cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
On the Stability of Tidal Streams
Creators: name: Schneider, Aurel
name: Moore, Ben
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We explore the stability of tidal streams to perturbations, motivated by recent claims that the clumpy structure of the stellar streams surrounding the globular cluster Palomar 5 are the result of gravitational instability. We calculate the Jeans length of tidal streams by treating them as a thin expanding cylinder of collisionless matter. We also find a general relation between the density and the velocity dispersion inside a stream, which is used to determine the longitudinal Jeans criterion. Our analytic results are checked by following the time evolution of the phase space density within streams using numerical simulations. We conclude that tidal streams within our galactic halo are stable on all length scales and over all timescales.
description: Accepted for publication in MNRAS
Nonrelativistic counterparts of twistors and the realizations of Galilean conformal algebra
Creators: name: Fedoruk, S.
name: Kosinski, P.
name: Lukierski, J.
name: Maslanka, P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Using the notion of Galilean conformal algebra (GCA) in arbitrary space dimension d, we introduce for d=3 quantized nonrelativistic counterpart of twistors as the spinorial representation of O(2,1){\oplus}SO(3) which is the maximal semisimple subalgebra of three-dimensional GCA. The GC-covariant quantization of such nonrelativistic spinors, which shall be called also Galilean twistors, is presented. We consider for d=3 the general spinorial matrix realizations of GCA, which are further promoted to quantum-mechanical operator representations, expressed as bilinears in quantized Galilean twistors components. For arbitrary Hermitian quantum-mechanical Galilean twistor realizations we obtain the result that the representations of GCA with positive-definite Hamiltonian do not exist. For non-positive H we construct for N{\geq}2 the Hermitian Galilean N-twistor realizations of GCA; for N=2 such realization is provided explicitly.
description: v3: 1+12 pages, with typos corrected in PLB proofs included
Electrodynamics a la Horava
Creators: name: Romero, Juan M.
name: Santiago, J. A.
name: Gonzalez-Gaxiola, O.
name: Zamora, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study an electrodynamics consistent with anisotropic transformations of space-time with an arbitrary dynamic exponent $z$. The equations of motion and conserved quantities are explicitly obtained. We show that the propagator of this theory can be regarded as a quantum correction to the usual propagator. Moreover we obtain that both the momentum and angular momentum are not modified, but their conservation laws do change. We also show that in this theory the speed of light and the electric charge are modified with $z$. The magnetic monopole in this electrodynamics and its duality transformations are also investigated. For that we found that there exists a dual electrodynamics, with higher derivatives in the electric field, invariant under the same anisotropic transformations.
description: 14 pages, no figures, version to appears in Mod. Phys. Lett. A
Entwicklung einer Immersed Boundary Methode für einen block-strukturierten CFD-Code
Creators: name: Jastrow, Benjamin
Publisher: name: Karlsruhe
Year: 2014
Subjects: Immersed Boundary Methode
kompressibel
block-strukturiert
Wandschichtmodell

description: Eine Immersed Boundary Methode für einen block-strukturierten CFD-Code wird vorgestellt, welche eine automatische Gittergenerierung erlaubt. Für die Behandlung der Randbedingungen wird ein Wandschichtmodell angewendet, welches auf den Vereinfachungen der Grenzschichttheorie und auf einem Diffusions-Ansatz basiert. Es werden ausgewählte Testfälle zur Validierung herangezogen. Weiterhin wird das Potential der Methode anhand komplexer dreidimensionaler Strömungskonfigurationen aufgezeigt.
Discovery of diffuse emission in the galaxy cluster A1689
Creators: name: Vacca, V.
name: Govoni, F.
name: Murgia, M.
name: Giovannini, G.
name: Feretti, L.
name: Tugnoli, M.
name: Verheijen, M. A.
name: Taylor, G. B.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The aim of this work is to investigate the possible presence of extended diffuse synchrotron radio emission associated with the intracluster medium of the complex galaxy cluster A1689. The radio continuum emission of A1689 has been investigated by analyzing archival observations at 1.2 and 1.4 GHz obtained with the Very Large Array in different configurations. We report the detection of an extended, diffuse, low-surface brightness radio emission located in the central region of A1689. The surface brightness profile of the diffuse emission at 1.2 GHz indicates a central radio brightness of ~1.7 μJy/arcsec^2 and the 3σradio isophothes reveal the largest linear size to be 730 kpc. Given its central location, the low-level surface brightness, and the comparatively large extension, we classify the diffuse cluster-wide emission in A1689 as a small radio halo.
description: 8 pages, 6 figures, A&A accepted
Parametric study for net zero energy building strategies in Brazil considering semi-transparent PV windows
Creators: name: Didoné, Evelise Leite
Publisher: name: Karlsruhe
Year: 2014
Subjects: semi-transparent PV windows
zero energy buildings (ZEB)
computer simulation
(sub)tropical climate
office building type

