cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Collective dynamics in atomistic models with coupled translational and spin degrees of freedom
Creators: name: Perera, Dilina
name: Nicholson, Don M.
name: Eisenbach, Markus
name: Stocks, G. Malcolm
name: Landau, David P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using an atomistic model that simultaneously treats the dynamics of translational and spin degrees of freedom, we perform combined molecular and spin dynamics simulations to investigate the mutual influence of the phonons and magnons on their respective frequency spectra and lifetimes in ferromagnetic bcc iron. By calculating the Fourier transforms of the space- and time-displaced correlation functions, the characteristic frequencies and the linewidths of the vibrational and magnetic excitation modes were determined. Comparison of the results with that of the stand-alone molecular dynamics and spin dynamics simulations reveals that the dynamic interplay between the phonons and magnons leads to a shift in the respective frequency spectra and a decrease in the lifetimes. Moreover, in the presence of lattice vibrations, additional longitudinal magnetic excitations were observed with the same frequencies as the longitudinal phonons.
Determining the HI content of galaxies via intensity mapping cross-correlations
Creators: name: Wolz, L.
name: Blake, C.
name: Wyithe, J. S. B.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We propose an innovative method for measuring the neutral hydrogen (HI) content of an optically-selected spectroscopic sample of galaxies through cross-correlation with HI intensity mapping measurements. We show that the HI-galaxy cross-power spectrum contains an additive shot noise term which scales with the average HI brightness temperature of the optically-selected galaxies, allowing constraints to be placed on the average HI mass per galaxy. This approach can estimate the HI content of populations too faint to directly observe through their 21cm emission over a wide range of redshifts. This cross-correlation, as a function of optical luminosity or colour, can be used to derive HI-scaling relations. We demonstrate that this signal will be detectable by cross-correlating upcoming Australian SKA Pathfinder (ASKAP) observations with existing optically-selected samples. We also use semi-analytic simulations to verify that the HI mass can be successfully recovered by our technique in the range M_HI > 10^8 M_solar, in a manner independent of the underlying power spectrum shape. We conclude that this method is a powerful tool to study galaxy evolution, which only requires a single intensity mapping dataset to infer complementary HI gas information from existing optical and infra-red observations.
description: 8 pages, 4 figures, submitted to MNRAS
Duality between k-essence and Rastall gravity
Creators: name: Bronnikov, Kirill A.
name: Fabris, Julio C.
name: Piattella, Oliver F.
name: Rodrigues, Denis C.
name: Santos, Edison C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The k-essence theory with a power-law function of $(\partialϕ)^2$ and Rastall's non-conservative theory of gravity with a scalar field are shown to have the same solutions for the metric under the assumption that both the metric and the scalar fields depend on a single coordinate. This equivalence (called k-R duality) holds for static configurations with various symmetries (spherical, plane, cylindrical, etc.) and all homogeneous cosmologies. In the presence of matter, Rastall's theory requires additional assumptions on how the stress-energy tensor non-conservation is distributed between different contributions. Two versions of such non-conservation are considered in the case of isotropic spatially flat cosmological models with a perfect fluid: one (R1) in which there is no coupling between the scalar field and the fluid, and another (R2) in which the fluid separately obeys the usual conservation law. In version R1 it is shown that k-R duality holds not only for the cosmological models themselves but also for their adiabatic perturbations. In version R2, among other results, a particular model is singled out that reproduces the same cosmological expansion history as the standard $Λ$CDM model but predicts different behaviors of small fluctuations in the k-essence and Rastall frameworks.
description: 10 pages, no figures. Two references added
Colloidal transport by active filaments
Creators: name: Manna, Raj Kumar
name: Kumar, P. B. Sunil
name: Adhikari, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Enhanced colloidal transport beyond the limit imposed by diffusion is usually achieved through external fields. Here, we demonstrate the ballistic transport of a colloidal sphere using internal sources of energy provided by an attached active filament. The latter is modeled as a chain of chemo-mechanically active beads connected by potentials that enforce semi-flexibility and self-avoidance. The fluid flow produced by the active beads and the forces they mediate are explicitly taken into account in the overdamped equations of motion describing the colloid-filament assembly. The speed and efficiency of transport depend on the dynamical conformational states of the filament. We characterize these states using filament writhe as an order parameter and identify ones yielding maxima in speed and efficiency of transport. The transport mechanism reported here has a remarkable resemblance to the flagellar propulsion of microorganisms which suggests its utility in biomimetic systems.
description: supplemental movies at https://goo.gl/28V9wY
Warnings and Caveats in Brain Controllability
Creators: name: Tu, Chengyi
name: Rocha, Rodrigo P.
