cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Cold atom simulation of interacting relativistic quantum field theories
Creators: name: Cirac, J. Ignacio
name: Maraner, Paolo
name: Pachos, Jiannis K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We demonstrate that Dirac fermions self-interacting or coupled to dynamic scalar fields can emerge in the low energy sector of designed bosonic and fermionic cold atom systems. We illustrate this with two examples defined in two spacetime dimensions. The first one is the self-interacting Thirring model. The second one is a model of Dirac fermions coupled to a dynamic scalar field that gives rise to the Gross-Neveu model. The proposed cold atom experiments can be used to probe spectral or correlation properties of interacting quantum field theories thereby presenting an alternative to lattice gauge theory simulations.
description: 5 pages, 3 figues, Phys. Rev. Lett. version
Magnetic Field Inhomogeneities and Their Influence on Transmission and Background at the KATRIN Main Spectrometer
Creators: name: Reich, Jan Christoph
Publisher: name: Karlsruhe
Year: 2013
Subjects: KATRIN
Main Spectrometer
Magnetic Field

description: The goal of the KATRIN experiment is to measure the absolute mass of the electron-antineutrino with a sensitivity of 200 meV by analyzing the shape of the tritium-beta-decay energy spectrum. The energy analysis is done with a large scale MAC-E filter (magnetic adiabatic collimation and electrostatic filter) with a magnetic field of 0.3 mT in the analyzing plane. This work investigates small disturbances of the magnetic field influencing the transmission and background properties of the setup.
Designing Infrastructures Allowing Higher Education Teachers to Reuse, Adapt and Exchange Open Educational Resources
Creators: name: , Schroeder
name: , Krah
name: Wendt
Publisher: name: Zenodo
Year: 2021

description: When designing OER infrastructures it is essential to be aware of practices higher education teachers have for digital environments while reusing and revising as well as sharing OER. Therefore, we conducted an interview study and designed a prototype concept based on expectations and requirements of higher education teachers regarding version management and collaborative elements.
Dynamic Capacity Control in Air Cargo Revenue Management
Creators: name: Hoffmann, Rainer
Publisher: name: Karlsruhe
Year: 2013

description: This work studies air cargo capacity control problems. The focus is on analyzing decision models with intuitive optimal decisions as well as on developing efficient heuristics and bounds. Three different models are studied: First, a model for steering the availability of cargo space on single legs. Second, a model that simultaneously optimizes the availability of both seats and cargo capacity. Third, a decision model that controls the availability of cargo capacity on a network of flights.
The Quasar / Galaxy Pair PKS 1327-206 / ESO 1327-2041: Absorption Associated with a Recent Galaxy Merger
Creators: name: Keeney, B. A.
name: Stocke, J. T.
name: Danforth, C. W.
name: Carilli, C. L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present HST/WFPC2 broadband and ground-based Halpha images, H I 21-cm emission maps, and low-resolution optical spectra of the nearby galaxy ESO 1327-2041, which is located 38 arcsec (14 kpc in projection) west of the quasar PKS 1327-206. Our HST images reveal that ESO 1327-2041 has a complex optical morphology, including an extended spiral arm that was previously classified as a polar ring. Our optical spectra show Halpha emission from several H II regions in this arm located ~5 arcsec from the quasar position (~2 kpc in projection) and our ground-based Halpha images reveal the presence of several additional H II regions in an inclined disk near the galaxy's center. Absorption associated with ESO 1327-2041 is found in H I 21-cm, optical, and near-UV spectra of PKS 1327-206. We find two absorption components at cz = 5255 and 5510 km/s in the H I 21-cm absorption spectrum, which match the velocities of previously discovered metal-line components. We attribute the 5510 km/s absorber to disk gas in the extended spiral arm and the 5255 km/s absorber to high-velocity gas that has been tidally stripped from the disk of ESO 1327-2041. The complexity of the galaxy/absorber relationships for these very nearby H I 21-cm absorbers suggests that the standard view of high redshift damped Lyman-alpha absorbers is oversimplified in many cases.
description: Replaced with accepted version; 16 pages
Indirect search for color octet electron at next generation linear colliders
Creators: name: Akay, A. N.
name: Karadeniz, H.
name: Sahin, M.
name: Sultansoy, S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this study we investigated indirect manifestations of color octet electron at the next generation linear colliders: International Linear Collider (ILC) and Compact Linear Collider (CLIC). Namely, production of two gluons via color octet electron exchange is considered. Signal and background analysis have been performed taking into account initial state radiation and beamstrahlung. We show that color octet electron (e_(8)) manifestation will be seen upto M(e_(8))=1.75 TeV and 1.70 TeV at ILC and CLIC with sqrt(s)=0.5 TeV, respectively. CLIC with sqrt(s)=3 TeV will be sensitive upto M(e_(8))=6.88 TeV.
description: 7 pages, 11 figures and 4 tables
Phase-field modeling of multi-domain evolution in ferromagnetic shape memory alloys and of polycrystalline thin film growth
Creators: name: Mennerich, Christian
Publisher: name: Karlsruhe
Year: 2013
Subjects: phase-field modeling
magnetic shape memory
thin film growth

