cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Synthetic photonic lattices: new routes towards all-optical photonic devices
Creators: name: Luo, Xi-Wang
name: Zhou, Xingxiang
name: Xu, Jin-Shi
name: Li, Chuan-Feng
name: Guo, Guang-Can
name: Zhang, Chuanwei
name: Zhou, Zheng-Wei
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: All-optical photonic devices are crucial for many important photonic technology and applications, ranging from optical communication to quantum information processing. Conventional design of all-optical devices is based on photon propagation and interference in real space, which may reply on large numbers of optical elements and are challenging for precise control. Here we propose a new route for engineering all-optical devices using photon internal degrees of freedom, which form photonic crystals in such synthetic dimensions for photon propagation and interference. We demonstrate this new design concept by showing how important optical devices such as quantum memory and optical filter can be realized using synthetic orbital angular momentum (OAM) lattices in a single main degenerate cavity. The new designing route utilizing synthetic photonic lattices may significantly reduce the requirement for numerous optical elements and their fine tuning in conventional design, paving the way for realistic all-optical photonic devices with novel functionalities.
description: 7 pages, 6 figures
Effects of rotation and boundaries on chiral symmetry breaking of relativistic fermions
Creators: name: Chernodub, M. N.
name: Gongyo, Shinya
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Other Condensed Matter (cond-mat.other)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In order to avoid unphysical causality-violating effects any rigidly rotating system must be bounded in directions transverse to the axis of rotation. We demonstrate that this requirement implies substantial dependence of properties of relativistically rotating system on the boundary conditions. We consider a system of interacting fermions described by the Nambu-Jona-Lasinio model in a space bounded by cylindrical surface of finite radius. In order to confine the fermions inside the cylinder we impose "chiral" MIT boundary conditions on its surface. These boundary conditions are parameterized by a continuous chiral angle Θ. We find that at any value of Θthe chiral restoration temperature T_c decreases as a quadratic function of the angular frequency Ω. However, the position and the slope of the critical curve T_c = T_c(Ω) in the phase diagram depends noticeably on the value of the chiral angle.
description: 10 pages, 9 figures
Path-sum solution of the Weyl Quantum Walk in 3+1 dimensions
Creators: name: D'Ariano, Giacomo Mauro
name: Mosco, Nicola
name: Perinotti, Paolo
name: Tosini, Alessandro
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We consider the Weyl quantum walk in 3+1 dimensions, that is a discrete-time walk describing a particle with two internal degrees of freedom moving on a Cayley graph of the group $\mathbb Z^3$, that in an appropriate regime evolves according to Weyl's equation. The Weyl quantum walk was recently derived as the unique unitary evolution on a Cayley graph of $\mathbb Z^3$ that is homogeneous and isotropic. The general solution of the quantum walk evolution is provided here in the position representation, by the analytical expression of the propagator, i.e. transition amplitude from a node of the graph to another node in a finite number of steps. The quantum nature of the walk manifests itself in the interference of the paths on the graph joining the given nodes. The solution is based on the binary encoding of the admissible paths on the graph and on the semigroup structure of the walk transition matrices.
description: 13 pages
The Lightcone Bootstrap and the Spectrum of the 3d Ising CFT
Creators: name: Simmons-Duffin, David
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We compute numerically the dimensions and OPE coefficients of several operators in the 3d Ising CFT, and then try to reverse-engineer the solution to crossing symmetry analytically. Our key tool is a set of new techniques for computing infinite sums of SL(2,R) conformal blocks. Using these techniques, we solve the lightcone bootstrap to all orders in an asymptotic expansion in large spin, and suggest a strategy for going beyond the large spin limit. We carry out the first steps of this strategy for the 3d Ising CFT, deriving analytic approximations for the dimensions and OPE coefficients of several infinite families of operators in terms of the initial data $\{Δ_σ,Δ_ε,f_{σσε},f_{εεε},c_T\}$. The analytic results agree with numerics to high precision for about 100 low-twist operators (correctly accounting for O(1) mixing effects between large-spin families). Plugging these results back into the crossing equations, we obtain approximate analytic constraints on the initial data.
description: 65+25 pages, 21 figures
On the embedding of Weyl manifolds
Creators: name: Avalos, R.
name: Dahia, F.
name: Romero, C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We discuss the possibility of extending different versions of the Campbell-Magaard theorem, which have already been established in the context of semi-Riemannian geometry, to the context of Weyl's geometry. We show that some of the known results can be naturally extended to the new geometric scenario, although new difficulties arise. In pursuit of solving the embedding problem we have obtained some no-go theorems. We also highlight some of the difficulties that appear in the embedding problem, which are typical of the Weylian character of the geometry. The establishing of these new results may be viewed as part of a program that highlights the possible significance of embedding theorems of increasing degrees of generality in the context of modern higher-dimensional space-time theories.
description: 31 pages, Journal of Mathematical Physics, Volume 58, Issue 1 (2017)
Barjols, atelier Fabre, fabrication du galoubet, apposition de la signature du luthier avec une marque à gravure coupante sur la partie inférieure du bec
Creators: name: Musée National Des Arts Et Traditions Populaires (Paris)
name: Centre D'ethnologie Française
Publisher: name: École des Hautes Études en Sciences Sociales; Institut  interdisciplinaire d'anthropologie du contemporain (Paris); Laboratoire d'anthropologie et d'histoire de l'institution de la culture (Paris)
Year: 2024

