cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Competing quantum spin liquids, gauge fluctuations, and anisotropic interactions in a breathing pyrochlore lattice
Creators: name: Chern, Li Ern
name: Kim, Yong Baek
name: Castelnovo, Claudio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We use the projective symmetry group analysis to classify the quantum spin liquids on the $S=1/2$ pyrochlore magnet with a breathing anisotropy. We find 40 $\mathbb{Z}_2$ spin liquids and 16 $U(1)$ spin liquids that respect the $F\bar{4}3m$ space group and the time reversal symmetry. As an application, we consider the antiferromagnetic Heisenberg model, which is proposed to be the dominant interaction in the candidate material Ba$_3$Yb$_2$Zn$_5$O$_{11}$. Focusing on the $U(1)$ spin liquid ansatze, we find that only two of them are physical when restricted to this model. We present an analytical solution to the parton mean field theory for each of these two $U(1)$ spin liquids. It is revealed that one of them has gapless, while the other one has gapped, spinon excitations. The two $U(1)$ spin liquids are equal in energy regardless of the degree of breathing anisotropy, and they can be differentiated by the low-temperature heat capacity contribution from the quadratically-dispersing gapless spinons. We further show that the latter is unaffected by fluctuations of the $U(1)$ gauge field within the random phase approximation. Finally, we demonstrate that a small Dzyaloshinskii-Moriya interaction lifts the degeneracy between the two $U(1)$ spin liquids, and it eventually causes the lattice to decouple into independent tetrahedra at strong coupling. While current model parameters for Ba$_3$Yb$_2$Zn$_5$O$_{11}$ place it indeed in the decoupled regime, other candidate materials may be synthesised in the near future that realize the spin liquid states discussed in our work.
description: 10+15 pages, 4+1 figures, 1+1 tables
On the Oort conjecture for Shimura varieties of unitary and orthogonal types
Creators: name: Chen, Ke
name: Lu, Xin
name: Zuo, Kang
Publisher: name: arXiv
Year: 2014
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 11G15, 14G35, 14H40

description: In this paper we study the Oort conjecture on Shimura subvarieties contained generically in the Torelli locus in the Siegel modular variety $\mathcal{A}_g$. Using the poly-stability of Higgs bundles on curves and the slope inequality of Xiao on fibred surfaces, we show that a Shimura curve $C$ is not contained generically in the Torelli locus if its canonical Higgs bundles contains a unitary Higgs subbundle of rank at least $(4g+2)/5$. From this we prove that a Shimura subvariety of $\mathbf{SU}(n,1)$-type is not contained generically in the Torelli locus when a numerical inequality holds, which involves the genus $g$, the dimension $n+1$, the degree $2d$ of CM field of the Hermitian space, and the type of the symplectic representation defining the Shimura subdatum. A similar result holds for Shimura subvarieties of $\mathbf{SO}(n,2)$-type, defined by spin groups associated to quadratic spaces over a totally real number field of degree at least 6 subject to some natural constraints of signatures.
description: Comments are welcome, accepted for publication in Compositio Mathematica
Second-order quantum nonlinear optical processes in single graphene nanostructures and arrays
Creators: name: Manzoni, Marco T.
name: Silveiro, Iván
name: de Abajo, F. Javier García
name: Chang, Darrick E.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Intense efforts have been made in recent years to realize nonlinear optical interactions at the single-photon level. Much of this work has focused on achieving strong third-order nonlinearities, such as by using single atoms or other quantum emitters while the possibility of achieving strong second-order nonlinearities remains unexplored. Here, we describe a novel technique to realize such nonlinearities using graphene, exploiting the strong per-photon fields associated with tightly confined graphene plasmons in combination with spatially nonlocal nonlinear optical interactions. We show that in properly designed graphene nanostructures, these conditions enable extremely strong internal down-conversion between a single quantized plasmon and an entangled plasmon pair, or the reverse process of second harmonic generation. A separate issue is how such strong internal nonlinearities can be observed, given the nominally weak coupling between these plasmon resonances and free-space radiative fields. On one hand, by using the collective coupling to radiation of nanostructure arrays, we show that the internal nonlinearities can manifest themselves as efficient frequency conversion of radiative fields at extremely low input powers. On the other hand, the development of techniques to efficiently couple to single nanostructures would allow these nonlinear processes to occur at the level of single input photons.
description: 25 pages, 6 figures
Possible discovery of Calvera's supernova remnant
Creators: name: Arias, M.
name: Botteon, A.
name: Bassa, C. G.
name: van der Jagt, S.
name: van Weeren, R. J.
name: O'Sullivan, S. P.
name: Bosschaart, Q.
name: Dullaart, R. S.
name: Hardcastle, M. J.
name: Hessels, J. W. T.
name: Shimwell, T.
name: Slob, M. M.
name: Sturm, J. A.
name: Tasse, C.
name: Theijssen, N. C. M. A.
