cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Sharing instructional knowledge via lesson analysis
Creators: name: Corey, Douglas Lyman
name: Jones, Steven R.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: Marine Biology
subject: Science Policy

description: In this article we introduce a type of teaching scholarship called Lesson Analysis (LA) that helps build instructional knowledge, and an associated genre of writing called Lesson Analysis Manuscript (LAM) that shares this instructional knowledge. We briefly describe the problem LA is intended to solve, as well as key features of a LAM. In LA, instructors develop lessons that overcome specific instructional challenges. LAMs are lesson-specific manuscripts that help others understand details of the lesson that addressed the instructional challenge, and include such information as the instructional context, the rationale behind the instructional decisions, typical student thinking, and guidance on carrying out discussions and implementing tasks. We have illustrated this genre by including an entire example LAM as supplemental material located online. The example LAM focuses on helping students understand the connection between dot products and the connection of dot products to measures of similarity between vectors.
An analysis of the relationship between high-school pre-calculus and university calculus grades
Creators: name: Barr, Darja
name: Clifton, Rodney
name: Renaud, Robert
name: Wang, Xikui
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences
subject: Plant Biology

description: First-year mathematics instructors at universities across North America and the globe have been noticing a decline in the mathematics skills and preparation of their incoming students, who have been failing out of first-year mathematics courses at alarming rates. Though some universities have implemented placement or diagnostic tests to measure students’ preparedness, many still use high school grades as the only indicator of readiness for university mathematics. However, researchers have questioned how effective these high school grades are at predicting success in university mathematics classes due to factors such as mis-aligned teaching methods, curriculum, and grade inflation. This study analyzes the relationship between grade 12 Pre-Calculus grades and first year university Calculus grades at a large Canadian university over the period from 2001–2015 in an attempt to quantify previous research in a large-scale, longitudinal manner. Results show that there is a significant disconnect between these grades, that the disconnect has been growing over time, and that it is is quite significant for students who are not performing well at the Calculus level. Recommendations moving forward include the implementation of placement examination in a wide-scale manner, and increased communication and collaboration between K-12 and university mathematics educators and administrators.
Ultra-high endurance silicon photonic memory using vanadium dioxide
Creators: name: Seoane, Juan José
name: Parra, Jorge
name: Navarro-Arenas, Juan
name: Recaman, María
name: Schouteden, Koen
name: Locquet, Jean Pierre
name: Sanchis, Pablo
Publisher: name: arXiv
Year: 2024
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Silicon photonics arises as a viable solution to address the stringent resource demands of emergent technologies, such as neural networks. Within this framework, photonic memories are fundamental building blocks of photonic integrated circuits that have not yet found a standardized solution due to several trade-off among different metrics such as energy consumption, speed, footprint, or fabrication complexity, to name a few. In particular, a photonic memory exhibiting ultra-high endurance performance (> 10^6 cycles) has been elusive to date. Here, we report an ultra-high endurance silicon photonic memory using vanadium dioxide (VO_2) exhibiting a record cyclability of up to 10^7 cycles without degradation. Moreover, our memory features an ultra-compact footprint below 5 μm with potential for nanosecond and picojoule programming performance. Our silicon photonic memory could find application in emerging photonic applications demanding high number of memory updates such as photonic neural networks with in-situ training.
Tensor network simulation of QED on infinite lattices: learning from (1+1)d, and prospects for (2+1)d
Creators: name: Zapp, Kai
name: Orus, Roman
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The simulation of lattice gauge theories with tensor network (TN) methods is becoming increasingly fruitful. The vision is that such methods will, eventually, be used to simulate theories in $(3+1)$ dimensions in regimes difficult for other methods. So far, however, TN methods have mostly simulated lattice gauge theories in $(1+1)$ dimensions. The aim of this paper is to explore the simulation of quantum electrodynamics (QED) on infinite lattices with TNs, i.e., fermionic matter fields coupled to a $U(1)$ gauge field, directly in the thermodynamic limit. With this idea in mind we first consider a gauge-invariant iDMRG simulation of the Schwinger model -i.e., QED in $(1+1)d$-. After giving a precise description of the numerical method, we benchmark our simulations by computing the substracted chiral condensate in the continuum, in good agreement with other approaches. Our simulations of the Schwinger model allow us to build intuition about how a simulation should proceed in $(2+1)$ dimensions. Based on this, we propose a variational ansatz using infinite Projected Entangled Pair States (PEPS) to describe the ground state of $(2+1)d$ QED. The ansatz includes $U(1)$ gauge symmetry at the level of the tensors, as well as fermionic (matter) and bosonic (gauge) degrees of freedom both at the physical and virtual levels. We argue that all the necessary ingredients for the simulation of $(2+1)d$ QED are, a priori, already in place, paving the way for future upcoming results.
