification and identification strength, is illustrated via numerical examples involving instrumental variables estimation of a structural equation with endogenous regressors. The results suggest that although the presence and origin of identification problems can in practice be obscure, the applied researcher can take comfort from the fact that probabilities and quantile values calculated using the new asymptotic sampling distributions of statistics constructed from the standard GMM criterion function will give accurate approximations in the presence of identification issues, irrespective of the latter's source.
Optically controlled waveplate at a telecom wavelength using a ladder transition in Rb atoms for all-optical switching and high speed Stokesmetric Imaging
Creators: name: Krishnamurthy, Subramanian
name: Tu, Y.
name: Wang, Y.
name: Tseng, S.
name: Shahriar, M. S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We demonstrate an optically controlled waveplate at ~1323 nm using the 5S1/2-5P1/2-6S1/2 ladder transition in a Rb vapor cell. The lower leg of the transitions represents the control beam, while the upper leg represents the signal beam. We show that we can place the signal beam in any arbitrary polarization state with a suitable choice of polarization of the control beam. Specifically, we demonstrate a differential phase retardance of ~180 degrees between the two circularly polarized components of a linearly polarized signal beam. We also demonstrate that the system can act as a Quarter Wave plate. The optical activity responsible for the phase retardation process is explained in terms of selection rules involving the Zeeman sublevels. As such, the system can be used to realize a fast Stokesmetric Imaging system with a speed of nearly 5 MHz. When implemented using a tapered nano fiber embedded in a vapor cell, this system can be used to realize an ultra-low power all-optical switch as well as a Quantum Zeno Effect based all-optical logic gate by combining it with an optically controlled polarizer, previously demonstrated by us. We present numerical simulations of the system using a comprehensive model which incorporates all the relevant Zeeman sub-levels in the system, using a novel algorithm recently developed by us for efficient computation of the evolution of an arbitrary large scale quantum system.
Optimization of WLS fiber readout for the HERD calorimeter
Creators: name: Liu, X.
name: Quan, Z.
name: Dong, Y. W.
name: Xu, M.
name: Wang, J. J.
name: Wang, R. J.
name: Wang, Z. G.
name: Cui, X. Z.
name: Bao, T. W.
name: Liao, C. L.
name: Han, J. F.
name: Chen, Y.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: A novel 3-D calorimeter, composed of about 7500 LYSO cubes, is the key and crucial detector of the High Energy cosmic-Radiation Detection (HERD) facility to be installed onboard the China Space Station. Energy deposition from cosmic ray in each LYSO cube is translated by multiple wavelength shifting (WLS) fibers for multi-range data acquisition and real-time triggering. In this study, various methods of surface finish and encapsulation of the LYSO cube were investigated to optimize the amplitude from the WLS fiber end with the aim of improving the signal-to-noise ratio of Intensified scientific CMOS (IsCMOS) collection. The LYSO cube with five rough surfaces and a specular reflector achieves the maximum amplitude at the low-range fiber end, which is increased by roughly 44% compared to the polished cube with PTFE wrapping. The non-uniformity of amplitude at different positions on the LYSO cube surface was measured by X-ray and the positional correlation factor was derived for the entire cube. A simulation based on HERD CALO was conducted, which revealed that both the LYSO cube with five rough surfaces and the cube with rough bottom face exhibit superior energy resolution for electrons compared to the other two configurations.
Exploring the multiband emission of TXS 0536+145: the most distant gamma-ray flaring blazar
Creators: name: Orienti, M.
name: D'Ammando, F.
name: Giroletti, M.
name: Finke, J.
name: Ajello, M.
name: Dallacasa, D.