name: Vink, J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report the discovery of a ring of low surface brightness radio emission around the Calvera pulsar, a high Galactic latitude, isolated neutron star, in the LOFAR Two-metre Sky Survey (LoTSS). It is centered at $α=14\mathrm{h}11\mathrm{m}12.6\mathrm{s}$, $δ=+79^\mathrm{o}23'15"$, has inner and outer radii of $14.2'$ and $28.4'$, and an integrated flux density at 144 MHz of $1.08\pm0.15$ Jy. The ring center is offset by $4.9'$ from the location of the Calvera pulsar. H$α$ observations with the Isaac Newton Telescope show no coincident optical emission, but do show a small ($\sim20"$) optical structure internal to the ring. We consider three possible interpretations for the ring: that it is an H~II region, a supernova remnant (SNR), or an Odd Radio Circle (ORC). The positional coincidence of the ring, the pulsar, and an X-ray-emitting non-equilibrium ionisation plasma previously detected, lead us to prefer the SNR interpretation. If the source is indeed a SNR and its association with the Calvera pulsar is confirmed, then Calvera's SNR, or G118.4+37.0, will be one of few SNRs in the Galactic halo.
description: Accepted in A&A
The Influence of Employee Role Identity on Attitudes Towards and Utilisation of Flexible Work Arrangements
Creators: name: BENTLEY, FRANK WILLIAM
Publisher: name: Monash University
Year: 2023
Subjects: Organisational behaviour

description: This study examined how ideal worker role identity, family role identity and caregiver role identity are related to employee attitudes towards, and subsequent utilisation of, flexible work arrangements (FWAs). Previously researchers have focused on social norms and workplace cultures that may influence utilization of FWAs, which involve modifying the time or place where work is done on a regular basis. The findings indicate that family and caregiver identities are associated with more favourable attitudes towards FWAs. Additionally, employees who have more favourable attitudes towards FWAs are 1.5 times more likely to use FWAs. The findings may be used by HR professionals to target attitude change, and better understand caregiver and family role responsibilities, as organisations seek to attract and retain key employees.
Optimization as a design strategy. Considerations based on building simulation-assisted experiments about problem decomposition
Creators: name: Brunetti, Gian Luca
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 49M27

description: In this article the most fundamental decomposition-based optimization method - block coordinate search, based on the sequential decomposition of problems in subproblems - and building performance simulation programs are used to reason about a building design process at micro-urban scale and strategies are defined to make the search more efficient. Cyclic overlapping block coordinate search is here considered in its double nature of optimization method and surrogate model (and metaphore) of a sequential design process. Heuristic indicators apt to support the design of search structures suited to that method are developed from building-simulation-assisted computational experiments, aimed to choose the form and position of a small building in a plot. Those indicators link the sharing of structure between subspaces ("commonality") to recursive recombination, measured as freshness of the search wake and novelty of the search moves. The aim of these indicators is to measure the relative effectiveness of decomposition-based design moves and create efficient block searches. Implications of a possible use of these indicators in genetic algorithms are also highlighted.
description: 48 pages. 12 figures, 3 tables
BeauVis: A Validated Scale for Measuring the Aesthetic Pleasure of Visual Representations
Creators: name: He, Tingying
name: Isenberg, Petra
name: Dachselt, Raimund
name: Isenberg, Tobias
Publisher: name: arXiv
Year: 2022
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences

description: We developed and validated a rating scale to assess the aesthetic pleasure (or beauty) of a visual data representation: the BeauVis scale. With our work we offer researchers and practitioners a simple instrument to compare the visual appearance of different visualizations, unrelated to data or context of use. Our rating scale can, for example, be used to accompany results from controlled experiments or be used as informative data points during in-depth qualitative studies. Given the lack of an aesthetic pleasure scale dedicated to visualizations, researchers have mostly chosen their own terms to study or compare the aesthetic pleasure of visualizations. Yet, many terms are possible and currently no clear guidance on their effectiveness regarding the judgment of aesthetic pleasure exists. To solve this problem, we engaged in a multi-step research process to develop the first validated rating scale specifically for judging the aesthetic pleasure of a visualization (osf.io/fxs76). Our final BeauVis scale consists of five items, "enjoyable," "likable," "pleasing," "nice," and "appealing." Beyond this scale itself, we contribute (a) a systematic review of the terms used in past research to capture aesthetics, (b) an investigation with visualization experts who suggested terms to use for judging the aesthetic pleasure of a visualization, and (c) a confirmatory survey in which we used our terms to study the aesthetic pleasure of a set of 3 visualizations.