name: Corbetta, Maurizio
name: Zampieri, Sandro
name: Zorzi, Marzo
name: Suweis, Samir
Publisher: name: arXiv
Year: 2017
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: In this work we challenge the main conclusions of Gu et al work (Controllability of structural brain networks. Nature communications 6, 8414, doi:10.1038/ncomms9414, 2015) on brain controllability. Using the same methods and analyses on four datasets we find that the minimum set of nodes to control brain networks is always larger than one. We also find that the relationships between the average/modal controllability and weighted degrees also hold for randomized data and the there are not specific roles played by Resting State Networks in controlling the brain. In conclusion, we show that there is no evidence that topology plays specific and unique roles in the controllability of brain networks. Accordingly, Gu et al. interpretation of their results, in particular in terms of translational applications (e.g. using single node controllability properties to define target region(s) for neurostimulation) should be revisited. Though theoretically intriguing, our understanding of the relationship between controllability and structural brain network remains elusive.
description: 9 pages, 1 Figure, 1 Table
Effects of hydrodynamic interactions on rectified transport of self-propelled particles
Creators: name: Ai, Bao-quan
name: He, Ya-feng
name: Zhong, Wei-rong
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Directed transport of self-propelled particles is numerically investigated in a three-dimensional asymmetric potential. Beside the steric repulsive forces, hydrodynamic interactions between particles have been taken into account in an approximate way. From numerical simulations, we find that hydrodynamic interactions can strongly affect the rectified transport of self-propelled particles. Hydrodynamic interactions enhance the performance of the rectified transport when particles can easily pass across the barrier of the potential, and reduce the rectified transport when particles are mainly trapped in the potential well.
description: 12 pages, 3 figures, Physical Review E 2017
Testing atomic collision theory with the two-photon continuum of astrophysical nebulae
Creators: name: Guzmán, F.
name: Badnell, N. R.
name: Chatzikos, M.
name: van Hoof, P. A. M.
name: Williams, R. J. R.
name: Ferland, G. J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Accurate rates for energy-degenerate l-changing collisions are needed to determine cosmological abundances and recombination. There are now several competing theories for the treatment of this process, and it is not possible to test these experimentally. We show that the H I two-photon continuum produced by astrophysical nebulae is strongly affected by l-changing collisions. We perform an analysis of the different underlying atomic processes and simulate the recombination and two-photon spectrum of a nebula containing H and He. We provide an extended set of effective recombination coefficients and updated l-changing 2s-2p transition rates using several competing theories. In principle, accurate astronomical observations could determine which theory is correct.
description: 7 pages, 6 fig, 2 tables, accepted in MNRAS
Vibrational-ground-state zero-width resonances for laser filtration: An extended semiclassical analysis
Creators: name: Jaouadi, Amine
name: Lefebvre, Roland
name: Atabek, Osman
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: J.2

description: A semiclassical model supporting the destructive interference interpretation of zero-width resonances (ZWR) is extended to wavelengths inducing c_minus-type curve crossing situations in Na2 strong field dissociation. This opens the possibility to get critical couples of wavelengths lambda and field intensities I to reach ZWRs associated with the ground vibrationless level v = 0, that, contrary to other vibrational states (v > 0), is not attainable for the commonly referred c+-type crossings. The morphology of such ZWRs in the laser (I; lambda) parameter plane and their usefulness in filtration strategies aiming at molecular cooling down to the ground v = 0 state are examined within the frame of an adiabatic transport scheme.
description: 17 pages, 4 Figures, 19 references. arXiv admin note: text overlap with arXiv:1607.07371
Generalized James' effective Hamiltonian method
Creators: name: Shao, Wenjun
name: Wu, Chunfeng
name: Feng, Xun-Li
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: James' effective Hamiltonian method has been extensively adopted to investigate largely detuned interacting quantum systems. This method is just corresponding to the second-order perturbation theory, and cannot be exploited to treat the problems which should be solved by using the third or higher-order perturbation theory. In this paper, we generalize James' effective Hamiltonian method to the higher-order case. Using the method developed here, we reexamine two examples published recently [Phys. Rev.Lett. 117, 043601 (2016), Phys. Rev A 92, 023842 (2015)], our results turn out to be the same as the original ones derived from the third-order perturbation theory and adiabatic elimination method respectively. For some specific problems, this method can simplify the calculating procedure, and the resultant effective Hamiltonian is more general.
description: 5 pages, no figure, submitted to Phys. Rev. A
Imaging the dynamics of individual hydrogen atom intercalated between two graphene sheets
Creators: name: Wang, Wen-Xiao
name: Wei, Yi-Wen
name: Li, Si-Yu
name: Li, Xinqi
name: Wu, Xiaosong
name: Feng, Ji
name: He, Lin
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The interlayer gallery between two adjacent sheets of van der Waals materials is expected to modify properties of atoms and molecules confined at the atomic interfaces. Here, we directly image individual hydrogen atom intercalated between two graphene sheets and investigate its dynamics by scanning tunnelling microscope (STM). The intercalated hydrogen atom is found to be remarkably different from atomic hydrogen chemisorbed on external surface of graphene. Our STM measurements, complemented by first-principles calculations, show that the hydrogen atom intercalated between two graphene sheets has dramatically reduced potential barriers for elementary migration steps. Especially, the confined atomic hydrogen dissociation energy from graphene is reduced to 0.34 eV, which is only about a third of a hydrogen atom chemisorbed on graphene. This offers a unique platform for direct imaging of the atomic dynamics of confined atoms. Our results suggest that the atomic interfaces of van der Waals materials may provide a confined environment to tune the interfacial chemical reactions.