description: 14 pages, 12 figures, 2 tables. Final version
Conformal (2+4)-Braneworld
Creators: name: Gogberashvili, Merab
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It is considered the 6D brane model where matter is trapped on the surface of a (2+4)-hyperboloid, as is suggested by the geometrical structure behind the 4D conformal group. The effective dimension of the bulk space-time for matter fields is five, with the extra space-like and time-like domains. Using the embedding theory the presence of the familiar factorizable 5D brane metrics in the both domains is shown. These metrics with exponential warp factors are able to provide with the additional reduction of the effective space-time dimensions down to four. It is demonstrated that the extra (1+1)-space is not simply connected and there is a gap in the range of the extra coordinates. This can explain stability of the model in the domain with the time-like effective fifth dimension and the appearance of the cosmological constant due to the tachyon condensation. It is found that the model exhibits orbifold symmetry and thus is free from the fermion chirality problem.
description: The version accepted by Int. J. Mod. Phys. D
HICOSMO - Cosmology with a complete sample of galaxy clusters: I. Data analysis, sample selection and luminosity-mass scaling-relation
Creators: name: Schellenberger, G.
name: Reiprich, T. H.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The X-ray regime, where the most massive visible component of galaxy clusters, the intra cluster medium (ICM), is visible, offers directly measured quantities, like the luminosity, and derived quantities, like the total mass, to characterize these objects. The aim of this project is to analyze a complete sample of galaxy clusters in detail and constrain cosmological parameters, like the matter density, OmegaM, or the amplitude of initial density fluctuations, sigma8. The purely X-ray flux-limited sample (HIFLUGCS) consists of the 64 X-ray brightest galaxy clusters, which are excellent targets to study the systematic effects, that can bias results. We analyzed in total 196 Chandra observations of the 64 HIFLUGCS clusters, with a total exposure time of 7.7 Ms. Here we present our data analysis procedure (including an automated substructure detection and an energy band optimization for surface brightness profile analysis) which gives individually determined, robust total mass estimates. These masses are tested against dynamical and Planck Sunyaev-Zeldovich (SZ) derived masses of the same clusters, where good overall agreement is found with the dynamical masses. The Planck SZ masses seem to show a mass dependent bias to our hydrostatic masses; possible biases in this mass-mass comparison are discussed including the Planck selection function. Furthermore, we show the results for the 0.1-2.4-keV-luminosity vs. mass scaling-relation. The overall slope of the sample (1.34) is in agreement with expectations and values from literature. Splitting the sample into galaxy groups and clusters reveals, even after a selection bias correction, that galaxy groups exhibit a significantly steeper slope (1.88) compared to clusters (1.06).
description: 21 pages + 29 pages appendix (figures and tables), accepted by MNRAS, small corrections incorporated
Bismuth iron garnet Bi3Fe5O12: a room temperature magnetoelectric material
Creators: name: Popova, Elena
name: Shengelaya, Alexander
name: Daraselia, Dimitri
name: Japaridze, David
name: Cherifi-Hertel, Salia
name: Bocher, Laura
name: Gloter, Alexandre
name: Stéphan, Odile
name: Dumont, Yves
name: Keller, Niels
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The possibility to control the magnetic properties of a material with an electric field at room temperature is highly desirable for modern applications. Moreover, a coupling between magnetic and electric orders within a single material presenting a wide range of exceptional physical properties, such as bismuth iron garnet (BIG), may lead to great advances in the field of spintronic applications. In particular, the combination of the magnetoelectric (ME) coupling with the low damping of spin waves in BIG can allow the control and manipulation of spin waves by an electric field in magnonic devices. Here we report the unambiguous observation of linear magnetoelectric coupling above 300 K in BIG using ferromagnetic resonance technique with electric field modulation. The measured coupling value is comparable with that observed for prototypal magnetoelectric Cr2O3. On the basis of our experimental results, the strength of this linear ME coupling is directly linked to the presence of bismuth ions inducing strong spin orbit coupling and to the appearance of local magnetic inhomogeneities related to the magnetic domain structure. The unprecedented combination of magnetic, optical and magnetoelectrical properties in BIG is expected to trigger significant interest for technological applications as well as for theoretical studies.
Desafios para a retomada do Programa Mais Médicos
Creators: name: Ney, M.S.
name: Maia, L.S.
name: Silva Jr., D.S.
name: Vieira, A.C.T.
name: Dal Poz, M.R.