description: This work develops strategies to transform typical Brazilian office buildings, built in different climatic zones, into zero energy buildings (ZEB). Special emphasis is placed on photovoltaic application, especially the new technology of semi-transparent PV windows. The work is based on parametric computer simulations using Daysim and EnergyPlus programs. The results reveal that a building envelope design that matches the building’s loads and resources is crucial for becoming a ZEB.
Keeping a Single Qubit Alive by Experimental Dynamic Decoupling
Creators: name: Szwer, David J.
name: Webster, Simon C.
name: Steane, Andrew M.
name: Lucas, David M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We demonstrate the use of dynamic decoupling techniques to extend the coherence time of a single memory qubit by nearly two orders of magnitude. By extending the Hahn spin-echo technique to correct for unknown, arbitrary polynomial variations in the qubit precession frequency, we show analytically that the required sequence of pi-pulses is identical to the Uhrig dynamic decoupling (UDD) sequence. We compare UDD and CPMG sequences applied to a single Ca-43 trapped-ion qubit and find that they afford comparable protection in our ambient noise environment.
description: 5 pages, 5 figures
Radiation Damage to the diamond-based Beam Condition Monitor of the CMS Detector at the LHC
Creators: name: Guthoff, Moritz
Publisher: name: Karlsruhe
Year: 2014
Subjects: Diamond detectors
Radiation damage
Polarization
TCT measurements
Simulation

description: In the Beam Condition Monitor at the CMS experiment at the LHC, CVD diamonds are used as detectors. During Run 1 operation of the LHC, significant reduction of signal efficiency due to radiation damage was observed. The decrease was significantly stronger than expected. The so-called polarization effect is responsible for this signal reduction. Electric field deformations due to trapped charge carriers are shown in measurements using the transient current technique and compared with simulations.
Localization and characterization of hydrothermal alteration zones in a geothermal reservoir and their significance for rock mechanics
Creators: name: Meller, Carola
Publisher: name: Karlsruhe
Year: 2014
Subjects: Deep Geothermal Energy
hydrothermal alteration
geomechanics