Abstract
High-scale validity of a two Higgs doublet scenario: predicting collider signals
Creators: name: Chakrabarty, Nabarun
name: Mukhopadhyaya, Biswarup
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: It is possible to ameliorate the Higgs vacuum stability problem by switching over to two Higgs doublet models (2HDM), ensuring a stable electroweak vacuum up to the Planck scale, even though the top quark mass may be on the high side. However, the simultaneous requirements of perturbative unitarity, and also compatibility with collider and flavour data, constrain the parameter space severely. We investigate the collider signals answering to the regions allowed by such constraints. In particular, the near degeneracy of the neutral heavy scalar and the pseudoscalar is a feature that is probed. The LHC allows distinguishability of these two states, together with signal significance of at least 3$σ$, in its high-luminosity run. While $e^+ e^-$ colliders may have rather low event rates, muon colliders, cashing on the principle of radiative return, can probe 2HDM scenarios with (pseudo)scalar masses up to a TeV or so, though with the price of losing distinction between the CP-even and odd states.
description: 19 pages, 5 figures
The Abelian distribution
Creators: name: Levina, Anna
name: Herrmann, J. Michael
Publisher: name: arXiv
Year: 2017
Subjects: subject: Probability (math.PR)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 60C05, 60E07, 92C20

description: We define the Abelian distribution and study its basic properties. Abelian distributions arise in the context of neural modeling and describe the size of neural avalanches in fully-connected integrate-and-fire models of self-organized criticality in neural systems.
Supplementary document for Needle of longitudinally polarized light using the circular Airy beam - 6768983.pdf
Creators: name: An, Zhe
name: Lu, Wanli
Publisher: name: Optica Publishing Group
Year: 2024
Subjects: Uncategorized

description: The difference between inward and outward circular Airy beams, the modulation effect of positive and negative cone angles, the importance of the evanescent waves, the detailed derivation of the angular spectrum using the stationary phase method, and
Destinations of Leavers from Higher Education in the United Kingdom, 1994/95-2015/16
DLHE
Creators: name: Higher Education Statistics Agency (HESA)
Publisher: name: UK Data Service
Year: 2018

description: The Destinations of Leavers from Higher Education in the United Kingdom dataset provides details of the destinations of UK and European Union domiciled leavers from UK higher education. the current data cover the academic years 1994/95 to 2015/16. Eligible qualifications and providers have changed over time and definitions provided in the documentation should be referred to for all time series analysis.

 Further information may be found on the Higher Education Statistics Agency (HESA) website, including links to further documentation may be found on the Data collection webpage. Links to publications are included on the GOV.UK Higher Education Statistics Agency webpage.
USDA Conservation Technical Assistance and Within-Field Resource Concerns
Creators: name: Rosenberg, Andrew
name: Wallander, Steven
name: Rosenberg, Andrew
name: Wallander, Steven
Publisher: name: Unknown
Year: 2022
Subjects: subject: Crop Production/Industries
subject: Farm Management
subject: Financial Economics
subject: Land Economics/Use
subject: Resource concerns
subject: technical assistance
subject: working lands conservation programs
subject: soil health
subject: conservation practice
subject: erosion
subject: soil compaction
subject: low organic matter
subject: poor drainage

description: The U.S. Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS) provides conservation planning and field-level assessments of conservation strategies, and serves as one of multiple sources from which agricultural producers can receive conservation technical assistance. This bulletin looks at how many fields in oats, cotton, wheat, and soybeans have farmer-reported, on-field resource concerns and whether farmers received technical assistance to address these concerns from USDA or other sources. Farmers report that 49 percent of these fields have at least one resource concern and 26 percent have multiple resource concerns. Of the fields represented with at least one resource concern, 24 percent received technical assistance. Sixty-seven percent of assisted fields received assistance from USDA, NRCS.
Biographical Interviews in Eastern Germany in 2007-08
Creators: name: Gallinat, A.
Publisher: name: UK Data Service
Year: 2018

