cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Towards smooth (010) beta-Ga2O3 films homoepitaxially grown by plasma assisted molecular beam epitaxy: The impact of substrate offcut and metal-to-oxygen flux ratio
Creators: name: Mazzolini, Piero
name: Bierwagen, Oliver
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Smooth interfaces and surfaces are beneficial for most (opto)electronic devices based on thin films and their heterostructures. For example, smoother interfaces in (010) beta-Ga2O3/(AlxGa1-x)2O3 heterostructures, whose roughness is ruled by that of the Ga2O3 layer, can enable higher mobility 2DEGs by reducing interface roughness scattering. To this end we experimentally prove that a substrate offcut along the [001] direction allows to obtain smooth beta-Ga2O3 layers in (010)-homoepitaxy under metal-rich conditions. Applying In-mediated metal-exchange catalysis (MEXCAT) in molecular beam epitaxy at high substrate temperatures (Tg = 900 °C) we compare the morphology of layers grown on (010)-oriented substrates with different unintentional offcuts. The layer roughness is generally ruled by (i) (110) and (-110)-facets visible as elongated features along the [001] direction (rms < 0.5 nm), and (ii) trenches (5-10 nm deep) orthogonal to [001]. We show that an unintentional substrate offcut of only 0.1° almost oriented along the [001] direction suppresses these trenches resulting in a smooth morphology with a roughness exclusively determined by the facets, i.e., rms 0.2 nm. Since we found the facet-and-trench morphology in layers grown by MBE with and without MEXCAT, we propose that the general growth mechanism for (010)-homoepitaxy is ruled by island growth whose coalescence results in the formation of the trenches. The presence of a substrate offcut in the [001] direction can allow for step-flow growth or island nucleation at the step edges, which prevents the formation of trenches. Moreover, we give experimental evidence for a decreasing surface diffusion length or increasing nucleation density with decreasing metal-to-oxygen flux ratio. Based on our results we can rule-out step bunching as cause of the trench formation as well as a surfactant-effect of indium during MEXCAT.
A new Bohm-Vitense gap in the temperature range 5560 to 5610K in the Main Sequence
Creators: name: Kovtyukh, V. V.
name: Soubiran, C.
name: Belik, S. I.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Highly precise temperatures (sigma = 10-15 K) have been determined from line depth ratios for a set of 248 F-K field dwarfs of about solar metallicity (-0.5 < [Fe/H] < +0.4), based on high resolution (R=42000), high S/N echelle spectra. A new gap has been discovered in the distribution of stars on the Main Sequence in the temperature range 5560 to 5610 K. This gap coincides with a jump in the microturbulent velocity Vt and the well-known Li depression near 5600 K in field dwarfs and open clusters. As the principal cause of the observed discontinuities in stellar properties we propose the penetration of the convective zone into the inner layers of stars slightly less massive than the Sun and related to it, a change in the temperature gradient.
description: 5 pages, 2 figures, 1 electronic table, in press in A&A
title: Youth, risk and identity
Creators: name: Merryweather, Dave
Publisher: name: The Open University
Year: 2012

description: Recent socio-economic and cultural changes have had major implications for young people's everyday lives: longer periods are spent in a state of youth-hood while more opportunities to engage in youth practices are available. This changing youth landscape has been accompanied by governmental risk discourses which problematise young people, constructing many youth practices as risky and defining broad sections of youth as a risk population. These issues have been the subject of much academic interest. Yet, questions of how young people experience and understand risk are rarely considered: still less is said of how risks are interwoven with their identities. It is these matters that are the central focus of my investigation. In this thesis I use data from risk narratives generated through focus groups comprising 14-24 year-olds to illustrate the complexity of the relationship between youth, risk and identity. Risk narratives were found to be patterned in different ways according to the material experiences and understandings of risk shared by young people occupying particular social, economic and cultural spaces in Liverpool. Narratives were also informed in a range of ways by governmental youth risk discourses, young people's own culturally related risk discourses and by their age, gender, ethnicity and class. My work shows that, in discussing everyday risks, young people positioned both themselves and others in various subject positions, simultaneously expressing and reproducing a range of social distinctions and hierarchies. Understandings and experiences of risk were, in this regard, found to be closely bound up with social identity. My investigation illustrates that youth does not constitute a risk population in any simplistic way: nor do all young people experience or understand risk in the same terms. Rather, I demonstrate that material and discursive aspects of risk are intricately interwoven with young people's identities. As such, my thesis contributes to extant academic knowledge by highlighting the complexity of the relationship between youth, risk and identity and advancing new ways of addressing these relations.
