cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Tilings, Chern-Simons Theories and M2 Branes
Creators: name: Hanany, Amihay
name: Zaffaroni, Alberto
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A new infinite class of Chern-Simons theories is presented using brane tilings. The new class reproduces all known cases so far and introduces many new models that are dual to M2 brane theories which probe a toric non-compact CY 4-fold. The master space of the quiver theory is used as a tool to construct the moduli space for this class and the Hilbert Series is computed for a selected set of examples.
description: 23 pages, minor changes, references added
Conditional dynamics induced by new configurations for Rydberg dipole-dipole interactions
Creators: name: Brion, E.
name: Mouritzen, A. S.
name: Molmer, K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We suggest a novel way to use strong Rydberg dipole-dipole interactions in order to induce non-trivial conditional dynamics in individual-atom systems and mesoscopic ensembles. Contrary to previous works, we suggest to excite atoms into different Rydberg states, which results in a potentially richer dynamical behaviour. Specifically, we investigate systems of individual hydrogen-like atoms or mesoscopic ensembles excited into high-lying hydrogen-like s, p or d states and show how to perform three-qubit conditional dynamics on the information they contain through a proper use of dipole-dipole interaction induced energy shifts.
description: 5 pages, 4 figures
Stability of asymptotically AdS wormholes in vacuum against scalar field perturbations
Creators: name: Correa, Diego H.
name: Oliva, Julio
name: Troncoso, Ricardo
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The stability of certain class of asymptotically AdS wormholes in vacuum against scalar field perturbations is analyzed. For a free massive scalar field, the stability of the perturbation is guaranteed provided the squared mass is bounded from below by a negative quantity. Depending on the base manifold of the AdS asymptotics, this lower bound could be more stringent than the Breitenlohner-Freedman bound. An exact expression for the spectrum is found analytically. For a scalar field perturbation with a nonminimal coupling, slow fall-off asymptotic behavior is also allowed, provided the squared mass fulfills certain negative upper bound. Although the Ricci scalar is not constant, an exact expression for the spectrum of the scalar field can also be found, and three different quantizations for the scalar field can be carried out. They are characterized by the fall-off of the scalar field, which can be fast or slow with respect to each asymptotic region. For these perturbations, stability can be achieved in a range of negative squared masses which depends on the base manifold of the AdS asymptotics. This analysis also extends to a class of gravitational solitons with a single conformal boundary.
description: 33 pages, 4 figures; v2: Analysis extended to gravitational solitons, references added, last version for JHEP
Bohmian trajectories and the Path Integral Paradigm. Complexified Lagrangian Mechanics
Creators: name: Sbitnev, Valeriy I.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: David Bohm shown that the Schr{ö}dinger equation, that is a "visiting card" of quantum mechanics, can be decomposed onto two equations for real functions - action and probability density. The first equation is the Hamilton-Jacobi (HJ) equation, a "visiting card" of classical mechanics, to be modified by the Bohmian quantum potential. And the second is the continuity equation. The latter can be transformed to the entropy balance equation. The Bohmian quantum potential is transformed to two Bohmian quantum correctors. The first corrector modifies kinetic energy term of the HJ equation, and the second one modifies potential energy term. Unification of the quantum HJ equation and the entropy balance equation gives complexified HJ equation containing complex kinetic and potential terms. Imaginary parts of these terms have order of smallness about the Planck constant. The Bohmian quantum corrector is indispensable term modifying the Feynman's path integral by expanding coordinates and momenta to imaginary sector.
description: 14 pages, 3 figures, 46 references, 48 equations
Darstellbarkeit - Zu einem Schlüsselbegriff romantischer Theoriebildung
Creators: name: Heinen, Sandra
Publisher: name: KULT_online
Year: 2005

description: Der von Claudia Albes und Christiane Frey herausgegebene Sammelband zum Problem der Darstellbarkeit rekonstruiert die um 1800 im ästhetischen wie philosophischen Diskurs virulente Frage nach den Möglichkeiten und Grenzen menschlicher Signifikation. Das große zeichentheoretische Interesse in der damaligen Theoriebildung und ästhetischen Praxis hat, so die These des Bandes, seine Ursache in einer "tiefgreifenden Krise des rationalistischen Zeichenmodells der Repräsentation" (S. 10): Die Annahme von transparenten, unsichtbaren Zeichen, die auf zeichenfreie Vorstellungen verweisen können, wird im letzten Drittel des 18. Jahrhunderts zunehmend zweifelhaft.
description: KULT_online, Nr. 07 (2005): KULT_online 07 (2005)
The radio properties of type II quasars
Creators: name: Lal, Dharam Vir
name: Ho, Luis C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Quasars (of type I) are the luminous analogs of type I Seyfert galaxies. Within the framework of unified models of active galaxies, the population of quasars of type II recently discovered with the Sloan Digital Sky Survey are the luminous analogs of type II Seyfert galaxies. Since our knowledge and understanding of the radio properties of these type II quasars are very limited, we have performed Very Large Array observations for a sub-sample of such sources. Our detection rate of 61% is consistent with the detection rate for other AGN samples. We do not find a correlation between radio and [O III] $λ$5007 luminosities for these sources. Although the distribution of spectral indices is similar to that of the 3C sources, the lack of dependence of radio luminosity on [O III] $λ$5007 luminosity suggests that not all sources in the sample are genuine AGNs.
description: 4 pages, 3 figures, To appear in "The Central Engine of Active Galactic Nuclei", ed. L. C. Ho and J.-M. Wang (San Francisco: ASP)
Ein produktiver Dialog zwischen Gender-Theorie und literarischen Texten
Creators: name: Stritzke, Nadyne
Publisher: name: KULT_online
Year: 2005