description: The purpose of the data is to investigate to what degree the socialist past is constructed in the post socialist present of eastern Germany. Specifically, the project sought to explore: (1) the contentious character of memories of the socialist period, the changing and still unstable evaluations of that period, and the moral ambiguities condensed in these memories; (2) the connections between history, memorializing and remembering at various levels of dialogue and reflection, from policies about the past over public discourse to private introspection; (3) and to examine how certain versions of the past are produced and given prominence in the news media, civic life and state politics, and in the flow of daily lives in one city in eastern Germany. The study is divided in 2 settings: a newspaper editorial office, and a state government (Landesregierung) in eastern Germany. Research collection was set in two institutions at the heart of the production and promotion of discourses about the past in one eastern German city. In eastern Germany there is a multiplicity of communal memories of the former German Democratic Republic ranging from nostalgic sentiments to government-sponsored critical examinations of the 'totalitarian state', all of which are contentious in the public.
Nuevas estrategias para combatir la resistencia a los antibióticos: Desarrollo de una vacuna trivalente en contra de Acinetobacter baumannii, Klebsiella pneumoniae y Pseudomonas aeruginosa
Creators: name: Corral-Lugo, Andrés
Publisher: name: Zenodo
Year: 2023
Subjects: multiresistencia; antibióticos; vacunas; Acinetobacter baumannii; Klebsiella pneumoniae; Pseudomonas aeruginosa; patógenos

description: RESUMEN La resistencia a los antimicrobianos es una gran amenaza para la salud pública mundial. La vacunación es un enfoque eficaz para prevenir infecciones bacterianas; sin embargo, no se ha aplicado con éxito para prevenir las infecciones causadas por los patógenos más problemáticos resistentes a antibióticos. Las vacunas tienen un enorme potencial para reducir la morbilidad causadas por las infecciones causadas por bacterias Gram-negativas multirresistentes. Sin embargo, hemos identificado algunos obstáculos en su desarrollo, entre los que incluimos: los obstáculos técnicos, logísticos y sociales, los cuales han limitado el desarrollo exitoso de vacunas para estas infecciones en el pasado. Así mismo, hemos evaluado los avances recientes que pueden contribuir a superar estos desafíos, incluyendo una síntesis de las tecnologías de vacunas que se han empleado en el desarrollo de vacunas, así como las tecnologías emergentes que pueden contribuir a éxitos futuros. La mayoría de las vacunas que se utilizan actualmente para la prevención de enfermedades infecciosas se han desarrollado utilizando un paradigma de patógeno único y enfermedad única. El objetivo de desarrollar una vacuna en contra de tres bacterias (Acinetobacter baumannii, Klebsiella pneumoniae y Pseudomonas aeruginosa), es un enfoque que pretende abordar el tema de la resistencia a los antibióticos, i) previniendo las infecciones por bacterias multirresistentes, que ii) causan una misma enfermedad, principalmente en iii) ambientes hospitalarios, lo que aporta una visión novedosa en la lucha contra la resistencia bacteriana a los antibióticos.
On beam models and their paraxial approximation
Creators: name: Waters, W. J.
name: King, B.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optics (physics.optics)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: We derive focused laser pulse solutions to the electromagnetic wave equation in vacuum. After reproducing beam and pulse expressions for the well-known paraxial Gaussian and axicon cases, we apply the method to analyse a laser beam with Lorentzian transverse momentum distribution. Whilst a paraxial approach has some success close to the focal axis and within a Rayleigh range of the focal spot, we find that it incorrectly predicts the transverse fall-off typical of a Lorentzian. Our vector-potential approach is particularly relevant to calculation of quantum electrodynamical processes in weak laser pulse backgrounds.
description: 8 pages, 9 figures
Structure and Magnetism in the Bond Frustrated Spinel, ZnCr2Se4
Creators: name: Zajdel, P.
name: Li, W-Y.
name: Van Beek, W.
name: Lappas, A.
name: Ziolkowska, A.
name: Jaskiewicz, S.
name: Stock, C.
name: Green, M. A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The crystal and magnetic structures of stoichiometric ZnCr2Se4 have been investigated using synchrotron X-ray and neutron powder diffraction, muon spin relaxation (muSR) and inelastic neutron scattering. Synchrotron X-ray diffraction shows a spin-lattice distortion from the cubic spinel to a tetragonal I41/amd lattice below TN = 21 K, where powder neutron diffraction confirms the formation of a helical magnetic structure with magnetic moment of 3.04(3) μB at 1.5 K; close to that expected for high-spin Cr3+. MuSR measurements show prominent local spin correlations that are established at temperatures considerably higher (< 100 K) than the onset of long range magnetic order. The stretched exponential nature of the relaxation in the local spin correlation regime suggests a wide distribution of depolarizing fields. Below TN, unusually fast (> 100 μs-1) muon relaxation rates are suggestive of rapid site hopping of the muons in static field. Inelastic neutron scattering measurements show a gapless mode at an incommensurate propagation vector of k = (0 0 0.4648(2)) in the low temperature magnetic ordered phase that extends to 0.8 meV. The dispersion is modelled by a two parameter Hamiltonian, containing ferromagnetic nearest neighbor and antiferromagnetic next nearest neighbor interactions with a Jnnn/Jnn = -0.337.
Within-household Inequalities and Public Policy, 2006-08
Creators: name: Bennett, F.
name: Sutherland, H.
name: Himmelweit, S., The Open University (OU)
Publisher: name: UK Data Service
Year: 2020