Poissonian resetting of subdiffusion in a linear potential
Creators: name: Stanislavsky, Aleksander A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Resetting a stochastic process is an important problem describing the evolution of physical, biological and other systems which are continually returned to their certain fixed point. We consider the motion of a subdiffusive particle with a constant drift under Poissonian resetting. In this model the stochastic process is Brownian motion subordinated by an inverse infinitely divisible process (subordinator). Although this approach includes a wide class of subdiffusive system with Poissonian resetting by using different subordinators, each of such systems has a stationary state with the asymmetric Laplace distribution in which the scale and asymmetric parameters depend on the Laplace exponent of the subordinators used. Moreover, the mean time for the particle to reach a target is finite and has a minimum, optimal with respect to the resetting rate. Features of Lévy motion under this resetting and the effect of a linear potential are discussed.
description: 12 pages, 5 figures
Probing the Kinematics of the Narrow-Line Region in Seyfert Galaxies with Slitless Spectroscopy: Observational Results
Creators: name: Ruiz, J. R.
name: Crenshaw, D. M.
name: Kraemer, S. B.
name: Bower, G. A.
name: Gull, T. R.
name: Hutchings, J. B.
name: Kaiser, M. E.
name: Weistrop, D.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present slitless spectra of 10 Seyfert galaxies observed with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. The spectra cover the [OIII] 4959, 5007 emission lines at a spectral resolving power of ~9000 and a spatial resolution of 0.1". We compare the slitless spectra with previous HST narrow-band images to determine the velocity shifts and dispersions of the bright emission-line knots in the narrow-line regions (NLRs) of these Seyferts. Many knots are spatially resolved with sizes of tenths of arcsecs, corresponding to tens of pcs, and yet they appear to move coherently with radial velocities between zero and +/- 1200 km/s with respect to the systemic velocities of their hostgalaxies. The knots also show a broad range in velocity dispersion, ranging from ~30 km/s (the velocity resolution) to ~1000 km/s FWHM. Most of the Seyfert galaxies in this sample show an organized flow pattern, with radial velocities near zero at the nucleus (defined by the optical continuum peak) and increasing to maximum blueshifts and redshifts within ~1'' of the nucleus, followed by a decline to the systemic velocity. The emission-line knots also follow a general trend of decreasing velocity dispersion with increasing distance. In the Seyfert 2 galaxies, the presence of blueshifts and redshifts on either side of the nucleus indicates that rotation alone cannot explain the observed radial velocities, and that radial outflow plays an important role. Each of the Seyfert galaxies in this sample (with the exception of Mrk 3) shows a bright, compact (FWHM < 0.5") [O III] knot at the position of its optical nucleus. These nuclear emission-line knots have radial-velocity centroids near zero, but they typically have the highest velocity dispersions.
description: 28 pages, 5 figures (on 9 pages), accepted for AJ
$Λ(1405)$ and $\barΛ(1405)$ in $J/ψ$ four-body decays
Creators: name: Li, Chiangbing
name: Oset, E.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study the structure of the baryon resonances $Λ(1405)$ and $\barΛ(1405)$ in $J/ψ$ four body decays $J/ψ\to Σ\bar Σππ$ in the framework of a coupled channel chiral unitary approach. With still sufficient freedom for model parameters, the $Λ(1405)$ and $\barΛ(1405)$ resonances are generated by simultaneously taking the meson baryon and meson anti-baryon final state interactions into account. The $πΣ$ ($π\barΣ$) invariant mass distributions peak around 1410 MeV, which favors the assertion that the $Λ(1405)$ ($\barΛ(1405)$) is a superposition of the two $Λ(1405)$ ($\barΛ(1405)$) states which dominantly couple to $\bar K N$ ($K\bar N$) and $πΣ$ ($π\barΣ$), respectively. We also calculate the amplitude for isospin I=1 which gives hints on a possible I=1 baryon resonance in the energy region of the $Λ(1405)$, which up to now has not been observed.
description: 17 pages, 5 figures, version accepted for publication in Phys. Rev. C
GDPR Implementation Case Study Protocol
Creators: name: Henriksen-Bulmer, Jane
name: Shamal Faily
Publisher: name: figshare
Year: 2020
Subjects: subject: 80602 Computer-Human Interaction
subject: FOS: Psychology
subject: 80605 Decision Support and Group Support Systems
subject: FOS: Computer and information sciences
subject: 80703 Human Information Behaviour
subject: FOS: Media and communications
subject: Information Systems
subject: 80609 Information Systems Management
subject: 80699 Information Systems not elsewhere classified
subject: 89999 Information and Computing Sciences not elsewhere classified
subject: 80707 Organisation of Information and Knowledge Resources
subject: 80708 Records and Information Management (excl. Business Records and Information Management)

description: Case Study Protocol With the introduction of GDPR many smaller businesses, including charities, struggled with understanding how best to implement the new provisions brought in by the new regulation. To this end, this is the case study protocol devised to support a case study conducted in collaboration with ta Local Charitable organisation in the UK to support them implementing GDPR across the organisation. This includes creating a Data Protection Impact Assessment to facilitate the charity being able to conduct repeatable, consistent DPIAs.