description: 5 figures
Integrated and Differential Accuracy in Resummed Cross Sections
Creators: name: Bertolini, Daniele
name: Solon, Mikhail P.
name: Walsh, Jonathan R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Standard QCD resummation techniques provide precise predictions for the spectrum and the cumulant of a given observable. The integrated spectrum and the cumulant differ by higher-order terms which, however, can be numerically significant. In this paper we propose a method, which we call the $σ\text{-improved}$ scheme, to resolve this issue. It consists of two steps: (i) include higher-order terms in the spectrum to improve the agreement with the cumulant central value, and (ii) employ profile scales that encode correlations between different points to give robust uncertainty estimates for the integrated spectrum. We provide a generic algorithm for determining such profile scales, and show the application to the thrust distribution in $e^+e^-$ collisions at NLL$'$+NLO and NNLL$'$+NNLO.
description: 8 pages, 8 figures
Vertical Structure of Radiation-Pressure-Dominated Thin Disks: Link between Vertical Advection and Convective Stability
Creators: name: Gong, Hong-Yu
name: Gu, Wei-Min
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In the classic picture of standard thin accretion disks, the viscous heating is balanced by the radiative cooling through the diffusion process, and the radiation-pressure-dominated inner disk suffers convective instability. However, recent simulations have shown that the vertical advection process owing to the magnetic buoyancy can make significant contribution to the energy transport. In addition, no convective instability has been found by comparing the simulation results with the local convective stability criterion. In this work, following the spirit of simulations, we revisit the vertical structure of radiation-pressure-dominated thin disks by including the vertical advection process. Our study indicates a link between the additional energy transport and the convectively stable property. Thus, the vertical advection not only has significant contribution to the energy transport, but also plays an important role to make the disk convectively stable. Our analyses may be helpful to understand the discrepancy between the classic theory and simulations on standard thin disks.
description: 6 pages, 3 figures, accepted for publication in ApJ
Editorial: Comparison and explanation: a long saga
Creators: name: Schriewer, Jürgen
Publisher: name: Humboldt-Universität zu Berlin
Year: 2021
Subjects: subject: Explanation
subject: complexity
subject: temporality
subject: historicity
subject: meaning
subject: meaning constellations
subject: culturepath-dependency
subject: 370 Bildung und Erziehung

description: This article was supported by the Open Access Publication Fund of Humboldt-Universität zu Berlin.
A gravitating Yang-Mills instanton
Creators: name: Cano, Pablo A.
name: Ortin, Tomas
name: Ramirez, Pedro F.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present an asymptotically flat, spherically symmetric, static, globally regular and horizonless solution of SU$(2)$-gauged $\mathcal{N}=1,d=5$ supergravity. The SU$(2)$ gauge field is that of the BPST instanton. We argue that this solution, analogous to the global monopoles found in $d=4$ $\mathcal{N}=2$ and $\mathcal{N}=4$ gauged supergravities, describes the field of a single string-theory object which does not contribute to the entropy of black holes when we add it to them and show that it is, indeed, the dimensional reduction on T$^{5}$ of the gauge 5-brane. We investigate how the energy of the solution is concentrated as a function of the instanton's scale showing that it never violates the hoop conjecture although the curvature grows unboundedly in the zero scale limit.
description: 19 pages, 4 figures. Some misprints corrected
Room-temperature Continuous-wave Lasing from Monolayer Molybdenum Ditelluride with a Silicon Nanobeam Cavity
Creators: name: Li, Yongzhuo
name: Zhang, Jianxing
name: Huang, Dandan
name: Sun, Hao
name: Fan, Fan
name: Feng, Jiabi
name: Wang, Zhen
name: Ning, C. Z.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Monolayer transition metal dichalcogenides (TMDs) provide the most efficient optical gain materials and have potential for making nanolasers with the smallest gain media with lowest energy consumption. But lasing demonstrations based on TMDs have so far been limited to low temperatures. Here, we demonstrate the first room-temperature laser operation in the infrared wavelengths from a monolayer of molybdenum ditelluride on a silicon photonic-crystal nanobeam cavity. Our demonstration is made possible by a unique choice of TMD material with emission wavelength below silicon absorption, combined with the high Q-cavity design by silicon nanobeam. Lasing at 1132 nm is demonstrated at room-temperature pumped by a continuous-wave laser, with a threshold density at 6.6 W/cm2. The room-temperature linewidth of 0.202 nm is the narrowest with the corresponding Q of 5603, the largest observed for a TMD laser. This demonstration establishes TMDs as practical nanolaser materials. The silicon structures provide additional benefits for silicon-compatible nanophotonic applications in the important infrared wavelengths.
