cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Market for Used Cars: A New Test of the Lemons Model
Creators: name: Emons, Winand
name: Sheldon, George
name: Emons, Winand
name: Sheldon, George
Publisher: name: Unknown
Year: 2002
Subjects: subject: Marketing
subject: FOS: Economics and business
subject: Adverse Selection
subject: Used Car Market
subject: Duration Models

description: The lemons model assumes that owners of used cars have an informational advantage over potential buyers with respect to the quality of their vehicles. Owners of bad cars will try to sell them to unsuspecting buyers while owners of good cars will hold on to theirs. Consequently, the quality of traded automobiles should be sub-average. In contrast to previous work, the following paper tests both the assumption of informational asymmetry and the prediction of sub-average traded car quality using a sample consisting of all 1985 cars registered in the Swiss canton of Basle-City over the period 1985-1991. Our data support both the assumption and the prediction of the lemons model. The lemons problem does not appear to be widespread, however. Das "Lemons"-Modell unterstellt, dass die Verkäufer von gebrauchten Automobilen einen Informationsvorsprung gegenüber potenziellen Käufern haben. Die Besitzer von minderwertigen Automobilen werden versuchen, diese an unwissende Interessierte zu verkaufen, während die Besitzer von hochrangigen Fahrzeugen diese eher behalten werden. Deshalb sollte die Qualität von gehandelten gebrauchten Automobilen unterdurchschnittlich niedrig sein. Im Gegensatz zu früheren Untersuchungen untersucht das vorliegende Papier die Annahme der Informationsasymmetrie und die Vorhersage der unterdurchschnittlichen Qualität von gehandelten Automobilen an Hand eines Datensatzes, der alle registrierten Automobile im Schweizer Kanton Basel-Stadt im Zeitraum 1985-1991 umfasst. Unsere Untersuchung bestätigt sowohl Annahme wie Vorhersage des "Lemons"-Modells, findet allerdings auch, dass das "Lemons"-Problem nicht weit verbreitet ist.
Boundary energy of the open XXZ chain from new exact solutions
Creators: name: Murgan, Rajan
name: Nepomechie, Rafael I.
name: Shi, Chi
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Bethe Ansatz solutions of the open spin-1/2 integrable XXZ quantum spin chain at roots of unity with nondiagonal boundary terms containing two free boundary parameters have recently been proposed. We use these solutions to compute the boundary energy (surface energy) in the thermodynamic limit.
description: 20 pages, LaTeX; amssymb, 3 figures
Nanoassembly technique of carbon nanotubes for hybrid circuit-QED
Creators: name: Cubaynes, T.
name: Contamin, L. C.
name: Dartiailh, M. C.
name: Desjardins, M. M.
name: Cottet, A.
name: Delbecq, M. R.
name: Kontos, T.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A complex quantum dot circuit based on a clean and suspended carbon nanotube embedded in a circuit quantum electrodynamique (cQED) architecture is a very attractive platform to investigate a large spectrum of physics phenomena ranging from qubit physics to nanomechanics. We demonstrate a carbon nanotube transfer process allowing us to integrate clean carbon nanotubes into complex quantum dot circuits inside a cQED platform. This technique is compatible with various contacting materials such as superconductors or ferromagnets. This makes it suitable for hybrid quantum devices. Our results are based on 8 different devices demonstrating the robustness of this technique.
description: 5 pages, 4 figures, 1 table
Testing Uncovered Interest Parity at Short and Long Horizons
Creators: name: Chinn, Menzie D.
name: Meredith, Guy
name: Chinn, Menzie D.