description: Die narrative Thematisierung und Inszenierung des gender-bending oder auch gender-blending, also das Spiel mit ambivalenten Geschlechtsidentitäten, in vornehmlich britischer Gegenwartsliteratur steht im Zentrum der Habilitationsschrift von Eveline Kilian. Dabei setzt die gender-theoretisch orientierte Studie auf das produktive Zusammenspiel von theoretischer Reflexion und literaturwissenschaftlicher Analyse. Das Resultat dieser dialogischen Vorgehensweise ist eine Reflexion und Demonstration des spezifischen Leistungsvermögens literarischer Erzähltexte im Rahmen der gender-orientierten Literaturwissenschaft sowie der kulturwissenschaftlichen gender studies. Gleichzeitig führt Kilian in zentrale Parameter der diskurstheoretischen Auseinandersetzung mit den Kategorien Geschlecht, Geschlechtsidentität und sexuelle Orientierung ein.
description: KULT_online, Nr. 07 (2005): KULT_online 07 (2005)
Guter Rat, nicht teuer
Creators: name: Basseler, Michael
Publisher: name: KULT_online
Year: 2005

description: Gute Einführungen für Studierende der Literaturwissenschaft sind selten: Meist liegt ihr Hauptproblem darin, dass die Autoren - in der Regel honorige Vertreter ihrer wissenschaftlichen Zunft - am Zielpublikum, also den Studierenden, vorbei schreiben. Das Resultat ist, dass sich der Frust und die Ablehnung gegenüber der Theorie auf Seiten der StudentInnen erhöht und die Kluft zwischen der fortschreitend theoretisierten Literaturwissenschaft und ihrem eigenen Nachwuchs weiter wächst - eine Entwicklung, an der weder Lehrenden noch Lernenden gelegen sein dürfte. Als löbliche Ausnahme kann der vorliegende Sammelband gelten, der die in der anglistischen/amerikanistischen Literaturwissenschaft zentralen Theorien verständlich vermittelt.
description: KULT_online, Nr. 07 (2005): KULT_online 07 (2005)
Kulturpoetik reloaded, oder: Die Bedienungsanleitung für den New Historicism
Creators: name: Butler, Martin
Publisher: name: KULT_online
Year: 2006

description: In seiner Studie Die kulturpoetische Funktion und das Archiv unternimmt Moritz Baßler, wie es der Untertitel seiner Studie bereits verrät, den Versuch einer literaturwissenschaftlichen Text-Kontext-Theorie. Auf der Basis einer - wie sich im Laufe seiner Argumentation herausstellt - äußerst fruchtbaren Verbindung neohistorischer Grundannahmen mit dem poststrukturalistischen Intertextualitätskonzept entwirft er ein theoretisch fundiertes Konzept zur Erfassung der Text-Kontext-Relation, welches durch seine Anwendbarkeit in der literatur- bzw. kulturwissenschaftlichen Praxis besticht und so der generellen Skepsis gegenüber dem New Historicism als praktikablen literaturtheoretischen Ansatz entgegentritt.
description: KULT_online, Nr. 08 (2006): KULT_online 08 (2006)
Conversion of glassy antiferromagnetic-insulating phase to equilibrium ferromagnetic-metallic phase by devitrification and recrystallization in Al substituted Pr${_{0.5}}$Ca$_{0.5}$MnO${_3}$
Creators: name: Banerjee, A.
name: Kumar, Kranti
name: Chaddah, P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We show that Pr${_{0.5}}$Ca$_{0.5}$MnO${_3}$ with 2.5% Al substitution and La${_{0.5}}$Ca$_{0.5}$MnO${_3}$ (LCMO) exhibit qualitatively similar and visibly anomalous M-H curves at low temperature. Magnetic field causes a broad first-order but irreversible antiferromagnetic (AF)-insulating (I) to ferromagnetic (FM)-metallic (M) transition in both and gives rise to soft FM state. However, the low temperature equilibrium state of Pr$_{0.5}$Ca$_{0.5}$Mn$_{0.975}$Al$_{0.025}$O$_3$ (PCMAO) is FM-M whereas that of LCMO is AF-I. In both the systems the respective equilibrium phase coexists with the other phase with contrasting order, which is not in equilibrium, and the cooling field can tune the fractions of the coexisting phases. It is shown earlier that the coexisting FM-M phase behaves like `magnetic glass' in LCMO. Here we show from specially designed measurement protocols that the AF-I phase of PCMAO has all the characteristics of magnetic glassy states. It devitrifies on heating and also recrystallizes to equilibrium FM-M phase after annealing. This glass-like AF-I phase also shows similar intriguing feature observed in FM-M magnetic glassy state of LCMO that when the starting coexisting fraction of glass is larger, successive annealing results in larger fraction of equilibrium phase. This similarity between two manganite systems with contrasting magnetic orders of respective glassy and equilibrium phases points toward a possible universality.
description: Highlights potential of CHUF (Cooling and Heating in Unequal Fields), a new measurement protocol
Von "Gesellschaft" zu "Gedächtnis" - Europäische Geschichte(n) von der Peripherie her betrachtet
Creators: name: Herweg, Nikola
Publisher: name: KULT_online
Year: 2006