Learning From GCSE Coursework : English and Geography, 1999-2000
Creators: name: Martin, S.
Publisher: name: UK Data Service
Year: 2001

description: This research explores the potential of GCSE coursework to promote teaching and learning strategies that foster independent learning, critical thinking and creativity. Although ill-defined, these constructs are highly valued and often invoked as the basis for a high skills economy and for individuals to develop a capacity for lifelong learning. The broad aim of this research was to study how GCSE coursework could provide a framework for learning. Within this aim, specific objectives were to investigate:
 the extent to which the original qualities attributed to coursework are achieved in current practice;
 the extent to which coursework contributes to the development of skills associated with independent learning, critical thinking and creativity;
 the influence of the demands of assessment upon students' learning.
 In six case study schools, current practice in English and geography GCSE coursework was scrutinised and appraised; students' understanding of their organisation of, and approaches to, learning through coursework was probed; and how teaching and learning styles are influenced by the coursework assessment framework was examined. Semi-structured interviews were carried out with students who had taken their GCSEs in 2000, other teachers involved in English and geography GCSE coursework, and the parents of the students.
 Grounding the data collection and analysis in practice, the research team identified indicators and dimensions of the three constructs and developed case studies of organisation, approaches and outcomes of coursework.
Does Explosive Nuclear Burning occur in Tidal Disruption Events of White Dwarfs by Intermediate Mass Black Holes ?
Creators: name: Tanikawa, Ataru
name: Sato, Yushi
name: Nomoto, Ken'ichi
name: Maeda, Keiichi
name: Nakasato, Naohito
name: Hachisu, Izumi
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We investigate nucleosynthesis in tidal disruption events (TDEs) of white dwarfs (WDs) by intermediate mass black holes (IMBHs). We consider various types of WDs with different masses and compositions by means of 3 dimensional (3D) smoothed particle hydrodynamics (SPH) simulations. We model these WDs with different numbers of SPH particles, $N$, from a few $10^4$ to a few $10^7$, in order to check mass resolution convergence, where SPH simulations with $N>10^7$ (or a space resolution of several $10^6$ cm) have unprecedentedly high resolution in this kind of simulations. We find that nuclear reactions become less active with increasing $N$, and that these nuclear reactions are excited by spurious heating due to low resolution. Moreover, we find no shock wave generation. In order to investigate the reason for the absence of a shock wave, we additionally perform 1 dimensional (1D) SPH and mesh-based simulations with a space resolution ranging from $10^4$ to $10^7$ cm, using characteristic flow structure extracted from the 3D SPH simulations. We find shock waves in these 1D high-resolution simulations. One of these shock waves triggers a detonation wave. However, we have to be careful of the fact that, if the shock wave emerged at a bit outer region, it could not trigger the detonation wave due to low density. Note that the 1D initial conditions lack accuracy to precisely determine where a shock wave emerges. We need to perform 3D simulations with $\lesssim 10^6$ cm space resolution in order to conclude that WD TDEs become optical transients powered by radioactive nuclei.
description: 16 pages, 17 figures, accepted in ApJ
Inhomogeneity growth in two-component fermionic systems
Creators: name: Napolitani, P.
name: Colonna, M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The dynamics of fermionic many-body systems is investigated in the framework of Boltzmann-Langevin (BL) stochastic one-body approaches. Within the recently introduced BLOB model, we examine the interplay between mean-field effects and two-body correlations, of stochastic nature, for nuclear matter at moderate temperature and in several density conditions, corresponding to stable or mechanically unstable situations. Numerical results are compared to analytic expectations for the fluctuation amplitude of isoscalar and isovector densities, probing the link to the properties of the employed effective interaction, namely symmetry energy (for isovector modes) and incompressibility (for isoscalar modes). For unstable systems, clusterization is observed. The associated features are compared to analytical results for the typical length and time scales characterizing the growth of unstable modes in nuclear matter and for the isotopic variance of the emerging fragments. We show that the BLOB model is generally better suited than simplified approaches previously introduced to solve the BL equation, and it is therefore more advantageous in applications to open systems, like heavy ion collisions.
description: 19 pages, 13 figures
Light assisted collisions in ultra-cold Tm atoms
Creators: name: Cojocaru, Ivan S.
name: Pyatchenkov, Sergey V.
name: Snigirev, Stepan A.
name: Luchnikov, Ilya A.
name: Kalganova, Elena S.
name: Vishnyakova, Gulnara A.
