cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Rogue periodic waves of the mKdV equation
Creators: name: Chen, Jinbing
name: Pelinovsky, Dmitry E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Mathematical Physics (math-ph)
subject: Analysis of PDEs (math.AP)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Traveling periodic waves of the modified Korteweg-de Vries (mKdV) equation are considered in the focusing case. By using one-fold and two-fold Darboux transformations, we construct explicitly the rogue periodic waves of the mKdV equation expressed by the Jacobian elliptic functions dn and cn respectively. The rogue dn-periodic wave describes propagation of an algebraically decaying soliton over the dn-periodic wave, the latter wave is modulationally stable with respect to long-wave perturbations. The rogue cn-periodic wave represents the outcome of the modulation instability of the cn-periodic wave with respect to long-wave perturbations and serves for the same purpose as the rogue wave of the nonlinear Schrodinger equation (NLS), where it is expressed by the rational function. We compute the magnification factor for the cn-periodic wave of the mKdV equation and show that it remains the same as in the small-amplitude NLS limit for all amplitudes. As a by-product of our work, we find explicit expressions for the periodic eigenfunctions of the AKNS spectral problem associated with the dn- and cn-periodic waves of the mKdV equation.
description: 24 pages, 3 figures
Convolutional Neural Networks for Automated Annotation of Cellular Cryo-Electron Tomograms
Creators: name: Chen, Muyuan
name: Dai, Wei
name: Sun, Ying
name: Jonasch, Darius
name: He, Cynthia Y
name: Schmid, Michael F.
name: Chiu, Wah
name: Ludtke, Steven J
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: FOS: Biological sciences

description: Cellular Electron Cryotomography (CryoET) offers the ability to look inside cells and observe macromolecules frozen in action. A primary challenge for this technique is identifying and extracting the molecular components within the crowded cellular environment. We introduce a method using neural networks to dramatically reduce the time and human effort required for subcellular annotation and feature extraction. Subsequent subtomogram classification and averaging yields in-situ structures of molecular components of interest.
description: 21 pages, 8 figures
A Sampling Framework for Solving Physics-driven Inverse Source Problems
Creators: name: Murray-Bruce, John
name: Dragotti, Pier Luigi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Information Theory (cs.IT)
subject: Analysis of PDEs (math.AP)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Partial differential equations are central to describing many physical phenomena. In many applications these phenomena are observed through a sensor network, with the aim of inferring their underlying properties. Leveraging from certain results in sampling and approximation theory, we present a new framework for solving a class of inverse source problems for physical fields governed by linear partial differential equations. Specifically, we demonstrate that the unknown field sources can be recovered from a sequence of, so called, generalised measurements by using multidimensional frequency estimation techniques. Next we show that---for physics-driven fields---this sequence of generalised measurements can be estimated by computing a linear weighted-sum of the sensor measurements; whereby the exact weights (of the sums) correspond to those that reproduce multidimensional exponentials, when used to linearly combine translates of a particular prototype function related to the Green's function of our underlying field. Explicit formulae are then derived for the sequence of weights, that map sensor samples to the exact sequence of generalised measurements when the Green's function satisfies the generalised Strang-Fix condition. Otherwise, the same mapping yields a close approximation of the generalised measurements. Based on this new framework we develop practical, noise robust, sensor network strategies for solving the inverse source problem, and then present numerical simulation results to verify their performance.