description:
The project involved three methods: (1) qualitative analysis of semi-structured interviews with 60 individuals in 30 couples; (2) quantitative analysis of household panel data (British Household Panel Survey); and (3) use of UK and EU policy simulation models of the tax-benefit system. The aim was to explore how the three approaches could be used to inform each other: for the econometric analysis to build on the qualitative findings, and for policy simulation to take account of within household inequalities beyond those of income, identified by the qualitative and quantitative analysis. The key research questions include: What are the policy-relevant gender specific parameters that affect the distribution of power, entitlements to and use of resources within households in the UK? In particular, do perceptions about entitlements and intra-household distribution of resources depend on the source and recipient of income? How do current and potential policy changes affecting access to different sources of income impact on gender roles and relationships within households? What ambiguities and tensions arise in attempting to improve both the distribution of resources between households and women's access to resources within the household? What lessons can be drawn from the above for developing policies that improve women's financial autonomy?

The project aimed to explore alternative approaches to understanding the behavioral and distributional impact of policy change which take account of gender inequalities in power and influence within the household, and to use such approaches to analyse the effects of changes in fiscal, social security and associated labour market policies in the UK. It has focused on approaches to conceptualising and measuring inequalities within male-female couples, and on understanding the concepts of entitlement and financial autonomy and the factors that influence individuals’ command over resources (entitlements) within such couples.
Deterministic nonclassicality for quantum mechanical oscillators in thermal states
Creators: name: Marek, Petr
name: Lachman, Lukas
name: Slodicka, Lukas
name: Filip, Radim
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum nonclassicality is the basic building stone for the vast majority of quantum information applications and methods of its generation are at the forefront of research. One of the obstacles any method needs to clear is the looming presence of decohorence and noise which act against the nonclassicality and often erase it completely. In this paper we show that nonclassical states of a quantum harmonic oscillators initially in thermal equilibrium states can be deterministically created by coupling it to a single two level system. This can be achieved even in the absorption regime in which the two level system is initially in the ground state. The method is resilient to noise and it may actually benefit from it, as witnessed by the systems with higher thermal energy producing more nonclassical states.
description: 9 pages, 8 figures
Updates on the background estimates for the X-IFU instrument onboard of the ATHENA mission
Creators: name: Lotti, Simone
name: Macculi, Claudio
name: D'Andrea, Matteo
name: Piro, Luigi
name: Molendi, Silvano
name: Gastaldello, Fabio
name: Mineo, Teresa
name: D'Ai, Antonino
name: Bulgarelli, Andrea
name: Fioretti, Valentina
name: Jacquey, Christian
name: Laurenza, Monica
name: Laurent, Philippe
Publisher: name: arXiv
Year: 2017
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: ATHENA, with a launch foreseen in 2028 towards the L2 orbit, addresses the science theme "The Hot and Energetic Universe", coupling a high-performance X-ray Telescope with two complementary focal-plane instruments. One of these, the X-ray Integral Field Unit (X-IFU) is a TES based kilo-pixel array providing spatially resolved high-resolution spectroscopy (2.5 eV at 6 keV) over a 5 arcmin FoV. The background for this kind of detectors accounts for several components: the diffuse Cosmic X-ray Background, the low energy particles (~100 MeV) crossing the spacecraft and reaching the focal plane from every direction. Each one of these components is under study to reduce their impact on the instrumental performances. This task is particularly challenging, given the lack of data on the background of X-ray detectors in L2, the uncertainties on the particle environment to be expected in such orbit, and the reliability of the models used in the Monte Carlo background computations. As a consequence, the activities addressed by the group range from the reanalysis of the data of previous missions like XMM-Newton, to the characterization of the L2 environment by data analysis of the particle monitors onboard of satellites present in the Earth magnetotail, to the characterization of solar events and their occurrence, and to the validation of the physical models involved in the Monte Carlo simulations. All these activities will allow to develop a set of reliable simulations to predict, analyze and find effective solutions to reduce the particle background experienced by the X-IFU, ultimately satisfying the scientific requirement that enables the science of ATHENA. While the activities are still ongoing, we present here some preliminary results already obtained by the group.
title: Compressive Sensing Methods and Applications for Electron Microscopy
Creators: name: Nicholls, Daniel
Publisher: name: University of Liverpool Repository
Year: 2023