name: Kublikova, D. N.
name: Bushmakin, V. S.
name: Davletov, E. T.
name: Tsyganok, V. V.
name: Belyaeva, Olesya V.
name: Khoroshilov, Andrei
name: Sorokin, Vadim N.
name: Sukachev, Denis D.
name: Akimov, Aleksey V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We studied light assisted collisions of Tm atoms in a magneto optical trap (MOT) for the first time, working on a weak cooling transition at 530.7 nm $(4f^{13}(^2F^0)6s^2,J=7/2,F=4$ to $4f^{12}(^3H_6)5d_{5/2}6s^2,J=9/2,F=5)$. We observed a strong influence from radiation trapping and light assisted collisions on the dynamics of this trap. We carefully separated these two contributions and measured the binary loss rate constant at different laser powers and detuning frequencies near the cooling transition. Analyzing losses from the MOT, we found the light assisted inelastic binary loss rate constant to reach values of up to $β=10^{-9}$ cm$^3$/s and gave the upper bound on a branching ratio $k<0.8\times 10^{-6}$ for the 530.7 nm transition.
Massive pre-main sequence stars in M17
Creators: name: Ramírez-Tannus, María Claudia
name: Kaper, Lex
name: de Koter, Alex
name: Tramper, Frank
name: Bik, Arjan
name: Ellerbroek, Lucas E.
name: Ochsendorf, Bram B.
name: Ramírez-Agudelo, Oscar H.
name: Sana, Hugues
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The formation process of massive stars is still poorly understood. Massive young stellar objects (mYSOs) are deeply embedded in their parental clouds, they are rare and thus typically distant, and their reddened spectra usually preclude the determination of their photospheric parameters. M17 is one of the best studied HII regions in the sky, is relatively nearby, and hosts a young stellar population. With X-shooter on the ESO Very Large Telescope we have obtained optical to near-infrared spectra of candidate mYSOs, identified by Hanson et al. (1997), and a few OB stars in this region. The large wavelength coverage enables a detailed spectroscopic analysis of their photospheres and circumstellar disks. We confirm the pre-main sequence (PMS) nature of six of the stars and characterise the O stars. The PMS stars have radii consistent with being contracting towards the main sequence and are surrounded by a remnant accretion disk. The observed infrared excess and the (double-peaked) emission lines provide the opportunity to measure structured velocity profiles in the disks. We compare the observed properties of this unique sample of young massive stars with evolutionary tracks of massive protostars by Hosokawa & Omukai (2009), and propose that these mYSOs near the western edge of the HII region are on their way to become main-sequence stars ($\sim 6 - 20$ $M_{\odot}$) after having undergone high mass-accretion rates (${\dot{M}_{\rm acc}} \sim 10^{-4} - 10^{-3}$ $M_{\odot}$ $\rm yr^{-1}$). Their spin distribution upon arrival at the zero age main sequence (ZAMS) is consistent with that observed for young B stars, assuming conservation of angular momentum and homologous contraction.
description: Accepted for publication in A&A. Appendixes A and B have been truncated due to size limitations, the full version will be available on A&A
Proceedings of the Third Workshop on Formal Integrated Development Environment
Creators: name: Dubois, Catherine
name: Masci, Paolo
name: Méry, Dominique
Publisher: name: arXiv
Year: 2017
Subjects: subject: Programming Languages (cs.PL)
subject: Logic in Computer Science (cs.LO)
subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: This volume contains the proceedings of F-IDE 2016, the third international workshop on Formal Integrated Development Environment, which was held as an FM 2016 satellite event, on November 8, 2016, in Limassol (Cyprus). High levels of safety, security and also privacy standards require the use of formal methods to specify and develop compliant software (sub)systems. Any standard comes with an assessment process, which requires a complete documentation of the application in order to ease the justification of design choices and the review of code and proofs. Thus tools are needed for handling specifications, program constructs and verification artifacts. The aim of the F-IDE workshop is to provide a forum for presenting and discussing research efforts as well as experience returns on design, development and usage of formal IDE aiming at making formal methods "easier" for both specialists and non-specialists.
Cohort effects in mortality modelling: a Bayesian state-space approach
Creators: name: Fung, Man Chung
name: Peters, Gareth W.
name: Shevchenko, Pavel V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Finance (q-fin.ST)
subject: FOS: Economics and business

description: Cohort effects are important factors in determining the evolution of human mortality for certain countries. Extensions of dynamic mortality models with cohort features have been proposed in the literature to account for these factors under the generalised linear modelling framework. In this paper we approach the problem of mortality modelling with cohort factors incorporated through a novel formulation under a state-space methodology. In the process we demonstrate that cohort factors can be formulated naturally under the state-space framework, despite the fact that cohort factors are indexed according to year-of-birth rather than year. Bayesian inference for cohort models in a state-space formulation is then developed based on an efficient Markov chain Monte Carlo sampler, allowing for the quantification of parameter uncertainty in cohort models and resulting mortality forecasts that are used for life expectancy and life table constructions. The effectiveness of our approach is examined through comprehensive empirical studies involving male and female populations from various countries. Our results show that cohort patterns are present for certain countries that we studied and the inclusion of cohort factors are crucial in capturing these phenomena, thus highlighting the benefits of introducing cohort models in the state-space framework. Forecasting of cohort models is also discussed in light of the projection of cohort factors.