description: Accepted manuscript
Comparative effectiveness of two- and three-dose COVID-19 vaccination schedules involving AZD1222 and BNT162b2 in people with kidney disease: a linked OpenSAFELY and UK Renal Registry cohort study
Creators: name: Collaborative, The OpenSAFELY
name: Parker, Edward PK
name: Horne, Elsie MF
name: Hulme, William J
name: Tazare, John
name: Zheng, Bang
name: Carr, Edward J
name: Loud, Fiona
name: Lyon, Susan
name: Mahalingasivam, Viyaasan
name: MacKenna, Brian
name: Mehrkar, Amir
name: Scanlon, Miranda
name: Santhakumaran, Shalini
name: Steenkamp, Retha
name: Goldacre, Ben
name: Sterne, Jonathan AC
name: Nitsch, Dorothea
name: Tomlinson, Laurie A
name: Collaborative, The LH&W NCS
Publisher: name: The Francis Crick Institute
Year: 2023
Subjects: subject: Infectious Disease
subject: Immunology
subject: FOS: Clinical medicine
subject: Cell Biology

description: Background: Kidney disease is a key risk factor for COVID-19-related mortality and suboptimal vaccine response. Optimising vaccination strategies is essential to reduce the disease burden in this vulnerable population. We therefore compared the effectiveness of two- and three-dose schedules involving AZD1222 (AZ; ChAdOx1-S) and BNT162b2 (BNT) among people with kidney disease in England. Methods: With the approval of NHS England, we performed a retrospective cohort study among people with moderate-to-severe kidney disease. Using linked primary care and UK Renal Registry records in the OpenSAFELY-TPP platform, we identified adults with stage 3–5 chronic kidney disease, dialysis recipients, and kidney transplant recipients. We used Cox proportional hazards models to compare COVID-19-related outcomes and non-COVID-19 death after two-dose (AZ–AZ vs BNT–BNT) and three-dose (AZ–AZ–BNT vs BNT–BNT–BNT) schedules. Findings: After two doses, incidence during the Delta wave was higher in AZ–AZ (n = 257,580) than BNT–BNT recipients (n = 169,205; adjusted hazard ratios [95% CIs] 1.43 [1.37–1.50], 1.59 [1.43–1.77], 1.44 [1.12–1.85], and 1.09 [1.02–1.17] for SARS-CoV-2 infection, COVID-19-related hospitalisation, COVID-19-related death, and non-COVID-19 death, respectively). Findings were consistent across disease subgroups, including dialysis and transplant recipients. After three doses, there was little evidence of differences between AZ–AZ–BNT (n = 220,330) and BNT–BNT–BNT recipients (n = 157,065) for any outcome during a period of Omicron dominance. Interpretation: Among individuals with moderate-to-severe kidney disease, two doses of BNT conferred stronger protection than AZ against SARS-CoV-2 infection and severe disease. A subsequent BNT dose levelled the playing field, emphasising the value of heterologous RNA doses in vulnerable populations. Funding: National Core Studies, Wellcome Trust, MRC, and Health Data Research UK.
Geons and the Quantum Information Metric
Creators: name: Sinamuli, Musema
name: Mann, Robert B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate the proposed duality between a quantum information metric in a $\mbox{CFT}_{d+1}$ and the volume of a maximum time slice in the dual $\mbox{AdS}_{d+2}$ for topological geons. Examining the specific cases of BTZ black holes and planar Schwarzschild-AdS black holes, along with their geon counterparts, we find that the proposed duality relation for geons is the same apart from a factor of 4. The information metric therefore provides a probe of the topology of the bulk spacetime.
description: 8 pages, 2 figures
Rational Complexity-One T-Varieties are Well-Poised
Creators: name: Ilten, Nathan
name: Manon, Christopher
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: Given an affine rational complexity-one $T$-variety $X$, we construct an explicit embedding of $X$ in affine space $\mathbb{A}^n$. We show that this embedding is well-poised, that is, every initial ideal of $I_X$ is a prime ideal, and determine the tropicalization of $X$. We then study valuations of the coordinate ring $R_X$ of $X$ which respect the torus action, showing that for full rank valuations, the natural generators of $R_X$ form a Khovanskii basis. This allows us to determine Newton-Okounkov bodies of rational projective complexity-one $T$-varieties, partially recovering (and generalizing) results of Petersen. We apply our results to describe all irreducible special fibers of $\mathbb{K}^*\times T$-equivariant degenerations of rational projective complexity-one $T$-varieties, generalizing a results of Süß and the first author.
description: v2 minor revisions, 25 pages, to appear in IMRN
Relationship between electronic and crystal structure in Nd1+xBa2-xCu3O6+d
Creators: name: Fetisov, A. V.
name: Estemirova, S. Kh.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In accordance with a relation between the lattice parameter c and the concentration of holes p, which has been found earlier for the YBa2Cu3O6+d compound, we obtain the p parameter in the same manner for the solid solution Nd1.2Ba1.8Cu3O6+d with substitution of Nd3+ for Ba2+ in barium sites. For this, structural and superconducting properties of the Nd1.2Ba1.8Cu3O6+d samples stored for specified times t after quenching from annealing temperatures have been studied. The investigation shows that Nd1.2Ba1.8Cu3O6+d stored for a long time has quite a low critical temperature Tc extending only to Tconset = 55 K for the most oxidized sample with d = 0.953. We find that the d-dependence of the lattice parameter c significantly changes with time t. When using the relation between c and p, the existence of electron doping of 0.045 per Cu in Nd1.2Ba1.8Cu3O6+d can be inferred. This doping explains well reduced Tc in Nd1.2Ba1.8Cu3O6+d. In addition, we observe a local drop of Tc by up to 20 K for the samples with p ~ 0.095 (d ~ 0.8) similar to decreasing Tc known as "anomaly 1/8".