description: The phase-field method is a powerful tool for the analysis of microstructure evolution. A multi-phase-field model is developed to run computer simulations in different areas of materials science: The anisotropic growth of MFI zeolite-like crystallites on a smooth substrate into a hydrothermal solution constituting thin films, and the analysis of the behavior of magnetic shape memory alloys, a class of active smart martensitic materials that are used as components in actuators and dampers.
On Dirac Zero Modes in Hyperdiamond Model
Creators: name: Drissi, Lalla Btissam
name: Saidi, El Hassan
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: Using the SU(5) symmetry of the 4D hyperdiamond and results on the study of 4D graphene given in "Four Dimensional Graphene" (L.B Drissi, E.H Saidi, M. Bousmina, CPM-11-01, Phys. Rev. D (2011)), we engineer a class of 4D lattice QCD fermions whose Dirac operators have two zero modes. We show that generally the zero modes of the Dirac operator in hyperdiamond fermions are captured by a tensor Ω_{μ}^{l} with 4\times5 complex components linking the Euclidean SO(4) vector μ; and the 5-dimensional representation of SU(5). The Boriçi-Creutz (BC) and the Karsten-Wilzeck (KW) models as well as their Dirac zero modes are rederived as particular realizations of Ω_{μ}^{l}. Other features are also given. Keywords: Lattice QCD, Boriçi-Creutz and Karsten-Wilzeck models, 4D hyperdiamond, 4D graphene, SU(5) Symmetry.
description: LaTex, 28 pages, To appear in Phys Rev D
Superconformal Technicolor: Models and Phenomenology
Creators: name: Azatov, Aleksandr
name: Galloway, Jamison
name: Luty, Markus A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In supersymmetric theories with a strong conformal sector, soft supersymmetry breaking naturally gives rise to confinement and chiral symmetry breaking in the strong sector at the TeV scale. We construct and analyze models where such a sector dynamically breaks electroweak symmetry, and take the first steps in studying their phenomenology. We consider two scenarios, one where the strong dynamics induces vacuum expectation values for elementary Higgs fields, and another where the strong dynamics is solely responsible for electroweak symmetry breaking. In both cases there is no fine tuning required to explain the absence of a Higgs boson below the LEP bound, solving the supersymmetry naturalness problem. Quark and lepton masses arise from conventional Yukawa couplings to elementary Higgs bosons, so there are no additional flavor-changing effects associated with the strong dynamics. A good precision electroweak fit can be obtained because the strong sector is an SU(2) gauge theory with one weak doublet, and has adjustable parameters that control the violation of custodial symmetry. In addition to the the standard supersymmetry signals, these models predict production of multiple heavy standard model particles (t, W, Z, and b) from decays of resonances in the strong sector. The strong sector has no approximate parity symmetry, so WW scattering is unitarized by states that can decay to WWW as well as WW.
description: 34 pages, 3 figures; v2: minor changes, references added
Aging of the frictional properties induced by temperature variations
Creators: name: Géminard, Jean-Christophe
name: Bertin, Eric
Publisher: name: arXiv
Year: 2010
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The dry frictional contact between two solid surfaces is well-known to obey Coulomb friction laws. In particular, the static friction force resisting the relative lateral (tangential) motion of solid surfaces, initially at rest, is known to be proportional to the normal force and independent of the area of the macroscopic surfaces in contact. Experimentally, the static friction force has been observed to slightly depend on time. Such an aging phenomenon has been accounted for either by the creep of the material or by the condensation of water bridges at the microscopic contacts points. Studying a toy-model, we show that the small uncontrolled temperature changes of the system can also lead to a significant increase of the static friction force.
description: 8 pages, 5 figures, final version, to appear in Phys. Rev. E
Theoretical confirmation of Feynman's hypothesis on the creation of circular vortices in Bose-Einstein condensates: III
Creators: name: Infeld, E.
name: Senatorski, A.
name: Skorupski, A. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: In two preceding papers (Infeld and Senatorski 2003 J. Phys.: Condens. Matter 15 5865, and Senatorski and Infeld 2004 J. Phys.: Condens. Matter 16 6589) the authors confirmed Feynman's hypothesis on how circular vortices can be created from oppositely polarized pairs of linear vortices (first paper), and then gave examples of the creation of several different circular vortices from one linear pair (second paper). Here in part III, we give two classes of examples of how the vortices can interact. The first confirms the intuition that the reconnection processes which join two interacting vortex lines into one, practically do not occur. The second shows that new circular vortices can also be created from pairs of oppositely polarized coaxial circular vortices. This seems to contradict the results for such pairs given in Koplik and Levine 1996 Phys. Rev. Lett. 76 4745.
description: 10 pages, 7 figures
Experiments on Superconducting Qubits Coupled to Resonators = Untersuchung an Resonatoren gekoppelter supraleitender Qubits
Creators: name: Jerger, Markus
Publisher: name: Karlsruhe
Year: 2013
Subjects: qubits
readout
multiplexing
scaling