CARACTERIZACION SOCIO-ECONÓMICA Y PRODUCTIVA DEL CULTIVO DE CACAO EN EL DEPARTAMENTO DE SANTANDER (COLOMBIA)
Creators: name: Pabón, Manuel
name: Pabón, Manuel
Publisher: name: Unknown
Year: 2016
Subjects: subject: Agribusiness
subject: Chocolate
subject: Theobroma cacao
subject: Moniliophthora

description: Cocoa cultivation is one of the main venture commitments of Colombia due to the social and commercial potential offered by this crop. Even though Colombia is not ranked among the top cocoa producers in the world, its cultivation is especially relevant at national level since it is developed in rural areas where social conflicts were common until a decade ago. From the commercial standpoint, the main exporting strength of Colombia focuses on fine cocoas (special and aroma-rich varieties). The Department of Santander is the main cocoa - producing region of Colombia. The purpose of this work is to present the socioeconomic and productive characterization of cocoa cultivation in this region of Colombia. This analysis is important since it serves as the support for the development of programs aiming at quality and competitiveness improvement as well as for determining the application of new agricultural techniques. In this sense, this research becomes the starting point for effective intervention in Colombia. The information for this study comes from a representative sample composed by 187 cocoa farmers located in this region. Results indicate that cocoa production in the Department of Santander is founded on very traditional activities where the age of farmers and their level of education can represent a hindrance for the adoption of new technologies. Furthermore, cocoa farming has two additional challenges consisting in the fighting against the monilia fungal disease and the Witches’ Broom disease, the two main pathologies affecting this crop.
Connecting Atmospheric Properties and Synthetic Emission of Shock Waves Using 3D RMHD Simulations of Quiet Sun
Creators: name: Sadykov, Viacheslav M.
name: Kitiashvili, Irina N.
name: Kosovichev, Alexander G.
name: Wray, Alan A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We analyze the evolution of shock waves in high-resolution 3D radiative MHD simulations of the quiet Sun and their synthetic emission characteristics. The simulations model the dynamics of a 12.8x12.8x15.2 Mm quiet-Sun region (including a 5.2 Mm layer of the upper convection zone and a 10 Mm atmosphere from the photosphere to corona) with an initially uniform vertical magnetic field of 10 G, naturally driven by convective flows. We synthesize the Mg II and C II spectral lines observed by the IRIS satellite and EUV emission observed by the SDO/AIA telescope. Synthetic observations are obtained using the RH1.5D radiative transfer code and temperature response functions at both the numerical and instrumental resolutions. We found that the Doppler velocity jumps of the C II 1334.5 A IRIS line and a relative enhancement of the emission in the 335 A SDO/AIA channel are the best proxies for the enthalpy deposited by shock waves into the corona (with Kendall's $τ$ correlation coefficients of 0.59 and 0.38, respectively). The synthetic emission of the lines and extreme ultraviolet passbands are correlated with each other during the shock wave propagation. All studied shocks are mostly hydrodynamic (i.e., the magnetic energy carried by horizontal fields is $\leq{}$2.6% of the enthalpy for all events) and have Mach numbers > 1.0-1.2 in the low corona. The study reveals the possibility of diagnosing energy transport by shock waves into the solar corona, as well as their other properties, by using IRIS and SDO/AIA sensing observations.
description: 31 pages, 8 figures, 2 tables
Ideal Chern bands are Landau levels in curved space
Creators: name: Estienne, B.
name: Regnault, N.
name: Crépel, V.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We prove that all the criteria proposed in the literature to identify a Chern band hosting exact fractional Chern insulating ground states, in fact, describe an equivalence with a lowest Landau level defined in curved space under a non-uniform magnetic field. In addition, we design an operational test for the most general instance of such lowest Landau level mapping, which only relies on the computationally inexpensive evaluation of Bloch wavefunctions' derivatives. Our work clarifies the common origin of various Chern-idealness criteria, proves that these criteria exhaust all possible lowest Landau levels, and hints at classes of Chern bands that may posses interesting phases beyond Landau level physics.