name: Venturi, T.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report results of a multiband monitoring campaign of the flat spectrum radio quasar TXS 0536+145 at redshift 2.69. This source was detected during a very high gamma-ray activity state in 2012 March by the Large Area Telescope on board Fermi, becoming the gamma-ray flaring blazar at the highest redshift detected so far. At the peak of the flare the source reached an apparent isotropic gamma-ray luminosity of 6.6 x 10^49 erg/s which is comparable to the values achieved by the most luminous blazars. This activity triggered radio-to-X-rays monitoring observations by Swift, Very Long Baseline Array, European VLBI Network, and Medicina single-dish telescope. Significant variability was observed from radio to X-rays supporting the identification of the gamma-ray source with TXS 0536+145. Both the radio and gamma-ray light curves show a similar behaviour, with the gamma-rays leading the radio variability with a time lag of about 4-6 months. The luminosity increase is associated with a flattening of the radio spectrum. No new superluminal component associated with the flare was detected in high resolution parsec-scale radio images. During the flare the gamma-ray spectrum seems to deviate from a power law, showing a curvature that was not present during the average activity state. The gamma-ray properties of TXS 0536+145 are consistent with those shown by the high-redshift gamma-ray blazar population.
description: 13 pages, 11 figures, accepted for publication in MNRAS
Pionic and radiative transitions from $T_{c\bar{s}0}^+(2900)$ to $D_{s1}^+(2460)$ as a probe of the structure of $D_{s1}^+(2460)$
Creators: name: Yue, Zi-Li
name: Xiao, Cheng-Jian
name: Chen, Dian-Yong
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In this work, we evaluated the widths of the pionic and radiative transitions from the $T_{c\bar{s}0}^{+}(2900)$ to the $D_{s1}^{+}(2460)$ in the $D_{s1}^{+}(2460)$ molecular frame and the $D_{s1}^{+}(2460)$ charmed-strange meson frame. Our estimations demonstrate that the transition widths in the $D_{s1}^{+}(2460)$ molecular frame are much larger than those in the the $D_{s1}^{+}(2460)$ charmed-strange meson frame. Specifically, the ratio of the widths of $Γ(T_{c\bar{s}0}^{+}(2900)\to D_{s1}^{+} π^{0})$ and $Γ(T_{c\bar{s}0}^{+}(2900)\to D^{+(0)}K^{0(+)})$ is estimated to be around 0.1 in the $D_{s1}^{+}(2460)$ charmed-strange meson frame, whereas the lower limit of this ratio is 0.67 in the $D_{s1}^{+}(2460)$ molecular frame. Thus, the aforementioned ratio could be employed as a tool for testing the nature of the $D_{s1}^{+}(2460)$.
description: 8 pages, 7 figures
Рихард Зорге: взгляд из ХХI века
Creators: name: Катасонова Елена Леонидовна
Publisher: name: Японские исследования
Year: 2017

description: Алексеев М.Н. «Верный Вам Рамзай». Рихард Зорге и советская военная разведка в Японии. 1933-1938 годы. Книга 1. М.: Алгоритм, 2017. 864 с. ISBN 978-5-906914-53-8. Алексеев М.Н. «Верный Вам Рамзай». Рихард Зорге и советская военная разведка в Японии. 1939-1941 годы. Книга 2. М.: Алгоритм, 2017. 688 с. ISBN 978-5-906947-30-7.
Quantum Phase Transition with a Simple Variational Ansatz
Creators: name: Lutsyshyn, Y.
name: Astrakharchik, G. E.
name: Cazorla, C.
name: Boronat, J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We study the zero-temperature quantum phase transition between liquid and hcp solid helium-4. We use the variational method with a simple yet exchange-symmetric and fully explicit wavefunction. It is found that the optimized wavefunction undergoes spontaneous symmetry breaking and describes the quantum solidification of helium at 22 atm. The explicit form of the wavefunction allows to consider various contributions to the phase transition. We find that the employed wavefunction is an excellent candidate for describing both a first-order quantum phase transition and the ground state of a Bose solid.