description: The present thesis introduces a method to localize hydrothermally altered zones in a crystalline geothermal reservoir. On the basis of synthetic clay content logs, the geomechanical significance of clay zones is demonstrated. It is shown that clay zones reduce the rock strength, thus creating aseismic slips on fractures and affecting the evolution of induced seismicity. The results of the thesis highlight the importance of hydrothermal alteration for hydro-mechanical reservoir characterization.
Dielectron production in Ar+KCl collisions at 1.76A GeV
Creators: name: Agakishiev, G.
name: Balanda, A.
name: Belver, D.
name: Belyaev, A.
name: Blanco, A.
name: Böhmer, M.
name: Boyard, J. L.
name: Cabanelas, P.
name: Castro, E.
name: Chernenko, S.
name: Christ, T.
name: Destefanis, M.
name: Dohrmann, F.
name: Dybczak, A.
name: Eberl, T.
name: Epple, E.
name: Fabbbietti, L.
name: Fateev, O.
name: Finocchiaro, P.
name: Fonte, P.
name: Friese, J.
name: Fröhlich, I.
name: Galatyuk, T.
name: Garzon, J. A.
name: Gernhäuser, R.
name: Gilardi, C.
name: Golubeva, M.
name: Gonzalez-Díaz, D.
name: Guber, F.
name: Gumberidze, M.
name: Heinz, T.
name: Hennino, T.
name: Holzmann, R.
name: Huck, P.
name: Iori, I.
name: Ivashkin, A.
name: Jurkovic, M.
name: Kämpfer, B.
name: Kanaki, K.
name: Karavicheva, T.
name: Koenig, I.
name: Koenig, W.
name: Kolb, B. W.
name: Kotte, R.
name: Krasa, A.
name: Krizek, F.
name: Krücken, R.
name: Kuc, H.
name: Kühn, W.
name: Kugler, A.
name: Kurepin, A.
name: Lang, S.
name: Lange, J. S.
name: Liu, K. Lapidus T.
name: Lopes, L.
name: Lorenz, M.
name: Maier, L.
name: Mangiarotti, A.
name: Markert, J.
name: Metag, V.
name: Michalska, B.
name: Michel, J.
name: Moriniere, E.
name: Mousa, J.
name: Müntz, C.
name: Naumann, L.
name: Otwinowski, J.
name: Pachmayer, Y. C.
name: Palka, M.
name: Pechenov, V.
name: Pechenova, O.
name: Pietraszko, J.
name: Przygoda, W.
name: Ramstein, B.
name: Reshetin, A.
name: Rustamov, A.
name: Sadovsky, A.
name: Sailer, B.
name: Salabura, P.
name: Schmah, A.
name: Schwab, E.
name: Siebenson, J.
name: Sobolev, Yu. G.
name: Spataro, S.
name: Spruck, B.
name: Ströbele, H.
name: Stroth, J.
name: Sturm, C.
name: Tarantola, A.
name: Teilab, K.
name: Tlusty, P.
name: Traxler, M.
name: Trebacz, R.
name: Tsertos, H.
name: Wagner, V.
name: Weber, M.
name: Wendisch, C.
name: Wisniowski, M.
name: Wüstenfeld, J.
name: Yurevich, S.
name: Zanevsky, Y.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We present results on dielectron production in Ar+KCl collisions at 1.76A GeV. For the first time $ω$ mesons could be reconstructed in a heavy-ion reaction at a bombarding energy which is well below the production threshold in free nucleon-nucleon collisions. The omega multiplicity has been extracted and compared to the yields of other particles, in particular of the phi meson. At intermediate e+e- invariant masses, we find a strong enhancement of the pair yield over a reference spectrum from elementary nucleon-nucleon reactions suggesting the onset of non-trivial effects of the nuclear medium. Transverse-mass spectra and angular distributions have been reconstructed in three invariant mass bins. In the former unexpectedly large slopes are found for high-mass pairs. The latter, in particular the helicity-angle distributions, are largely consistent with expectations for a pair cocktail dominated at intermediate masses by delta Dalitz decays.
description: 16 pages, 14 figures, accepted for publication by Phys. Rev. C
Field-induced decay dynamics in square-lattice antiferromagnet
Creators: name: Mourigal, M.
name: Zhitomirsky, M. E.
name: Chernyshev, A. L.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Dynamical properties of the square-lattice Heisenberg antiferromagnet in applied magnetic field are studied for arbitrary value S of the spin. Above the threshold field for two-particle decays, the standard spin-wave theory yields singular corrections to the excitation spectrum with logarithmic divergences for certain momenta. We develop a self-consistent approximation applicable for S >= 1, which avoids such singularities and provides regularized magnon decay rates. Results for the dynamical structure factor obtained in this approach are presented for S = 1 and S = 5/2.
description: 12 pages, 11 figures, final version
First order parent formulation for generic gauge field theories
Creators: name: Barnich, Glenn
name: Grigoriev, Maxim
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We show how a generic gauge field theory described by a BRST differential can systematically be reformulated as a first order parent system whose spacetime part is determined by the de Rham differential. In the spirit of Vasiliev's unfolded approach, this is done by extending the original space of fields so as to include their derivatives as new independent fields together with associated form fields. Through the inclusion of the antifield dependent part of the BRST differential, the parent formulation can be used both for on and off-shell formulations. For diffeomorphism invariant models, the parent formulation can be reformulated as an AKSZ-type sigma model. Several examples, such as the relativistic particle, parametrized theories, Yang-Mills theory, general relativity and the two dimensional sigma model are worked out in details.
description: 36 pages, additional sections and minor corrections
The energy landscape of fullerene materials: a comparison between boron, boron-nitride and carbon
Creators: name: De, Sandip
name: Willand, Alexander
name: Amsler, Maximilian
name: Pochet, Pascal
name: Genovese, Luigi
name: Goedecker, Stefan
Publisher: name: arXiv
Year: 2010
Subjects: subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using the minima hopping global geometry optimization method on the density functional potential energy surface we study medium size and large boron clusters. Even though for isolated medium size clusters the ground state is a cage like structure they are unstable against external perturbations such as contact with other clusters. The energy landscape of larger boron clusters is glass like and has a large number of structures which are lower in energy than the cages. This is in contrast to carbon and boron nitride systems which can be clearly identified as structure seekers in our minima hopping runs. The differences in the potential energy landscape explain why carbon and boron nitride systems are found in nature whereas pure boron fullerenes have not been found.
description: 5 pages 5 figures
Loxoblemmus (Asonicogryllus) bronzus He 2021, sp. nov.
Creators: name: Xu, Jing-Yi
name: Liu, Yi-Jiao
name: Li, Shi-Yu
name: He, Zhu-Qing
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Gryllidae
Loxoblemmus
Loxoblemmus bronzus