Theory overview of $B_{s,d}\to μ^+μ^-$ decays
Creators: name: Knegjens, Robert
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this talk I give a theoretical overview of the rare decays $B_{s} \to μ^+ μ^-$ and $B_{d} \to μ^+ μ^-$. The branching ratios of these decays are promising probes of New Physics, both independently and relative to each other. Recent experimental progress at the LHC has confirmed the existence of the $B_{s} \to μ^+ μ^-$ decay, and has not revealed any large signals of New Physics that may have been present. This raises the question of whether moderate New Physics effects can be identified in the LHC era. To that end I review several important developments in the Standard Model branching ratio predictions, and discuss how the latest measurements currently constrain New Physics. Furthermore, I highlight how a time-dependent analysis of $B_{s} \to μ^+ μ^-$, which may be feasible at the upgraded CMS and LHCb detectors, can complement the search for and identification of New Physics.
description: 7 pages, 8 figures, to appear in the proceedings of DIS 2014 workshop, Warsaw, Poland, 28/4-2/5, 2014. Corrected typo in formula (1.4)
Core-collapse Supernova Constraint on the Origin of Sterile Neutrino Dark Matter via Neutrino Self-interactions
Creators: name: Chen, Yu-Ming
name: Sen, Manibrata
name: Tangarife, Walter
name: Tuckler, Douglas
name: Zhang, Yue
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Novel neutrino self-interaction can open up viable parameter space for the relic abundance of sterile-neutrino dark matter (S$ν$DM). In this work, we constrain the relic target using core-collapse supernova which features the same fundamental process and a similar environment to the early universe era when S$ν$DM is dominantly produced. We present a detailed calculation of the effects of a massive scalar mediated neutrino self-interaction on the supernova cooling rate, including the derivation of the thermal potential in the presence of non-zero chemical potentials from plasma species. Our results demonstrate that the supernova cooling argument can cover the neutrino self-interaction parameter space that complements terrestrial and cosmological probes.
description: 22 pages, 7 Figures, 3 appendices
Mobility Models used in Simulation Area of Mobile Ad Hoc Networks
Creators: name: Tanweer Alam
Publisher: name: figshare
Year: 2020
Subjects: Computer Engineering

description: Simulation environments are an important tool for the evaluation of new concepts in networking. The study of mobile ad hoc networks depends on understanding protocols from simulations, before these protocols are implemented in a real-world setting. In the performance evaluation of a protocol for an ad hoc network, the protocol should be tested under realistic conditions including, but not limited to, a sensible transmission range, limited buffer space for the storage of messages, representative data traffic models and realistic movements of the mobile users (i.e. a mobility model). Network simulators emerged as the most common method of evaluating the performance of large and complex networking systems. Existing mobility models vary widely in their realism, from completely artificial to very realistic as well as in their statistical properties. This paper is a survey of mobility models that are used in the simulations of ad hoc networks. We describe several mobility models that represent mobile nodes whose movements are independent of each other (i.e. entity mobility models) and several mobility models that represent mobile nodes whose movements are dependent on each other (i.e. group mobility models). In this paper we provide an overview of those mobility models and their most important properties.
DEVELOPING THE SELF-DIRECTION SKILL THROUGH SCIENCE TEACHING USING THE LEARNING CONTRACTS METHOD
Creators: name: Dr. MOHAMMAD ABEDRABBU ALKHAWALDEH
name: Dr. MOHAMAD AHMAD SALEEM KHASAWNEH
Publisher: name: Zenodo
Year: 2023
Subjects: Learning Contracts Strategy, Teachers, Learners, Teaching Science, Self-Direction Skill.

description: Abstract 
The objective of this study was to explore the impact of utilizing the learning contracts strategy in teaching science to develop the self-direction skills of sixth-grade primary students. The study relied on the quasi-experimental approach to answer the research objectives. The study population was represented by sixth-grade students in Usayd bin Al Hudayr Primary School (boys) and Al Tahfidz Fourth Primary School.  There were (120) male and female students in the study sample, and they were split into two groups for each category. The first group, which included 30 male and 30 female students, was an experimental group. The second group, which included 30 male and 30 female students, was a control group. A pre- and post-test measuring the self-direction abilities of the two groups was utilized as the study's instrument. According to the study's findings, there were variations between the two groups of students (male and female) on the post-test of the self-direction scale, favoring the experimental group. The findings also indicated that there were variations in the experimental group students' average scores on the self-direction ability scale in the post-test, with males doing better on average.
Impact of first-order phase transitions on dark matter production in the scotogenic model
Creators: name: Shibuya, Hiroto
name: Toma, Takashi
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work, we investigate the effects of first-order phase transitions on the singlet fermionic dark matter in the scotogenic model. It is known that this dark matter candidate tends to conflict with the relevant constraints such as the neutrino oscillation data and charged lepton flavor violating processes if its thermal production mechanism is assumed. We find that the dark matter production mechanisms are modified by first-order phase transitions at some specific parameter regions, where the phase transitions can be one-step or two-step depending on the parameters. If the phase transition is one-step, a sufficiently low nucleation temperature is required to reproduce the observed relic abundance of dark matter. If the phase transition is two-step, the dark matter should never be thermalized, otherwise the abundance would remain too much and overclose the universe. This is because the nucleation temperature cannot be low as in the one-step case. Therefore we require another way of dark matter production, the freeze-in mechanism for the two-step case. We show that the freeze-in mechanism is modified by the temporary vacuum expectation value of the inert scalar field. In both cases, the first-order phase transitions could produce observable gravitational wave spectra. In particular for the one-step phase transition, the generated gravitational waves with sizable energy density are intrinsically correlated with the dark matter production mechanism, and can be detectable by future space-based interferometers.