description: Scanning Transmission Electron Microscopy (STEM) is at the forefront of high resolution material characterisation. Modern STEMs can be outfitted with a wide variety of ancillary equipment that each provides additional support alongside regular imaging capability. A proficient microscopist can use these tools to characterise a number of materials, though many prove difficult and most are incapable of being characterised with the current techniques available - biological, battery, and catalyst materials are, for example, often much too sensitive to image using standard techniques. The limiting factor for most of these materials is that they suffer from beam damage during characterisation - they are destroyed or changed under the electron beam. Many techniques have arisen to aid with imaging these materials, either by reducing the electron dose rate required to perform the necessary characterisation or increasing the material's tolerance for exposure to the electron beam. A secondary limiting factor to STEM analysis is the acquisition speed. Many transient phenomena, such as atoms moving across the surface of a material, happen at such speeds that exceed the current capabilities of STEM. Transient phenomena such as drift also act as a resolution limiter which plagues every microscope aiming to perform high resolution imaging. Compressive sensing (CS) STEM is a low-dose imaging technique that reduces the number of pixels required to form STEM images. It accomplishes this by combining subsampling, the act of deliberately forming incomplete images by manipulating the electron beam path, and inpainting, a method of infilling gaps in incomplete images. This technique, however, is still in its infancy with regards to electron imaging. The initial attempts to apply CS to scanning electron microscope modalities has done so successfully, but that success has not been explained or justified in great detail. Validation of compressive sensing for electron microscopy is vital at this stage, as while the technique has shown promise, it has not been rigorously examined. The goals of this thesis are then to develop and use compressive sensing as a low-dose STEM imaging technique, investigate and explain why subsampling and inpainting is beneficial, and apply it to various microscopy techniques with a focus on maximising the output from these techniques.
Disadvantaged Young Adults' Perceptions and Understandings of Electronic Cigarettes, 2015-2016
Creators: name: Amos, A.
name: Lucherini, M.
name: Rooke, C.
Publisher: name: UK Data Service
Year: 2018

description: Background: Smoking uptake has been declining in young adults (16-24 year olds) in the UK. However, concerns have been expressed that the emergence of e-cigarettes, while offering the potential to reduce smoking in adults, may have a negative impact on smoking in young people. Particular concern has focused on the possible gateway effect of e-cigarettes. Also that the increased visibility of e-cigarettes and the messages and imagery used in e-cigarette marketing, which often echoes that used in now banned tobacco advertising, has the potential to renormalize smoking. However, little research has been undertaken to explore how young people and young adults perceive and experience e-cigarettes, and how this may be influencing social norms around smoking.

 Aims: The aim of this project was to explore young adults' (16-24 year olds) understandings of and engagement with e-cigarettes, and whether and in what ways this may be influencing social norms around smoking tobacco.