description: In the present thesis, a system to simultaneously measure many superconducting quantum bits using frequency-division multiplexing is developed. The theoretical and experimental foundations are introduced and parallel measurements on up to six qubits are demonstrated.
Full Reconstruction And Search For Charged Higgs Effects In Semi-Tauonic B Decays
Creators: name: Zander, Daniel
Publisher: name: Karlsruhe
Year: 2013

description: We present a significantly improved Full Reconstruction algorithm and the application in the search for charged Higgs effects in semi-tauonic B decays. We measure the values for R and R* and find them in agreement with Standard Model expectations.
D5.1 – Human factors identification
Creators: name: Finke-Gröne, Katharina
name: Ehrmann, Dominic
name: Hermanns, Norbert
Publisher: name: Zenodo
Year: 2021
Subjects: diabetes
human factors
BIP
Ethical implications

description: This report summarises the work carried out within WP 5, namely “Human factors and ethical implications”. The goal of this task was to identify relevant human factors as well as possible perceived benefits and barriers associated with the BIP (Bionic Invisible Pancreas). Human factors consist of potentially influencing aspects for acceptance, device uptake, and continuous and effective use in socio-technical systems and human-machine systems. In this case, human factors could only be applied in a limited way, since the BIP will be a paradigm shift in the treatment of diabetes. For the same reason, analyzing human factors specifically related to the BIP is important also in view of conditioning further developments for the uptake of BIP. In order to achieve the task goals, semi-structured interviews on different topics related to BIP were conducted, combining both qualitative and quantitative methods. Overall, participants highly appreciated the development of the BIP and were eager to learn more about the project. These results are now used to develop an assessment tool to select participants who will likely benefit the most from the BIP.
Ansätze zum methodischen Systemleichtbau und dessen Unterstützung durch numerische Topologieoptimierung bei dynamischer Belastung
Creators: name: Hessenauer, Benjamin
Publisher: name: Karlsruhe
Year: 2014
Subjects: Leichtbau
Topologieoptimierung
System
Dynamik

description: Der Leichtbau im Gesamtsystem sowie das Spannungsfeld von Leichtbau und Verbesserung der Akustik werden analysiert und neue Ansätze zur Lösung solcher Zielkonflikte vorgestellt. Die konsequente Betrachtung des Gesamtsystems als Erfolgsfaktor für Leichtbauentwicklungsprozesse wird aufgezeigt. Der Zielkonflikt zwischen Gewichtsreduzierung und Komforterhöhung wird mittels der Topologieoptimierung durch Homogenisierung des Frequenzspektrums eines Bauteils unter harmonischer Last aufgelöst.
Evaluation of a NEMO model of the Strait of Georgia and insights into mixing and transport of the Fraser River plume
Creators: name: Liu, Jie
Publisher: name: University of British Columbia
Year: 2017

description: The goals of this modeling study of the Fraser River plume, located in the Strait of Georgia, British Columbia, are twofold. Firstly, it aims at improving the Fraser River plume properties by evaluating the model results with various available observations. Secondly, mixing and transport processes within the plume, driven by different forcing factors, are investigated with the improved configuration to understand the plume dynamics in the model. The problems found by comparing with ferry-based salinity data, drifter data and CTD data in the modeled Fraser River properties are: (1) too weak cross-strait velocities; (2) too strong along-strait flows; (3) too salty surface water. To fix the problems, a longer and deeper river channel was created and added into the model. The results show promising improvements with stronger cross-strait motions. Background vertical eddy viscosity was reduced from 1 x10-⁴to 1 x 10-⁵ m²s-¹, which tends to reduce the along-strait velocities. In addition, background vertical eddy diffusivity was reduced to 1 x 10-⁶ m²s-¹ which reduced the surface salinity. Furthermore, effects of river discharge, tides, winds and the Coriolis force are explored on plume mixing and transport. As expected, plume size increases with increasing river outflow. Tides are important in mixing at the river mouth and inside the river channel during low and moderate river flow periods with wind magnitude smaller than 5 m s-¹, whereas winds become the dominant factor in mixing over almost the entire plume domain when wind speed is greater than 5 m s-¹ . The Coriolis force strengths the northward flux across a transect north of the river mouth when winds are not strong, resulting in a fresher plume in English Bay, north of the City of Vancouver. This thesis provides both a guide to accurately modeling the Fraser River plume and insight into plume dynamics.
Gain and plasmon dynamics in negative-index metamaterials
Creators: name: Wuestner, Sebastian
name: Pusch, Andreas
name: Tsakmakidis, Kosmas L.
name: Hamm, Joachim M.
name: Hess, Ortwin
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Photonic metamaterials allow for a range of exciting applications unattainable with ordinary dielectrics. However, the metallic nature of their meta-atoms may result in increased optical losses. Gain-enhanced metamaterials are a potential solution to this problem, but the conception of realistic, three-dimensional designs is a challenging task. Starting from fundamental electrodynamic and quantum-mechanical equations we establish and deploy a rigorous theoretical model for the spatial and temporal interaction of lightwaves with free and bound electrons inside and around metallic (nano-) structures and gain media. The derived numerical framework allows us to self-consistently study the dynamics and impact of the coherent plasmon-gain interaction, nonlinear saturation, field enhancement, radiative damping and spatial dispersion. Using numerical pump-probe experiments on a double-fishnet metamaterial structure with dye molecule inclusions we investigate the build-up of the inversion profile and the formation of the plasmonic modes in the low-Q cavity. We find that full loss compensation occurs in a regime where the real part of the effective refractive index of the metamaterial becomes more negative compared to the passive case. Our results provide a deep insight into how internal processes affect the over-all optical properties of active photonic metamaterials fostering new approaches to the design of practical loss-compensated plasmonic nanostructures.
description: Accepted for publication in Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
Infrastructure-as-a-Service Usage Determinants in Enterprises
Creators: name: Strebel, Jörg
Publisher: name: Karlsruhe
Year: 2014
Subjects: Infrastructure-as-a-Service
Cloud Computing