Publisher: name: Zenodo
Year: 2023

description: Em 2013 o governo federal editou a Medida Provisória nº 621 convertida na Lei nº 12.871, (BRASIL, 2013), instituindo o Programa Mais Médicos (PMM/13). O Programa idealizado e implantado no Governo Dilma Rousseff teve como principais objetivos, diminuir a carência de médicos nas regiões consideradas prioritárias para o Sistema Único de Saúde (SUS), a fim de reduzir as desigualdades regionais na área da saúde; fortalecer nacionalmente a prestação de serviços na atenção primária e proporcionar um campo de experiências e prática ao processo de formação médica do país, por meio de uma abordagem familiar e comunitária (Brasil 2013). Ao longo do tempo o Programa sofreu diversas mudanças, principalmente nos últimos seis anos, quando em 2019 foi renomeado e relançado pela Lei 13.958 como Programa Médicos pelo Brasil - PMpB (Brasil, 2019). Desta forma, no governo de Jair Bolsonaro passa a ser operado pela Agência de Desenvolvimento da Atenção Primária à Saúde (Adaps) sob supervisão do Ministério da Saúde (MS) tendo em vista o atendimento prioritariamente em municípios de difícil provimento e alta vulnerabilidade. A contratação realizada através de processo seletivo para médicos brasileiros possibilitava o vínculo conforme a Consolidação das Leis do Trabalho (CLT), ao invés de bolsistas, selecionados após especialização em medicina e comunidade. Em março de 2023, o presidente Luiz Inácio Lula da Silva anunciou a retomada do Programa Mais Médicos propondo a reconstrução de uma política para prover e fixar profissionais de saúde na atenção primária. Para tal propôs a abertura de editais com 15.000 vagas para médicos em áreas de vulnerabilidade social e especialmente em áreas de extrema pobreza, podendo chegar a 28.000 novas vagas no país, com a previsão de um investimento de R$712 milhões de reais para o programa ao longo do primeiro ano. Além de investimentos para construção e estruturação das unidades de atenção primária do país. A previsão é que ao final de 2023, já estejam fixados em âmbito nacional 28 mil médicos (Brasil, 2023).
Effective time-dependent temperature for fermionic master equations beyond the Markov and the secular approximations
Creators: name: Litzba, Lukas
name: Kleinherbers, Eric
name: König, Jürgen
name: Schützhold, Ralf
name: Szpak, Nikodem
Publisher: name: arXiv
Year: 2024
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider a fermionic quantum system exchanging particles with an environment at a fixed temperature and study its reduced evolution by means of a Redfield-I equation with time-dependent (non-Markovian) coefficients. We find that the description can be efficiently reduced to a standard-form Redfield-II equation, however, with a time-dependent effective bath temperature obeying a universal law. At early times, after the system and environment start in a product state, the effective temperature appears to be very high, yet eventually it settles down towards the true environment value. In this way, we obtain a time-local master equation, offering high accuracy at all times and preserving the crucial properties of the density matrix. It includes non-Markovian relaxation processes beyond the secular approximation and time-averaging methods and can be further applied to various types of Gorini-Kossakowski-Sudarshan-Lindblad equations. We derive the theory from first principles and discuss its application using a simple example of a single quantum dot.
description: 16 pages, 13 figures
Evolution of Entanglement Entropy in Orbifold CFTs
Creators: name: Caputa, Pawel
name: Kusuki, Yuya
name: Takayanagi, Tadashi
name: Watanabe, Kento
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: In this work we study the time evolution of Renyi entanglement entropy for locally excited states created by twist operators in cyclic orbifold $(T^2)^n/\mathbb{Z}_n$ and symmetric orbifold $(T^2)^n/S_n$. We find that when the square of its compactification radius is rational, the second Renyi entropy approaches a universal constant equal to the logarithm of the quantum dimension of the twist operator. On the other hand, in the non-rational case, we find a new scaling law for the Renyi entropies given by the double logarithm of time $\log\log t$ for the cyclic orbifold CFT.
description: 28 pages, 7 figures. Invited contribution to the special issue of J. Phys. A: "John Cardy's scale-invariant journey in low dimensions: a special issue for his 70th birthday". v2: typos corrected, refs added, sec.5 improved. v3: affiliation, ref updated
Robotic Task Success Evaluation Under Multi-modal Non-Parametric Object Pose Uncertainty
Creators: name: Naik, Lakshadeep
name: Iversen, Thorbjørn Mosekjær
name: Kramberger, Aljaz
name: Krüger, Norbert
Publisher: name: arXiv
Year: 2024
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Accurate 6D object pose estimation is essential for various robotic tasks. Uncertain pose estimates can lead to task failures; however, a certain degree of error in the pose estimates is often acceptable. Hence, by quantifying errors in the object pose estimate and acceptable errors for task success, robots can make informed decisions. This is a challenging problem as both the object pose uncertainty and acceptable error for the robotic task are often multi-modal and cannot be parameterized with commonly used uni-modal distributions. In this paper, we introduce a framework for evaluating robotic task success under object pose uncertainty, representing both the estimated error space of the object pose and the acceptable error space for task success using multi-modal non-parametric probability distributions. The proposed framework pre-computes the acceptable error space for task success using dynamic simulations and subsequently integrates the pre-computed acceptable error space over the estimated error space of the object pose to predict the likelihood of the task success. We evaluated the proposed framework on two mobile manipulation tasks. Our results show that by representing the estimated and the acceptable error space using multi-modal non-parametric distributions, we achieve higher task success rates and fewer failures.