name: Meredith, Guy
Publisher: name: Unknown
Year: 2000
Subjects: subject: Financial Economics
subject: International Investment
subject: Long-Term Capital Movements
subject: Foreign Exchange
subject: Open Economy Macroeconomics

description: The unbiasedness hypothesis - the joint hypothesis of uncovered interest parity (UIP) and rational expectations - has been almost universally rejected in studies of exchange rate movements. In contrast to previous studies, which have used short-horizon data, we test this hypothesis using interest rates on longer-maturity bonds for the G-7 countries. The results of these long-horizon regressions are much more positive - the coefficients on interest differentials are of the correct sign, and almost all are closer to the predicted value of unity than to zero. These results are robust to changes in data type and to base currency (i.e., Deutschemark versus US dollar). We appeal to an econometric interpretation of the results, which focuses on the presence of simultaneity in a cointegration framework. Die Unverzerrtheitshypothese, die von gleichzeitiger ungedeckter Zinsparität und rationalen Erwartungen ausgeht, ist in empirischen Analysen von Wechselkursbewegungen nahezu einhellig verworfen worden. Im Gegensatz zu früheren Untersuchungen, denen Daten mit kurzfristigem Zeithorizont zugrundeliegen, wird die Hypothese in dem vorliegenden Papier mit langfristigen Anleihezinsen für die G-7-Länder getestet. Die Ergebnisse dieser Regressionen sind weitaus positiver. Die Koeffizienten für die Zinsdifferenzen weisen korrekte Vorzeichen auf und sind nahezu durchgehend näher bei dem vorhergesagten Wert von eins als bei Null angesiedelt. Die Ergebnisse erweisen sich als robust gegenüber Veränderungen in den Datensätzen und der Basiswährung (D-Mark oder US-Dollar). Die Autoren neigen zu einer ökonometrischen Interpretation der Ergebnisse, die das Vorhandensein von Simultanität unter Kointegration betont.
The Bolivian Decentralization Process and the Role of Municipal Associations
Creators: name: Seemann, Miriam
name: Seemann, Miriam
Publisher: name: Unknown
Year: 2004
Subjects: subject: Political Economy
subject: Decentralization
subject: Poverty Reduction
subject: Bolivia

description: This discussion paper looks at the Bolivian decentralization model. The objective of Bolivian decentralization is to consolidate the process of popular participation, and to promote regional economic development by means of a more equitable distribution of national income and improved administration of public resources. The legal framework of Bolivian decentralization is established by two principled laws; firstly, the LPP, defines decentralization on the municipal level and represents a new dimension of governmental reform, creating an important link between the state and civil society. Second, the Law of Administrative decentralization (LAD-adm) organizes the structure of the executive power in each Department so as to underpin administrative decentralization. Overall the decentralization process in Bolivia can be seen as an important step towards restructuring the old centralized state into a more democratic one. However, as the social uprising and protests which took place in October 2003 show, the decentralization laws alone didn't solve the economic and social problems in Bolivia.
Additional file 3 of Genetic Dissection of Seed Dormancy in Rice (Oryza sativa L.) by Using Two Mapping Populations Derived from Common Parents
Creators: name: Chaopu Zhang
name: Zhiyang Yuan
name: Yuntong Wang
name: Wenqiang Sun
name: Xinxin Tang
name: Yongjian Sun
name: Yu, Sibin
Publisher: name: figshare
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Plant Biology

description: Additional file 3: Table S2. Seed dormancy of the parents Nipponbare and 9311, CSSLs and BILs.
Anomalous extinction towards NGC 1938
Creators: name: De Marchi, Guido
name: Panagia, Nino
name: Milone, Antonino P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Intrigued by the extended red-giant clump (RC) stretching across the colour-magnitude diagram of the stars in a 50x50 pc^2 region of the Large Magellanic Cloud (LMC) containing the clusters NGC 1938 and NGC 1939, we have studied the stellar populations to learn about the properties of the interstellar medium (ISM) in this area. The extended RC is caused by a large and uneven amount of extinction across the field. Its slope reveals anomalous extinction properties, with Av/E(B-V)=4.3, indicating the presence of an additional grey component in the optical contributing about 30% of the total extinction in the field and requiring big grains to be about twice as abundant as in the diffuse ISM. This appears to be consistent with the amount of big grains injected into the surrounding ISM by the about 70 SNII explosions estimated to have occurred during the lifetime of the ~120 Myr old NGC 1938. Although this cluster appears today relatively small and would be hard to detect beyond the distance of M 31, with an estimated initial mass of ~4800 Msun NGC 1938 appears to have seriously altered the extinction properties in a wide area. This has important implications for the interpretation of luminosities and masses of star-forming galaxies, both nearby and in the early universe.