description: 14 pages, 7 figures
Efficiency of prompt quarantine measures on a susceptible-infected-removed model in networks
Creators: name: Hasegawa, Takehisa
name: Nemoto, Koji
Publisher: name: arXiv
Year: 2017
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: This study focuses on investigating the manner in which a prompt quarantine measure suppresses epidemics in networks. A simple and ideal quarantine measure is considered in which an individual is detected with a probability immediately after it becomes infected and the detected one and its neighbors are promptly isolated. The efficiency of this quarantine in suppressing a susceptible-infected-removed (SIR) model is tested in random graphs and uncorrelated scale-free networks. Monte Carlo simulations are used to show that the prompt quarantine measure outperforms random and acquaintance preventive vaccination schemes in terms of reducing the number of infected individuals. The epidemic threshold for the SIR model is analytically derived under the quarantine measure, and the theoretical findings indicate that prompt executions of quarantines are highly effective in containing epidemics. Even if infected individuals are detected with a very low probability, the SIR model under a prompt quarantine measure has finite epidemic thresholds in fat-tailed scale-free networks in which an infected individual can always cause an outbreak of a finite relative size without any measure. The numerical simulations also demonstrate that the present quarantine measure is effective in suppressing epidemics in real networks.
description: 10 pages, 7 figures
Micromagnetic Simulations for Coercivity Improvement through Nano-Structuring of Rare-Earth Free L1$_0$-FeNi Magnets
Creators: name: Kovacs, Alexander
name: Fischbacher, Johann
name: Oezelt, Harald
name: Schrefl, Thomas
name: Kaidatzis, Andreas
name: Salikhov, Ruslan
name: Farle, Michael
name: Giannopoulos, George
name: Niarchos, Dimitris
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this work we investigate the potential of tetragonal L1$_0$ ordered FeNi as candidate phase for rare earth free permanent magnets taking into account anisotropy values from recently synthesized, partially ordered FeNi thin films. In particular, we estimate the maximum energy product ($BH$)$_\mathrm{max}$ of L1$_0$-FeNi nanostructures using micromagnetic simulations. The maximum energy product is limited due to the small coercive field of partially ordered L1$_0$-FeNi. Nano-structured magnets consisting of 128 equi-axed, platelet-like and columnar-shaped grains show a theoretical maximum energy product of 228 kJ/m$^3$, 208 kJ/m$^3$, 252 kJ/m$^3$, respectively.
Beta-plane turbulence above monoscale topography
Creators: name: Constantinou, Navid C.
name: Young, William R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Using a one-layer QG model, we study the effect of random monoscale topography on forced beta-plane turbulence. The forcing is a uniform steady wind stress that produces both a uniform large-scale zonal flow $U(t)$ and smaller-scale macroturbulence (both standing and transient eddies). The flow $U(t)$ is retarded by Ekman drag and by the domain-averaged topographic form stress produced by the eddies. The topographic form stress typically balances most of the applied wind stress, while the Ekman drag provides all of the energy dissipation required to balance the wind work. A collection of statistically equilibrated solutions delineates the main flow regimes and the dependence of the time-mean $U$ on the problem parameters and the statistical properties of the topography. If $β$ is smaller than the topographic PV gradient then the flow consists of stagnant pools attached to pockets of closed geostrophic contours. The stagnant dead zones are bordered by jets and the flow through the domain is concentrated into a narrow channel of open geostrophic contours. If $β$ is comparable to, or larger than, the topographic PV gradient then all geostrophic contours are open and the flow is uniformly distributed throughout the domain. In this case there is an "eddy saturation" regime in which $U$ is insensitive to changes in the wind stress. We show that eddy saturation requires strong transient eddies that act as PV diffusion. This PV diffusion does not alter the energy of the standing eddies, but it does increase the topographic form stress by enhancing the correlation between topographic slope and the standing-eddy pressure field. Last, using bounds based on the energy and enstrophy we show that as the wind stress increases the flow transitions from a regime in which form stress balances the wind stress to a regime in which the form stress is very small and large transport ensues.
description: 32 pages, 21 figures. Major revisions in the abstract, introduction and discussion and conclusion sections
Jump Start: Creating a Query Library for Code Re(use)
Creators: name: Milliken, Genevieve
name: Contaxis, Nicole
name: Yee, Michelle
Publisher: name: Zenodo
Year: 2022
Subjects: query library
code reuse
information retrieval
code discovery

description: Code reuse saves time and can help automate repetitive tasks. Following several cross-departmental conversations and library-led activities, data analysts expressed a need for more practical avenues to reuse and share code, especially for SQL queries, used to extract data from medical records. This poster, presented at the 2022 Annual Meeting of the Medical Library Association, describes the community-centered approach employed to develop a query library for researchers to reuse code to search patient and medical databases (e.g., EPIC) more efficiently.