description: Zwei Thesen stellt der Historiker Dan Diner seinem Essayband Gedächtniszeiten. Über Jüdische und andere Geschichten voran: Ein seiner Meinung nach anstehender Perspektivenwechsel in den Geschichtswissenschaften von einem linearen, am Nationalstaat orientieren Geschichtsverständnis zu einem gleichberechtigten Nebeneinander verschiedener Geschichten sowie die paradigmatische Bedeutung jüdischer Geschichte(n) für die Geschichtswissenschaft. In 14 zwischen 1985 und 2002 verfassten Essays konkretisiert Diner verschiedene Aspekte dieser Kernthesen und fragt nach den Möglichkeiten und Bedingungen einer europäischen Identität.
description: KULT_online, Nr. 08 (2006): KULT_online 08 (2006)
Verfassung, Staat und Demokratie in Europa: Ein Debattenbeitrag von Kleger, Karolewski und Munke
Creators: name: Wiesner, Claudia
Publisher: name: KULT_online
Year: 2006

description: Kleger, Karolewski und Munke liefern einen innovativen und umfassend angelegten Beitrag zur hochaktuellen Debatte um die europäische Verfassung. Die Autoren verbinden die demokratietheoretisch angelegte Diskussion der Verfassungsbildung der EU mit einer umfangreichen Darstellung verschiedenster Aspekte, die von einem Aufriss der europäischen Integration über eine Skizze der Rolle von Nationalstaaten und nationaler Identität zu einer Diskussion der Osterweiterung und osteuropäischer Europadebatten reichen. Diese Breite des Bandes führt allerdings dazu, dass viele wesentliche Bereiche nur grob angerissen und zu vereinfacht dargestellt werden.
description: KULT_online, Nr. 08 (2006): KULT_online 08 (2006)
A canonical Frobenius structure
Creators: name: Douai, Antoine
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 32S40

description: We show that it makes sense to speak of THE Frobenius manifold attached to a convenient and nondegenerate Laurent polynomial
description: 24 pages
Self-Motions of General 3-RPR Planar Parallel Robots
Creators: name: Briot, Sébastien
name: Bonev, Ilian
name: Chablat, Damien
name: Wenger, Philippe
name: Arakelian, Vigen
Publisher: name: arXiv
Year: 2008
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: This paper studies the kinematic geometry of general 3-RPR planar parallel robots with actuated base joints. These robots, while largely overlooked, have simple direct kinematics and large singularity-free workspace. Furthermore, their kinematic geometry is the same as that of a newly developed parallel robot with SCARA-type motions. Starting from the direct and inverse kinematic model, the expressions for the singularity loci of 3-RPR planar parallel robots are determined. Then, the global behaviour at all singularities is geometrically described by studying the degeneracy of the direct kinematic model. Special cases of self-motions are then examined and the degree of freedom gained in such special configurations is kinematically interpreted. Finally, a practical example is discussed and experimental validations performed on an actual robot prototype are presented.
Utilizing salt affected ecosystem by growing Banana cultivars for sustainable production
Creators: name: Devi, A Nithya
name: Auxcilia, J
name: Kumanan, K
Publisher: name: Zenodo
Year: 2021
Subjects: Banana sodicity tolerance cultivars

description: Salt affected soil (SAS) is a holistic term used to designate the soils having either excess soluble salts and/or exchangeable sodium. Soils are classified into normal, saline, sodic and saline-sodic. High ESP (>15) deteriorates the structure, impedes the water and air flows, reduces water intake capacity and hampers the root penetration in sodic soils. Several trees species slowly improve the physical, chemical and biological properties of sodic soils. Considering relatively less returns from agro-forestry trees, efforts have been made for raising more profitable fruit crops in sodic lands. Fifteen banana genotypes were evaluated for growth, yield and physiological parameters under saline – sodic condition.The soil is characterised with a pH of 8.9, EC of 1.4dsm-1 and ESP of 15%. The irrigation water recorded a pH of 8.4 and EC of 1.87 dsm-1 and 12% RSC. In this study on screening for resistance to sodic stress, field evaluation was carried out. Yield attributes showed highest yield in FHIA -1 (23.5 kg), Saba (22.2 kg), Udhayam (22.5 kg) and Karpooravalli (22.0 kg). FHIA – 1(1.0), Saba (1.0) and Karpooravalli (2.0) recorded the minimum sodicity damage score. Comparative performance evaluation revealed that the cvs. Saba, FHIA – 1 and Karpooravalli were found to be field tolerant under sodic conditions. The cultivars Grand Naine, Rasthali and Co-1 were ranked as sensitive to sodicity stress.
Genetic Variability And Selection Of Superior Genotypes Of Star Gooseberry Growing In Mizoram, India.
Creators: name: Rody Ngurthankhumi
name: T.K. Hazarika
Publisher: name: Zenodo
Year: 2021