description: 28 pages, 11 figures, version to appear in JHEP
Power-Constrained Sparse Gaussian Linear Dimensionality Reduction over Noisy Channels
Creators: name: Shirazinia, Amirpasha
name: Dey, Subhrakanti
Publisher: name: arXiv
Year: 2014
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In this paper, we investigate power-constrained sensing matrix design in a sparse Gaussian linear dimensionality reduction framework. Our study is carried out in a single--terminal setup as well as in a multi--terminal setup consisting of orthogonal or coherent multiple access channels (MAC). We adopt the mean square error (MSE) performance criterion for sparse source reconstruction in a system where source-to-sensor channel(s) and sensor-to-decoder communication channel(s) are noisy. Our proposed sensing matrix design procedure relies upon minimizing a lower-bound on the MSE in single-- and multiple--terminal setups. We propose a three-stage sensing matrix optimization scheme that combines semi-definite relaxation (SDR) programming, a low-rank approximation problem and power-rescaling. Under certain conditions, we derive closed-form solutions to the proposed optimization procedure. Through numerical experiments, by applying practical sparse reconstruction algorithms, we show the superiority of the proposed scheme by comparing it with other relevant methods. This performance improvement is achieved at the price of higher computational complexity. Hence, in order to address the complexity burden, we present an equivalent stochastic optimization method to the problem of interest that can be solved approximately, while still providing a superior performance over the popular methods.
description: Accepted for publication in IEEE Transactions on Signal Processing (16 pages)
Coherent chemical kinetics as quantum walks II: Radical-pair reactions in Arabidopsis thaliana
Creators: name: Chia, A.
name: Gorecka, A.
name: Kurzynski, P.
name: Paterek, T.
name: Kaszlikowski, D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We apply the quantum-walk approach recently proposed in arXiv:quant-ph-1506.04213 to a radical-pair reaction where realistic estimates for the intermediate transition rates are available. The well-known average hitting time from quantum walks can be adopted as a measure of how quickly the reaction occurs and we calculate this for varying degrees of dephasing in the radical pair. The time for the radical pair to react to a product is found to be independent of the amount of dephasing introduced, even in the limit of no dephasing where the transient population dynamics exhibit strong coherent oscillations. This can be seen to arise from the existence of a rate-limiting step in the reaction and we argue that in such examples, a purely classical model based on rate equations can be used for estimating the timescale of the reaction but not necessarily its population dynamics.
An Analysis of the Historical Development of Community in Li Qiao's (Lee Ch'iao) Wintry Night Trilogy
Creators: Lupke, Christopher
Publisher: name: University of Alberta Library
Year: 2007

This essay focuses on the notions of filiality, kinship, and uxorilocal marriage as represented in the first book of Li Qiao's novel trilogy Wintry Night.
New Graduate Nurses' Transition in Critical Care: A Systematic Review of Qualitative Evidence
Creators: name: Stevenson, Lana
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2023
Subjects: new graduate nurse
transition
critical care
transition shock
systematic review

description: Background: The nursing shortage has been heightened by the COVID-19 pandemic. To mitigate shortages, we must rely on a steady influx of new graduate nurses. A considerable preparation-practice gap is affecting transition to practice. The transition experience to critical care is further amplified, as these environments involve specialized training and knowledge. Objective: To describe the transition of new graduate nurses into critical care nursing practice Design: Qualitative evidence synthesis Setting(s): Critical care settings: intensive care units and emergency departments. Participants: New graduate nurses with at least 2 years’ experience beginning their career in critical care Methods: We searched Ovid MEDLINE® ALL, including EPub, Ahead of Print and In-Process; Other Non-Indexed Citations, Embase Classic + Embase, PsycINFO, CINAHL and Education Source on EBSCO and the Nursing and Allied Health and ERIC databases on ProQuest. Results: Twelve studies met inclusion criteria. Seventy-eight findings were extracted and grouped into six synthesized themes: (i) Barriers and Facilitators to Communication in Critical Care; (ii) Struggling with Uncertainty during Difficult Situations; (iii) Support and Its Impact on Acceptance and Attaining Desirable Nursing Qualities in Critical Care; (iv) Knowledge Develops with Time and Exposure to Complex Clinical Situations; (v) Being a Student in Critical Care; and (vi) Novel Perspectives Related to COVID-19. Conclusions: This qualitative evidence synthesis affirms that NGN transition is a complex phenomenon in critical care. Offering support, guidance and ensuring access to resources during transition to professional practice could improve new graduate nurse retention, as well as improving confidence and competence in the workplace.