description: 8 pages
Reconstructing the star formation rate for compact binary populations with the Einstein telescope
Creators: name: Singh, Neha
name: Bulik, Tomasz
name: Belczynski, Krzysztof
name: Cieslar, Marek
name: Calore, Francesca
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Einstein Telescope (ET) is a proposed third-generation, wide-band gravitational wave (GW) detector. Given its improved detection sensitivity in comparison to the second-generation detectors, it will be capable of exploring the Universe with GWs up to very high redshifts. In this paper, we present a population-independent method to infer the functional form of star formation rate density (SFR) for different populations of compact binaries originating in stars from Population (Pop) I+II and Pop III using ET as a single instrument. We use an algorithm to answer three major questions regarding the SFR of different populations of compact binaries. Specifically, these questions refer to the termination redshift of the formation of Pop III stars, the redshift at peak SFR, and the functional form of SFR at high redshift, all of which remain to be elucidated. We show that the reconstruction of SFR as a function of redshift for the different populations of compact binaries is independent of the time-delay distributions up to $z \sim 14,$ and that the accuracy of the reconstruction only strongly depends on this distribution at higher redshifts of $z\gtrsim 14$. We define the termination redshift for Pop III stars as the redshift where the SFR drops to 1\% of its peak value. In this analysis, we constrain the peak of the SFR as a function of redshift and show that ET as a single instrument can distinguish the termination redshifts of different SFRs for Pop III stars, which have a true separation of at least $Δz \sim 2$. The accurate estimation of the termination redshift depends on correctly modelling the tail of the time-delay distribution, which constitutes delay times of $\gtrsim 8$ Gyr.
description: 19 pages, 9 figures, Accepted for publication in A&A
Topological superconductivity in doped magnetic moiré semiconductors
Creators: name: Crépel, Valentin
name: Guerci, Daniele
name: Cano, Jennifer
name: Pixley, J. H.
name: Millis, Andrew
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show that topological superconductivity may emerge upon doping of transition metal dichalcogenide heterobilayers above an integer-filling magnetic state of the topmost valence moiré band. The effective attraction between charge carriers is generated by an electric p-wave Feshbach resonance arising from interlayer excitonic physics and has a tuanble strength, which may be large. Together with the low moiré carrier densities reachable by gating, this robust attraction enables access to the long-sought p-wave BEC-BCS transition. The topological protection arises from an emergent time reversal symmetry occurring when the magnetic order and long wavelength magnetic fluctuations do not couple different valleys. The resulting topological superconductor features helical Majorana edge modes, leading to half-integer quantized spin-thermal Hall conductivity and to charge currents induced by circularly polarized light or other time-reversal symmetry-breaking fields.
description: 5+2 pages, 4 figures
“Professional trading”, exchange rate risk and the growth of international banking: a note
Creators: name: CALLIER, P.
Publisher: name: PSL Quarterly Review
Year: 2013
Subjects: subject: International banking, speculation, foreign exchange, risk, capital mobility
subject: F31, F33, G21

description: The movement from fixed to floating exchange rates led to predictions that foreign exchange markets might become more volatile. In particular, the issue whether speculation in the market was stabilising or destabilising was widely debated. Concern was also expressed whether sufficient speculative funds would be available to ensure capital mobility. The author argues that the development of international banking has allowed banks to undertake more speculative foreign exchange trading without incurring greater risk, thus alleviating the problem of capital mobility. JEL: F31, F33, G21
description: PSL Quarterly Review, V. 39, N. 159 (1986)
title: CAD and creativity at Key Stage 3 : towards a new pedagogy
Creators: name: Winn, Deborah
Publisher: name: The Open University
Year: 2012

description: In recent decades there has been a major shift in the Design and Technology curriculum in secondary schools away from manual techniques and towards digital processes and products. CAD/CAM (computer-aided design/computer-aided manufacturing) is not only commonplace it is also embedded into the English National Curriculum. There is much evidence to suggest that this shift of emphasis has not been without problems. The equipment used to design and quickly modify products mirrors the technological advancement in everyday life. This rapid change can be a source of uncertainty especially when one considers that software taught to Year 7 (11-12 years old) students today will often be outdated by the time they finish compulsory secondary education in Year 11 (16 years old). Perhaps more significantly, because of these issues teachers struggle to encourage creativity when teaching CAD/CAM within design and technology education. 3D solid modelling software is particularly difficult to use and be creative with in the early stages of learning the software. Furthermore Design and Technology teachers often struggle to keep up to date with rapidly changing software and frequently lack the confidence to teach it, which, in turn, affects their students' progress. This research investigates the effects of teaching and learning CAD/CAM software and the impact this has on encouraging creativity in the classroom with Key Stage 3 students and their teachers. It suggests we require some rethinking concerning what we want students to know and be able to do and considers an alternative pedagogy which may help students to achieve more creative outcomes when using CAD. The research is undertaken through an intervention study within an action research framework. It outlines new methods and strategies to improve the confidence and creativity of students when using 3D modelling software and addresses the reality of day-to-day teaching pressures.