description: Star gooseberry like aonla can be considered as an important fruit crop due to its rich source of nutrients especially in its vitamin C content. Although it can also be classified as an important horticulture fruit crop its selection and genetic variability has not been researched as much as its counterpart Aonla. During 2017-2018, an experiment was conducted to find superior genotypes of star gooseberry of Mizoram and to assess variability for physical and biochemical parameters. 30 different accessions were collected from 6 districts of Mizoram.Substantial difference across genotypes was observed in fruit weight, fruit length, fruit diameter, fruit volume, specific gravity, pulp weight, pulp-seed ratio, pulp percentage, seed weight, moisture content, TSS, acidity, ascorbic acid, total sugars, reducing sugar, non-reducing sugar, sugar: acid ratio, TSS: acid ratio.Therefore, from the present investigation, the superior genotypes that were identified can be considered as elite star gooseberry genotypes from Mizoram and could further be subjected for future improvement programme.
Mathematical Model of a Counter-Flow Rotary Dryer for Automation Control A case study in a Granulated Organic Fertilizer Drying Process in a Chicken Farm
Creators: name: Chayaphan Sringak
name: Ratchaphon  Suntivarakorn
name: Thana Radpukdee
Publisher: name: Faculty of Engineering, Khon Kaen Univeristy
Year: 2012
Subjects: Biogas, Variable structure control

description: 3, 39, KKU Engineering Journal
Interdigital Electrode Water Level Sensor
Creators: name: Titinan Tapaonoi
name: Pornchai Phukpattaranont
name: Wannarat Suntiamorntut
name: Kanadit Chetpattananondh
Publisher: name: Faculty of Engineering, Khon Kaen Univeristy
Year: 2012
Subjects: Interdigital sensors, Water level sensors, Liquid level measurement, Capacitance sensors

description: 3, 39, KKU Engineering Journal
Evaluation of Genetic Diversity of Carambola using RAPD marker in North east India
Creators: name: R. Lalmuanpuii
name: R. Singh
Publisher: name: Zenodo
Year: 2021

description: Looking at the importance of Carambola with respect to its medicinal and nutritional value, the demand for the planting material of this underutilized fruit gradually increased. However, there is no specific recommended variety available although wide variability exists throughout the length and width of North East India, showing wide variation in fruit quality (sweet and sour), shape, sizes and yield. Moreover, these variabilities have neither been exploited nor properly documented and are grown in homestead garden or wild form. Farmers have been using planting materials of seedling origin with unknown yield potential and fruit quality. Thus, emphasizing on these facts an extensive survey was conducted in different parts of North East India (Arunachal Pradesh, Assam, Manipur and Meghalaya) during 2017-19 to study the genetic diversity of carambola using morphological and molecular marker to assess variability within the genotypes as well as to evaluate superior genotypes of Carambola having sweet taste and high yield potential based on the descriptor of NBPGR of carambola. The experimental results showed significant difference with respect to individual fruit weight, fruit length, volume of fruit, fruit yield, TSS, Oxalic Acid, Ascorbic acid and acidity. RAPD molecular marker also showed considerable variation in which out of the 20 RAPD markers used 15 primers generated 92 total numbers of band and 64 polymorphic bands with a mean of 4.26 bands per primer and 69.34% polymorphism. Key words: Carambola, morphological marker and RAPD marker
Are there long-time tails in granular flows?
Creators: name: Hayakawa, Hisao
name: Otsuki, Michio
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The long-time behaviors of the velocity autocorrelation function (VACF) for granular flows based on the optimal velocity fluid model are investigated theoretically. It is found the long-time tail of VACF disappears in a granular flow under the gravity.
description: 7 pages, submitted to Prog. Theor. Phys. Suppl. as a proceedings of Symposium on the 50th anniversary of the Alder transition
X-rays profiles in symmetric and asymmetric supernova remnants
Creators: name: Zaninetti, Lorenzo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The non-thermal X-rays from the SN 1006 NE rim present characteristic scale lengths that are interpreted in the context of diffusion of a relativistic electron. The adopted theoretical framework is the mathematical diffusion in 3D, 1D and 1D with drift as well as the Monte Carlo random walk in 1D with drift. The asymmetric random walk with diffusion from a plane can explain the scale widths of 0.04 pc upstream and 0.2 pc downstream in the non thermal intensity of X-ray emission in SN 1006. A mathematical image of the non thermal X-flux from an supernova remnant as well as profiles function of the distance from the center can be simulated. This model provides a reasonable description of both the limbs and the central region of SN 1006. A new method to deduce the magnetic field in supernova remnant is suggested.
description: 18 low quality figures, 46 pages
title: 107 - Étameur sur fer-blanc des usines de Commentry (Allier - France)
title: 107 - Tin-Worker at the Commentry Factories (Allier - France)
Creators: name: Généro, Jean-Damien
Publisher: name: NAKALA - https://nakala.fr (Huma-Num - CNRS)
publisherIdentifier: https://ror.org/04ces3204
publisherIdentifierScheme: ROR
Year: 2025