Room Temperature DNP of Diamond Powder Using Frequency Modulation
Creators: name: Shimon, Daphna
name: Cantwell, Kelly A.
name: Joseph, Linta
name: Ramanathan, Chandrasekhar
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Dynamic nuclear polarization (DNP) is a method of enhancing NMR signals via the transfer of polarization from electron spins to nuclear spins using on-resonance microwave (MW) irradiation. In most cases, monochromatic continuous-wave (MCW) MW irradiation is used. Recently, several groups have shown that the use of frequency modulation of the MW irradiation can result in an additional increase in DNP enhancement above that obtained with MCW. The effect of frequency modulation on the solid effect (SE) and the cross effect (CE) has previously been studied using the stable organic radical 4-hydroxy TEMPO (TEMPOL) at temperatures under 20 K. Here, in addition to the SE and CE, we discuss the effect of frequency modulation on the Overhauser effect (OE) and the truncated CE (tCE) in the room-temperature $^{13}$C-DNP of diamond powders. We recently showed that diamond powders can exhibit multiple DNP mechanisms simultaneously due to the heterogeneity of P1 (substitutional nitrogen) environments within diamond crystallites. We explore the enhancement obtained via the two most important parameters for frequency modulation 1) Modulation frequency, $f_{m}$ (how fast the modulation frequency is varied) and 2) Modulation amplitude, $Δω$ (the magnitude of the change in microwave frequency) influence the enhancement obtained via each mechanism. Frequency modulation during DNP not only allows us to improve DNP enhancement, but also gives us a way to control which DNP mechanism is most active. By choosing the appropriate modulation parameters, we can selectively enhance some mechanisms while simultaneously suppressing others.
Phase change near $N=70$ in the wave function of the $I^π=11/2^-$ isomers along the cadmium-isotope chain
Creators: name: Lei, Y.
name: Jiang, H.
name: Pittel, S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The electromagnetic features of the $11/2^-$ isomers in the $^{111-127}$Cd isotopes are reproduced by numerically optimized shell-model wave-functions. A sudden phase change of the wave functions at $N = 70$ is identified and further confirmed by the evolution of B(E2, $7/2^-_1\rightarrow 11/2^-_1$) values. This phase change gives rise to different linear relations for the $Q$ and $μ$ values with $N<70$ and $N>70$, as needed to reproduce the experimental data. The particle-hole transformation properties for $h_{11/2}$ neutrons in a well-isolated subshell involving degenerate $s_{1/2}$, $d_{3/2}$, $d_{5/2}$ and $h_{11/2}$ orbits is suggested as a possible explanation for this phase change.
description: 5 pages, 3 figures, regular article
Towards VLBI Observations of Black Hole Structure
Creators: name: Carballo-Rubio, Raúl
name: Cardoso, Vitor
name: Younsi, Ziri
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Black holes hold a tremendous discovery potential. In this paper the extent to which the Event Horizon Telescope and its next generation upgrade can resolve their structure is quantified. Black holes are characterized by a perfectly absorptive boundary, with a specific area determined by intrinsic parameters of the black hole. We use a general parametrization of spherically symmetric spacetimes describing deviations from this behavior, with parameters controlling the size of the central object and its interaction with light, in particular through a specular reflection coefficient $Γ$ and an intrinsic luminosity measured as a fraction $η$ of that of the accretion disc. This enables us to study exotic compact objects and compare them with black holes in a model-independent manner. We determine the image features associated with the existence of a surface in the presence of a geometrically thin and optically thick accretion disc, identifying requirements for VLBI observations to be able to cast meaningful constraints on these parameters, in particular regarding angular resolution and image dynamic range. For face-on observations, constraints of order $η\lesssim 10^{-4}, Γ\lesssim 10^{-1}$ are possible with an enhanced EHT array, imposing strong constraints on the nature of the central object.
description: 12 pages, 10 figures
Fate of many-body localization under periodic driving
Creators: name: Lazarides, Achilleas
name: Das, Arnab
name: Moessner, Roderich
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study many-body localised quantum systems subject to periodic driving. We find that the presence of a mobility edge anywhere in the spectrum is enough to lead to delocalisation for any driving strength and frequency. By contrast, for a fully localised many-body system, a delocalisation transition occurs at a finite driving frequency. We present numerical studies on a system of interacting one-dimensional bosons and the quantum random energy model, as well as simple physical pictures accounting for those results.