description: 8 pages, 4 figures, accepted for publication in The Astrophysical Journal
On the origin of the anomalous precession of Mercury's perihelion
Creators: name: Giné, Jaume
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Action at distance in Newtonian physics is replaced by finite propagation speeds in classical post--Newtonian physics. As a result, the differential equations of motion in Newtonian physics are replaced by functional differential equations, where the delay associated with the finite propagation speed is taken into account. Newtonian equations of motion, with post--Newtonian corrections, are often used to approximate the functional differential equations. In ``On the origin of quantum mechanics'', preprint, physics/0505181, May 2005, a simple atomic model based on a functional differential equation which reproduces the quantized Bohr atomic model was presented. The unique assumption was that the electrodynamic interaction has a finite propagation speed. In ``On the origin of the gravitational quantization: The Titius--Bode Law'', preprint, physics/0507072, Jul 2005, a simple gravitational model based on a functional differential equation which gives a gravitational quantification and an explanation of the modified Titius--Bode law is described. Firstly, in this work, we recall the calculations made by Einstein to arrive at the explanation of the anomalous precession of Mercury's perihelion. Secondly, we recover an ancient work of Gerber in 1898 as a precursor of the retarded theories. In this paper Gerber gave an explanation of the anomalous precession of the Mercury's perihelion in terms of a velocity--dependent potential. In this paper an explanation of the anomalous precession of Mercury's perihelion is given in terms of a simple retarded potential, which, at first order, coincides with Gerber's potential, and which agrees with the author's previous works.
description: 11 pages, 1 figure
Calculation of the Mass Spectrum of QED-2 in Light-Front Coordinates
Creators: name: Paston, S. A.
name: Prokhvatilov, E. V.
name: Franke, V. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: With the aim of a further investigation of the nonperturbative Hamiltonian approach in gauge field theories, the mass spectrum of QED-2 is calculated numerically by using the corrected Hamiltonian that was constructed previously for this theory on the light front. The calculations are performed for a wide range of the ratio of the fermion mass to the fermion charge at all values of the parameter \hatθrelated to the vacuum angle θ. The results obtained in this way are compared with the results of known numerical calculations on a lattice in Lorentz coordinates. A method is proposed for extrapolating the values obtained within the infrared-regularized theory to the limit where the regularization is removed. The resulting spectrum agrees well with the known results in the case of θ=0; in the case of θ=π, there is agreement at small values of the fermion mass (below the phase-transition point).
description: LaTex 2.09, 20 pages, 7 figures. New improved expression for the effective LF Hamiltonian was added
Nonlinear Fractional Dynamics on a Lattice with Long Range Interactions
Creators: name: Laskin, N.
name: Zaslavsky, G.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: A unified approach has been developed to study nonlinear dynamics of a 1D lattice of particles with long-range power-law interaction. A classical case is treated in the framework of the generalization of the well-known Frenkel-Kontorova chain model for the non-nearest interactions. Quantum dynamics is considered following Davydov's approach for molecular excitons. In the continuum limit the problem is reduced to dynamical equations with fractional derivatives resulting from the fractional power of the long-range interaction. Fractional generalizations of the sine-Gordon, nonlinear Schrodinger, and Hilbert-Schrodinger equations have been found. There exists a critical value of the power s of the long-range potential. Below the critical value (s<3) we obtain equations with fractional derivatives while for s>3 we have the well-known nonlinear dynamical equations with space derivatives of integer order. Long-range interaction impact on the quantum lattice propagator has been studied. We have shown that the quantum exciton propagator exhibits transition from the well-known Gaussian-like behavior to a power-law decay due to the long-range interaction. A link between 1D quantum lattice dynamics in the imaginary time domain and a random walk model has been discussed.
description: 28 pages, submitted to Physica A
Additional file 2 of Genetic Dissection of Seed Dormancy in Rice (Oryza sativa L.) by Using Two Mapping Populations Derived from Common Parents
Creators: name: Chaopu Zhang
name: Zhiyang Yuan
name: Yuntong Wang
name: Wenqiang Sun
name: Xinxin Tang
name: Yongjian Sun
name: Yu, Sibin
Publisher: name: figshare
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Plant Biology

description: Additional file 2: Table S1. Primers used in this study to genotype the NY38- and NY61-derived F2 populations.