description: Submitted to IROS 2024
Formation of the Young Massive Cluster R136 triggered by Tidally-driven Colliding HI Flows
Creators: name: Fukui, Yasuo
name: Tsuge, Kisetsu
name: Sano, Hidetoshi
name: Bekki, Kenji
name: Yozin, Cameron
name: Tachihara, Kengo
name: Inoue, Tsuyoshi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Understanding of massive cluster formation is one of the important issues of astronomy. By analyzing the HI data, we have identified that the two HI velocity components (L- and D-components) are colliding toward the HI Ridge, in the southeastern end of the LMC, which hosts the young massive cluster R136 and $\sim$400 O/WR stars (Doran et al. 2013) including the progenitor of SN1987A. The collision is possibly evidenced by bridge features connecting the two HI components and complementary distributions between them. We frame a hypothesis that the collision triggered the formation of R136 and the surrounding high-mass stars as well as the HI & Molecular Ridge. Fujimoto & Noguchi (1990) advocated that the last tidal interaction between the LMC and the SMC about 0.2 Gyr ago induced collision of the L- and D-components. This model is consistent with numerical simulations (Bekki & Chiba 2007b). We suggest that a dense HI partly CO cloud of 10$^{6}$ $M_{\odot}$, a precursor of R136, was formed at the shock-compressed interface between the colliding L- and D-components. We suggest that part of the low-metalicity gas from the SMC was mixed in the tidal interaction based on the $Planck/IRAS$ data of dust optical depth (Planck Collaboration et al. 2014).
description: 6 pages, 4 figures, accepted to Publications of the Astronomical Society of Japan
title: Wohnbedürfnisse und deren Umsetzung in die Praxis - Bemühungen um die Wohnqualität innerhalb der Wohnungen in der Schweiz
Creators: name: Huber, Verena
Publisher: name: Bauhaus-Universität Weimar
Year: 2007
Subjects: subject: Wohnen
subject: 720

description: Wissenschaftliches Kolloquium vom 27. bis 30. Juni 1989 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: ‚Produktivkraftentwicklung und Umweltgestaltung. Sozialer und wissenschaftlich-technischer Fortschritt in ihren Auswirkungen auf Architektur und industrielle Formgestaltung in unserer Zeit. Zum 100. Geburtstag von Hannes Meyer'
description: Produktivkraftentwicklung und Umweltgestaltung, sozialer und wissenschaftlich-technischer Fortschritt in ihren Wirkungen auf Architektur und industrielle Formgestaltung in unserer Zeit: 5. Internationales Bauhaus-Kolloquium Weimar 1989, vol. 36, 1990, no. 1-3, p. 125
description: Wissenschaftliche Zeitschrift der Hochschule für Architektur und Bauwesen Weimar, vol. 36, 1990, no. 1-3, p. 125
Magnetic behavior of new compounds, Gd3RuSn6 and Tb3RuSn6
Creators: name: Upadhyay, Sanjay K
name: Iyer, Kartik K
name: Sampathkumaran, E. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report temperature (T) dependence of dc magnetization, electrical resistivity (rho(T)), and heat-capacity of rare-earth (R) compounds, Gd3RuSn6 and Tb3RuSn6, which are found to crystallize in the Yb3CoSn6-type orthorhombic structure (space group: Cmcm). The results establish that there is an onset of antiferromagnetic order near (T_N) 19 and 25 K respectively. In addition, we find that there is another magnetic transition for both the cases around 14 and 17 K respectively. In the case of the Gd compound, the spin-scattering contribution to rho is found to increase below 75 K as the material is cooled towards T_N, thereby resulting in a minimum in the plot of rho(T) unexpected for Gd based systems. Isothermal magnetization at 1.8 K reveals an upward curvature around 50 kOe. Isothermal magnetoresistance plots show interesting anomalies in the magnetically ordered state. There are sign reversals in the plot of isothermal entropy change versus T in the magnetically ordered state, indicating subtle changes in the spin reorientation with T. The results reveal that these compounds exhibit interesting magnetic properties.
description: 7 figures
Numerical studies of the transmission of light through a two-dimensional randomly rough interface
Creators: name: Hetland, Øyvind S.
name: Maradudin, Alexei A.
name: Nordam, Tor
name: Letnes, Paul Anton
name: Simonsen, Ingve
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The transmission of polarized light through a two-dimensional randomly rough interface between two dielectric media has been much less studied, by any approach, than the reflection of light from such an interface. We have derived a reduced Rayleigh equation for the transmission amplitudes when p- or s-polarized light is incident on this type of interface, and have obtained rigorous, purely numerical, nonperturbative solutions of it. The solutions are used to calculate the transmissivity and transmittance of the interface, the mean differential transmission coefficient, and the full angular distribution of the intensity of the transmitted light. These results are obtained for both the case where the medium of incidence is the optically less dense medium and in the case where it is the optically more dense medium. Optical analogues of Yoneda peaks observed in the scattering of x-rays from metal surfaces are present in the results obtained in the former case. For p-polarized incident light we observe Brewster scattering angles, angles at which the diffuse transmitted intensity is zero in a single-scattering approximation, which depend on the angle of incidence in contrast to the Brewster angle for flat-surface reflection.