 Methods: This qualitative study undertook interviews with small friendship groups of young people aged between 16-24 years. Purposive sampling will aim to include a diverse range of participants who are ever-smokers, including those who have used and not used e-cigarettes, males and females, different age groups and educational and occupational groups. The study focused primarily on 16-24 year olds living in disadvantaged areas as they are most at risk of becoming tobacco smokers. Fieldwork took place August 2015-April 2016 in Central Scotland. Twenty-two friendship groups of 2-4 participants and 11 individual interviews were conducted of which 16 were included in this data collection. Thirty-nine of the 72 participants were female. 31 participants were not in education, employment or training (NEETs), 19 were in education/training, and 22 were working or volunteering. 44 participants were smokers, 13 ex-smokers, nine ever-smokers and five never smokers. The smoking status of one participant was unclear. Most participants (60), had tried e-cigarettes.
Cosmic-ray induced destruction of CO in star-forming galaxies
Creators: name: Bisbas, Thomas G.
name: van Dishoeck, Ewine F.
name: Papadopoulos, Padelis P.
name: Szücs, László
name: Bialy, Shmuel
name: Zhang, Zhi-Yu
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We explore the effects of the expected higher cosmic ray (CR) ionization rates $ζ_{\rm CR}$ on the abundances of carbon monoxide (CO), atomic carbon (C), and ionized carbon (C$^+$) in the H$_2$ clouds of star-forming galaxies. The study of Bisbas et al. (2015) is expanded by: a) using realistic inhomogeneous Giant Molecular Cloud (GMC) structures, b) a detailed chemical analysis behind the CR-induced destruction of CO, and c) exploring the thermal state of CR-irradiated molecular gas. CRs permeating the interstellar medium with $ζ_{\rm CR}$$\gtrsim 10\times$(Galactic) are found to significantly reduce the [CO]/[H$_2$] abundance ratios throughout the mass of a GMC. CO rotational line imaging will then show much clumpier structures than the actual ones. For $ζ_{\rm CR}$$\gtrsim 100\times$(Galactic) this bias becomes severe, limiting the utility of CO lines for recovering structural and dynamical characteristics of H$_2$-rich galaxies throughout the Universe, including many of the so-called Main Sequence (MS) galaxies where the bulk of cosmic star formation occurs. Both C$^+$ and C abundances increase with rising $ζ_{\rm CR}$, with C remaining the most abundant of the two throughout H$_2$ clouds, when $ζ_{\rm CR}\sim (1-100)\times$(Galactic). C$^+$ starts to dominate for $ζ_{\rm CR}$$\gtrsim 10^3\times$(Galactic). The thermal state of the gas in the inner and denser regions of GMCs is invariant with $T_{\rm gas}\sim 10\,{\rm K}$ for $ζ_{\rm CR}\sim (1-10)\times$(Galactic). For $ζ_{\rm CR}$$\sim 10^3\times$(Galactic) this is no longer the case and $T_{\rm gas}\sim 30-50\,{\rm K}$ are reached. Finally we identify OH as the key species whose $T_{\rm gas}-$sensitive abundance could mitigate the destruction of CO at high temperatures.
description: 17 pages, 12 figures, accepted by ApJ
Statistical study of solar dimmings using CoDiT
Creators: name: Krista, Larisza D.
name: Reinard, Alysha A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the results from analyzing the physical and morphological properties of 154 dimmings (transient coronal holes) and the associated flares and coronal mass ejections (CMEs). Each dimming in our 2013 catalog was processed with the semi-automated Coronal Dimming Tracker using Solar Dynamics Observatory AIA 193 A observations and HMI magnetograms. Instead of the typically used difference images, we used our coronal hole detection algorithm to detect transient dark regions "directly" in extreme ultraviolet (EUV) images. This allowed us to study dimmings as the footpoints of CMEs - in contrast with the larger, diffuse dimmings seen in difference images that represent the projected view of the rising, expanding plasma. Studying the footpoint-dimming morphology allowed us to better understand the CME structure in the low corona. While comparing the physical properties of dimmings, flares, and CMEs we were also able to identify relationships between the different parts of this complex eruptive phenomenon. We found that larger dimmings are longer-lived, suggesting that it takes longer to "close down" large open magnetic regions. Also, during their growth phase, smaller dimmings acquire a higher magnetic flux imbalance (i. e., become more unipolar) than larger dimmings. Furthermore, we found that the EUV intensity of dimmings (indicative of local electron density) correlates with how much plasma was removed and how energetic the eruption was. Studying the morphology of dimmings (single, double, fragmented) also helped us identify different configurations of the quasi-open magnetic field.
description: http://adsabs.harvard.edu/abs/2017ApJ...839...50K
Atomically thin semiconductors as nonlinear mirrors
Creators: name: Zeytinoglu, Sina
name: Roth, Charlaine
name: Huber, Sebastian
name: Imamoglu, Atac
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show that a transition metal dichalcogenide monolayer with a radiatively broadened exciton resonance would exhibit perfect extinction of a transmitted field. This result holds for s- or p-polarized weak resonant light fields at any incidence angle, due to the conservation of in-plane momentum of excitons and photons in a flat defect-free two dimensional crystal. In contrast to extinction experiments with single quantum emitters, exciton-exciton interactions lead to an enhancement of reflection with increasing power for incident fields that are blue detuned with respect to the exciton resonance. We show that the interactions limit the maximum reflection that can be achieved by depleting the incoming coherent state into an outgoing two-mode squeezed state.
description: Comments welcome
Applications of ternary rings to $C^*$-algebras
Creators: name: Abadie, Fernando
name: Ferraro, Damián
Publisher: name: arXiv
Year: 2016
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L08 (Primary), 46L06 (Secondary)

description: We show that there is a functor from the category of positive admissible ternary rings to the category of $*$-algebras, which induces an isomorphism of partially ordered sets between the families of $C^*$-norms on the ternary ring and its corresponding $*$-algebra. We apply this functor to obtain Morita-Rieffel equivalence results between cross sectional $C^*$-algebras of Fell bundles, and to extend the theory of tensor products of $C^*$-algebras to the larger category of full Hilbert $C^*$-modules. We prove that, like in the case of $C^*$-algebras, there exist maximal and minimal tensor products. As applications we give simple proofs of the invariance of nuclearity and exactness under Morita-Rieffel equivalence of $C^*$-algebras.
Developing Character Skills in Schools, 2015-2016
Creators: name: NatCen Social Research
Publisher: name: UK Data Service
Year: 2018

description: Increasing emphasis has been placed on character education in recent years, including significant investment by the Department for Education (DfE) in projects aimed at developing desirable character traits in children and young people through the Character Innovation Fund. Character education can be defined in various ways, and can be seen to overlap with concepts in the literature such as 'non-cognitive skills' or 'social and emotional skills'. The primary aim of this survey was to gain a representative profile of provision within schools, colleges and other educational institutions, as well as providing an understanding of the issues that institutions face in delivering character education.