description: 41 pages, 12 figures
Generalized Pascal triangle for binomial coefficients of words
Creators: name: Leroy, Julien
name: Rigo, Michel
name: Stipulanti, Manon
Publisher: name: arXiv
Year: 2017
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 28A80 (primary), and 28A78, 11B85, 68R15 (secondary)

description: We introduce a generalization of Pascal triangle based on binomial coefficients of finite words. These coefficients count the number of times a word appears as a subsequence of another finite word. Similarly to the Sierpiński gasket that can be built as the limit set, for the Hausdorff distance, of a convergent sequence of normalized compact blocks extracted from Pascal triangle modulo $2$, we describe and study the first properties of the subset of $[0, 1] \times [0, 1]$ associated with this extended Pascal triangle modulo a prime $p$.
description: 20 pages, 15 figures
Electronic Structure and Magnetism in the Layered Triangular Lattice Compound CeAuAl$_4$Ge$_2$
Creators: name: Zhang, S.
name: Aryal, N.
name: Huang, K.
name: Chen, K. -W.
name: Lai, Y.
name: Graf, D.
name: Besara, T.
name: Siegrist, T.
name: Manousakis, E.
name: Baumbach, R. E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Results are reported for the $f$-electron intermetallic CeAuAl$_4$Ge$_2$, where the atomic arrangement of the cerium ions creates the conditions for geometric frustration. Despite this, magnetic susceptibility measurements reveal that the low temperature magnetic exchange interaction is weak, resulting in marginally frustrated behavior and ordering near $T_{\rm{M}}$ $\approx$ 1.4 K. This occurs within a metallic Kondo lattice, where electrical resistivity and heat capacity measurements show that the Kondo-driven electronic correlations are negligible. Quantum oscillations are detected in ac-magnetic susceptibility measurements and uncover small charge carrier effective masses. Electronic structure calculations reveal that when the experimentally observed antiferromagnetic exchange interaction and the on-$f$-site Coulomb repulsion (Hubbard) U are considered, the $f$-electron bands move away from the Fermi level, resulting in electronic behavior that is dominated by the $s$-, $p$-, and $d$- bands, which are all characterized by light electron masses. Thus, CeAuAl$_4$Ge$_2$ provides a starting point for investigating geometric magnetic frustration in a cerium lattice without strong Kondo hybridization, where calculations provide useful guidance.
description: 8 pages, 8 figures
Complex Network Tools to Understand the Behavior of Criminality in Urban Areas
Creators: name: Spadon, Gabriel
name: Scabora, Lucas C.
name: Araujo, Marcus V. S.
name: Oliveira, Paulo H.
name: Machado, Bruno B.
name: Sousa, Elaine P. M.
name: Traina-Jr, Caetano
name: Rodrigues-Jr, Jose F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Social and Information Networks (cs.SI)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: G.2.2; G.2.3; H.2.8; H.3.3; I.5
subject: 05C82, 91C20, 68R10

description: Complex networks are nowadays employed in several applications. Modeling urban street networks is one of them, and in particular to analyze criminal aspects of a city. Several research groups have focused on such application, but until now, there is a lack of a well-defined methodology for employing complex networks in a whole crime analysis process, i.e. from data preparation to a deep analysis of criminal communities. Furthermore, the "toolset" available for those works is not complete enough, also lacking techniques to maintain up-to-date, complete crime datasets and proper assessment measures. In this sense, we propose a threefold methodology for employing complex networks in the detection of highly criminal areas within a city. Our methodology comprises three tasks: (i) Mapping of Urban Crimes; (ii) Criminal Community Identification; and (iii) Crime Analysis. Moreover, it provides a proper set of assessment measures for analyzing intrinsic criminality of communities, especially when considering different crime types. We show our methodology by applying it to a real crime dataset from the city of San Francisco - CA, USA. The results confirm its effectiveness to identify and analyze high criminality areas within a city. Hence, our contributions provide a basis for further developments on complex networks applied to crime analysis.