HomPINNs: homotopy physics-informed neural networks for solving the inverse problems of nonlinear differential equations with multiple solutions
Creators: name: Zheng, Haoyang
name: Huang, Yao
name: Huang, Ziyang
name: Hao, Wenrui
name: Lin, Guang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Numerical Analysis (math.NA)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Due to the complex behavior arising from non-uniqueness, symmetry, and bifurcations in the solution space, solving inverse problems of nonlinear differential equations (DEs) with multiple solutions is a challenging task. To address this, we propose homotopy physics-informed neural networks (HomPINNs), a novel framework that leverages homotopy continuation and neural networks (NNs) to solve inverse problems. The proposed framework begins with the use of NNs to simultaneously approximate unlabeled observations across diverse solutions while adhering to DE constraints. Through homotopy continuation, the proposed method solves the inverse problem by tracing the observations and identifying multiple solutions. The experiments involve testing the performance of the proposed method on one-dimensional DEs and applying it to solve a two-dimensional Gray-Scott simulation. Our findings demonstrate that the proposed method is scalable and adaptable, providing an effective solution for solving DEs with multiple solutions and unknown parameters. Moreover, it has significant potential for various applications in scientific computing, such as modeling complex systems and solving inverse problems in physics, chemistry, biology, etc.
description: 20 pages, 15 figures, 7 tables
Instanton calculus for the self-avoiding manifold model
Creators: name: David, François
name: Wiese, Kay J.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We compute the normalisation factor for the large order asymptotics of perturbation theory for the self-avoiding manifold (SAM) model describing flexible tethered (D-dimensional) membranes in d-dimensional space, and the epsilon-expansion for this problem. For that purpose, we develop the methods inspired from instanton calculus, that we introduced in a previous publication (Nucl. Phys. B 534 (1998) 555), and we compute the functional determinant of the fluctuations around the instanton configuration. This determinant has UV divergences and we show that the renormalized action used to make perturbation theory finite also renders the contribution of the instanton UV-finite. To compute this determinant, we develop a systematic large-d expansion. For the renormalized theory, we point out problems in the interplay between the limits epsilon->0 and d->infinity, as well as IR divergences when epsilon= 0. We show that many cancellations between IR divergences occur, and argue that the remaining IR-singular term is associated to amenable non-analytic contributions in the large-d limit when epsilon= 0. The consistency with the standard instanton-calculus results for the self-avoiding walk is checked for D = 1.
description: LaTeX+revtex4+eps figures. 129 pages. A few changes in the introduction section
Privatising the Third World
Creators: name: SHACKLETON, J.R.
Publisher: name: PSL Quarterly Review
Year: 2013
Subjects: subject: Third World countries, privatisation, developing countries
subject: O20

description: A remarkable feature of recent economic policy in many Third World countries has been the adoption of privatisation and deregulation by previously “statist” governments. Perhaps more fundamentally, this process is being accompanied by measures to liberalise markets and encourage competition, going against the ideal of centralised planning that has been so powerful on development thinking. The work examines these trends and the seemingly genuine changes of attitudes towards the state’s role in the economy in many Third World countries. JEL: O20
description: PSL Quarterly Review, V. 39, N. 159 (1986)
$D\to4$ Einstein-Gauss-Bonnet Gravity and Beyond
Creators: name: Easson, Damien A.
name: Manton, Tucker
name: Svesko, Andrew
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A `novel' pure theory of Einstein-Gauss-Bonnet gravity in four-spacetime dimensions can be constructed by rescaling the Gauss-Bonnet coupling constant, seemingly eluding Lovelock's theorem. Recently, however, the well-posedness of this model has been called into question. Here we apply a `dimensional regularization' technique, first used by Mann and Ross to write down a $D\to2$ limit of general relativity, to the case of pure Einstein-Gauss-Bonnet gravity. The resulting four-dimensional action is a particular Horndeski theory of gravity matching the result found via a Kaluza-Klein reduction over a flat internal space. Some cosmological solutions of this four-dimensional theory are examined. We further adapt the technique to higher curvature Lovelock theories of gravity, as well as a low-energy effective string action with an $α'$ correction. With respect to the $D\to4$ limit of the $α'$-corrected string action, we find we must also rescale the dilaton to have a non-singular action in four dimensions. Interestingly, when the conformal rescaling $Φ$ is interpreted as another dilaton, the regularized string action appears to be a special case of a covariant multi-Galileon theory of gravity.