 For the purpose of this survey, character education was defined as any activities that aim to develop desirable character traits in children and young people. Ultimately, character education seeks to prepare children and young people for well-rounded and successful adult lives; supporting improved academic attainment, employability and citizenship. This survey was commissioned in order to understand what schools in England currently do to try and develop desirable character traits among their pupils, and to explore their experiences of putting this provision into place. The DfE intend for this evidence to provide a basis for future work, including research into effective practice and gaps in provision. The survey forms part of a wider, mixed methods project exploring mental health and character education provision in schools and colleges across England. A sample of 6,907 primary schools, secondary schools (with and without sixth forms), post-16 institutions (FE colleges and sixth form colleges) and other less common types of institutions (including Pupil Referral Units (PRUs), alternative provision and special schools) in England was drawn from the most up-to-date extract from Edubase (March 2016) for the dual topic survey of mental health and character education provision. The survey of character education was carried out in the final term of the 2015-2016 academic year. The related survey covering mental health, Supporting Mental Health in Schools and Colleges, 2016-2017, is available under SN 8354.
Modelling the electronic properties of GaAs polytype nanostructures: impact of strain on the conduction band character
Creators: name: Marquardt, Oliver
name: Ramsteiner, Manfred
name: Corfdir, Pierre
name: Geelhaar, Lutz
name: Brandt, Oliver
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the electronic properties of GaAs nanowires composed of both the zincblende and wurtzite modifications using a ten-band k.p model. In the wurtzite phase, two energetically close conduction bands are of importance for the confinement and the energy levels of the electron ground state. These bands form two intersecting potential landscapes for electrons in zincblende/wurtzite nanostructures. The energy difference between the two bands depends sensitively on strain, such that even small strains can reverse the energy ordering of the two bands. This reversal may already be induced by the non-negligible lattice mismatch between the two crystal phases in polytype GaAs nanostructures, a fact that was ignored in previous studies of these structures. We present a systematic study of the influence of intrinsic and extrinsic strain on the electron ground state for both purely zincblende and wurtzite nanowires as well as for polytype superlattices. The coexistence of the two conduction bands and their opposite strain dependence results in complex electronic and optical properties of GaAs polytype nanostructures. In particular, both the energy and the polarization of the lowest intersubband transition depends on the relative fraction of the two crystal phases in the nanowire.
description: 8 pages / 6 figures
The effects of massive graviton on the equilibrium between the black hole and radiation gas in an isolated box
Creators: name: Hu, Ya-Peng
name: Pan, Feng
name: Wu, Xin-Meng
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: It is well known that the black hole can has temperature and radiate the particles with black body spectrum, i.e. Hawking radiation. Therefore, if the black hole is surrounded by an isolated box, there is a thermal equilibrium between the black hole and radiation gas. A simple case considering the thermal equilibrium between the Schwarzschild black hole and radiation gas in an isolated box has been well investigated previously in detail, i.e. taking the conservation of energy and principle of maximal entropy for the isolated system into account. In this paper, following the above spirit, the effects of massive graviton on the thermal equilibrium will be investigated. For the gravity with massive graviton, we will use the de Rham-Gabadadze-Tolley (dRGT) massive gravity which has been proven to be ghost free. Because the graviton mass depends on two parameters in the dRGT massive gravity, here we just investigate two simple cases related to the two parameters, respectively. Our results show that in the first case the massive graviton can suppress or increase the condensation of black hole in the radiation gas although the $T-E$ diagram is similar like the Schwarzschild black hole case. For the second case, a new $T-E$ diagram has been obtained. Moreover, an interesting and important prediction is that the condensation of black hole just increases from the zero radius of horizon in this case, which is very different from the Schwarzschild black hole case.
description: 9 pages, 4 figures
Constraining the Orbit of Supermassive Black Hole Binary 0402+379
Creators: name: Bansal, Karishma
name: Taylor, Greg B.
name: Peck, Alison. B.
name: Zavala, Robert T.
name: Romani, Roger W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The radio galaxy 0402+379 is believed to host a supermassive black hole binary (SMBHB). The two compact core sources are separated by a projected distance of 7.3 pc, making it the most (spatially) compact resolved SMBHB known. We present new multi-frequency VLBI observations of 0402+379 at 5, 8, 15 and 22 GHz, and combine with previous observations spanning 12 years. A strong frequency dependent core shift is evident, which we use to infer magnetic fields near the jet base. After correcting for these shifts we detect significant relative motion of the two cores at $β=v/c=0.0054 \pm 0.0003$ at $PA= -34.4^\circ$. With some assumptions about the orbit, we use this measurement to constrain the orbital period $P\approx 3 \times 10^4$ y and SMBHB mass $M \approx 15 \times 10^9\ M_\odot$. While additional observations are needed to confirm this motion and obtain a precise orbit, this is apparently the first black hole system resolved as a visual binary.
Metric for two equal Kerr black holes
Creators: name: Manko, V. S.
name: Ruiz, E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We show that the exact solution of Einstein's equations describing a system of two aligned identical Kerr black holes separated by a massless strut follows straightforwardly from the extended 2-soliton solution possessing equatorial symmetry, and we give its concise analytic representation in terms of physical parameters.
description: 14 pages, 2 figures; new section added
Millennium Village Impact Evaluation in Northern Ghana, 2012-2016
Millennium Village Impact Evaluation in Northern Ghana, 2012-
MVP; SADA-North Ghana Household Survey
Creators: name: University Of Sussex, Institute Of Development Studies
name: Columbia University (New York), Earth Institute
Publisher: name: UK Data Service
Year: 2019