description: 7 pages, 2 figures, 14th International Conference on Information Technology : New Generations
Inverse problems for magnetic Schrödinger operators in transversally anisotropic geometries
Creators: name: Krupchyk, Katya
name: Uhlmann, Gunther
Publisher: name: arXiv
Year: 2017
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 35R01, 35R30, 58J32, 53C65

description: We study inverse boundary problems for magnetic Schrödinger operators on a compact Riemannian manifold with boundary of dimension $\ge 3$. In the first part of the paper we are concerned with the case of admissible geometries, i.e. compact Riemannian manifolds with boundary which are conformally embedded in a product of the Euclidean line and a simple manifold. We show that the knowledge of the Cauchy data on the boundary of the manifold for the magnetic Schrödinger operator with $L^\infty$ magnetic and electric potentials, determines the magnetic field and electric potential uniquely. In the second part of the paper we address the case of more general conformally transversally anisotropic geometries, i.e. compact Riemannian manifolds with boundary which are conformally embedded in a product of the Euclidean line and a compact manifold, which need not be simple. Here, under the assumption that the geodesic ray transform on the transversal manifold is injective, we prove that the knowledge of the Cauchy data on the boundary of the manifold for a magnetic Schrödinger operator with continuous potentials, determines the magnetic field uniquely. Assuming that the electric potential is known, we show that the Cauchy data determines the magnetic potential up to a gauge equivalence.
Higgs-differential cross section at NNLO in dimensional regularisation
Creators: name: Dulat, Falko
name: Lionetti, Simone
name: Mistlberger, Bernhard
name: Pelloni, Andrea
name: Specchia, Caterina
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present an analytic computation of the Higgs production cross section in the gluon fusion channel, which is differential in the components of the Higgs momentum and inclusive in the associated partonic radiation through NNLO in perturbative QCD. Our computation includes the necessary higher order terms in the dimensional regulator beyond the finite part that are required for renormalisation and collinear factorisation at N$^3$LO. We outline in detail the computational methods which we employ. We present numerical predictions for realistic final state observables, specifically distributions for the decay products of the Higgs boson in the $γγ$ decay channel.
description: 27 pages, 6 awesome figures
Thickness dependent properties in oxide heterostructures driven by structurally induced metal-oxygen hybridization variations
Creators: name: Liao, Zhaoliang
name: Gauquelin, Nicolas
name: Green, Robert J.
name: Macke, Sebastian
name: Gonnissen, Julie
name: Thomas, Sean
name: Zhong, Zhicheng
name: Li, Lin
name: Si, Liang
name: Van Aert, Sandra
name: Hansmann, Philipp
name: Held, Karsten
name: Xia, Jing
name: Verbeeck, Johan
name: Van Tendeloo, Gustaaf
name: Sawatzky, George A.
name: Koster, Gertjan
name: Huijben, Mark
name: Rijnders, Guus
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Thickness driven electronic phase transitions are broadly observed in different types of functional perovskite heterostructures. However, uncertainty remains whether these effects are solely due to spatial confinement, broken symmetry or rather to a change of structure with varying film thickness. Here, we present direct evidence for the relaxation of oxygen 2p and Mn 3d orbital (p-d) hybridization coupled to the layer dependent octahedral tilts within a La2/3Sr1/3MnO3 film driven by interfacial octahedral coupling. An enhanced Curie temperature is achieved by reducing the octahedral tilting via interface structure engineering. Atomically resolved lattice, electronic and magnetic structures together with X-ray absorption spectroscopy demonstrate the central role of thickness dependent p-d hybridization in the widely observed dimensionality effects present in correlated oxide heterostructures.
description: Accepted by Adv. Funct. Mater
Sosyal Medya Bağlamında Gelişmeleri Kaçırma Korkusu (FoMO)
Creators: name: ÇELİK, Fatih
Publisher: name: Zenodo
Year: 2022
Subjects: Gelişmeleri Kaçırma Korkusu
FoMO
Sosyal Medya
Sosyal Medyanın Karanlık Yüzü

description: -
Small and Medium-sized Enterprises (SMEs) and Electronic Commerce, 2000
Creators: name: Daniel, E.
Publisher: name: UK Data Service
Year: 2001

description: The proposed objectives for the study were to explore the use and barriers to use of electronic commerce by small and medium-sized enterprises (SMEs) in Great Britain. By means of a postal questionnaire, the study sought to understand:
 which SMEs are using electronic commerce (e-commerce) applications and for what business activities?
 What benefits they are reaping - are these consistent with those forecast for larger corporations or can SMEs gain unique advantages from adopting e-commerce?
 What are the challenges faced in developing and adopting such services - what are the key success factors for SMEs achieving business benefits from e-commerce?
 In particular, it was intended that the research would demonstrate the following: the characteristics and incidence of SMEs adopting e-commerce; the business applications it is being used for in those companies; the benefits and challenges of e-commerce adoption; best practice for deployment of e-commerce.
Innovation in the London Region, 1999-2000
Creators: name: Simmie, J.
Publisher: name: UK Data Service
Year: 2001

description: The theoretical aim of this research is to examine and understand why innovative and competitive firms tend to cluster in a limited number of particular cities. The project is also seeking to understand the observed variety of supplier and customer arrangements among firms and the interactions between these and the firms' home city regions.