description: 23 pages, 15 figures
First-order factors of linear Mahler operators
Creators: name: Chyzak, Frédéric
name: Dreyfus, Thomas
name: Dumas, Philippe
name: Mezzarobba, Marc
Publisher: name: arXiv
Year: 2024
Subjects: subject: Symbolic Computation (cs.SC)
subject: Number Theory (math.NT)
subject: Rings and Algebras (math.RA)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We develop and compare two algorithms for computing first-order right-hand factors in the ring of linear Mahler operators$\ell_r M^r + \dots + \ell_1 M + \ell_0$where $\ell_0, \dots, \ell_r$ are polynomials in~$x$ and $Mx = x^b M$ for some integer $b \geq 2$. In other words, we give algorithms for finding all formal infinite product solutions of linear functional equations$\ell_r(x) f(x^{b^r}) + \dots + \ell_1(x) f(x^b) + \ell_0(x) f(x) = 0$. The first of our algorithms is adapted from Petkovšek's classical algorithm forthe analogous problem in the case of linear recurrences. The second one proceeds by computing a basis of generalized power series solutions of the functional equation and by using Hermite-Pad{é} approximants to detect those linear combinations of the solutions that correspond to first-order factors. We present implementations of both algorithms and discuss their use in combination with criteria from the literature to prove the differential transcendence of power series solutions of Mahler equations.
description: Dedicated to the memory of Marko Petkov\v{s}ek. Accepted for publication in the Journal of Symbolic Computation
Randomized benchmarking of barrier versus tilt control of a singlet-triplet qubit
Creators: name: Zhang, Chengxian
name: Throckmorton, Robert E.
name: Yang, Xu-Chen
name: Wang, Xin
name: Barnes, Edwin
name: Sarma, S. Das
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Decoherence due to charge noise is one of the central challenges in using spin qubits in semiconductor quantum dots as a platform for quantum information processing. Recently, it has been experimentally demonstrated in both Si and GaAs singlet-triplet qubits that the effects of charge noise can be suppressed if qubit operations are implemented using symmetric barrier control instead of the standard tilt control. Here, we investigate the key issue of whether the benefits of barrier control persist over the entire set of single-qubit gates by performing randomized benchmarking simulations. We find the surprising result that the improvement afforded by barrier control depends sensitively on the amount of spin noise: for the minimal nuclear spin noise levels present in Si, the coherence time improves by more than two orders of magnitude whereas in GaAs, by contrast the coherence time is essentially the same for barrier and tilt control. However, we establish that barrier control becomes beneficial if qubit operations are performed using a new family of composite pulses that reduce gate times by up to 90%. With these optimized pulses, barrier control is the best way to achieve high-fidelity quantum gates in singlet-triplet qubits.
description: 4+6 pages
Asymmetric Dark Matter and the hadronic spectra of hidden QCD
Creators: name: Lonsdale, Stephen J.
name: Schroor, Martine
name: Volkas, Raymond R.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The idea that dark matter may be a composite state of a hidden nonabelian gauge sector has received great attention in recent years. Frameworks such as asymmetric dark matter motivate the idea that dark matter may have similar mass to the proton, while mirror matter and $G \times G$ grand unified theories provide rationales for additional gauge sectors which may have minimal interactions with standard model particles. In this work we explore the hadronic spectra that these dark QCD models can allow. The effects of the number of light colored particles and the value of the confinement scale on the lightest stable state, the dark matter candidate, are examined in the hyperspherical constituent quark model for baryonic and mesonic states.
description: 22 pages, 11 figures. Additional discussion, matches published version
title: Räumliche und soziale Strategie zur Sicherung des Wärmekomforts
Creators: name: Gallo, Emmanuelle
Publisher: name: Bauhaus-Universität Weimar
Year: 2007
Subjects: subject: Raumklima
subject: Behaglichkeit
subject: 720

description: Wissenschaftliches Kolloquium vom 27. bis 30. Juni 1989 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: ‚Produktivkraftentwicklung und Umweltgestaltung. Sozialer und wissenschaftlich-technischer Fortschritt in ihren Auswirkungen auf Architektur und industrielle Formgestaltung in unserer Zeit. Zum 100. Geburtstag von Hannes Meyer'
description: Produktivkraftentwicklung und Umweltgestaltung, sozialer und wissenschaftlich-technischer Fortschritt in ihren Wirkungen auf Architektur und industrielle Formgestaltung in unserer Zeit: 5. Internationales Bauhaus-Kolloquium Weimar 1989, vol. 36, 1990, no. 1-3, p. 127
description: Wissenschaftliche Zeitschrift der Hochschule für Architektur und Bauwesen Weimar, vol. 36, 1990, no. 1-3, p. 127
Photo absorption enhancement in strained silicon nanowires: An atomistic study
Creators: name: Shiri, Daryoush
name: Rabbani, M. Golam
name: Qi, Jianqing
name: Buin, Andrei
name: Anantram, M. P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The absorption spectra of silicon nanowires (SiNW) are calculated using semi-empirical $sp^{3}d^{5}s^{*}$ tight binding (TB) and Density Functional Theory (DFT) methods. The role of diameter, wave function symmetry, strain and crystallographic direction in determining the absorption are discussed. We find that compressive strain can change the band edge absorption by more than one order of magnitude due to change in wave function symmetry. In addition, photon polarization with respect to the nanowire axis significantly alters the band edge absorption. Overall, the band edge absorption of [110] and [100] silicon nanowires can differ by as much as three orders of magnitude. We find that compared to bulk Silicon, a strained Silicon nanowire array can absorb infrared photons (1.1 eV) approximately one hundred times better. Finally, we compare a fully numerical and a computationally efficient semi-analytical method, and find that they both yield satisfactory values of the band edge absorption.