description: 12 pages, references added, published in JCAP, https://doi.org/10.1088/1475-7516/2020/10/026
Probing new physics from top quark FCNC processes at linear colliders : a mini review
Creators: name: Yang, Jin Min
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We briefly review the studies on the top quark FCNC processes at a next-generation linear collider. Such processes, including various FCNC top quark rare decays and top-charm associated productions, are extremely suppressed in the standard model (SM) but could be significantly enhanced in some extensions. We compared the predictions from different typical new physics models: the SM, the minimal supersymmetric model (MSSM), the general two-higgs-doublet model (2HDM) and the topcolor-assisted technicolor (TC2) model. Our conclusion is: (1) While all the new physics models can enhance the rates by several orders relative to the SM predictions, the TC2 model predicts much larger rates than other models; (2) The optimal channel for probing the top quark FCNC is the top-charm associated production in γ-γcollision, which occurs at a much higher rate than e^+ e^- or e^- γcollision and can reach the detectable level for a large part of the parameter space.
description: 12 pages, 12 figs, talk given at APPI2004, Iweta, Japan
Gamma-Ray Emission in the Seyfert Galaxy NGC 4151: Investigating the Role of Jet and Coronal Activities
Creators: name: Inoue, Yoshiyuki
name: Khangulyan, Dmitry
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: NGC 4151, a nearby Seyfert galaxy, has recently been reported to emit gamma rays in the GeV range, posing an intriguing astrophysical mystery. The star formation rate of NGC 4151 is too low to explain the observed GeV flux, but the galaxy is known for its coronal activity in X-ray and jet activity in radio. We propose that either the combination of these two activities or the jet activity alone can account for the gamma-ray spectrum. An energy-dependent variability search will allow one to distinguish between the two scenarios, as the coronal component can only contribute at energies of $\lesssim1$ GeV. Our analysis also indicates that it might still be difficult to see coronal neutrinos from the apparently X-ray brightest Seyfert NGC 4151 with current-generation neutrino observatories.
description: 7 pages, 4 figures, published in PASJ
Global and local perspectives of gravitationally assisted negative-phase-velocity propagation of electromagnetic waves in vacuum
Creators: name: Lakhtakia, Akhlesh
name: Mackay, Tom G.
name: Setiawan, Sandi
Publisher: name: arXiv
Year: 2004
Subjects: subject: Classical Physics (physics.class-ph)
subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Consistently with the Einstein equivalence principle and using an electromagnetic formulation first suggested by Tamm, we show that a local observer cannot observe negative-phase-velocity (NPV) propagation of electromagnetic waves in vacuum, whereas a global observer can appreciate that phenomenon. Using the specific example of the Kerr metric, we also demonstrate the possibility of NPV propagation within the ergosphere of a rotating black hole.
Luigi Ceriani, 1912-1999
Creators: name: RONCAGLIA, A.
Publisher: name: PSL Quarterly Review
Year: 2013
Subjects: subject: Obituary, Commercial finance companies, Lease financing, Banca Nazionale del Lavoro, Ceriani, Luigi
subject: A11

description: Luigi Ceriani (1912-1999) was the founder of Moneta e Credito and Banca Nazionale del Lavoro Quarterly Review, and their editor for the first forty years of their lives. The article illustrates his life history, in particular his role in the founding and in the successive life of the two journals as well as in the Banca Nazionale del Lavoro as director of its Economic Research Department. JEL Codes: A11
description: PSL Quarterly Review, V. 52, N. 210 (1999)
Demixing in athermal mixtures of colloids and excluded-volume polymers from a density functional theory
Creators: name: Bryk, Pawel
Publisher: name: arXiv
Year: 2004
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the structure and interfacial properties of model athermal mixtures of colloids and excluded volume polymers. The colloid particles are modeled as hard spheres whereas the polymer coils are modeled as chains formed from tangentially bonded hard spheres. Within the framework of the nonlocal density functional theory we study the influence of the chain length on the surface tension and the interfacial width. We find that the interfacial tension of the colloid-interacting polymer mixtures increases with the chain length and is significantly smaller than that of the ideal polymers. For certain parameters we find oscillations on the colloid-rich parts of the density profiles of both colloids and polymers with the oscillation period of the order of the colloid diameter. The interfacial width is few colloid diameters wide and also increases with the chain length. We find the interfacial width for the end segments to be larger than that for the middle segments and this effect is more pronounced for longer chains.
description: 11 pages, 8 figures
The employment issue: investment, flexibility and the competition of developing countries
Creators: name: SYLOS LABINI, P.