description: Images et édition numérique (XML, LaTeX, PDF) de *Étameur sur fer-blanc des usines de Commentry (Allier — France), ouvrier-propriétaire dans le système des engagements momentanés, d'après les renseignements recueillis sur les lieux en 1889 et aout 1890, avec notes sur la situation en 1905, par M. Fénelon Gibon, secrétaire de la Société générale d'éducation et d'enseignement*, série 3, vol. 2, fasc. 16 (1908), monographie n°107, 1908, p. 433-495.
description: Source: https://ouvriersdeuxmondes.huma-num.fr/monographie/etameur-fer-blanc-usines-commentry-107
Multifractality in non-unitary random dynamics
Creators: name: Iaconis, Jason
name: Chen, Xiao
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We explore the multifractality of the steady state wave function in non-unitary random quantum dynamics in one dimension. We focus on two classes of random systems: the hybrid Clifford circuit model and the non-unitary free fermion dynamics. In the hybrid Clifford model, we map the measurement driven transition to an Anderson localization transition in an effective graph space by using properties of the stabilizer state. We show that the volume law phase with nonzero measurement rate is non-ergodic in the graph space and exhibits weak multifractal behavior. We apply the same method to the hybrid Clifford quantum automaton circuit and obtain similar multifractality in the volume law phase. For the non-unitary random free fermion system with a critical steady state, we compute the moments of the probability distribution of the single particle wave function and demonstrate that it is also weakly multifractal and has strong variations in real space.
description: 13 pages, 13 figures
Time correlation function of the shear stress in sheared particle systems
Creators: name: Otsuki, Michio
name: Hayakawa, Hisao
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The long-time behaviors of the time correlation function $C_η(t)$ of the shear stress for three-dimensional sheared fluids are investigated theoretically. It is found that there are the cross-overs in $C_η(t)$ from $t^{-3/2}$ to $t^{-2}$ for sheared fluids of elastic particles without any thermostat, and from $t^{-3/2}$ to $t^{-5/2}$ for isothermal sheared fluids including granular fluids.
description: 8 pages, submitted to Prog. Theor. Phys. Suppl. as a proceedings of Symposium on the 50th anniversary of the Alder transition
Magnetic order, disorder, and excitations under pressure in the Mott insulator Sr$_2$IrO$_4$
Creators: name: Li, Xiang
name: Cooper, S. E.
name: Krishnadas, A.
name: de la Torre, A.
name: Perry, R. S.
name: Baumberger, F.
name: Silevitch, D. M.
name: Hsieh, D.
name: Rosenbaum, T. F.
name: Feng, Yejun
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Protected by the interplay of on-site Coulomb interactions and spin-orbit coupling, Sr$_2$IrO$_4$ at high pressure is a rare example of a Mott insulator with a paramagnetic ground state. Here, using optical Raman scattering, we measure both the phonon and magnon evolution in Sr$_2$IrO$_4$ under pressure, and identify three different magnetically-ordered phases, culminating in a spin-disordered state beyond 18 GPa. A strong first-order structural phase transition drives the magnetic evolution at $\sim$10 GPa with reduced structural anisotropy in the IrO$_6$ cages, leading to increasingly isotropic exchange interactions between the Heisenberg spins and a spin-flip transition to $c$-axis-aligned antiferromagnetic order. In the disordered phase of Heisenberg $J_\mathrm{eff}=1/2$ pseudospins, the spin excitations are quasi-elastic and continuous to 10 meV, potentially hosting a gapless quantum spin liquid in Sr$_2$IrO$_4$.
Finite-dimensional modules for the polynomial ring in one variable as a vertex algebra
Creators: name: Tanabe, Kenichiro
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 17B69