Ruling out Initially Clustered Primordial Black Holes as Dark Matter
Creators: name: De Luca, V.
name: Franciolini, G.
name: Riotto, A.
name: Veermäe, H.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Combining constraints from microlensing and Lyman-$α$ forest, we provide a simple argument to show that large spatial clustering of stellar-mass primordial black holes at the time of formation, such as the one induced by the presence of large non-Gaussianities, is ruled out. Therefore, it is not possible to evade existing constraints preventing stellar-mass primordial black holes to be a dominant constituent of the dark matter by boosting their initial clustering.
description: 5 pages + supplementary material. 2 figures. v2: matching version published in PRL
Enabling Dask Interoperability with XRootD Storage Systems
Creators: name: Demarest, Scott
Publisher: name: Zenodo
Year: 2022

description: This lightning talk will introduce fsspec-xrootd, a newly published middleware software package that allows Dask and other popular data analysis packages to directly access XRootD storage systems. These packages use the fsspec api as their storage backends and fsspec-xrootd adds an XRootD implementation to fsspec. This means that when using fsspec-xrootd, the user will be able to access XRootD content within Dask itself without resorting to an external program. The talk will include an explanation of fsspec-xrootd as well as a demonstration in jupyter notebook.
Property-Driven Fence Insertion using Reorder Bounded Model Checking
Creators: name: Joshi, Saurabh
name: Kroening, Daniel
Publisher: name: arXiv
Year: 2014
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Modern architectures provide weaker memory consistency guarantees than sequential consistency. These weaker guarantees allow programs to exhibit behaviours where the program statements appear to have executed out of program order. Fortunately, modern architectures provide memory barriers (fences) to enforce the program order between a pair of statements if needed. Due to the intricate semantics of weak memory models, the placement of fences is challenging even for experienced programmers. Too few fences lead to bugs whereas overuse of fences results in performance degradation. This motivates automated placement of fences. Tools that restore sequential consistency in the program may insert more fences than necessary for the program to be correct. Therefore, we propose a property-driven technique that introduces "reorder-bounded exploration" to identify the smallest number of program locations for fence placement. We implemented our technique on top of CBMC; however, in principle, our technique is generic enough to be used with any model checker. Our experimental results show that our technique is faster and solves more instances of relevant benchmarks as compared to earlier approaches.
description: 18 pages, 3 figures, 4 algorithms. Version change reason : new set of results and publication ready version of FM 2015
Native point defects in few-layer phosphorene
Creators: name: Wang, V.
name: Kawazoe, Y.
name: Geng, W. T.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using hybrid density functional theory combined with a semiempirical van der Waals dispersion correction, we have investigated the structural and electronic properties of vacancies and self-interstitials in defective few-layer phosphorene. We find that both a vacancy and a self-interstitial defect are more stable in the outer layer than in the inner layer. The formation energy and transition energy of both a vacancy and a self-interstitial P defect decrease with increasing film thickness, mainly due to the upward shift of the host valence band maximum in reference to the vacuum level. Consequently, both vacancies and self-interstitials could act as shallow acceptors, and this well explains the experimentally observed p-type conductivity in few-layer phosphorene. On the other hand, since these native point defects have moderate formation energies and are stable in negatively charged states, they could also serve as electron compensating centers in n-type few-layer phosphorene.
description: 10 pages, 12 figures
Refined critical balance in strong Alfvenic turbulence
Creators: name: Mallet, A.
name: Schekochihin, A. A.
name: Chandran, B. D. G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Chaotic Dynamics (nlin.CD)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We present numerical evidence that in strong Alfvenic turbulence, the critical balance principle---equality of the nonlinear decorrelation and linear propagation times---is scale invariant, in the sense that the probability distribution of the ratio of these times is independent of scale. This result only holds if the local alignment of the Elsasser fields is taken into account in calculating the nonlinear time. At any given scale, the degree of alignment is found to increase with fluctuation amplitude, supporting the idea that the cause of alignment is mutual dynamical shearing of Elsasser fields. The scale-invariance of critical balance (while all other quantities of interest are strongly intermittent, i.e., have scale-dependent distributions) suggests that it is the most robust of the scaling principles used to describe Alfvenic turbulence. The quality afforded by situ fluctuation measurements in the solar wind allows for direct verification of this fundamental principle.
description: revtex, 5 pages, 5 figures; replaced to match published version
Distinct vortex-glass phases in Yb$_{3}$Rh$_{4}$Sn$_{13}$ at high and low magnetic fields
Creators: name: Mazzone, D. G.
name: Gavilano, J. L.
name: Sibille, R.
name: Ramakrishnan, M.
name: Dewhurst, C. D.