Measuring Majorana non-locality and spin structure with a quantum dot
Creators: name: Prada, Elsa
name: Aguado, Ramón
name: San-Jose, Pablo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Robust zero bias transport anomalies in semiconducting nanowires with proximity-induced superconductivity have been convincingly demonstrated in various experiments. While these are compatible with the existence of Majorana zero modes at the ends of the nanowire, a direct proof of their non-locality and topological protection is now needed. Here we show that a quantum dot at the end of the nanowire may be used as a powerful spectroscopic tool to quantify the degree of Majorana non-locality through a local transport measurement. Moreover, the spin polarization of dot sub-gap states at singlet-doublet transitions in the Coulomb blockade regime allows the dot to directly probe the spin structure of the Majorana wave function, and indirectly measure the spin-orbit coupling of the nanowire.
description: 11 pages, 7 figures. Published version (includes an extended study of the effects of disorder and nanowire inhomogeneities)
Browser Friendly: Developing Data Catalog Metadata Using MeSH Terms
Creators: name: Yee, Michelle
Publisher: name: Zenodo
Year: 2022
Subjects: data discovery
data catalog
MeSH
medical subject headings
information retrieval

description: The NYU Data Catalog was launched in 2015 to support the discovery of data for secondary analysis. The catalog employs “Subject Domains,” a set of high-level descriptors to assist users who want to browse rather than perform targeted searches. An original set of Subject Domains were developed based on the initial datasets entered in the catalog that focused primarily on population health research. To accommodate growth, a project coordinator developed a systematic approach to expand the Subject Domains to include more concepts.
MPEC 2023-R140 : 2023 QB20
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 QB20

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Evaluating a Pilot Program to Support Secondary Use of EHR Data at an Academic Medical Center
Creators: name: Yee, Michelle
name: Contaxis, Nicole
Publisher: name: Zenodo
Year: 2022
Subjects: electronic health records
ehr
data reuse
secondary data

description: In 2021, the NYU Health Sciences Library (NYU HSL) developed an evaluation protocol to identify research outcomes from datasets generated from electronic health records (EHR) at the medical center. This evaluation stems from a pilot program in 2018, where the NYU HSL collaborated with DataCore, a clinical research data management unit, to catalog queries underlying researcher requests for data abstraction from the EHR. This poster, presented at the 2022 Annual Meeting of the Medical Library Association, describes the methodology and findings from the evaluation, which focused on two characteristics of secondary data use: the intended purpose of the data extract and research outputs associated with the extract.
A Quantum Description of Wave Dark Matter
Creators: name: Cheong, Dhong Yeon
name: Rodd, Nicholas L.
name: Wang, Lian-Tao
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We outline a fundamentally quantum description of bosonic dark matter (DM) from which the conventional classical-wave picture emerges in the limit $m \ll 10~\textrm{eV}$. As appropriate for a quantum system, we start from the density matrix which encodes the full information regarding the possible measurements we could make of DM and their fluctuations. Following fundamental results in quantum optics, we argue that for DM it is most likely that the density matrix takes the explicitly mixed form of a Gaussian over the basis of coherent states. Deviations from this would generate non-Gaussian fluctuations in DM observables, allowing a direct probe of the quantum state of DM. Our quantum optics inspired approach allows us to rigorously define and interpret various quantities that are often only described heuristically, such as the coherence time or length. The formalism further provides a continuous description of DM through the wave-particle transition, which we exploit to study how density fluctuations over various physical scales evolve between the two limits and to reveal the unique behavior of DM near the boundary of the wave and particle descriptions.
description: 30 pages, 3 figures; v2: journal version
The X-ray Decay of the ultraluminous supernova SN 1978K in NGC 1313
Creators: name: Zhao, Hai-Hui
name: Weng, Shan-Shan
name: Ng, C. -Y.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The Type IIn supernova (SN) 1978K in the nearby galaxy NGC 1313 has remained bright in multiwavelengths for more than $\sim 25$ yr. The archival data of SN 1978K collected with ROSAT, ASCA, XMM-Newton, and Chandra from 1990 to 2006 show no significant variation of the soft X-ray emission but a hint of flux decrease in hard X-rays. In this work, we perform a detailed analysis using more than 15 yr of XMM-Newton observations. Both the 0.5-2 keV and 2-10 keV light-curves decline as $t^{-1}$ from 2000 to 2015. The transition of light curve profiles can be explained in a way that the reverse shock was radiative at an early phase and then became adiabatic at late times. Such a scenario is also supported by the spectral analysis results. We also found a decrease in the absorption column density, which indicates the presence of a cool shell during the radiative phase.