description: The thesis focuses on the research question, what the determinants of Infrastructure-as-a-Service usage of enterprises are. A wide range of IaaS determinants is collected for an IaaS adoption model of enterprises, which is evaluated in a Web survey. As the economical determinants are especially important, they are separately investigated using a cost-optimizing decision support model. This decision support model is then applied to a potential IaaS use case of a large automobile manufacturer.
Effiziente Berechnung des Epsilon-Nash-Equilibriums einer Poker-Variante
Creators: name: Kujath, Holger
Publisher: name: Karlsruhe
Year: 2014

description: Poker ist eine Menge von verschiedenen, komplexen Null-Summen Spielen. Die Komplexität hat ihren Ursprung in Zufallsereignissen und den unvollständigen Informationen der Spieler. Für Null-Summen Spiele existiert mindestens eine Strategie, das sogenannte Nash-Equilibrium, die eine Erwartungswert größer gleich Null besitzt und damit als perfekte Strategie gelten kann. Schon in seinem berühmten Beweis aus dem Jahr 1951 schlussfolgerte der Nobelpreisträger John Nash, dass "die Analyse eines realistischeren Pokerspiels, welches über unser vereinfachtes Model hinaus ginge, eine interessante Angelegenheit" sein müsste. Obwohl der Beweis der Existenz des Nash-Equilibriums von 1951 stammt, gelangen erst ab 2006, durch die Entdeckung des CFR Algorithmus, die ersten, vielversprechenden Versuche das Nash-Equilibrium mithilfe von Software zu berechnen. Diese Arbeit stellt mit dem CGH einen neuen Algorithmus vor, der im Vergleich zum CFR um Größenordnungen schneller das Nash-Equilibrium approximiert. Außerdem werden neue Verfahren zur Erzeugung von verlustfreieren Abstraktionen für die Spielkarten vorgestellt, die eine noch fehlerfreiere Approximation des Nash-Equilibriums ermöglichen. Diese neuen Methoden werden an der populären Poker-Variante "Texas No Limit Hold'em Heads-up" evaluiert.

Abstract in englisch:
Poker consists of many complex, zero-sum games. Its complexity is a consequence of random events in the game and the incomplete information available to the players. The Nash equilibrium is a strategy for zero-sum games which has an expected payoff of zero or better, thus making it a perfect strategy. In his renowned original 1951 proof John Nash commented that "The analysis of a more realistic poker game than our very simple model should be quite an interesting affair". However, despite evidence of the existence of a Nash equilibrium dating back to 1951, the first significant attempt to calculate it came with the discovery of the CFR algorithm in 2006.
This dissertation introduces CGH, a new algorithm which calculates an approximate Nash equilibrium orders of magnitude faster than CFR, and also allows much more complicated problems to be solved. Additionally, it introduces new techniques for generating lossless abstractions of the cards, which allow a more precise approximation of the Nash equilibrium. These new methods are applied to the popular poker game "Texas No Limit Hold'em Heads-up".
Modification of the halo mass function by kurtosis associated with primordial non-Gaussianity
Creators: name: Yokoyama, Shuichiro
name: Sugiyama, Naoshi
name: Zaroubi, Saleem
name: Silk, Joseph
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the halo mass function in the presence of the kurtosis type of primordial non-Gaussianity. The kurtosis corresponds to the trispectrum as defined in Fourier space. The primordial trispectrum is commonly characterized by two parameters, $τ_{\rm NL}$ and $g_{\rm NL}$. As applications of the derived non-Gaussian mass function, we consider the effect on the abundance of void structure, the effect on early star formation and on formation of the most massive object at high redshift. We show that by comparing the effects of primordial non-Gaussianity on cluster abundance with that on void abundance, we can distinguish between the skewness and the kurtosis types of primordial non-Gaussianity. As for early star formation, we show that the kurtosis type of primordial non-Gaussianity seems not to affect the reionization history of the Universe on average. However, at high redshifts (up to $z\simeq 20$) such non-Gaussianity does somewhat affect the early stages of reionization.
description: 14 pages, 7 figures, accepted for publication in MNRAS
Determinanten von Entscheidungen zur Versicherung von Schäden aus Naturkatastrophen
Creators: name: Zahn, Ferdinand Leopold
Publisher: name: Karlsruhe
Year: 2014
Subjects: Versicherungsnachfrage
Katastrophenrisiken
Ambiguität
Katastrophenerfahrung
Experiment