description: 35 Pages, 11 Figures, 2 Tables, 89 references
Do AGN outflows quench or enhance star formation?
Creators: name: Zubovas, Kastytis
name: Bourne, Martin A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: AGN outflows can remove large quantities of gas from their host galaxy spheroids, potentially shutting off star formation. On the other hand, they can compress this gas, potentially enhancing or triggering star formation, at least for short periods. We present a set of idealised simulations of AGN outflows affecting turbulent gas spheres, and investigate the effect of the outflow and the AGN radiation field upon gas fragmentation. We show that AGN outflows of sufficient luminosity shut off fragmentation while the nucleus is active, but gas compression results in a burst of fragmentation after the AGN switches off. Self-shielding of gas against the AGN radiation field allows some fragmentation to occur during outbursts, but too much shielding results in a lower overall fragmentation rate. For our idealised simulation setup, there is a critical AGN luminosity which results in the highest fragmentation rate, with outflows being too efficient at removing gas when $L > L_{\rm crit}$ and not efficient enough to compress the gas to high densities otherwise. These results, although preliminary, suggest that the interaction between AGN and star formation in their host galaxies is particularly complex and requires careful study in order to interpret observations correctly.
description: 13 pages, 8 figures. Accepted for publication in MNRAS (v2: minor updates to references and acknowledgments)
Magnetic behavior of metallic kagome lattices, Tb3Ru4Al12 and Er3Ru4Al12
Creators: name: Upadhyay, Sanjay Kumar
name: Iyer, Kartik K
name: Sampathkumaran, E. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report magnetic behavior of two intermetallics-based kagome lattices, Tb3Ru4Al12 and Er3Ru4Al12, crystallizing in the Gd3Ru4Al12-type hexagonal crystal structure, by measurements in the range 1.8-300 K with bulk experimental techniques (ac and dc magnetization, heat-capacity and magnetoresistance). The main finding is that the Tb compound, known to order antiferromagnetically below (T_N=) 22 K, shows glassy characteristics at lower temperatures (<15K), thus characterizing this compound as a re-entrant spin-glass. The data reveal that glassy phase is quite complex and is of a cluster type. Since the glassy behavior was not seen for the Gd analogue in the past literature, this finding for the Tb compound emphasizes that this kagome family could provide an opportunity to explore the role of higher order (such as quadrupole) in bringing out magnetic frustration. Additional findings reported here for this compound are: (i) The temperature dependence of magnetic susceptibility and electrical resistivity in the range 12 - 20 K are found to be hysteretic leading to a magnetic phase in this temperature range, mimicking disorder-induced first-order magnetic phase-transition. (ii) Features attributable to an interesting magnetic phase co-existence phenomenon in the magnetoresistance in zero field, after cycling across metamagnetic transition fields, are observed. With respect to the Er compound, we do not find any evidence for long-range magnetic ordering down to 2 K, but this appears to be on the verge of magnetic order at 2 K.
description: 11 figures. JPCM (in press)
Can we observe neutrino flares in coincidence with explosive transients?
Creators: name: Guépin, Claire
name: Kotera, Kumiko
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The new generation of powerful instruments is reaching sensitivities and temporal resolutions that will allow multi-messenger astronomy of explosive transient phenomena, with high-energy neutrinos as a central figure. We derive general criteria for the detectability of neutrinos from powerful transient sources, for given instrument sensitivities. In practice, we provide the minimal photon flux necessary for neutrino detection based on two main observables, the bolometric luminosity and the time variability of the emission. This limit can be compared to the observations in specified wavelengths in order to target the most promising sources for follow-ups. Our criteria can also help discriminating false associations of neutrino events with a flaring source. We find that relativistic transient sources such as High- and Low-Luminosity GRBs, Blazar flares, Tidal Disruption Events and magnetar flares could be observed with IceCube, as they have a good chance to occur within a detectable distance. Among non-relativistic transient sources, only luminous supernovae appear as promising candidates. We caution that our criterion should not be directly applied to low-luminosity GRBs and Type Ibc supernovae, as these objects could have hosted a choked GRB, leading to neutrino emission without a relevant counterpart radiation. We treat a set of concrete examples and show that several transients, some of which are being monitored by IceCube, are far from meeting the criterion for detectability (e.g., Crab flares or Swift J1644+57).