description: 5 pages, 1 figure, 3 tables, published in MNRAS
Evaluation of Trace Alignment Quality and its Application in Medical Process Mining
Creators: name: Zhou, Moliang
name: Yang, Sen
name: Lv, Shuyu
name: Li, Xinyu
name: Chen, Shuhong
name: Marsic, Ivan
name: Farneth, Richard
name: Burd, Randall
Publisher: name: arXiv
Year: 2017
Subjects: subject: Other Computer Science (cs.OH)
subject: FOS: Computer and information sciences

description: Trace alignment algorithms have been used in process mining for discovering the consensus treatment procedures and process deviations. Different alignment algorithms, however, may produce very different results. No widely-adopted method exists for evaluating the results of trace alignment. Existing reference-free evaluation methods cannot adequately and comprehensively assess the alignment quality. We analyzed and compared the existing evaluation methods, identifying their limitations, and introduced improvements in two reference-free evaluation methods. Our approach assesses the alignment result globally instead of locally, and therefore helps the algorithm to optimize overall alignment quality. We also introduced a novel metric to measure the alignment complexity, which can be used as a constraint on alignment algorithm optimization. We tested our evaluation methods on a trauma resuscitation dataset and provided the medical explanation of the activities and patterns identified as deviations using our proposed evaluation methods.
description: 10 pages, 6 figures and 5 tables
Double helix nodal line superconductor
Creators: name: Sun, Xiao-Qi
name: Lian, Biao
name: Zhang, Shou-Cheng
Publisher: name: arXiv
Year: 2017
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Time-reversal invariant superconductors in three dimensions may contain nodal lines in the Brillouin zone, which behave exactly as Wilson loops of 3d momentum-space Chern-Simons theory of the Berry connection. Here we study the conditions of realizing linked nodal lines (Wilson loops), which yield a topological contribution to the thermal magnetoelectric coefficient that is given by the Chern-Simons action. We find the essential conditions are the existence of torus or higher genus fermi surfaces and spiral spin textures. We construct such a model with two torus fermi surfaces, where a generic spin-dependent interaction leads to double-helix-like linked nodal lines as the superconductivity is developed.
description: 9 pages, 6 figures, including Supplemental Material. Published version
Anderson transition for light in three dimensions
Creators: name: Yamilov, Alexey
name: Cao, Hui
name: Skipetrov, Sergey E.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Optics (physics.optics)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We study Anderson transition for light in three dimensions by performing large-scale ab-initio simulations of electromagnetic wave transport in disordered ensembles of conducting spheres. A mobility edge that separates diffusive transport and Anderson localization is identified, revealing a sharp transition from diffusion to localization for light. Critical behavior in the vicinity of the mobility edge is well described by a single-parameter scaling law. The critical exponent is found to be consistent with the value known for the Anderson transition of the orthogonal universality class. Statistical distribution of total transmission at the mobility edge is described without any fit parameter by the diagrammatic perturbation theory originally developed for scalar wave diffusion, but notable deviation from the theory is found when Anderson localization sets in.
description: 6 pages, 4 figures
title: Aspect-oriented modelling
Creators: name: Wallis, Tom
Publisher: name: University of Glasgow
Year: 2024

description: Aspect-oriented programming is a software engineering paradigm used to modularise parts of a program which are difficult to separate using other means. It does this using aspects: combinations of program modifications and places to apply them. While it has received some academic interest, aspect orientation has seen lukewarm adoption from industry and its practical benefits are not well demonstrated. The paradigm lacks a use-case for which aspects are particularly well-suited.

One such use-case may be in producing and maintaining codebases for research purposes. In many fields, research is conducted with the aid of software models. Changes to these models are delicate: they may invalidate results, add complexity to a codebase, or absorb researchers’ time. These changes could be represented as aspects, but the paradigm is yet to be applied to codebases for scientific models. We propose that aspects are particularly well-suited to describe these changes and that aspect-oriented modelling may ease model maintenance.

This thesis investigates the viability of aspect-oriented modelling for simulation purposes. An aspect-oriented programming framework is implemented which addresses criticisms of the paradigm, and contributes new kinds of aspects which are useful for describing changes to models. With this tool, a case study of aspect-oriented modelling is constructed using a model of a real-world mobile game and its players’ activity. This forms the foundation of three experiments. They demonstrate that aspects can be used to successfully augment models, can add new behaviours and parameters to models, and can be reused across different models in some cases. As these contributions invite new research in many fields, the thesis also enumerates the possibilities enabled for others researching aspect orientation, simulation & modelling, and research software engineering, as well as the methodological implications for researchers whose hypotheses are encoded within software models.