description: A commutative associative algebra $A$ over ${\mathbb C}$ with a derivation is one of the simplest examples of a vertex algebra. However, the differences between the modules for $A$ as a vertex algebra and the modules for $A$ as an associative algebra are not well understood. In this paper, I give the classification of finite-dimensional indecomposable untwisted or twisted modules for the polynomial ring in one variable over ${\mathbb C}$ as a vertex algebra.
description: 17 pages
Modeling Carbon Chain Anions in L1527
Creators: name: Harada, Nanase
name: Herbst, Eric
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The low-mass protostellar region L1527 is unusual because it contains observable abundances of unsaturated carbon-chain molecules including CnH radicals, H2Cn carbenes, cyanopolyynes, and the negative ions C4H- and C6H-, all of which are more associated with cold cores than with protostellar regions. Sakai et al. suggested that these molecules are formed in L1527 from the chemical precursor methane, which evaporates from the grains during the heat-up of the region. With the gas-phase osu.03.2008 network extended to include negative ions of the families Cn-, and CnH-, as well as the newly detected C3N-, we modeled the chemistry that occurs following methane evaporation at T~ 25-30 K. We are able to reproduce most of the observed molecular abundances in L1527 at a time of ~5000 yr. At later times, the overall abundance of anions become greater than that of electrons, which has an impact on many organic species and ions. The anion-to-neutral ratio in our calculation is in good agreement with observation for C6H- but exceeds the observed ratio by more than three orders of magnitude for C4H-. In order to explain this difference, further investigation is needed on the rate coefficients for electron attachment and other reactions regarding anions.
description: 28 pages, 8 figures, ApJ accepted
Geometrical Representation of Sum Frequency Generation and Adiabatic Frequency Conversion
Creators: name: Suchowski, Haim
name: Oron, Dan
name: Arie, Ady
name: Silberberg, Yaron
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present a geometrical representation of sum frequency generation process in the undepleted pump approximation. The analogy of such dynamics with the known optical Bloch equations is discussed. We use this analogy to present a novel technique for the achievement of both high efficiency and large bandwidth in a sum frequency conversion processes using adiabatic inversion scheme, adapted from NMR and light-matter interaction. The adiabatic constraints are derived in this context. Last, this adiabatic frequency conversion scheme is realized experimentally by a proper design of adiabatic aperiodically poled KTP device, using quasi phased matched method. In the experiments we achieved high efficiency signal to idler conversion over a bandwidth of 140nm.
description: 4 pages, 4 figures
Crossed ratchet effects for magnetic domain wall motion
Creators: name: Perez-Junquera, A.
name: Marconi, V. I.
name: Kolton, A. B.
name: Alvarez-Prado, L. M.
name: Souche, Y.
name: Alija, A.
name: Velez, M.
name: Anguita, J. V.
name: Alameda, J. M.
name: Martin, J. I.
name: Parrondo, J. M. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We study both experimentally and theoretically the driven motion of domain walls in extended amorphous magnetic films patterned with a periodic array of asymmetric holes. We find two crossed ratchet effects of opposite sign that change the preferred sense for domain wall propagation, depending on whether a flat or a kinked wall is moving. By solving numerically a simple $ϕ^4$-model we show that the essential physical ingredients for this effect are quite generic and could be realized in other experimental systems involving elastic interfaces moving in multidimensional ratchet potentials.
description: 4 pages, 4 figures, submitted to PRL
Recursion Relations from Space-time Supersymmetry
Creators: name: Basu, Anirban
name: Sethi, Savdeep
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We describe a method for obtaining relations between higher derivative interactions in supersymmetric effective actions. The method extends to all orders in the momentum expansion. As an application, we consider the string coupling dependence of the \hat{G}^{2k} λ^{16} interaction in type IIB string theory. Using supersymmetry, we show that each of these interactions satisfies a Poisson equation on the moduli space with sources determined by lower momentum interactions. We argue that these protected couplings are only renormalized by a finite number of string loops together with non-perturbative terms. Finally, we explore some consequences of the Poisson equation for low values of k.
description: 43 pages, LaTeX
Key Point Agnostic Frequency-Selective Mesh-to-Grid Image Resampling using Spectral Weighting
Creators: name: Heimann, Viktoria
name: Genser, Nils
name: Kaup, André
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Many applications in image processing require resampling of arbitrarily located samples onto regular grid positions. This is important in frame-rate up-conversion, super-resolution, and image warping among others. A state-of-the-art high quality model-based resampling technique is frequency-selective mesh-to-grid resampling which requires pre-estimation of key points. In this paper, we propose a new key point agnostic frequency-selective mesh-to-grid resampling that does not depend on pre-estimated key points. Hence, the number of data points that are included is reduced drastically and the run time decreases significantly. To compensate for the key points, a spectral weighting function is introduced that models the optical transfer function in order to favor low frequencies more than high ones. Thereby, resampling artefacts like ringing are supressed reliably and the resampling quality increases. On average, the new AFSMR is conceptually simpler and gains up to 1.2 dB in terms of PSNR compared to the original mesh-to-grid resampling while being approximately 14.5 times faster.
description: 6 pages, 5 figures; Originally submitted to IEEE MMSP 2020
Nonequilibrium spin-dependent phenomena in mesoscopic superconductor-normal metal tunnel structures
Creators: name: Giazotto, F.
name: Taddei, F.
name: D'Amico, P.
name: Fazio, Rosario
name: Beltram, F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We analyze the broad range of spin-dependent nonequilibrium transport properties of hybrid systems composed of a normal region tunnel coupled to two superconductors with exchange fields induced by the proximity to thin ferromagnetic layers and highlight its functionalities. By calculating the quasiparticle distribution functions in the normal region we find that they are spin-dependent and strongly sensitive to the relative angle between exchange fields in the two superconductors. The impact of inelastic collisions on their properties is addressed. As a result, the electric current flowing through the system is found to be strongly dependent on the relative angle between exchange fields, giving rise to a huge value of magnetoresistance. Moreover, the current presents a complete spin-polarization in a wide range of bias voltages, even in the quasiequilibrium case. In the nonequilibrium limit we parametrize the distributions with an ``effective`` temperature, which turns out to be strongly spin-dependent, though quite sensitive to inelastic collisions. By tunnel coupling the normal region to an additional superconducting electrode we show that it is possible to implement a spin-polarized current source of both spin species, depending on the bias voltages applied.
description: Published version: 12 pages, 14 figures; new text added and one figure modified
Diffusion of a passive scalar by convective flows under parametric disorder
Creators: name: Goldobin, Denis S.
name: Shklyaeva, Elizaveta V.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study transport of a weakly diffusive pollutant (a passive scalar) by thermoconvective flow in a fluid-saturated horizontal porous layer heated from below under frozen parametric disorder. In the presence of disorder (random frozen inhomogeneities of the heating or of macroscopic properties of the porous matrix), spatially localized flow patterns appear below the convective instability threshold of the system without disorder. Thermoconvective flows crucially effect the transport of a pollutant along the layer, especially when its molecular diffusion is weak. The effective (or eddy) diffusivity also allows to observe the transition from a set of localized currents to an almost everywhere intense "global" flow. We present results of numerical calculation of the effective diffusivity and discuss them in the context of localization of fluid currents and the transition to a "global" flow. Our numerical findings are in a good agreement with the analytical theory we develop for the limit of a small molecular diffusivity and sparse domains of localized currents. Though the results are obtained for a specific physical system, they are relevant for a broad variety of fluid dynamical systems.
description: 12 pages, 4 figures, the revised version of the paper for J. Stat. Mech. (Special issue for proceedings of 5th Intl. Conf. on Unsolved Problems on Noise and Fluctuations in Physics, Biology & High Technology, Lyon (France), June 2-6, 2008)
Does That Count?
Creators: name: Ladson-Billings, Gloria
Publisher: name: Journal of Urban Mathematics Education
Year: 2021