description: 19 pages, 4 figures, 2 tables; minor changes, accepted by A&A
Developing robust incomplete Cholesky factorizations in half precision arithmetic
Creators: name: Scott, Jennifer
name: Tůma, Miroslav
Publisher: name: arXiv
Year: 2024
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65F08, 65F10

description: Incomplete factorizations have long been popular general-purpose algebraic preconditioners for solving large sparse linear systems of equations. Guaranteeing the factorization is breakdown free while computing a high quality preconditioner is challenging. A resurgence of interest in using low precision arithmetic makes the search for robustness more important and more challenging. In this paper, we focus on ill-conditioned symmetric positive definite problems and explore a number of approaches for preventing and handling breakdowns: prescaling of the system matrix, a look-ahead strategy to anticipate breakdown as early as possible, the use of global shifts, and a modification of an idea developed in the field of numerical optimization for the complete Cholesky factorization of dense matrices. Our numerical simulations target highly ill-conditioned sparse linear systems with the goal of computing the factors in half precision arithmetic and then achieving double precision accuracy using mixed precision refinement. We also consider the often overlooked issue of growth in the sizes of entries in the factors that can occur when using any precision and can render the computed factors ineffective as preconditioners.
description: 21 pages
Scalar products of Bethe vectors in the models with $\mathfrak{gl}(m|n)$ symmetry
Creators: name: Hutsalyuk, A.
name: Liashyk, A.
name: Pakuliak, S. Z.
name: Ragoucy, E.
name: Slavnov, N. A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study scalar products of Bethe vectors in the models solvable by the nested algebraic Bethe ansatz and described by $\mathfrak{gl}(m|n)$ superalgebra. Using coproduct properties of the Bethe vectors we obtain a sum formula for their scalar products. This formula describes the scalar product in terms of a sum over partitions of Bethe parameters. We also obtain recursions for the Bethe vectors. This allows us to find recursions for the highest coefficient of the scalar product.
description: LATEX, 33 pages, no figures, typos are corrected
Low-Temperature Microwave Properties of Biaxial YAlO3
Creators: name: Carvalho, N. C.
name: Goryachev, M.
name: Krupka, J.
name: Bushev, P.
name: Tobar, M. E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Low-loss crystals with defects due to paramagnetic or rare earth impurity ions is a major area of investigation for quantum hybrid systems at both optical and microwave frequencies. In this work we examine the single crystal yttrium aluminium perovskite, YAlO$_3$ using the Whispering Gallery Mode Technique. Multiple resonant microwave modes were measured from room temperature to 20 mK allowing precise characterization of the permittivity tensor at microwave frequencies. We show that it is biaxial and characterize the tensor as a function of temperature with estimated uncertainties below 0.26%. Electron spin resonance spectroscopy was also performed at 20 mK, with new transitions identified with Zero-Field splittings of 16.72 and 9.92 GHz. Spin-photon couplings of order 4.2 and 8.4 MHz were observed for residual levels of concentration, which are stronger than the photon cavity linewidths of 116 kHz but the same order of the linewidths of the discovered spin transitions.
Lateral diffusion induced by active proteins in a biomembrane
Creators: name: Hosaka, Yuto
name: Yasuda, Kento
name: Okamoto, Ryuichi
name: Komura, Shigeyuki
Publisher: name: arXiv
Year: 2017
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We discuss the hydrodynamic collective effects due to active protein molecules that are immersed in lipid bilayer membranes and modeled as stochastic force dipoles. We specifically take into account the presence of the bulk solvent which surrounds the two-dimensional fluid membrane. Two membrane geometries are considered: the free membrane case and the confined membrane case. Using the generalized membrane mobility tensors, we estimate the active diffusion coefficient and the drift velocity as a function of the size of a diffusing object. The hydrodynamic screening lengths distinguish the two asymptotic regimes of these quantities. Furthermore, the competition between the thermal and non-thermal contributions in the total diffusion coefficient is characterized by two length scales corresponding to the two membrane geometries. These characteristic lengths describe the crossover between different asymptotic behaviors when they are larger than the hydrodynamic screening lengths.
description: 11 pages, 4 figures
A tale of two dyons
Creators: name: Clément, Gérard
name: Gal'tsov, Dmitri
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present a one-parameter family of stationary, asymptotically flat solutions of the Einstein-Maxwell equations with only a mild singularity, which are endowed with mass, angular momentum, a dipole magnetic moment and a quadrupole electric moment. We briefly analyze the structure of this solution, which we interpret as a system of two extreme co-rotating black holes with equal masses and electric charges, and opposite magnetic and gravimagnetic charges, held apart by an electrically charged, magnetized string which also acts as a Dirac-Misner string.