description: Loxoblemmus (Asonicogryllus) bronzus He sp. nov. ffiů濯Dz Figs 1–5 Holotype: male, CHINA, Yunnan, Dehong, Ruili (E 97.86 N 24.02), 26-iv-2018, coll. He Zhu-Qing. Paratypes: 3 females & 2 males, same data as holotype; 1 female, CHINA, Yunnan, Dehong, Longchuan (E 97.79 N 24.18), Alt. 1600 m, 10-vi-2018, coll. Bi Wen-Xuan. Description. Male. Head: shining, vertex little protruding, frontal rostrum flat, 2 times as wide as the 1st antennal joint, median ocellus lower than lateral ocelli, maxillary palpi normal (Fig. 2 CDE); Thorax: pronotum setose, anterior and posterior margin almost straight, without border between disc and lateral lobes, one oval tympanum on outside of foretibia and one small tympanum on inner side (Fig. 2 FG); forewings well developed, 2–2.5 times as long as pronotum (Fig. A). Hind tibia with 5 pairs of dorsal spines, three inner apical spurs and three outer spurs (Fig. 2 H), epiproct normal (Fig. 2 I). Genitalia: posterior epiphallic lobes elongate and apically little curved upwards, mesal posterior epiphallus protruding but little concave in middle, posterior edge of ectoparameron large and swollen; as long as posterior epiphallic lobes (Fig. 3 ABC). Female. Similar to male; forewing 1.5 times the length of pronotum (Fig. 2 B), ovipositor long and straight (Fig. 2 J). Coloration. Hatchlings: head light yellow and antennae white (Fig. 4 A). Nymphs: posterior part of head with a white stripe, antennae white with black apex (Fig. 4 B). Adults: almost black, forewing brown (Fig. 4 CD). Etymology. The name bronzus is used to emphasize the color of its forewings. Measurements (in mm). Male: body length 12.02–13.06, pronotum length 2.59–2.88, hind femur length 6.80–7.40, forewing length 6.01–6.38 Female: body length 11.87–13.32, pronotum length 2.54–2.80, hind femur length 6.74–7.05, forewing length 3.57–3.63, ovipositor length 6.61–7.17. Song. The song rate is about 98 pulse groups/minute. One pulse group consists of 9.029±1.243 pulses. The duration of pulse group is 0.419± 0.068s. The interval of pulse group is 0.205± 0.032s, as in Fig. 5. Distribution. China (Yunnan).
description: Published as part of Xu, Jing-Yi, Liu, Yi-Jiao, Li, Shi-Yu & He, Zhu-Qing, 2021, A new species of subgenus Asonicogryllus He, 2019 from Yunnan (Orthoptera: Gryllidae: Gryllinae), pp. 238-246 in Zootaxa 5040 (2) on pages 242-245, DOI: 10.11646/zootaxa.5040.2.4, http://zenodo.org/record/5531315
Scalar radiation from Chameleon-shielded regions
Creators: name: Silvestri, Alessandra
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: I study the profile of the Chameleon field around a radially pulsating mass. Focusing on the case in which the background (static) Chameleon profile exhibits a thin-shell, I add small perturbations to the source in the form of time-dependent radial pulsations. It is found that the Chameleon field inherits a time-dependence, there is a resultant scalar radiation from the region of the source and the metric outside the spherically symmetric mass is not static. This has several interesting and potentially testable consequences.
description: 4 pages, 4 figures, slightly edited version matching the journal version
Band-tail shape and transport near the metal-insulator transition in Si-doped Al(0.3)Ga(0.7)As
Creators: name: Misuraca, Jennifer
name: Trbovic, Jelena
name: Lu, Jun
name: Zhao, Jianhua
name: Ohno, Yuzo
name: Ohno, Hideo
name: Xiong, Peng
name: von Molnár, Stephan
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In the present work, an infrared LED is used to photodope MBE-grown Si:Al(0.3)Ga(0.7)As, a well known persistent photoconductor, to vary the effective electron concentration of samples in situ. Using this technique, we examine the transport properties of two samples containing different nominal doping concentrations of Si (1x10^19 cm^-3 for sample 1 (S1) and 9x10^17 cm^-3 for sample 2 (S2)) and vary the effective electron density between 10^14 and 10^18 cm^-3. The metal-insulator transition (MIT) for S1 is found to occur at a critical carrier concentration of 5.7x10^16 cm^-3 at 350 mK. The mobilities in both samples are found to be limited by ionized impurity scattering in the temperature range probed, and are adequately described by the Brooks-Herring screening theory for higher carrier densities. The shape of the band-tail of the density of states (DOS) in Al(0.3)Ga(0.7)As is found electrically through transport measurements. It is determined to be exponential in character, with an exponent of -1.25 for S1 and -1.38 for S2.
description: 16 pages, 8 figures
Supersums for all supersymmetric amplitudes
Creators: name: Sogaard, Mads
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present an on-shell graphical framework for superamplitudes in super Yang-Mills theory with arbitrary supersymmetry. Our diagrammatic procedure is derived through manipulations of the full N = 4 superamplitude and illustrated by a number of explicit examples.
description: 13 pages, 5 figures; v2: typos corrected, references added
Effects of yoga experience compared to exercise on functional connectivity in distributed brain networks
Creators: name: Sande, Peder
Publisher: name: University of British Columbia
Year: 2017

description: Introduction: During a difficult life event, such as dealing with a chronic health condition, practicing acceptance of the difficulty alters the context in which a person views that difficulty. Acceptance of that difficulty reduces negative avoidant emotions that are key aspects of anxiety and depression. Acceptance is a central training feature of many contemplative practices, such as yoga. However, we lack a complete understanding of the underlying mechanisms that successfully train acceptance, and methods for validating their successful transfer ‘off the matt’ in order to benefit the general public in their everyday lives. Method: During rest, functional magnetic imaging was used in yoga practitioners (YP) and recreational athletes (RA) to determine how practice of these activities induces lasting functional connectivity changes. In a previous study, the right Supramarginal gyrus (rSMG) was shown to be active during emotionally eliciting video clips in YP when compared to RA (Wadden et al., 2015). We examined both whole brain resting state, independent component analysis (ICA) of the rSMG as a region of interest (ROI), and cortical thickness. Results: Whole brain resting state analysis showed YP group activated clusters of voxels in the L Preceneus and R Superior Frontal Gyrus and RA group activated clusters of voxels in the Left Frontal Pole and R MFG. The rSMG ROI formed a network with YP group activated clusters of voxels in the L Superior ii Frontal Gyrus, R Precentral Gyrus, and R Precuneus and RA group activated clusters of voxels in the R Superior Medial Gyrus, R Lingual Gyrus, and L Thalamus. Conclusions: During whole brain resting state and ROI rSMG analysis YP compared to RA showed integration with the Precuneus, a region typically implicated in the default mode network (DMN), and the LDLPFC and the rSMG, both parts of the Frontoparietal network (FPN). This greater integration within and between networks indicates a relationship between individuals who practice habitual attentional training practices and typical anticorrelated systems of attention and the narrative self.
Simulation und Optimierung logistischer Prozesse in der Wärmebehandlung von Stahl
Creators: name: Ebermann, Eric
Publisher: name: Karlsruhe
Year: 2013
Subjects: Scheduling
Logistik
Stahlindustrie