name: Kenzelmann, M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The vortex lattice (VL) in the mixed state of the stannide superconductor Yb$_{3}$Rh$_{4}$Sn$_{13}$ has been studied using small-angle neutron scattering (SANS). The field dependencies of the normalized longitudinal and transverse correlation lengths of the VL, $ξ_L/a_0$ and $ξ_T /a_0$, reveal two distinct anomalies that are associated with vortex-glass phases below $μ_0H_l$~$\approx$~700~G and above $μ_{0}H_h$~$\sim$~1.7~T ($a_0$ is the intervortex distance). At high fields, around 1.7~T, the longitudinal correlation decreases abruptly with increasing fields indicating a weakening (but not a complete destruction) of the VL due to a phase transition into a glassy phase, below $μ_{0}H_{c_2}$(1.8 K)~$\approx$~2.5~T. $ξ_L/a_0$ and $ξ_T /a_0$, gradually decrease for decreasing fields of strengths less than 1~T and tend towards zero. The shear elastic modulus $c_{66}$ and the tilting elastic modulus $c_{44}$ vanish at a critical field $μ_0H_l$~$\approx$~700~G, providing evidence for a disorder-induced transition into a vortex-glass. A 'ring' of scattered intensity is observed for fields lower than 700~G, $i.e.$, $μ_{0}H_{c_1}$~=~135~G~$
High Metal Content of Highly Accreting Quasars: Analysis of an Extended Sample
Creators: name: Garnica, Karla
name: Negrete, C. Alenka
name: Marziani, Paola
name: Dultzin, Deborah
name: Śniegowska, Marzena
name: Panda, Swayamtrupta
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present an analysis of UV spectra of quasars at intermediate redshifts believed to belong to the extreme Population A (xA), aimed to estimate the chemical abundances of the broad line emitting gas. We follow the approach described in a previous work extending the sample to 42 sources. Our aim is to test the robustness of the analysis carried out previously, as well as to confirm the two most intriguing results of this investigation: evidence of very high solar metallicities, and deviation of the relative abundance of elements with respect to solar values. The basis of our analysis is multi-component fits in three regions of the spectra centered at 1900, 1550 and 1400 A in order to deblend the broad components of AlIII1860, CIII]1909, CIV1549, HeII1640, and SiIV1397+OIV]1402 and their blue excess. By comparing the observed flux ratios of these components with the same ratios predicted by photoionization code CLOUDY we found that the virialized gas (broad components) presents a metallicity Z higher than 10Z$_\odot$. For non-virialized clouds we derive a lower limit to the metallicity around $\sim$ 5Z$_\odot$ under the assumption of chemical composition proportional to the solar one, confirming the previous results. We especially rely on the ratios between metal lines and HeII1640. This allowed us to confirm systematic differences in the solar-scaled metallicity derived from the lines of Aluminium and Silicon, and of Carbon, with the first being a factor 2 higher. For luminous quasars accreting at high rates, high Z values are likely, but that Z scaled values are affected by the possible pollution due to highly-enriched gas associated with the circumnuclear star formation. The high-Z values suggest a complex process involving nuclear and circumnuclear star formation, interaction between nuclear compact objects and accretion disk, possibly with the formation of accretion-modified stars.
description: Accepted for publication in Astronomy and Astrophysics. 29 pages plus an appendix with full spectral analysis
JWST unveils heavily obscured (active and passive) sources up to z~13
Creators: name: Rodighiero, Giulia
name: Bisigello, Laura
name: Iani, Edoardo
name: Marasco, Antonino
name: Grazian, Andrea
name: Sinigaglia, Francesco
name: Cassata, Paolo
name: Gruppioni, Carlotta
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: A wealth of extragalactic populations completely missed at UV-optical wavelengths has been identified in the last decade, combining the deepest HST and Spitzer observations. These dark sources are thought to be very dusty and star-forming systems at 3
description: Final accepted version as MNRAS letter on the 20th of September 2022. The current version has been revised accounting for the updated NIRCam Zero Points. The main results are confirmed
Cutting arcs for torus links and trees
Creators: name: Misev, Filip
Publisher: name: arXiv
Year: 2014
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: Among all torus links, we characterise those arising as links of simple plane curve singularities by the property that their fibre surfaces admit only a finite number of cutting arcs that preserve fibredness. The same property allows a characterisation of Coxeter-Dynkin trees (i.e., $A_n$, $D_n$, $E_6$, $E_7$ and $E_8$) among all positive tree-like Hopf plumbings.
description: 27 pages, 18 figures. Results have been extended to cover all Coxeter-Dynkin trees in the new version
Running Out of Bank Runs
Creators: name: Libich, Jan
name: Nguyen, DT
name: Kiss, HJ
Publisher: name: La Trobe
Year: 2023
Subjects: classificationCode: 3502
subject: Banking, finance and investment
classificationCode: 3501
subject: Accounting, auditing and accountability

description: The theoretical literature on bank runs has modeled depositors’ withdrawal decision as a one-off choice, made simultaneously by all depositors. Our game-theoretic framework gives depositors a heterogeneous, stochastic opportunity to change their minds about withdrawing their money. They can run out of (or run into) the crowd in front of the bank based on their observation of what others have done. Depositors’ opportunity to change their decision supports implicit coordination, which in some circumstances reduces the probability that self-fulfilling bank runs will occur.