L^2-Betti numbers of rigid C*-tensor categories and discrete quantum groups
Creators: name: Kyed, David
name: Raum, Sven
name: Vaes, Stefaan
name: Valvekens, Matthias
Publisher: name: arXiv
Year: 2017
Subjects: subject: Operator Algebras (math.OA)
subject: Group Theory (math.GR)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics

description: We compute the $L^2$-Betti numbers of the free $C^*$-tensor categories, which are the representation categories of the universal unitary quantum groups $A_u(F)$. We show that the $L^2$-Betti numbers of the dual of a compact quantum group $G$ are equal to the $L^2$-Betti numbers of the representation category $Rep(G)$ and thus, in particular, invariant under monoidal equivalence. As an application, we obtain several new computations of $L^2$-Betti numbers for discrete quantum groups, including the quantum permutation groups and the free wreath product groups. Finally, we obtain upper bounds for the first $L^2$-Betti number in terms of a generating set of a $C^*$-tensor category.
description: v4: Minor changes, final version, to appear in Analysis and PDE. v3: We corrected a mistake in Section 3.2 without impact on the main results of the paper. v2: No major changes, but several remarks and a few references were added
Driven quantum dynamics: will it blend?
Creators: name: Banchi, Leonardo
name: Burgarth, Daniel
name: Kastoryano, Michael J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Randomness is an essential tool in many disciplines of modern sciences, such as cryptography, black hole physics, random matrix theory and Monte Carlo sampling. In quantum systems, random operations can be obtained via random circuits thanks to so-called q-designs, and play a central role in the fast scrambling conjecture for black holes. Here we consider a more physically motivated way of generating random evolutions by exploiting the many-body dynamics of a quantum system driven with stochastic external pulses. We combine techniques from quantum control, open quantum systems and exactly solvable models (via the Bethe-Ansatz) to generate Haar-uniform random operations in driven many-body systems. We show that any fully controllable system converges to a unitary q-design in the long-time limit. Moreover, we study the convergence time of a driven spin chain by mapping its random evolution into a semigroup with an integrable Liouvillean and finding its gap. Remarkably, we find via Bethe-Ansatz techniques that the gap is independent of q. We use mean-field techniques to argue that this property may be typical for other controllable systems, although we explicitly construct counter-examples via symmetry breaking arguments to show that this is not always the case. Our findings open up new physical methods to transform classical randomness into quantum randomness, via a combination of quantum many-body dynamics and random driving.
description: 22 pages, 7 figures, accepted version in Phys. Rev. X
Theory of the Spin Seebeck Effect at a Topological-Insulator/Ferromagnetic-Insulator Interface
Creators: name: Okuma, Nobuyuki
name: Masir, Massoud Ramezani
name: MacDonald, Allan H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The spin-Seebeck effect refers to voltage signals induced in metals by thermally driven spin currents in adjacent magnetic systems. We present a theory of the spin-Seebeck signal in the case where the conductor that supports the voltage signal is the topologically protected two-dimensional surface-state system at the interface between a ferromagnetic insulator (FI) and a topological insulator (TI). Our theory uses a Dirac model for the TI surface-states and assumes Heisenberg exchange coupling between the TI quasiparticles and the FI magnetization. The spin-Seebeck voltage is induced by the TI surface states scattering off the nonequilibrium magnon population at the surface of the semi-infinite thermally driven FI. Our theory is readily generalized to spin-Seebeck voltages in any two-dimensional conductor that is exchange-coupled to the surface of a FI. Surface-state carrier-density-dependent signal strengths calculated using Bi$_2$Te$_3$ and yttrium iron garnet material parameters are consistent with recent experiments.
description: 10 pages, 7 figures
Charmonium: Conventional and $XYZ$ States in a Relativistic Screened Potential Model
Creators: name: Bokade, Chaitanya Anil
name: Bhaghyesh
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work a comprehensive analysis of the mass spectrum and decay properties of charmonium states within a relativistic framework is carried out. The present experimental status of charmonium states is reviewed. Utilizing a screened potential model, we compute the spectra and various decay widths for $c\bar{c}$ bound system, comparing our results with experimental data and existing theoretical models. We calculate the decay constants, $E1$ and $M1$ transitions, and annihilation decay widths, confirming the consistency of our model with experimental observations for well-established charmonium states. The interpretation of charmonium-like states, $X(4140)$, $X(4274)$, and $X(4500)$ as $P$ wave charmonium states and $ψ(4040)$, $ψ(3770)$, $ψ(4160)$, $ψ(4230)$, $ψ(4360)$, $ψ(4415)$, $Y(4500)$ and $Y(4360)$ as $S-D$ mixed charmonium states are carried out.
description: 24 pages
Graphene Transport Mediated by Micropatterned Substrates
Creators: name: Hinnefeld, J. Henry
name: Mason, Nadya
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Engineered substrates offer a promising avenue towards graphene devices having tunable properties. In particular, topographically patterned substrates can expose unique behavior due to their ability to induce local variations in strain and electrostatic doping. However, to explore the range of possible science and applications, it is important to create topographic substrates which both have tunable features and are suitable for transport measurements. In this Letter we describe the fabrication of tunable, topographically patterned substrates suitable for transport measurements. We report both optical and transport measurements of graphene devices fabricated on these substrates, and demonstrate characteristic strain and local doping behavior induced by the topographic features.