Spacetime topology from the tomographic histories approach: Part II
Creators: name: Raptis, I.
name: Wallden, P.
name: Zapatrin, R. R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: As an inverse problem, we recover the topology of the effective spacetime that a system lies in, in an operational way. This means that from a series of experiments we get a set of points corresponding to events. This continues the previous work done by the authors. Here we use the existence of upper bound in the speed of transfer of matter and information to induce a partial order on the set of events. While the actual partial order is not known in our operational set up, the grouping of events to (unordered) subsets corresponding to possible histories, is given. From this we recover the partial order up to certain ambiguities that are then classified. Finally two different ways to recover the topology are sketched and their interpretation is discussed.
description: 21 pages, slight change in title and certain minor corrections in this second version. To apear in IJTP
Irrotational Momentum Fluctuations Conditioning the Quantum Nature of Physical Processes
Creators: name: Tzenov, Stephan I.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Starting from a simple classical framework and employing some stochastic concepts, the basic ingredients of the quantum formalism are recovered. It has been shown that the traditional axiomatic structure of quantum mechanics can be rebuilt, so that the quantum mechanical framework resembles to a large extent that of the classical statistical mechanics. The main assumption used here is the existence of a random irrotational component in the classical momentum. Various basic elements of the quantum formalism (calculation of expectation values, the Heisenberg uncertainty principle, the correspondence principle) are recovered by applying traditional techniques, borrowed from classical statistical mechanics.
description: 8 pages, no figures
Additional file 10 of Genetic Dissection of Seed Dormancy in Rice (Oryza sativa L.) by Using Two Mapping Populations Derived from Common Parents
Creators: name: Chaopu Zhang
name: Zhiyang Yuan
name: Yuntong Wang
name: Wenqiang Sun
name: Xinxin Tang
name: Yongjian Sun
name: Yu, Sibin
Publisher: name: figshare
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Plant Biology

description: Additional file 10: Fig. S3. ABA sensitivity of the after-ripened seeds of NIL (qSD3.1), NIL (qSD3.2) and 9311. The germination rate on the y-axis indicates the maximum germination rate at 168 h after imbibition. Error bar represents the mean ± SD (n = 3).
Synchronised gravitational atoms from mergers of bosonic stars
Creators: name: Sanchis-Gual, Nicolas
name: Zilhão, Miguel
name: Herdeiro, Carlos
name: Di Giovanni, Fabrizio
name: Font, José A.
name: Radu, Eugen
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: If ultralight bosonic fields exist in Nature as dark matter, superradiance spins down rotating black holes (BHs), dynamically endowing them with equilibrium bosonic clouds, here dubbed synchronised gravitational atoms (SGAs). The self-gravity of these same fields, on the other hand, can lump them into (scalar or vector) horizonless solitons known as bosonic stars (BSs). We show that the dynamics of BSs yields a new channel forming SGAs. We study BS binaries that merge to form spinning BHs. After horizon formation, the BH spins up by accreting the bosonic field, but a remnant lingers around the horizon. If just enough angular momentum is present, the BH spin up stalls precisely as the remnant becomes a SGA. Different initial data lead to SGAs with different quantum numbers. Thus, SGAs may form both from superradiance-driven BH spin down and accretion-driven BH spin up. The latter process, moreover, can result in heavier SGAs than those obtained from the former: in one example herein, $\sim 18\%$ of the final system's energy and $\sim 50\%$ of its angular momentum remain in the SGA. We suggest that even higher values may occur in systems wherein both accretion and superradiance contribute to the SGA formation.
description: 6 pages, 7 figures
GEM -- An Energy Conserving Electromagnetic Gyrofluid Model
Creators: name: Scott, Bruce D.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The details of fluctuation free energy conservation in the gyrofluid model are examined. The polarisation equation relates ExB flow and eddy energy to combinations of the potential and the density and perpendicular temperature. These determine the combinations which must appear under derivatives in the moment equations so that not only thermal free energy but its combination with the ExB energy is properly conserved by parallel and perpendicular compressional effects. The resulting system exhibits the same qualitative energy transfer properties as corresponding Braginskii or Landau fluid models. One clear result is that the numerical model built on these equations is well behaved for arbitrarily large perpendicular wavenumber, allowing exploration of two scale phenomena linking dynamics at the ion and electron gyroradii. When the numerical formulation is done in the globally consistent flux tube model, the results with adiabatic electrons are consistent with the ``Cyclone Base Case'' results of gyrokinetic models.