description: Die vorliegende Arbeit wurde in Kooperation mit der AG der Dillinger Hüttenwerke, Europas führendem Hersteller von Qualitätsgrobblechen, angefertigt. Gegenstand der Arbeit sind die in Verbindung mit der Wärmebehandlung der Bleche stehenden logistischen Prozesse. Es konnte festgestellt werden, dass aus der betrachteten, realen Problemstellung ein in der Literatur bislang nicht vergleichbares Maschinenbelegungsproblem resultiert.
Transcendence degree of zero-cycles and the structure of Chow motives
Creators: name: Gorchinskiy, Sergey
name: Guletskii, Vladimir
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14C15, 14C25

description: We show how the notion of the transcendence degree of a zero-cycle on a smooth projective variety X is related to the structure of the motive M(X). This can be of particular interest in the context of Bloch's conjecture, especially for Godeaux surfaces, when the surface is given as a finite quotient of a suitable quintic in P^3.
description: 13 pages, added references
Daten- und termingesteuerte Entscheidungsmethodik der Fabrikplanung unter Berücksichtigung der Produktentstehung
Creators: name: Loos, Manuel Norbert
Publisher: name: Karlsruhe
Year: 2013
Subjects: Fabrikplanung
Produktentstehung
virtuelle Planung
Prozessintegration

description: Die Fabrikplanung ist heute mit diversen Trends und Herausforderungen konfrontiert, wie beispielsweise der Planung nachhaltiger Fabriken oder der Integration von Produkt und Fabrik. Hierzu leistet die vorliegende Arbeit einen Beitrag, virtuelle Methoden termingesteuert in einen Planungsprozess zu implementieren. Anhand einer generischen Vorgehensweise wird die Integration des Planungsprozesses in die Produktentstehung definiert, was durch zwei Industriebeispiele validiert wird.
Running coupling: Does the coupling between dark energy and dark matter change sign during the cosmological evolution?
Creators: name: Li, Yun-He
name: Zhang, Xin
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: In this paper we put forward a running coupling scenario for describing the interaction between dark energy and dark matter. The dark sector interaction in our scenario is free of the assumption that the interaction term $Q$ is proportional to the Hubble expansion rate and the energy densities of dark sectors. We only use a time-variable coupling $b(a)$ (with $a$ the scale factor of the universe) to characterize the interaction $Q$. We propose a parametrization form for the running coupling $b(a)=b_0a+b_e(1-a)$ in which the early-time coupling is given by a constant $b_e$, while today the coupling is given by another constant, $b_0$. For investigating the feature of the running coupling, we employ three dark energy models, namely, the cosmological constant model ($w=-1$), the constant $w$ model ($w=w_0$), and the time-dependent $w$ model ($w(a)=w_0+w_1(1-a)$). We constrain the models with the current observational data, including the type Ia supernova, the baryon acoustic oscillation, the cosmic microwave background, the Hubble expansion rate, and the X-ray gas mass fraction data. The fitting results indicate that a time-varying vacuum scenario is favored, in which the coupling $b(z)$ crosses the noninteracting line ($b=0$) during the cosmological evolution and the sign changes from negative to positive. The crossing of the noninteracting line happens at around $z=0.2-0.3$, and the crossing behavior is favored at about 1$σ$ confidence level. Our work implies that we should pay more attention to the time-varying vacuum model and seriously consider the phenomenological construction of a sign-changeable or oscillatory interaction between dark sectors.
description: 8 pages, 5 figures; refs added; to appear in EPJC
Samara no. 10 [Spanish].
Creators: name: Millennium Seed Bank Project
Publisher: name: Royal Botanic Gardens, Kew
Year: 2006
Subjects: Lebanon
Madagascar
China
Namibia
Australia
Seed banks
Seed conservation
Kirstenbosch National Botanical Gardens (South Africa)
Ex situ conservation
Guyana
Kenya
Plant conservation
Seeds of Success (Program)
Brazil
Millennium Seed Bank Project

description: IF = none.
description: Ardingly, West Sussex, UK
Finite temperature fidelity susceptibility for one-dimensional quantum systems
Creators: name: Sirker, J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We calculate the fidelity susceptibility chi_f for the Luttinger model and show that there is a universal contribution linear in temperature T (or inverse length 1/L). Furthermore, we develop an algorithm - based on a lattice path integral approach - to calculate the fidelity F(T) in the thermodynamic limit for one-dimensional quantum systems. We check the Luttinger model predictions by calculating chi_f(T) analytically for free spinless fermions and numerically for the XXZ chain. Finally, we study chi_f at the two phase transitions in this model.
description: typo in Eq. (9) corrected, published version
Physikalische Analyse der Ansprechverhaltens des CMS Siliziumdetektors beim Betrieb am LHC = Performance of the CMS Tracker under Irradiation
Creators: name: Barth, Christian
Publisher: name: Karlsruhe
Year: 2013
Subjects: radiation damage
silicon sensors
Hamburg model
leakage current
full depletion voltage