Publisher: name: PSL Quarterly Review
Year: 2013
Subjects: subject: Research, Economic aspects, Economic research, Developing countries, Labor market
subject: E24, J21

description: The labor markets of developing countries are analysed, focusing on the importance of investment and flexibility. JEL Codes: E24, J21
description: PSL Quarterly Review, V. 52, N. 210 (1999)
title: Parental choice of minority language education in language shift situations in Brittany and Scotland
Creators: name: Goalabré, Fabienne
Publisher: name: The Open University
Year: 2012

description: This thesis addresses issues associated with the impact of bilingual education (immersion and language maintenance programmes) and the vitality of minority languages. It explores multiple factors, including parental expectations, that influence the decisions of parents who have chosen to educate their children through the medium of the standard variety of minority languages, specifically Breton and Gaelic. The thesis considers parental choice in terms of their socioeconomic profile, their language background and their patterns of language use. It is anticipated that this will contribute to explaining how educationally-based interventions work at different levels, including the sociolinguistic impact on the vitality of minority languages. The fieldwork was undertaken for Breton in western Brittany and for Gaelic in the core Gaelic-speaking area of Scotland (Western Isles), and was principally conducted by means of a semi-structured interview schedule administered to 51 sets of parents. In both locations, results indicated that most parents were highly qualified compared to the surrounding population and that they were attracted by early bilingualism and its educational benefits. Most parents had a basic level of skill in the minority language. This was especially the case in Brittany, where parents' skill levels were insufficient to sustain use of the minority language within the family unit and outside the home as an everyday language of communication. For most children, their first contact with the minority language was through school, and the language did not appear to be used outside the classroom. In the Western Isles, the majority of the parents were fluent in Gaelic, although Gaelic was seldom the main household language. For the overwhelming majority of children, parents reported Gaelic as being rarely spoken outside school either within their family or among themselves. This suggests that knowing the minority language does not automatically lead to its use outside the formal classroom setting and that bilingual education does not provide a way to produce active speakers when intergenerational transmission is failing.
Asymmetric simple exclusion processes with diffusive bottlenecks
Creators: name: Klumpp, Stefan
name: Lipowsky, Reinhard
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: One-dimensional asymmetric simple exclusion processes (ASEPs) which are coupled to external reservoirs via diffusive transport are studied. These ASEPs consist of active compartments characterized by directed movements of the particles and diffusive compartments in which the particles undergo unbiased diffusion. Phase diagrams are obtained by a self-consistent mean field approach and by Monte Carlo simulations. The diffusive compartments act as diffusive bottlenecks if the velocity of the driven compartments or ASEPs is sufficiently large. A diffusive bottleneck at the boundary of the system leads to the absence of a maximal current phase, while a diffusive bottleneck in the interior of the system leads to a new phase characterized by different densities in the two active compartments adjacent to the diffusive one and to a maximal current defined by the bottleneck.
description: revtex (PRE style), 21 pages, 9 figures, to appear in PRE
Energy conservation and equivalence principle in General Relativity
Creators: name: Mensky, Michael B.
Publisher: name: arXiv
Year: 2004
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The generalized Stokes theorem (connecting integrals of dimensions 3 and 4) is formulated in a curved space-time in terms of paths in Minkowski space (forming Path Group). A covariant integral form of the conservation law for the energy-momentum of matter is then derived in General Relativity. It extends Einstein's equivalence principle on the energy conservation, since it formulates the conservation law for the energy-momentum of matter without explicit including the gravitational field in the formulation.
description: 9 pages, Latex, one figure
Holgraphy and BMS field theory
Creators: name: Arcioni, Giovanni
name: Dappiaggi, Claudio
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study the key ingredients of a candidate holographic correspondence in an asymptotically flat spacetimes; in particular we develop the kinematical and the classical dynamical data of a BMS invariant field theory living at null infinity.
description: 3 pages, to appear in the Proceedings for the ``XVI SIGRAV Conference'' in Vietri sul Mare (SA) 13-16 September
Metaplectic Gabor Frames and Symplectic Analysis of Time-Frequency Spaces
Creators: name: Cordero, Elena
name: Giacchi, Gianluca
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 42C15, 42B35, 42A38

description: We introduce new frames, called \textit{metaplectic Gabor frames}, as natural generalizations of Gabor frames in the framework of metaplectic Wigner distributions. Namely, we develop the theory of metaplectic atoms in a full-general setting and prove an inversion formula for metaplectic Wigner distributions on $\mathbb{R}^d$. Its discretization provides metaplectic Gabor frames.
 Next, we deepen the understanding of the so-called shift-invertible metaplectic Wigner distributions, showing that they can be represented, up to chirps, as rescaled short-time Fourier transforms. As an application, we derive a new characterization of modulation and Wiener amalgam spaces. Thus, these metaplectic distributions (and related frames) provide meaningful definitions of local frequencies and can be used to measure effectively the local frequency content of signals.
Determination of Lambda in quenched and full QCD - an update
Creators: name: Göckeler, M.
name: Horsley, R.
name: Irving, A. C.
name: Pleiter, D.
name: Rakow, P. E. L.
name: Schierholz, G.
name: Stüben, H.