description: RevTeX 4, 27 pages, 3 figures, submitted to Physics of Plasmas
Quantum limit of measurement and the projection postulate
Creators: name: Gurvitz, S. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We study an electrostatic qubit monitored by a point-contact detector. Projecting an entire qubit-detector wave function on the detector eigenstates we determine the precision limit for the qubit measurements, allowed by quantum mechanics. We found that this quantity is determined by qubit dynamics as well as decoherence, generated by the measurement. Our results show how the quantum precision limit can be improved by a proper design of a measurement procedure.
description: References added, typo-errors corrected. This paper is based on work presented at the 9th International Conference on Squeezed States and Uncertainty Relations, Besancon, France, May 2-6, 2005. To be published in Special issue of the Journal of Optics B: Quantum and Semiclassical Optics, May 2006
Introduction to half-metallic Heusler alloys: Electronic Structure and Magnetic Properties
Creators: name: Galanakis, I.
name: Mavropoulos, Ph.
name: Dederichs, P. H.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Intermetallic Heusler alloys are amongst the most attractive half-metallic systems due to the high Curie temperatures and the structural similarity to the binary semiconductors. In this review we present an overview of the basic electronic and magnetic properties of both Heusler families: the so-called half-Heusler alloys like NiMnSb and the the full-Heusler alloys like Co$_2$MnGe. \textit{Ab-initio} results suggest that both the electronic and magnetic properties in these compounds are intrinsically related to the appearance of the minority-spin gap. The total spin magnetic moment $M_t$ scales linearly with the number of the valence electrons $Z_t$, such that $M_t=Z_t-24$ for the full-Heusler and $M_t=Z_t-18$ for the half-Heusler alloys, thus opening the way to engineer new half-metallic alloys with the desired magnetic properties.
description: 28 pages, submitted for a special issue of 'Journal of Physics D: Applied Physics' on Heusler alloys
Measurement of the KL meson lifetime with the KLOE detector
Creators: name: The KLOE Collaboration
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present a measurement of the KL lifetime using the KLOE detector. From a sample of 4 x 10^8 KS KL pairs following the reaction e+ e- -> phi -> KS KL we select 15 x 10^6 KL -> p0 p0 p0 decays tagged by KS -> pi+ pi- events. From a fit of the proper time distribution we find tau_L = (50.92 +- 0.17{stat} +- 0.25{syst})$ ns. This is the most precise measurement of the KL lifetime performed to date.
description: 14 pages, 14 figures
Homotopy formulas for cyclic groups acting on rings
Creators: name: Kassel, Christian
Publisher: name: arXiv
Year: 2005
Subjects: subject: Group Theory (math.GR)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 20J06, 20K01, 16W22, 18G35

description: The positive cohomology groups of a finite group acting on a ring vanish when the ring has a norm-one element. In this note we give explicit homotopies on the level of cochains when the group is cyclic, which allows us to express any cocycle of a cyclic group as the coboundary of an explicit cochain. The formulas in this note are closely related to the effective problems considered in previous joint work with Eli Aljadeff.
description: 6 pages
Two Tunnels to Inflation
Creators: name: Aguirre, Anthony
name: Johnson, Matthew C.
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate the formation via tunneling of inflating (false-vacuum) bubbles in a true-vacuum background, and the reverse process. Using effective potentials from the junction condition formalism, all true- and false-vacuum bubble solutions with positive interior and exterior cosmological constant, and arbitrary mass are catalogued. We find that tunneling through the same effective potential appears to describe two distinct processes: one in which the initial and final states are separated by a wormhole (the Farhi-Guth-Guven mechanism), and one in which they are either in the same hubble volume or separated by a cosmological horizon. In the zero-mass limit, the first process corresponds to the creation of an inhomogenous universe from nothing, while the second mechanism is equivalent to the nucleation of true- or false-vacuum Coleman-De Luccia bubbles. We compute the probabilities of both mechanisms in the WKB approximation using semi-classical Hamiltonian methods, and find that -- assuming both process are allowed -- neither mechanism dominates in all regimes.
description: 16 PRD-style pages, 13 figures. PRD, in press. Revised to match published version
Optical follow-up of BL Lac candidates in the 2BL sample
Creators: name: Nesci, R.
name: Sclavi, S.