description: The subject of this thesis is the analysis of the evolution of silicon sensors' leakage current and full depletion voltage of the CMS silicon strip tracker. In this scope two newly developed measurement techniques for the full depletion voltage are presented. The results are compared with the established radiation damage models and a forecast for the evolution of the silicon sensors' properties is given.
The iterated integrals of ln(1 + x^2)
Creators: name: Amdeberhan, Tewodros
name: Koutschan, Christoph
name: Moll, Victor H.
name: Rowland, Eric S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 26A09, 11A25

description: For a polynomial P, we consider the sequence of iterated integrals of ln P(x). This sequence is expressed in terms of the zeros of P(x). In the special case of ln(1 + x^2), arithmetic properties of certain coefficients arising are described. Similar observations are made for ln(1 + x^3).
description: 21 pages, 1 figure; publication version
MPEC 2023-X132 : DAILY ORBIT UPDATE (2023 December 7)
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Multimodal Computational Attention for Scene Understanding
Creators: name: Schauerte, Boris
Publisher: name: Karlsruhe
Year: 2014
Subjects: Attention
Visual Saliency
Auditory Saliency
Scene Exploration
Human-Robot Interaction

description: Robotic systems have limited computational capacities. Hence, computational attention models are important to focus on specific stimuli and allow for complex cognitive processing. For this purpose, we developed auditory and visual attention models that enable robotic platforms to efficiently explore and analyze natural scenes. To allow for attention guidance in human-robot interaction, we use machine learning to integrate the influence of verbal and non-verbal social signals into our models.
The method of densities for non-isotropic Boolean models
Creators: name: Hörrmann, Julia
Publisher: name: Karlsruhe
Year: 2014
Subjects: Stochastic geometry
Boolean model
anisotropy
method of densities

description: This thesis deals with the Boolean model, a basic model of stochastic geometry for the description of porous structures like the pore space in sand stone. The main result is a formula which gives in two and three dimensions a series representation of the most important model parameter, the intensity, using densities of so-called harmonic intrinsic volumes, which are new observable geometric quantities.
Atmospheric Influences on Space-Based Observations of Extremely High-Energy Cosmic Rays
Creators: name: Falk, Stefanie Elfriede
Publisher: name: Karlsruhe
Year: 2014
Subjects: Astroparticle Physics
Cosmic Rays
JEM-EUSO
Atmosphere
Ozone

description: Air showers in the Earth's atmosphere emit UV light detectable from space. The impact of atmospheric conditions on light emission/transmission has been studied for a space-based CR observatory. The importance of scattering/ground reflection on the fraction of Cherenkov and fluorescence light received is pointed out. Measuring UV light from above, the attenuation by the ozone layer cannot be disregarded. Based upon air shower simulation, quantitative numbers of ozone attenuation are presented.
Computational studies of membrane-active antimicrobial peptides and comparison with NMR data
Creators: name: Reißer, Sabine
Publisher: name: Karlsruhe
Year: 2014
Subjects: Antimikrobielle Peptide
Molekulardynamik-Simulationen
Hydrophobes Moment
Lichtschaltbare Peptide
19F-Festkörper-NMR

description: Anhand von Computer-basierten Methoden wurde die Wechselwirkung zwischen antimikrobiellen Peptiden und Phospholipid-Membranen studiert. Die Orientierung helikaler Peptide wurde durch Membransimulationen bestimmt und mit experimentellen Ergebnissen verglichen. Mit dem neuen 3D-Hydrophoben-Moment-Vektor kann eine Orientierung eines Peptids in der Membran vorhergesagt werden. Außerdem enthält die Arbeit Studien zu lichtschaltbaren Analoga von Gramicidin S und 19F-Festkörper-NMR-Markierungen.
Strong Enhancement of High Voltage Electronic Transport in Chiral Electrical Nanotube Superlattices
Creators: name: Dietel, Juergen
name: Kleinert, Hagen
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We consider metallic carbon nanotubes with an overlying unidirectional electrical chiral (wavevector out of the radial direction, where the axial direction is included) superlattice potential. We show that for superlattices with a wavevector close to the axial direction, the electron velocity assumes the same value as for nanotubes without superlattice. Due to an increased number of phonons with different momenta but lower electron-phonon scattering probabilities, we obtain a large enhancement of the high-voltage conductance and current sustainability in comparison with the nanotube without superlattice.
description: 5 pages, 3 figures, published version
Quantum phase diagram of the half filled Hubbard model with bond-charge interaction
Creators: name: Dobry, A. O.
name: Aligia, A. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Using quantum field theory and bosonization, we determine the quantum phase diagram of the one-dimensional Hubbard model with bond-charge interaction $X$ in addition to the usual Coulomb repulsion $U$ at half-filling, for small values of the interactions. We show that it is essential to take into account formally irrelevant terms of order $X$. They generate relevant terms proportional to $X^2$ in the flow of the renormalization group (RG). These terms are calculated using operator product expansions. The model shows three phases separated by a charge transition at $U=U_c$ and a spin transition at $U=U_s>U_c$. For $UU_s$, the system is in the spin-density wave phase as in the usual Hubbard model. For intermediate values $U_c
description: 29 pages, 2 figures
Explicit drain-current model of graphene field-effect transistors targeting analog and radio-frequency applications
Creators: name: Jimenez, David
name: Moldovan, Oana
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present a compact physics-based model of the current-voltage characteristics of graphene field-effect transistors, of especial interest for analog and radio-frequency applications where bandgap engineering of graphene could be not needed. The physical framework is a field-effect model and drift-diffusion carrier transport. Explicit closed-form expressions have been derived for the drain current covering continuosly all operation regions. The model has been benchmarked with measured prototype devices, demonstrating accuracy and predictive behavior. Finally, we show an example of projection of the intrinsic gain as a figure of merit commonly used in RF /analog applications.
description: 10 pages, 4 figures
Constraints on Transport Models for Galactic Cosmic Rays and their Implications for the Anomalous Positron Abundance
Creators: name: Kunz, Simon Michael
Publisher: name: Karlsruhe
Year: 2014