 These concerns raise questions about the characteristics of different stages of the innovation process and why firms' activities have been seen to vary from flexibly specialised local production networks, in mainly craft-based older industries, in new industrial districts; to individually produced innovations linked primarily in the context of competitive secrecy to major international customers.
 Research on the London region was informed by the comparative perspective of innovation studies in the four European cities of Amsterdam, Milan, Paris and Stuttgart (see the companion study to this one, SN:4361 'Innovation in Amsterdam, London, Milan, Paris and Stuttgart, 1999-2000'). A common questionnaire was administered in the five cities to a common sample frame of innovative companies who had won awards for basic research in industrial technologies for Europe (BRITE). In addition to this common sample frame, innovative firms drawn from local databases were also interviewed. The lessons from the first stage of the research were taken forward into a more in-depth research study of innovative and external support systems in the London metropolitan region where the sampling frame was identified using a variety of innovation awards. The purpose of this follow-up stage was to gather more specific data on aspects which were shown to be relatively important in London.
A 1D Radiative Transfer Benchmark with Polarization via Doubling and Adding
Creators: name: Ganapol, B. D.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: Highly precise numerical solutions to the radiative transfer equation with polarization present a special challenge. Here, we establish a precise numerical solution to the radiative transfer equation with combined Rayleigh and isotropic scattering in a 1D-slab medium with simple polarization. The 2- Stokes vector solution for the fully discretized radiative transfer equation in space and direction derives from the method of doubling and adding enhanced through convergence acceleration. Updates to benchmark solutions found in the literature to 7 places for reflectance and transmittance as well as for angular flux follow. Finally, we conclude with the numerical solution in a partially randomly absorbing heterogeneous medium.
description: 44 pages 9 Tables 4 Figures
Numerical studies on the link between radioisotopic signatures on Earth and the formation of the Local Bubble. I. 60Fe transport to the solar system by turbulent mixing of ejecta from nearby supernovae into a locally homogeneous ISM
Creators: name: Schulreich, Michael Mathias
name: Breitschwerdt, Dieter
name: Feige, Jenny
name: Dettbarn, Christian
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The discovery of radionuclides like 60Fe with half-lives of million years in deep-sea crusts and sediments offers the unique possibility to date and locate nearby supernovae. We want to quantitatively establish that the 60Fe enhancement is the result of several supernovae which are also responsible for the formation of the Local Bubble, our Galactic habitat. We performed three-dimensional hydrodynamic adaptive mesh refinement simulations (with resolutions down to subparsec scale) of the Local Bubble and the neighbouring Loop I superbubble in different homogeneous, self-gravitating environments. For setting up the Local and Loop I superbubble, we took into account the time sequence and locations of the generating core-collapse supernova explosions, which were derived from the mass spectrum of the perished members of certain stellar moving groups. The release of 60Fe and its subsequent turbulent mixing process inside the superbubble cavities was followed via passive scalars, where the yields of the decaying radioisotope were adjusted according to recent stellar evolution calculations. The models are able to reproduce both the timing and the intensity of the 60Fe excess observed with rather high precision, provided that the external density does not exceed 0.3 cm-3 on average. Thus the two best-fit models presented here were obtained with background media mimicking the classical warm ionised and warm neutral medium. We also found that 60Fe (which is condensed onto dust grains) can be delivered to Earth via two physical mechanisms: either through individual fast-paced supernova blast waves, which cross the Earth's orbit sometimes even twice as a result of reflection from the Local Bubble's outer shell, or, alternatively, through the supershell of the Local Bubble itself, injecting the 60Fe content of all previous supernovae at once, but over a longer time range.
description: 14 pages, 7 figures, accepted for publication in A&A
Joint denoising and distortion correction of atomic scale scanning transmission electron microscopy images
Creators: name: Berkels, Benjamin
name: Wirth, Benedikt
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Nowadays, modern electron microscopes deliver images at atomic scale. The precise atomic structure encodes information about material properties. Thus, an important ingredient in the image analysis is to locate the centers of the atoms shown in micrographs as precisely as possible. Here, we consider scanning transmission electron microscopy (STEM), which acquires data in a rastering pattern, pixel by pixel. Due to this rastering combined with the magnification to atomic scale, movements of the specimen even at the nanometer scale lead to random image distortions that make precise atom localization difficult. Given a series of STEM images, we derive a Bayesian method that jointly estimates the distortion in each image and reconstructs the underlying atomic grid of the material by fitting the atom bumps with suitable bump functions. The resulting highly non-convex minimization problems are solved numerically with a trust region approach. Well-posedness of the reconstruction method and the model behavior for faster and faster rastering are investigated using variational techniques. The performance of the method is finally evaluated on both synthetic and real experimental data.