Beyond E11
Creators: name: Bossard, Guillaume
name: Kleinschmidt, Axel
name: Palmkvist, Jakob
name: Pope, Christopher N.
name: Sezgin, Ergin
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the non-linear realisation of E11 originally proposed by West with particular emphasis on the issue of linearised gauge invariance. Our analysis shows even at low levels that the conjectured equations can only be invariant under local gauge transformations if a certain section condition that has appeared in a different context in the E11 literature is satisfied. This section condition also generalises the one known from exceptional field theory. Even with the section condition, the E11 duality equation for gravity is known to miss the trace component of the spin connection. We propose an extended scheme based on an infinite-dimensional Lie superalgebra, called the tensor hierarchy algebra, that incorporates the section condition and resolves the above issue. The tensor hierarchy algebra defines a generalised differential complex, which provides a systematic description of gauge invariance and Bianchi identities. It furthermore provides an E11 representation for the field strengths, for which we define a twisted first order self-duality equation underlying the dynamics.
description: 97 pages. v2: Minor changes, references added. Published version
Waking and Scrambling in Holographic Heating up
Creators: name: Ageev, D. S.
name: Aref'eva, I. Ya.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider a holographic model of the heating up process. As a dual background we take a geometry describing thin shell accretion on a black brane. We find explicitly the time evolution of the mutual information during the non-equlibrium heating process from the initial temperature $T_i$ to the final temperature $T_f$ for the system of two intervals in the 1+1 dimensional case. We calculate widths and separation of twointervals for which the time dependence of the mutual information has the bell-like form, i.e. it starts from zero value at the wake up time, then reaches a maximal value and vanishes at the scrambling time. This form of the mutual information evolution was previously found in photosynthesis. The zone of the bell-like configurations exists for small distances $x>\log 2/2πT_i$, it exists only for large enough interval sizes and this zone becomes more narrow when $T_i$ increases and becomes larger with increasing of $T_f$.
description: 17 pages, 9 figures. v2: typos corrected; references added
Accumulation effects in modulation spectroscopy with high repetition rate pulses: recursive solution of optical Bloch equations
Creators: name: Osipov, Vladimir Al.
name: Pullerits, Tonu
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Application of the phase modulated pulsed light for advance spectroscopic measurements is the area of growing interest. The phase modulation of the light causes modulation of the signal. Separation of the spectral components of the modulations allows to distinguish the contributions of various interaction pathways. The lasers with high repetition rate used in such experiments can lead to appearance of the accumulation effects, which become especially pronounced in systems with long-living excited states. Recently it was shown, that such accumulation effects can be used to evaluate parameters of the dynamical processes in the material. In this work we demonstrate that the accumulation effects are also important in the quantum characteristics measurements provided by modulation spectroscopy. In particular, we consider a model of quantum two-level system driven by a train of phase-modulated light pulses, organised in analogy with the 2D spectroscopy experiments. We evaluate the harmonics' amplitudes in the fluorescent signal and calculate corrections appearing from the accumulation effects. We show that the corrections can be significant and have to be taken into account at analysis of experimental data.
description: 10 pages, 5 figures
Another Approach to Juhl's Conformally Covariant Differential Operators from $S^n$ to $S^{n-1}$
Creators: name: Clerc, Jean-Louis
Publisher: name: arXiv
Year: 2016
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 22E45, 43A85

description: A family $({\mathbf D}_λ)_{λ\in \mathbb C}$ of differential operators on the sphere $S^n$ is constructed. The operators are conformally covariant for the action of the subgroup of conformal transformations of $S^n$ which preserve the smaller sphere $S^{n-1}\subset S^n$. The family of conformally covariant differential operators from $S^n$ to $S^{n-1}$ introduced by A. Juhl is obtained by composing these operators on $S^n$ and taking restrictions to $S^{n-1}$.
Interface defect-assisted phonon scattering of hot carriers in graphene
Creators: name: Menabde, Sergey
name: Cho, Hyunwoo
name: Park, Namkyoo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The broadband and ultrafast photoresponse of graphene has been extensively studied in recent years, although the photoexcited carrier dynamics is still far from being completely understood. Different experimental approaches imply either one of two fundamentally different scattering mechanisms for hot electrons. One is high-energy optical phonons, while the other is disorder-driven supercollisions with acoustic phonons. However, the concurrent relaxation via both optical and acoustic phonons has not been considered so far, hindering the interpretation of different experiments within a unified framework. Here we expand the optical phonon-mediated cooling model, to include electron scattering with the acoustic phonons. By assuming the enhancement of electron-acoustic phonon supercollisions from the localized defect at the photothermoelectric current-generating interface, we provide a broader perspective to the ultrafast photoresponse of graphene, highlighting the previously overlooked effect of the interface for cooling dynamics. We show that the transient photothermoelectric response, which has been attributed exclusively to supercollisions, can be successfully explained without rejecting the established optical phonon relaxation pathway, demonstrating that the two cooling mechanisms are not mutually exclusive but complement each other.