description: While supernova remnants account for most of the cosmic rays in the Galaxy, they do not produce essential amounts of antimatter. The predicted amount of positrons, which are assumed to be purely secondary produced by cosmic ray interactions, cannot explain the measurements from PAMELA and very recently from AMS-02. In this work current cosmic ray transport models are investigated and the transport related uncertainty on the expected secondary positron flux is quantified.
Study of Orbitally Excited B(s) Mesons and Evidence for a New B pi Resonance with the CDF II Detector
Creators: name: Kambeitz, Manuel
Publisher: name: Karlsruhe
Year: 2014

description: Mithilfe von Daten des CDF-Experiments wurden die Eigenschaften angeregter B0-, B+- und Bs-Mesonen bestimmt. Die Ergebnisse umfassen Evidenz für eine bisher unbeobachtete Anregung und teils welterste oder weltbeste Messungen.
Spectroscopic follow-up of 70μm sources in Spitzer Wide-area Infrared Extragalactic Legacy Survey
Creators: name: Patel, H.
name: Clements, D. L.
name: Rowan-Robinson, M.
name: Vaccari, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present spectroscopic follow-up observations of 70μm selected galaxies from the SWIRE XMMLSS and Lockman Hole fields. We have measured spectroscopic redshifts for 293 new sources down to a 70μm flux limit of 9mJy and R < 22. The redshift distribution peaks at z ~ 0.3 and has a high redshift tail out to z = 3.5. We perform emission line diagnostics for 91 sources where [OIII], Hβ, [NII], Hα and [SII] emission lines are available to determine their power source. We find in our sample 13 QSOs, 1 Seyfert II galaxy, 33 star forming galaxies, 30 composite galaxies, 5 LINERs and 21 ambiguous galaxies. We fit single temperature dust spectral energy distributions (SEDs) to 81 70μm sources with 160μm photometry to estimate dust temperatures and masses. Assuming the dust emissivity factor (β) as 1.5, we determine temperatures in the range ~ 20-60K and dust masses with a range of 10{^6}-10{^9} M{_\odot}. Plotting these objects in the luminosity-temperature diagram suggests that these objects have lower dust temperatures than local IR luminous galaxies. The Herschel Space Observatory will be crucial in understanding the nature of these sources and to accurately determining the shape of the Rayleigh-Jeans tail of the dust SED. We then model SEDs from optical to far-IR for each source using a set of galaxy and quasar templates in the optical and near-IR (NIR) and with a set of dust emission templates (cirrus, M82 starburst, Arp 220 starburst and AGN dust torus) in the mid-IR (MIR) to far-IR (FIR). The number of objects fit with each dust template are: 57 Arp 220, 127 M82, 9 cirrus, 1 AGN dust torus, 70 M82 and cirrus, 26 M82 and AGN dust torus and 3 Arp 220 and AGN dust torus. We determine the total IR luminosity (LIR) in range 10{^8}-10{^{15}} L{_\odot} by integrating the SED models from 8 to 1000μm.
description: 14 pages, 13 figures
Algorithms for Graph Connectivity and Cut Problems - Connectivity Augmentation, All-Pairs Minimum Cut, and Cut-Based Clustering
Creators: name: Hartmann, Tanja
Publisher: name: Karlsruhe
Year: 2014

description: We address a collection of related connectivity and cut problems in simple graphs that reach from the augmentation of planar graphs to be k-regular and c-connected to new data structures representing minimum separating cuts and algorithms that smoothly maintain Gomory-Hu trees in evolving graphs, and finally to an analysis of the cut-based clustering approach of Flake et al. and its adaption to dynamic scenarios.
Cloud Standby - Eine Methode zur Vorhaltung eines Notfallsystems in der Cloud
Creators: name: Lenk, Alexander
Publisher: name: Karlsruhe
Year: 2014