description: 10 pages, one figure, published version
Complementarity Analysis of Interference between Frequency-Displaced Photonic Wave-Packets
Creators: name: Amaral, Gustavo C.
name: Carneiro, Elisa F.
name: Temporão, Guilherme P.
name: von der Weid, Jean Pierre
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The complementarity relation between the visibility and the spectral distinguishability of frequency-displaced photonic wave-packets in a Hong-Ou-Mandel interferometer is studied. An experimental definition of $K$, the distinguishability parameter, is proposed and tested for the $K^2+\mathcal{V}^2\leq 1$ complementarity inequality when a consistent visibility parameter is defined. The results show that the spectral distinguishability is, indeed, complementary to the visibility and that the quantum aspect of the two-photon interference phenomenon can be examined by employing weak-coherent states.
description: 8 pages, 6 figures, submitted to Optics Letters
Homotopy Type Theory in Lean
Creators: name: van Doorn, Floris
name: von Raumer, Jakob
name: Buchholtz, Ulrik
Publisher: name: arXiv
Year: 2017
Subjects: subject: Logic in Computer Science (cs.LO)
subject: Logic (math.LO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 03B70, 03B15, 55U35

description: We discuss the homotopy type theory library in the Lean proof assistant. The library is especially geared toward synthetic homotopy theory. Of particular interest is the use of just a few primitive notions of higher inductive types, namely quotients and truncations, and the use of cubical methods.
description: 17 pages, accepted for ITP 2017
First-principles investigation of spin wave dispersions in surface-reconstructed Co thin films on W(110)
Creators: name: Santos, Flaviano José dos
name: Dias, Manuel dos Santos
name: Lounis, Samir
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We computed spin wave dispersions of surface-reconstructed Co films on the W(110) surface in the adiabatic approximation. The magnetic exchange interactions are obtained via first-principles electronic structure calculations using the Korringa-Kohn-Rostoker Green function method. We analyze the strength and oscillatory behavior of the intralayer and interlayer magnetic interactions and investigate the resulting spin wave dispersions as a function of the thickness of Co films. In particular, we highlight and explain the strong impact of hybridization of the electronic states at the Co-W interface on the magnetic exchange interactions and on the spin wave dispersions. We compare our results to recent measurements based on electron energy loss spectroscopy [E. Michel, H. Ibach, and C.M. Schneider, Phys. Rev. B 92, 024407 (2015)]. Good overall agreement with experimental findings can be obtained by considering the possible overestimation of the spin splitting, stemming from the local spin density approximation, and adopting an appropriate correction.
description: 14 pages, 14 figures
title: New technologies in paediatric acuity assessment
Creators: name: Livingstone, I.A.T.
Publisher: name: University of Glasgow
Year: 2019
Subjects: subject: "Infant vision", "digital health", acuity, "high spatial frequency gratings", iPad, "tablet computer", "photometric compliance".

description: The present research has evaluated the utility of the computer tablet as a means to test vision in an infant population. The following points summarise the main findings: Regards the physical properties of mobile tablet computer with reference to National and International Standards for Chart Design: Photometric standards of luminance, contrast, and luminance uniformity are met more effectively by the range of iPads under test than by dedicated ETDRS (Early Treatment Diabetic Retinopathy Study) charts in active clinical use in a tertiary referral unit. The study met its aim of documenting the suitability of this mobile technology regards high contrast acuity standards, providing a practical guide to health care professionals working within eye care. These standards were then, where possible, extended to card-based infant vision tests. There are intrinsic advantages to digital platforms regards achieving a mean average luminance “grey” background relative to the black and white values of composite foreground gratings. There is marked heterogeneity across traditional card-based platforms regards luminance and contrast measurements relating to black, white and grey components. These observations informed the design of a prototype build of a computer-tablet based infant acuity test, peekaboo vision (PVb1). This build was evaluated in a blurred adult cohort. PVb1 performed well across a range of artificially degraded acuities, with observed potential benefits regards test-retest repeatability. PVb1 was then evaluated in an infant population in rural Africa in a pilot study (Study 1). A subsequent formal build (PVi) was evaluated in a UK setting with a similar methodology (Study 2), comparing with Keeler Acuity Cards for Infants (KACI) as the reference standard. Across Studies 1 and 2, the mean difference between reference standard and digital version was modest (-0.03 to 0.01), with notable differences in upper and lower limits of agreement in favour of the digital platform (exhibiting narrower LoA). Peekaboo Vision evidenced improved repeatability than KACI: coefficients of repeatability were 0.27 for Peekaboo Vision versus 0.37 for Keeler cards in study 1, and 0.32 for Peekaboo Vision versus 0.42 for Keeler cards in study 2. The mean time-to-test was over 1 minute shorter (by 26%) for Peekaboo Vision than for Keeler cards (p= 0.0021).