description: Weltweit ist nur ein geringer Teil der monetären Schäden aus Naturkatastrophen versichert. Die Arbeit geht der Frage nach, welche Faktoren die Zahlungsbereitschaft für Versicherungsschutz gegen Schäden aus Naturkatastrophen beeinflussen. Insbesondere werden Faktoren im Zusammenhang mit der Ambiguität der Eintrittswahrscheinlichkeiten von Katastrophenereignissen sowie im Zusammenhang mit der Katastrophenerfahrung mit Hilfe eines Online-Computerspiels experimentell untersucht.
The overlap parameter across an inverse first order phase transition in a 3D spin-glass
Creators: name: Paoluzzi, Matteo
name: Leuzzi, Luca
name: Crisanti, Andrea
Publisher: name: arXiv
Year: 2010
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate the thermodynamic phase transition taking place in the Blume-Capel model in presence of quenched disorder in three dimensions (3D). In particular, performing Exchange Montecarlo simulations, we study the behavior of the order parameters accross the first order phase transition and its related coexistence region. This transition is an Inverse Freezing.
description: 9 pages, 6 figures, Contribution to the XII International Workshop on Complex Systems
Crosswind stability of vehicles under nonstationary wind excitation
Creators: name: Zhang, Xiaoyu
Publisher: name: Karlsruhe
Year: 2015
Subjects: Crosswind stability
nonstationary wind
vehicle dynamics
risk analysis

description: This work has studied the crosswind stability of vehicles under nonstationary wind excitation in various scenarios. Railway vehicles running on curved and straight track with varying vehicle speed are studied. Road vehicles are classified into different categories. For each vehicle class, a corresponding worst-case vehicle model has been built. As the wind excitation on the vehicle is a stochastic process, a risk analysis has to be carried out and failure probabilities are computed and analyzed.
Generische Simulationsmodelle für Sorptionswärmepumpen zum Heizen und Kühlen
Creators: name: Glück, Christian
Publisher: name: Karlsruhe
Year: 2015
Subjects: Gaswärmepumpe
Sorption
Adsorption
Modellierung
Gebäudesimulation

description: In der Dissertation wurden thermodynamische Berechnungsmodelle für Sorptionswärmepumpen zum Heizen und Kühlen entwickelt, implementiert und in Simulationsstudien für Gebäudeanwendungen evaluiert. Die Modelle greifen nicht auf Maschinendaten zurück und beinhalten die Berücksichtigung der Wärmeübertrager und im Falle der Adsorption maschineninterner Wärmerückgewinnung. Sie eignen sich besonders in der Vorentwicklung zur Potentialanalyse von Wärmepumpen- und Betriebskonzepten.
Three-sublattice ordering of the SU(3) Heisenberg model of three-flavor fermions on the square and cubic lattices
Creators: name: Toth, Tamas A.
name: Laeuchli, Andreas M.
name: Mila, Frederic
name: Penc, Karlo
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Combining a semi-classical analysis with exact diagonalizations, we show that the ground state of the SU(3) Heisenberg model on the square lattice develops three-sublattice long-range order. This surprising pattern for a bipartite lattice with only nearest-neighbor interactions is shown to be the consequence of a subtle quantum order-by-disorder mechanism. By contrast, thermal fluctuations favor two-sublattice configurations via entropic selection. These results are shown to extend to the cubic lattice, and experimental implications for the Mott-insulating states of three-flavor fermionic atoms in optical lattices are discussed.
description: 4 pages, 3 figures, minor changes, references added
Potenziale zur Erzeugung von Biomasse aus Mikroalgen in Europa unter besonderer Berücksichtigung der Flächen- und CO2-Verfügbarkeit
Creators: name: Skarka, Johannes
Publisher: name: Karlsruhe
Year: 2020
Subjects: Mikroalgen
Potenzial
CO2
Kosten
Geoinformationssystem