description:
The Millennium Villages Project (MVP) is a 'proof of concept' project to support African rural communities in meeting the Millennium Development Goals (MDGs). Scientists in agriculture, nutrition and health, economics, energy, water, environment and information technology, working together with communities, local partners, and governments empower and backstop villages to accelerate progress in achieving the MDGs. The concept to prove is that science-based interventions, appropriate local institutions and community participation and empowerment can be combined to achieve the MDGs, within the cost estimates derived by The UN Millennium Project. The UK Department for International Development (DFID) has provided a grant of £11.5 million to implement a new Millennium Village in northern Ghana (distributed via its DFID-Ghana centre, based in Accra). The MV ran for several years from 2012 to 2016 with interventions targeting a cluster of communities with a total population of around 26,000. In the survey rounds of 2012, 2014 and 2016 the full MVP package of questionnaires was administered by the Earth Institute to track progress on the MDGs. The additional survey rounds of 2013 and 2015 administered a restricted version of the MVP household questionnaire focusing on tracking progress in poverty reduction. Users should note that the current study includes data from Years 0, 1, 2, 3 and 4 of the study, conducted in 2012, 2013, 2014, 2015 and 2016 respectively.

The site is located in Savannah Accelerated Development Authority (SADA) Region in Northern Ghana. It encompasses 34 communities located in three Area Councils, in the poorest sections of two District Assemblies. While MVPs across Africa have established their own monitoring and evaluation systems, designed by the Earth Institute at Columbia University, DFID has requested that the new MVP in northern Ghana be accompanied by an independent evaluation to build on, expand and validate the MVP's own monitoring and evaluation systems. The independent evaluation team of the northern Ghana MVP will use a difference-in-difference (DD) approach, by comparing the change in outcomes in the MVP areas before implementation to post-implementation, with changes in the same outcomes for an explicit control group. DD allows the evaluation to isolate the MVP impact on the MDGs from effects of other variables changing over time.

Further information may be found on the Institute for Development Studies Millennium Villages in Northern Ghana Impact Evaluation webpage.
Social contagion with degree-dependent thresholds
Creators: name: Lee, Eun
name: Holme, Petter
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We investigate opinion spreading by a threshold model in a situation where the influence of people is heterogeneously distributed. We focus on the response of the average opinion as a function between the trend between out-degree (number of neighbors)---effectively the strength of influence of a node---and the threshold for adopting a new product or opinion. We find that if the coupling is very positive, the final state of the system will be a mix of different opinions otherwise it will it converges to a consensus state. We find that this cannot be simply explained as a phase transition, but emerges from a combination of mechanisms and their relative dominance in different regions of parameter space.
description: 7 pages, 6 figures
Non-Abelian holonomic transformation in the presence of classical noise
Creators: name: Jing, Jun
name: Lam, Chi-Hang
name: Wu, Lian-Ao
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: It is proposed that high-speed universal quantum gates can be realized by using non-Abelian holonomic transformation. A cyclic evolution path which brings the system periodically back to a degenerate qubit subspace is crucial to holonomic quantum computing. The cyclic nature and the resulting gate operations are fully dependent on the precise control of driving parameters, such as the modulated envelop function of Rabi frequency and the control phases. We investigate the effects of fluctuations in these driving parameters on the transformation fidelity of a universal set of single-qubit quantum gates. We compare the damage effects from different noise sources and determine the "sweet spots" in the driving parameter space. The nonadiabatic non-Abelian quantum gate is found to be more susceptible to classical noises on the envelop function than that on the control phases. We also extend our study to a two-qubit quantum gate.
description: 7 pages, 3 figures