description: 4 figurs
Tapering Enhanced Stimulated Superradiant Oscillator
Creators: name: Duris, J.
name: Musumeci, P.
name: Sudar, N.
name: Murokh, A.
name: Gover, A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: In this paper, we present a new kind of high power and high efficiency free-electron laser oscillator based on the application of the tapering enhanced stimulated superradiant amplification (TESSA) scheme. The main characteristic of the TESSA scheme is a high intensity seed pulse which provides high gradient beam deceleration and efficient energy extraction. In the oscillator configuration, the TESSA undulator is driven by a high repetition rate electron beam and embedded in an optical cavity. A beam-splitter is used for outcoupling a fraction of the amplified power and recirculate the remainder as the intense seed for the next electron beam pulse. The mirrors in the oscillator cavity refocus the seed at the undulator entrance and monochromatize the radiation. In this paper we discuss the optimization of the system for a technologically relevant example at 1 $μ$m using a 1~MHz repetition rate electron linac starting with an externally injected igniter pulse.
description: 24 pages, 13 figures
Allee dynamics: Growth, extinction and range expansion
Creators: name: Bose, Indrani
name: Pal, Mainak
name: Karmakar, Chiranjit
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cell Behavior (q-bio.CB)
subject: FOS: Biological sciences

description: In population biology, the Allee dynamics refer to negative growth rates below a critical population density. In this Letter, we study a reaction-diffusion (RD) model of population growth and dispersion in one dimension, which incorporates the Allee effect in both the growth and mortality rates. In the absence of diffusion, the bifurcation diagram displays regions of both finite population density and zero population density, i.e., extinction. The early signatures of the transition to extinction at a bifurcation point are computed in the presence of additive noise. For the full RD model, the existence of travelling wave solutions of the population density is demonstrated. The parameter regimes in which the travelling wave advances (range expansion) and retreats are identified. In the weak Allee regime, the transition from the pushed to the pulled wave is shown as a function of the mortality rate constant. The results obtained are in agreement with the recent experimental observations on budding yeast populations.
description: 11 pages, International Journal of Modern Physics C (2017)
Curious Minds Wonder Alike: Studying Multimodal Behavioral Dynamics to Design Social Scaffolding of Curiosity
Creators: name: Sinha, Tanmay
name: Bai, Zhen
name: Cassell, Justine
Publisher: name: arXiv
Year: 2017
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Curiosity is the strong desire to learn or know more about something or someone. Since learning is often a social endeavor, social dynamics in collaborative learning may inevitably influence curiosity. There is a scarcity of research, however, focusing on how curiosity can be evoked in group learning contexts. Inspired by a recently proposed theoretical framework that articulates an integrated socio-cognitive infrastructure of curiosity, in this work, we use data-driven approaches to identify fine-grained social scaffolding of curiosity in child-child interaction, and propose how they can be used to elicit and maintain curiosity in technology-enhanced learning environments. For example, we discovered sequential patterns of multimodal behaviors across group members and we describe those that maximize an individual's utility, or likelihood, of demonstrating curiosity during open-ended problem-solving in group work. We also discovered, and describe here, behaviors that directly or in a mediated manner cause curiosity related conversational behaviors in the interaction, with twice as many interpersonal causal influences compared to intrapersonal ones. We explain how these findings form a solid foundation for developing curiosity-increasing learning technologies or even assisting a human coach to induce curiosity among learners.
description: 14 pages, 12th European Conference on Technology Enhanced Learning (ECTEL 2017)
Towards Secure and Intelligent Regulatory Technology (Regtech):
Creators: name: Broby, Daniel
name: Daly, Angela
name: Legg, David
Publisher: name: Technology and Regulation
Year: 2022

description: We present a research agenda for secure and intelligent regulatory technology (’regtech’). This encompasses an overview of the conceptual, theoretical, and practical challenges that arise when using digital technologies to comply with regulatory regimes. Intelligent regtech ‘solutions’ are often tailor-made to achieve better oversight and compliance outcomes. Such tools can make regulation and compliance easier and more efficient. Their use poses security challenges in respect of data, cybersecurity, and the consumer. Regtech also raises competition and antitrust issues, as well as commercial and operational ones. We explore these by a targeted review of the literature. In doing this, we deliver new insights and highlight considerations for scholars. We articulate the concepts requiring further investigation. Our contribution is in defining regtech and establishing an interdisciplinary roadmap for further scholarly study.
description: Technology and Regulation, Vol. 2022 (2022)