description: In dieser Dissertation wurde das Potenzial der großmaßstäbigen Erzeugung von Mikroalgenbiomasse analysiert. Dazu wurde ein auf einem Geoinformationssystem basierendes Modell entwickelt, welches eine räumlich differenzierte Analyse ermöglicht. Dabei wurden insbesondere die Flächen- und CO2-Verfügbarkeit berücksichtigt. Das kostenbezogene Mikroalgenpotenzial wurde für verschiedene Szenarien ermittelt und der Einfluss der CO2-Verfügbarkeit auf die Gesamtkosten untersucht.
Asymptotics of physical solutions to the Lorentz-Dirac equation for a planar motion in constant electromagnetic fields
Creators: name: Kazinski, P. O.
name: Shipulya, M. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present a study of planar physical solutions to the Lorentz-Dirac equation in a constant electromagnetic field. In this case, we reduced the Lorentz-Dirac equation to the one second order differential equation. We obtained the asymptotics of physical solutions to this equation at large proper times. It turns out that, in the crossed constant uniform electromagnetic field with vanishing invariants, a charged particle goes to a universal regime at large times. We found the ratio of momentum components which tends to a constant determined only by the external field. This effect is essentially due to a radiation reaction. There is not such an effect for the Lorentz equation in this field.
description: 24 pp; Appendix added; minor textual changes, references added
Kazhdan-Lusztig polynomials and drift configurations
Creators: name: Li, Li
name: Yong, Alexander
Publisher: name: arXiv
Year: 2010
Subjects: subject: Combinatorics (math.CO)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: The coefficients of the Kazhdan-Lusztig polynomials $P_{v,w}(q)$ are nonnegative integers that are upper semicontinuous on Bruhat order. Conjecturally, the same properties hold for $h$-polynomials $H_{v,w}(q)$ of local rings of Schubert varieties. This suggests a parallel between the two families of polynomials. We prove our conjectures for Grassmannians, and more generally, covexillary Schubert varieties in complete flag varieties, by deriving a combinatorial formula for $H_{v,w}(q)$. We introduce \emph{drift configurations} to formulate a new and compatible combinatorial rule for $P_{v,w}(q)$. From our rules we deduce, for these cases, the coefficient-wise inequality $P_{v,w}(q)\preceq H_{v,w}(q)$.
description: 26 pages. To appear in Algebra & Number Theory
Diffusion of Neon in White Dwarf Stars
Creators: name: Horowitz, C. J.
name: Hughto, J.
name: Schneider, A. S.
name: Berry, D. K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Sedimentation of the neutron rich isotope $^{22}$Ne may be an important source of gravitational energy during the cooling of white dwarf stars. This depends on the diffusion constant for $^{22}$Ne in strongly coupled plasma mixtures. We calculate self-diffusion constants $D_i$ from molecular dynamics simulations of carbon, oxygen, and neon mixtures. We find that $D_i$ in a mixture does not differ greatly from earlier one component plasma results. For strong coupling (coulomb parameter $Γ>$ few), $D_i$ has a modest dependence on the charge $Z_i$ of the ion species, $D_i \propto Z_i^{-2/3}$. However $D_i$ depends more strongly on $Z_i$ for weak coupling (smaller $Γ$). We conclude that the self-diffusion constant $D_{\rm Ne}$ for $^{22}$Ne in carbon, oxygen, and neon plasma mixtures is accurately known so that uncertainties in $D_{\rm Ne}$ should be unimportant for simulations of white dwarf cooling.
description: 6 pages, 5 figures, minor changes, Phys. Rev. E in press
Perturbative Approach to the Gravitational Lensing by a Non-spherically Distorted Compact Object
Creators: name: Saijo, Amano
name: Kasai, Masumi
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We investigate the gravitational lens effect caused by a non-spherically distorted compact object. The non-spherical property of the gravitational potential is modeled by a quadrupole moment. Under the assumption that the quadrupole contribution is small, we solve perturbatively the lens equation and obtain the image positions and the amplification factors. We show that the separation angle of two major images is only slightly changed by the existence of the quadrupole contribution, whereas the difference of the amplification factors may be significantly modified. Our results indicate that even a tiny non-spherical distortion of the lens potential may cause significant amount of flux anomalies in the lensed images.
description: 10 pages, version accepted for publication in PTP
Non-universal behavior of helicity modulus in a dense defect system
Creators: name: Sinha, Suman
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Extensive Monte Carlo simulation has been performed on a 2D modified XY model which behaves like a dense defect system. Topological defects are shown to introduce disorders in the system which makes the helicity modulus jump non-universal. The results corroborate the experimental observation of non-universal jump of the superconducting density in high-$T_c$ superconducting films.
description: 4 pages, 5 figures, double column, Accepted for publication as a Rapid Communication in Phys. Rev. E (In Press)
Approximation of Geodesics in Metabelian Groups
Creators: name: Kharlampovich, O.
name: Moghaddam, A. Mohajeri
Publisher: name: arXiv
Year: 2011
Subjects: subject: Group Theory (math.GR)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 20F10, 20D10

description: It is known that the bounded Geodesic Length Problem in free metabelian groups is NP-complete (in particular, the Geodesic Problem is NP-hard). We construct a 2-approximation polynomial time deterministic algorithm for the Geodesic Problem. We show that the Geodesic Problem in the restricted wreath product of a finitely generated non-trivial group with a finitely generated abelian group containing $Z^2$ is NP-hard and there exists a Polynomial Time Approximation Scheme for this problem. We also show that the Geodesic Problem in the restricted wreath product of two finitely generated non-trivial abelian groups is NP-hard if and only if the second abelian group contains $Z^2$.
description: 10 pages, 1 figure; International Journal of Algebra and Computation (IJAC), 2011
Concision vs. Precision: Analysis of the French Translation of the Film The Adventures of Tintin by Steven Spielberg
Creators: Xilan Huang
Publisher: name: University of Alberta Library
Year: 2023

This article analyses the methods used in the French translation of the animation The

Adventures of Tintin by Steven Spielberg. The French translation of this film includes subtitling

and dubbing. I will use Katharina Reiß’s framework to analyze and evaluate the quality of this

work. Both the linguistic and non-linguistic factors related to this work will be discussed.