description: Many mathematics educators feel that their work is not amenable to questions of diversity, equity, or justice. However, this article argues that “numbers” are not neutral. What we count and how we count are directly related to basic issues of human difference and social disparity. It also argues that mathematics knowledge and skills are fundamental to civic participation and engagement. Mathematics educators do have a stake in helping us achieve equitable social outcomes.
description: Journal of Urban Mathematics Education, Vol. 14 No. 1B (2021): Special Issue – Mathematics for Social Justice
Design and Synthesis of New Biologically Active Heterocycles Derived from [2.2]Paracyclophanes and 2-Quinolones = Design und Synthese von neuartigen bioaktiven Heterozyklen basierend auf [2.2]Paracyclophanen und 2-Chinolonen
Creators: name: Abd El-Haleem, Lamiaa Elsayed
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2021
Subjects: Five-membered heterocycles
Thiosemicarbazides
[2.2]paracyclophanes
4-Hydroxy-2-quinolones
Biologically active anticancer activity

description: Fünfgliedrige, stickstoffhaltige Heterozyklen bilden eine der größten Molekülsparten in der organischen Chemie und die Untersuchung ihres chemischen Verhaltens und ihrer pharmakologischen Aktivitäten hat in den letzten Jahren stetig zugenommen. Krebs ist eine der häufigsten Todesursachen und wird statistisch gesehen nur durch Herzkrankheiten übertroffen. Daher ist die Entwicklung von neuartigen Krebsmedikamenten einer der wichtigsten Bereiche der Wissenschaft der heutigen Zeit. Das Ziel ist eine Methode zu finden und zu etablieren, mit welcher neue Wirkstoffe entwickelt werden, indem man verschiedene Substanzklassen kombiniert, welche in der synthetischen und pharmazeutischen Chemie bedeutsam sind. Thiosemicarbazide sind Derivate der Carbothioamide und ideale Kandidaten und wertvolle Bausteine der Synthese von verschiedenen fünfgliedrigen Heterozyklen. Darüber hinaus haben sich [2.2]Paracyclophane auf dem Gebiet der stereoselektiven Synthese etabliert und wurden in heterozyklische Strukturen eingebaut. Des Weiteren ist die Chemie der 4-Hydroxy-2-chinolone aufgrund der biologischen und pharmakologischen Bedeutung der Derivate dieser Substanzklasse einzigartig. In der vorliegenden Arbeit werden die Synthesen und Anwendungen von neuartigen stickstoffhaltigen Heterozyklen sowohl basierend auf substituierten und mit [2.2]Paracyclophanen verbundenen Thiosemicarbaziden, als auch die Synthese und Anwendung von mit 4-Hydroxy-2-chinolonen verbundenen fünfgliedrigen Heterozyklen untersucht. Zunächst wurde hierfür die Synthese und Verlinkung von [2.2]Paracyclophanen und Thiosemicarbaziden vorgenommen. Anschließend wurden verschiedene Klassen von fünfgliedrigen Heterozyklen entworfen und mittels Zyklisierungsreaktionen und Donor-Akzeptor-Interaktion zwischen [2.2]Paracyclophanyl-N-substituierten Hydrazincarbothiami-den und verschiedenen Akzeptoren synthetisiert. Im Anschluss wurden die erhaltenen Substanzen gegen 60 Krebszell-Linien getestet. Einige der Substrate zeigten antikanzerogene Aktivität gegen die Leukämie-Zelllinie RPMI-8226 und SR-Zelllinien oder auch gegen SK-MEL-5 Melanom-Krebszellen. Schließlich wurde eine neuartige Serie von fusionierten fünfgliedrigen Ringen, welche mit 4-Hydroxy-2-chinolonen verbunden sind, synthetisiert. Die Synthese erfolgte mittels der Reaktion zwischen 4-Hydroxy-2-chinolonen als Donoren und verschiedenen Akzeptor-Klassen wie 3,4,5,6-Tetrachloro-1,2-benzochinonen, 2,3-Dichloro-pyrazinen und E-Dibenzoylethenen.
A complex environment around Cir X-1
Creators: name: D'Ai, A.
name: Iaria, R.
name: Di Salvo, T.
name: Lavagetto, G.
name: Robba, N. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of an archival 54 ks long Chandra observation of the peculiar source Cir X--1 during the phase passage 0.223-0.261. A comparative analysis of X-ray spectra, selected at different flux levels of the source, allows us to distinguish between a very hard state, at a low countrate, and a brighter, softer, highly absorbed spectrum during episodes of flaring activity, when the unabsorbed source luminosity is about three times the value in the hard state. The spectrum of the hard state clearly shows emission lines of highly ionized elements, while, during the flaring state, the spectrum also shows strong resonant absorption lines. The most intense and interesting feature in this latter state is present in the Fe K alpha region: a very broadened absorption line at energies ~ 6.5 keV that could result from a smeared blending of resonant absorption lines of moderately ionized iron ions (Fe XX - Fe XXIV). We also observe strong resonant absorption lines of Fe XXV and Fe XXVI, together with a smeared absorption edge above 7 keV. We argue that the emitting region during the quiescent/hard state is constituted of a purely photo-ionized medium, possibly present above an accretion disk, or of a photo-ionized plasma present in a beamed outflow. During the flaring states the source undergoes enhanced turbulent accretion that modifies both the accretion geometry and the optical depth of the gas surrounding the primary X-ray source.
description: Accepted for publication in ApJ
Coverings of Laura Algebras: the Standard Case
Creators: name: Assem, Ibrahim
name: Bustamante, Juan Carlos
name: Meur, Patrick Le
Publisher: name: arXiv
Year: 2008
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 16G10; 16G60; 16G70; 16E65