description: Ziel dieser Arbeit ist es, eine neue Methode für die Vorhaltung eines Notfallsystems in der Cloud zu entwickeln, die aus einer Methode zur Notfallwiederherstellung und einer modellbasierten Deployment-Methode besteht. Die Methode zur Notfallwiederherstellung besteht aus einem Notfallwiederherstellungsprozess, eines Notfallwiederherstellungsprotokolls und einer Entscheidungsunterstützung zur Konfiguration des Prozesses besteht.
Magnetic Exchange Interactions in BaMn2As2: A Case Study of the J1-J2-Jc Heisenberg Model
Creators: name: Johnston, D. C.
name: McQueeney, R. J.
name: Lake, B.
name: Honecker, A.
name: Zhitomirsky, M. E.
name: Nath, R.
name: Furukawa, Y.
name: Antropov, V. P.
name: Singh, Yogesh
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: BaMn2As2 is unique among BaT2As2 compounds crystallizing in the body-centered-tetragonal ThCr2Si2 structure, which contain stacked square lattices of 3d transition metal T atoms, since it has an insulating large-moment (3.9 muB/Mn) G-type (checkerboard) antiferromagnetic AF ground state. We report measurements of the anisotropic magnetic susceptibility chi versus temperature T from 300 to 1000 K of single crystals of BaMn2As2, and magnetic inelastic neutron scattering measurements at 8 K and 75As NMR measurements from 4 to 300 K of polycrystalline samples. The Neel temperature determined from the chi(T) measurements is TN = 618(3) K. The measurements are analyzed using the J1-J2-Jc Heisenberg model. Linear spin wave theory for G-type AF ordering and classical and quantum Monte Carlo simulations and molecular field theory calculations of chi(T) and of the magnetic heat capacity Cmag(T) are presented versus J1, J2 and Jc. We also obtain band theoretical estimates of the exchange couplings in BaMn2As2. From analyses of our chi(T), NMR, neutron scattering, and previously published heat capacity data for BaMn2As2 on the basis of the above theories for the J1-J2-Jc Heisenberg model and our band-theoretical results, our best estimates of the exchange constants in BaMn2As2 are J1 = 13 meV, J2/J1 = 0.3 and Jc/J1 = 0.1, which are all antiferromagnetic. From our classical Monte Carlo simulations of the G-type AF ordering transition, these exchange parameters predict TN = 640 K for spin S = 5/2, in close agreement with experiment. Using spin wave theory, we also utilize these exchange constants to estimate the suppression of the ordered moment due to quantum fluctuations for comparison with the observed value and again obtain S = 5/2 for the Mn spin.
description: 48 pages, 33 figures, 11 tables, 86 references; v2: Added discussion to introduction, additional classical Monte Carlo data added; published version
Modeling of the response function and measurement of transmission properties of the KATRIN experiment
Creators: name: Groh, Stefan
Publisher: name: Karlsruhe
Year: 2015
Subjects: Neutrino
KATRIN
Monte Carlo
Kassiopeia
Transmissions
Spectrometer
Responsefunction

description: This thesis was performed in the context of the Karlsruhe Tritium Neutrino (KATRIN) experiment which aims to determine the effective mass of the electron antineutrino with an unprecedented sensitivity of 200 meV/c^2 (90% C.L.). The main goals of this thesis were to perform large scale Monte Carlo simulations of signal electrons to model the properties of the response function of the experiment with great precision as well as to determine the transmission properties of the main spectrometer.
Feasibility of quantum key distribution through dense wavelength division multiplexing network
Creators: name: Qi, Bing
name: Zhu, Wen
name: Qian, Li
name: Lo, Hoi-Kwong
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper, we study the feasibility of conducting quantum key distribution (QKD) together with classical communication through the same optical fiber by employing dense-wavelength-division-multiplexing (DWDM) technology at telecom wavelength. The impact of the classical channels to the quantum channel has been investigated for both QKD based on single photon detection and QKD based on homodyne detection. Our studies show that the latter can tolerate a much higher level of contamination from the classical channels than the former. This is because the local oscillator used in the homodyne detector acts as a "mode selector" which can suppress noise photons effectively. We have performed simulations based on both the decoy BB84 QKD protocol and the Gaussian modulated coherent state (GMCS) QKD protocol. While the former cannot tolerate even one classical channel (with a power of 0dBm), the latter can be multiplexed with 38 classical channels (0dBm power each channel) and still has a secure distance around 10km. Preliminary experiment has been conducted based on a 100MHz bandwidth homodyne detector.
description: 18 pages, 5 figures
Continuous Market Engineering - Focusing Agent Behavior, Interfaces, and Auxiliary Services
Creators: name: Kranz, Tobias Theodor
Publisher: name: Karlsruhe
Year: 2015
Subjects: Market Engineering
Prediction Markets
Continuous Market Engineering

description: Electronic markets spread out amongst business entities as well as private individuals. Albeit numerous approaches on developing electronic markets exist, a unified approach targeting market development, redesign, and refinement has been lacking. This thesis studies the potential of continuously improving electronic markets. Thereby, the experiments? design focuses on Agent Behavior, Interfaces, and Auxiliary Services and thus unveils the potential of continuously improving electronic markets.