Analysis of the subtitling is the primary focus of this essay while the dubbing will also be briefly

discussed with the comparison of a few notable examples to illustrate the differences between

these two strategies and the major constraints of audiovisual translation.
Effect of pressure on the pseudogap and charge density wave phases of the cuprate Nd-LSCO probed by thermopower measurements
Creators: name: Gourgout, Adrien
name: Ataei, Amirreza
name: Boulanger, Marie-Eve
name: Badoux, S.
name: Thériault, Steven
name: Graf, D.
name: Zhou, J.-S.
name: Pyon, Sunseng
name: Takayama, T.
name: Takagi, H.
name: Doiron-Leyraud, Nicolas
name: Taillefer, Louis
Publisher: name: American Physical Society
Year: 2021
Subjects: thermopower

description: We report thermopower measurements under hydrostatic pressure on the cuprate superconductor La1.6−xNd0.4SrxCuO4 (Nd-LSCO), at low temperature in the normal state accessed by suppressing superconduc- tivity with a magnetic ﬁeld up to H = 31 T. Using an ac thermopower measurement technique suitable for high pressure and high ﬁeld, we track the pressure evolution of the Seebeck coefﬁcient S. At ambient pressure and low temperature, S/T in Nd-LSCO was recently found to suddenly increase below the pseudogap critical doping p ⋆ = 0.23, consistent with a drop in carrier density n from n = 1 + p above p⋆ to n = p below. Under a pressure of 2.0 GPa, we observe that the large S/T value just below p ⋆ is suppressed. This conﬁrms a previous pressure study based on electrical resistivity and Hall effect, which found that pressure lowers p ⋆, thereby reinforcing the interpretation that this effect is driven by the pressure-induced shift of the van Hove point. It implies that the pseudogap only exists when the Fermi surface is hole-like, which puts strong constraints on theories of the pseudogap phase. We also report thermopower measurements on Nd-LSCO and La1.8−xEu0.2SrxCuO4 in the charge density wave phase near p ∼ 1/8, which reveals a weakening of this phase under pressure.
Modulational instability of few cycle pulses in optical fibers
Creators: name: Sarma, Amarendra K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Classical Physics (physics.class-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We investigate the modulational instability of a mathematical model [based on the model proposed by T. Brabec and F. Krausz, Phys.Rev. Lett. 78, 3282(1997)] appropriate for few cycle optical pulses with pulse duration as short as one carrier oscillation cycle in the context of a standard silica fiber operating at the telecommunication wavelength 1550 nm.
description: 5 pages
How can we make antimalarial medicine faster?
Creators: name: Dimitrova, Tanya
name: Yoshimoto, Francis K.
Publisher: name: figshare
Year: 2021
Subjects: subject: 110103 Medical Biochemistry: Inorganic Elements and Compounds
subject: FOS: Clinical medicine