description: In this paper, we study the covering theory of laura algebras. We prove that if a connected laura algebra is standard (that is, it is not quasi-tilted of canonical type and its connecting components are standard), then this algebra has nice Galois coverings associated to the coverings of the connecting component. As a consequence, we show that the first Hochschild cohomology group of a standard laura algebra vanishes if and only if it has no proper Galois coverings.
description: The main result on the non-standard case was reformulated due to an inaccuracy in the previous version. Lemma 6.1 was removed due to a simplification. The last section on the special biserial case was removed. Typos corrected and bibliography updated. Final version to appear in Journal of Algebra
Constraints on the massive graviton dark matter from pulsar timing and precision astrometry
Creators: name: Pshirkov, Maxim
name: Tuntsov, Artem
name: Postnov, Konstantin A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The effect of a narrow-band isotropic stochastic GW background on pulsar timing and astrometric measurements is studied. Such a background appears in some theories of gravity. We show that the existing millisecond pulsar timing accuracy ($\sim 0.2 \rm{μs}$) strongly constrains possible observational consequences of theory of massive gravity with spontaneous Lorentz braking \cite{dtt:2005}, essentially ruling out significant contribution of massive gravitons to the local dark halo density. The present-day accuracy of astrometrical measurements ($\sim 100 \rm{μas}$) sets less stringent constraints on this theory.
description: 4 pages, 1 figure; changes in content, references added, accepted for publication in PRL
Theoretical study of elastic electron scattering off stable and exotic nuclei
Creators: name: Roca-Maza, X.
name: Centelles, M.
name: Salvat, F.
name: Vinas, X.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Results for elastic electron scattering by nuclei, calculated with charge densities of Skyrme forces and covariant effective Lagrangians that accurately describe nuclear ground states, are compared against experiment in stable isotopes. Dirac partial-wave calculations are performed with an adapted version of the ELSEPA package. Motivated by the fact that studies of electron scattering off exotic nuclei are intended in future facilities in the commissioned GSI and RIKEN upgrades, we survey the theoretical predictions from neutron-deficient to neutron-rich isotopes in the tin and calcium isotopic chains. The charge densities of a covariant interaction that describes the low-energy electromagnetic structure of the nucleon within the Lagrangian of the theory are used to this end. The study is restricted to medium and heavy mass nuclei because the charge densities are computed in mean field approach. Since the experimental analysis of scattering data commonly involves parameterized charge densities, as a surrogate exercise for the yet unexplored exotic nuclei, we fit our calculated mean field densities with Helm model distributions. This procedure turns out to be helpful to study the neutron-number variation of the scattering observables and allows us to identify correlations of potential interest among some of these observables within the isotopic chains.
description: 18 pages, 14 figures, revtex4; modifications in text and figures
Quantum simulation of interacting high-dimensional systems: the influence of noise
Creators: name: Dür, Wolfgang
name: Bremner, Michael J.
name: Briegel, Hans J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the simulation of interacting high-dimensional systems using pairwise interacting qubits. The main tool in this context is the generation of effective many-body interactions, and we examine a number of different protocols for obtaining them. These methods include the usage of higher-order processes (commutator method), unitary conjugation or graph state encoding, as well as teleportation based approaches. We illustrate and compare these methods in detail and analyze the time cost for simulation. In the second part of the article, we investigate the influence of noise on the simulation process. We concentrate on errors in the interaction Hamiltonians and consider two generic noise models, (i) timing errors in pairwise interactions and (ii) noisy pairwise interactions described by Master equations of Lindblad form. We analyze and compare the effect of noise for the different simulation methods and propose a way to significantly reduce the influence of noise by making use of entanglement purification together with a teleportation based protocol.
description: 38 pages, 10 figures