Konzeption, Simulation und technische Umsetzung neuartiger, mikrostrukturierter LED-Flächenstrahler auf der Basis von Lichtleitern
Creators: name: Jakubowsky, Michael
Publisher: name: Technische Universität Dortmund
Year: 2020
Subjects: subject: Microstructure
subject: Microoptic
subject: Light guide
subject: Light
subject: Micro
subject: Optic
subject: PMMA
subject: Bonding
subject: Luminaire
subject: 620
subject: Beleuchtung
subject: Mikrooptik

description: Die Beleuchtung von Räumen ist in der Architektur und der Energiepolitik ein wichtiges Thema. Dies betrifft vor allem Konzepte, die neues Potential in der architektonischen Gestaltung eröffnen und den Energiebedarf von Gebäuden verbessern. Der Einsatz von mikrostrukturierten, durchsichtigen Flächenstrahlern zur Raumbeleuchtung eröffnet hier neue Möglichkeiten. In dieser Arbeit wird eine solche Leuchte basierend auf dem Konzept lichtleitender Platten entwickelt und hergestellt. Hierzu wird ein Entwicklungsschema entworfen, zu dem Herstellungsverfahren identifiziert und angepasst werden. Die industriell gefertigten Muster werden erfolgreich in eine Fassade integriert, um einen Raum von dort aus indirekt über die Decke zu beleuchten. Für die Charakterisierung des Abstrahlverhaltens und der subjektiven Wahrnehmung der hergestellten mikrostrukturierten Flächenstrahler werden neue Simulations- und Messverfahren entwickelt, die das Optimierungspotential der entwickelten Systeme identifizierbar machen. Darauf aufbauend werden optimierte Flächenstrahler mit hinterschnittenen Mikrostrukturen entworfen und neue Verfahren zu deren Herstellung entwickelt. Eine sozioökologische Einordnung bringt Aufschluss über die Nachhaltigkeit der neuartigen Beleuchtung.
description: Room illumination is an important topic in architecture and energy politics, regarding mainly concepts that introduce new possibilities in design and improvement in energy consumption of a building. Microstructured transparent large area surface emitters open up new potentials in this field. In this work the development and manufacturing of such a luminaire based on the concept of light guiding plates are presented. For this purpose, a development scheme is formulated and feasible manufacturing methods are identified and adapted. The industrially manufactured samples are successfully integrated in a façade to light up the room’s ceiling and thereby realize an indirect room illumination. The out-coupling and subjective perception of the manufactured microstructured surface emitters are characterized by simulations and novel measurement setups developed for this purpose and further to show potential for optimization. Based on findings by this characterization, optimized surface emitters with undercut microstructures and feasible manufacturing methods are invented. A socio-ecological classification gives an outlook on the sustainability of the novel lighting solution.
The Cosmic Ray Antiproton Background for AMS-02
Creators: name: Kappl, Rolf
name: Winkler, Martin Wolfgang
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The AMS-02 experiment is measuring the cosmic ray antiproton flux with high precision. The interpretation of the upcoming data requires a thorough understanding of the secondary antiproton background. In this work, we employ newly available data of the NA49 experiment at CERN, in order to recalculate the antiproton source term arising from cosmic ray spallations on the interstellar matter. We systematically account for the production of antiprotons via hyperon decay and discuss the possible impact of isospin effects on antineutron production. A detailed comparison of our calculation with the existing literature as well as with Monte Carlo based evaluations of the antiproton source term is provided. Our most important result is an updated prediction for the secondary antiproton flux which includes a realistic assessment of the particle physics uncertainties at all energies.
description: 24 pages, 10 figures, source term and secondary flux available in the ancillary files
The Submillimeter Polarization Spectrum of M17
Creators: name: Zeng, Lingzhen
name: Bennett, Charles L.
name: Chapman, Nicholas L.
name: Chuss, David T.
name: Jimenez-Serra, Izaskun
name: Novak, Giles
name: Vaillancourt, John E.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present 450 μm polarimetric observations of the M17 molecular cloud obtained with the SHARP polarimeter at the Caltech Submillimeter Observatory. Across the observed region, the magnetic field orientation is consistent with previous submillimeter and far-infrared polarization measurements. Our observations are centered on a region of the molecular cloud that has been compressed by stellar winds from a cluster of OB stars. We have compared these new data with previous 350 μm polarimetry and find an anti-correlation between the 450 to 350 μm polarization magnitude ratio and the ratio of 21 cm to 450 μm intensity. The polarization ratio is lower near the east end of the studied region where the cloud is exposed to stellar winds and radiation. At the west end of the region, the polarization ratio is higher. We interpret the varying polarization spectrum as evidence supporting the radiative alignment torque (RAT) model for grain alignment, implying higher alignment efficiency in the region that is exposed to a higher anisotropic radiation field.
description: 24 pages, 10 figures