Informing and developing professional practice: How international educational programs influence nurse and midwife professional practice
Creators: name: Johnston, Jacqueline
name: McKenna, Lisa
name: Malik, Gulzar
name: Reisenhofer, Sonia
Publisher: name: La Trobe
Year: 2023
Subjects: classificationCode: 4204
subject: Midwifery
classificationCode: 390110
subject: Medicine, nursing and health curriculum and pedagogy
classificationCode: 3901
subject: Curriculum and pedagogy
classificationCode: 4205
subject: Nursing
subject: FOS: Health sciences

description: Aim: This paper forms part of a grounded theory study that aimed to determine the impact of an international mobility program during a nurse's or midwife's pre-registration program on their subsequent nursing and/or midwifery practice. The focus of this article is on how nursing and midwifery professional practice was informed and developed through participation in international educational programs. Background: Participation in an international educational program during a nurse's or midwife's pre-registration education is known to have many positive benefits, however, previous studies have highlighted a need to investigate long-term outcomes on professional practice. Methods: Using Charmaz's constructivist grounded theory approach, 13 general nurses, 2 mental health nurses, 3 midwives, and 4 dual-qualified nurse/midwives from 8 different countries were interviewed. Data were analysed following coding procedures, with three categories constructed. This paper focuses on the category conceptualised as Informing and developing professional practice. Findings: Participants experienced different healthcare systems and being reflective and applying knowledge to current practice contributed to the development of professional practice. International educational programs were also found to assist in aspiring and cementing decisions for many regarding their future nursing or midwifery practice. Conclusion: Participation in an international educational program has an ongoing and positive influence on a nurse's or midwife's professional practice.
A Density Spike on Astrophysical Scales from an N-Field Waterfall Transition
Creators: name: Halpern, Illan F.
name: Hertzberg, Mark P.
name: Joss, Matthew A.
name: Sfakianakis, Evangelos I.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Hybrid inflation models are especially interesting as they lead to a spike in the density power spectrum on small scales, compared to the CMB, while also satisfying current bounds on tensor modes. Here we study hybrid inflation with $N$ waterfall fields sharing a global $SO(N)$ symmetry. The inclusion of many waterfall fields has the obvious advantage of avoiding topologically stable defects for $N>3$. We find that it also has another advantage: it is easier to engineer models that can simultaneously (i) be compatible with constraints on the primordial spectral index, which tends to otherwise disfavor hybrid models, and (ii) produce a spike on astrophysically large length scales. The latter may have significant consequences, possibly seeding the formation of astrophysically large black holes. We calculate correlation functions of the time-delay, a measure of density perturbations, produced by the waterfall fields, as a convergent power series in both $1/N$ and the field's correlation function $Δ(x)$. We show that for large $N$, the two-point function is $\,\proptoΔ^2(|{\bf x}|)/N$ and the three-point function is $\,\proptoΔ(|{\bf x}-{\bf y}|)Δ(|{\bf x}|)Δ(|{\bf y}|)/N^2$. In accordance with the central limit theorem, the density perturbations on the scale of the spike are Gaussian for large $N$ and non-Gaussian for small $N$.
description: 15 pages in double column format, 6 figures. V2: Further clarifications, updated to coincide with version published in Physics Letters B
First Post-Minkowskian approach to turbulent gravity
Creators: name: Bini, Donato
name: Kauffman, Stuart
name: Succi, Sauro
name: Tello, Pablo G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We compute the metric fluctuations induced by a turbulent energy-matter tensor within the first order Post-Minkowskian approximation. It is found that the turbulent energy cascade can in principle interfere with the process of black hole formation, leading to a potentially strong coupling between these two highly nonlinear phenomena. It is further found that a power-law turbulent energy spectrum $E(k) \sim k^{-n}$ generates metric fluctuations scaling like $x^{n-2}$, where $x$ is a four-dimensional distance from an arbitrary origin in spacetime. This highlights the onset of metric singularities whenever $n <2$, meaning that $2d$ fluid turbulence ($n=3$) yields smooth %(differentiable) metric fluctuations, scaling like $x$, while $3d$ turbulence ($n=5/3$) yields a weakly singular metric $x^{-1/3}$and purely random fluctuations, $n=1$, generate a stronger $1/x$ singularity. Finally, the effect of metric fluctuations on the geodesic motion of test particles is also discussed as a potential technique to extract information on the spectral characteristics of fluctuating spacetime.
description: 11 pages; 5 figures
Analysis of Smart Contract using Ethereum Blockchain
Creators: name: Harikesh Singh
Publisher: name: figshare
Year: 2020
Subjects: subject: 80402 Data Encryption
subject: FOS: Computer and information sciences
subject: 80607 Information Engineering and Theory

description: iA iblockchain iis, iin ithe ieasiest iof iterms, ia iperiod istepped iarrangement iof iunchanging irecords iof iinformation ithat iis ioverseen iby ia igroup iof iPCs inot ipossessed iby iany isingle ielement. iEvery ione iof ithese isquares iof iinformation iis imade isure iabout iand ibound ito ione ianother iutilizing icryptographic istandards. Ethereum iis ia iworldwide, idecentralized istage ifor icash iand inew isorts iof iutilizations. iOn iEthereum, iyou ican icompose icode ithat icontrols ithe icash, iand imanufacture iapplications iavailable ianyplace ion ithe iplanet. I