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present an update on our previous determination of the Lambda parameter in QCD. The main emphasis is on results for two flavours of light dynamical quarks, where we can now almost double the amount of data used, including values at smaller lattice spacings. The calculations are performed using $O(a)$ improved Wilson fermions. Little change is found to previous numerical values.
description: Lattice2004(spectrum), Fermilab, June 21-26, 2004, 3 pages
Quantum communication networks with optical vortices
Creators: name: Suciu, S.
name: Bulzan, G. A.
name: Isdraila, T. A.
name: Palici, A. M.
name: Ataman, S.
name: Kusko, C.
name: Ionicioiu, R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum communications bring a paradigm change in internet security by using quantum resources to establish secure keys between parties. Present-day quantum communications networks are mainly point-to-point and use trusted nodes and key management systems to relay the keys. Future quantum networks, including the quantum internet, will have complex topologies in which groups of users are connected and communicate with each-other. Here we investigate several architectures for quantum communication networks. We show that photonic orbital angular momentum (OAM) can be used to route quantum information between different nodes. Starting from a simple, point-to-point network, we will gradually develop more complex architectures: point-to-multipoint, fully-connected and entanglement-distribution networks. As a particularly important result, we show that an $n$-node, fully-connected network can be constructed with a single OAM sorter and $n-1$ OAM values. Our results pave the way to construct complex quantum communication networks with minimal resources.
description: updated to the published version
A Monte Carlo Investigation of the Hamiltonian Mean Field Model
Creators: name: Pluchino, Alessandro
name: Andronico, Giuseppe
name: Rapisarda, Andrea
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present a Monte Carlo numerical investigation of the Hamiltonian Mean Field (HMF) model. We begin by discussing canonical Metropolis Monte Carlo calculations, in order to check the caloric curve of the HMF model and study finite size effects. In the second part of the paper, we present numerical simulations obtained by means of a modified Monte Carlo procedure with the aim to test the stability of those states at minimum temperature and zero magnetization (homogeneous Quasi Stationary States) which exist in the condensed phase of the model just below the critical point. For energy densities smaller than the limiting value $U\sim 0.68$, we find that these states are unstable, confirming a recent result on the Vlasov stability analysis applied to the HMF model.
description: 13 pages, 5 figures, submitted to Physica A
Unsupervised Learning for Identifying Events in Active Target Experiments
Creators: name: Solli, Robert
name: Bazin, Daniel
name: Kuchera, Michelle P.
name: Strauss, Ryan R.
name: Hjorth-Jensen, Morten
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: This article presents novel applications of unsupervised machine learning methods to the problem of event separation in an active target detector, the Active-Target Time Projection Chamber (AT-TPC). The overarching goal is to group similar events in the early stages of the data analysis, thereby improving efficiency by limiting the computationally expensive processing of unnecessary events. The application of unsupervised clustering algorithms to the analysis of two-dimensional projections of particle tracks from a resonant proton scattering experiment on $^{46}$Ar is introduced. We explore the performance of autoencoder neural networks and a pre-trained VGG16 convolutional neural network. We study clustering performance on both data from a simulated $^{46}$Ar experiment, and real events from the AT-TPC detector. We find that a $k$-means algorithm applied to simulated data in the VGG16 latent space forms almost perfect clusters. Additionally, the VGG16+$k$-means approach finds high purity clusters of proton events for real experimental data. We also explore the application of clustering the latent space of autoencoder neural networks for event separation. While these networks show strong performance, they suffer from high variability in their results.
Socio-technical systems integration and design: a multi-objective optimisation method based on integrative preference maximisation
Creators: name: van Heukelum, Harold
name: Binnekamp, Ruud
name: Wolfert, Rogier
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: Current systems design optimisation methodologies are one-sided, as these ignore the socio-technical integration between stakeholder preferences ('what a human wants') and the capability of technical assets ('what a system can deliver'). Moreover, classical multi-objective optimisation methods contain fundamental mathematical flaws. Also, the often-used classical Pareto front does not provide a single best-fit design configuration, but rather a set of design alternatives. This leaves designers without a unique solution to their problems. Finally, current multi-objective optimisation processes are not well aligned with design practices, because they do not sufficiently involve decision makers and do not translate their interests into a single common preference domain to find an overall group optimum. This paper introduces a new Open Design Systems (Odesys) methodology and a new Integrative Maximisation of Aggregated Preferences (IMAP) method, implemented in the Preferendus tool. Its added value and use are exemplified in two infrastructure design applications, which show how to achieve the pure best-fit for common-purpose design results.
description: 32 pages, 8 figures, 4 tables. Source code repository at https://github.com/TUDelft-Odesys/Preferendus