description: Adapted for children from the original reserach paper "Synthesis of [15,15,15‐H3]‐Dihydroartemisinic Acid and Isotope Studies Support a Mixed Mechanism in the Endoperoxide Formation to Artemisinin" in the Journal of Natural Products
Higher-dimensional Rotating Charged Black Holes
Creators: name: Caldarelli, Marco M.
name: Emparan, Roberto
name: Van Pol, Bert
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Using the blackfold approach, we study new classes of higher-dimensional rotating black holes with electric charges and string dipoles, in theories of gravity coupled to a 2-form or 3-form field strength and to a dilaton with arbitrary coupling. The method allows to describe not only black holes with large angular momenta, but also other regimes that include charged black holes near extremality with slow rotation. We construct explicit examples of electric rotating black holes of dilatonic and non-dilatonic Einstein-Maxwell theory, with horizons of spherical and non-spherical topology. We also find new families of solutions with string dipoles, including a new class of prolate black rings. Whenever there are exact solutions that we can compare to, their properties in the appropriate regime are reproduced precisely by our solutions. The analysis of blackfolds with string charges requires the formulation of the dynamics of anisotropic fluids with conserved string-number currents, which is new, and is carried out in detail for perfect fluids. Finally, our results indicate new instabilities of near-extremal, slowly rotating charged black holes, and motivate conjectures about topological constraints on dipole hair.
description: 61 pages. v2: improved version. v3: final published version
Anisotropic dark energy and ellipsoidal universe
Creators: name: Campanelli, L.
name: Cea, P.
name: Fogli, G. L.
name: Tedesco, L.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: A cosmological model with anisotropic dark energy is analyzed. The amount of deviation from isotropy of the equation of state of dark energy, the skewness δ, generates an anisotropization of the large-scale geometry of the Universe, quantifiable by means of the actual shear Σ_0. Requiring that the level of cosmic anisotropization at the time of decoupling is such to solve the "quadrupole problem" of cosmic microwave background radiation, we find that |δ| \sim 10^{-4} and |Σ_0| \sim 10^{-5}, compatible with existing limits derived from the magnitude-redshift data on type Ia supernovae.
description: 10 pages, 3 figures. Revised version to match published version. References added
Water vapor emission reveals a highly obscured, star forming nuclear region in the QSO host galaxy APM08279+5255 at z=3.9
Creators: name: van der Werf, Paul P.
name: Alba, Alicia Berciano
name: Spaans, Marco
name: Loenen, Edo
name: Meijerink, Rowin
name: Riechers, Dominik
name: Cox, Pierre
name: Weiss, Axel
name: Walter, Fabian
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present the detection of four rotational emission lines of water vapor, from energy levels Eu/k= 101 - 454 K, in the gravitationally lensed z=3.9 QSO host galaxy APM08279+5255. While the lowest H2O lines are collisionally excited in clumps of warm, dense gas (density of hydrogen nuclei n_H=(3.1 +/- 1.2) x 10^6 cm^-3, gas temperature T_g ~ 105 +/- 21 K), we find that the excitation of the higher lines is dominated by the intense local infrared radiation field. Since only collisionally excited emission contributes to gas cooling, we conclude that H2O is not a significant coolant of the warm molecular gas. Our excitation model requires the radiatively excited gas to be located in an extended region of high 100 micron opacity (tau_100 = 0.9 +/- 0.2). Locally, such extended infrared-opaque regions are found only in the nuclei of ultraluminous infrared galaxies. We propose a model where the infrared-opaque circumnuclear cloud, which is penetrated by the X-ray radiation field of the QSO nucleus, contains clumps of massive star formation where the H2O emission originates. The radiation pressure from the intense local infrared radiation field exceeds the thermal gas pressure by about an order of magnitude, suggesting close to Eddington-limited star formation in these clumps.
description: accepted for publication in Astrophysical Journal Letters; typos fixed
Thermal fluctuations in the lattice Boltzmann method for non-ideal fluids
Creators: name: Gross, M.
name: Adhikari, R.
name: Cates, M. E.
name: Varnik, F.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We introduce thermal fluctuations in the lattice Boltzmann method for non-ideal fluids. A fluctuation-dissipation theorem is derived within the Langevin framework and applied to a specific lattice Boltzmann model that approximates the linearized fluctuating Navier-Stokes equations for fluids based on square-gradient free energy functionals. The obtained thermal noise is shown to ensure equilibration of all degrees of freedom in a simulation to high accuracy. Furthermore, we demonstrate that satisfactory results for most practical applications of fluctuating hydrodynamics can already be achieved using thermal noise derived in the long wavelength-limit.
description: 15 pages, 5 figures
Overcoming losses with gain in a negative refractive index metamaterial
Creators: name: Wuestner, Sebastian
name: Pusch, Andreas
name: Tsakmakidis, Kosmas L.
name: Hamm, Joachim M.
name: Hess, Ortwin
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: On the basis of a full-vectorial three-dimensional Maxwell-Bloch approach we investigate the possibility of using gain to overcome losses in a negative refractive index fishnet metamaterial. We show that appropriate placing of optically pumped laser dyes (gain) into the metamaterial structure results in a frequency band where the nonbianisotropic metamaterial becomes amplifying. In that region both the real and the imaginary part of the effective refractive index become simultaneously negative and the figure of merit diverges at two distinct frequency points.
description: 4 pages, 4 figures
Ideal Gas in a strong Gravitational field: Area dependence of Entropy
Creators: name: Kolekar, Sanved
name: Padmanabhan, T.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the thermodynamic parameters like entropy, energy etc. of a box of gas made up of indistinguishable particles when the box is kept in various static background spacetimes having a horizon. We compute the thermodynamic variables using both statistical mechanics as well as by solving the hydrodynamical equations for the system. When the box is far away from the horizon, the entropy of the gas depends on the volume of the box except for small corrections due to background geometry. As the box is moved closer to the horizon with one (leading) edge of the box at about Planck length (L_p) away from the horizon, the entropy shows an area dependence rather than a volume dependence. More precisely, it depends on a small volume A*L_p/2 of the box, upto an order O(L_p/K)^2 where A is the transverse area of the box and K is the (proper) longitudinal size of the box related to the distance between leading and trailing edge in the vertical direction (i.e in the direction of the gravitational field). Thus the contribution to the entropy comes from only a fraction O(L_p/K) of the matter degrees of freedom and the rest are suppressed when the box approaches the horizon. Near the horizon all the thermodynamical quantities behave as though the box of gas has a volume A*L_p/2 and is kept in a Minkowski spacetime. These effects are: (i) purely kinematic in their origin and are independent of the spacetime curvature (in the sense that Rindler approximation of the metric near the horizon can reproduce the results) and (ii) observer dependent. When the equilibrium temperature of the gas is taken to be equal to the the horizon temperature, we get the familiar A/L_p^2 dependence in the expression for entropy. All these results hold in a D+1 dimensional spherically symmetric spacetime.
description: 19 pages, added some discussion, matches published version