name: Massaro, E.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the nature of the BL Lac candidates in the northern part of the 2BL sample (\cite{Londish02}) searching for optical variability by means of $R_C$ band photometry with the Asiago 1.8 and Loiano 1.5 meter telescopes during years 2002, 2003 and 2004. We also made aperture photometry of the candidates on the plates available on the web from the Palomar and UK Schmidt telescopes. No significant variability was detected for the majority of the objects without detected radio and/or X-ray emissions, while clear variability was found for the few sources of the sample with strong radio and/or X-ray emission, which is a constant feature of the "classical" BL Lacs. Some considerations on the nature of the 2BL sources are made, taking into account their most recent data available in proper motions catalogues (SuperCOSMOS, USNO-B1) and in the Sloan Digital Sky Survey.
description: 14 pages, 7 figures, accepted for Astron. Astrophys
The Elusive Distance Gradient in the Ultra-Faint Dwarf Galaxy Hercules: A Combined Hubble Space Telescope and Gaia View
Creators: name: Mutlu-Pakdil, Burçin
name: Sand, David J.
name: Crnojević, Denija
name: Olszewski, Edward W.
name: Zaritsky, Dennis
name: Strader, Jay
name: Collins, Michelle L.
name: Seth, Anil C.
name: Willman, Beth
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The ultra-faint dwarf galaxy Hercules has an extremely elongated morphology with both photometric overdensities and kinematic members at large radii, suggesting that it may be tidally disrupting due to a previous close encounter with the Milky Way. To explain its observational peculiarities, we present a deep Hubble Space Telescope (HST) imaging study of Hercules and its surrounding regions and investigate its tidal history through a careful search for a distance gradient along its stretched body. Our off-center HST data clearly resolve a main sequence, showing that the stellar extension seen along the major-axis of Hercules is genuine, not a clump of background galaxies. Utilizing Gaia DR2 data, we clean the region around Hercules of field contamination, and find four new plausible member stars, all of which are located at the outskirts of the dwarf galaxy. We update the distance to Hercules, and find $130.6\pm1.2$ kpc ($m-M=20.58\pm0.02$) for the main body, which is consistent with earlier estimates in the literature. While we find no conclusive evidence for a distance gradient, our work demonstrates that constraining a distance gradient in such a faint system is not trivial, and the possible thickness of the dwarf along the line of sight and field contamination make it harder to make decisive conclusions even with these high-precision data. Future studies coupled with tailored theoretical models are needed to understand the true nature of Hercules and of tidal distortion observables in ultra-faint galaxies in general.
description: 17 pages, 7 figures, submitted to ApJ
Asymmetries in symmetric quantum walks on two-dimensional networks
Creators: name: Muelken, Oliver
name: Volta, Antonio
name: Blumen, Alexander
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study numerically the behavior of continuous-time quantum walks over networks which are topologically equivalent to square lattices. On short time scales, when placing the initial excitation at a corner of the network, we observe a fast, directed transport through the network to the opposite corner. This transport is not ballistic in nature, but rather produced by quantum mechanical interference. In the long time limit, certain walks show an asymmetric limiting probability distribution; this feature depends on the starting site and, remarkably, on the precise size of the network. The limiting probability distributions show patterns which are correlated with the initial condition. This might have consequences for the application of continuous time quantum walk algorithms.
description: 9 pages, 12 figures, revtex4
Microfinance Games
Creators: name: Gine, Xavier
name: Jakiela, Pamela
name: Karlan, Dean S.
name: Morduch, Jonathan
name: Gine, Xavier
name: Jakiela, Pamela
name: Karlan, Dean S.
name: Morduch, Jonathan
Publisher: name: Unknown
Year: 2006
Subjects: Financial Economics

description: Microfinance has been heralded as an effective way to address imperfections in credit markets. From a theoretical perspective, however, the success of microfinance contracts has puzzling elements. In particular, the group-based mechanisms often employed are vulnerable to free-riding and collusion, although they can also reduce moral hazard and improve selection. We created an experimental economics laboratory in a large urban market in Lima, Peru and over seven months conducted eleven different games that allow us to unpack microfinance mechanisms in a systematic way. We find that risk-taking broadly conforms to predicted patterns, but that behavior is safer than optimal. The results help to explain why pioneering microfinance institutions have been moving away from group-based contracts.
String "Baryon'' in Four-Dimensional $\mathcal{N} = 2$ Supersymmetric QCD from 2D-4D Correspondence
Creators: name: Ievlev, E.
name: Shifman, M.
name: Yung, A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study non-Abelian vortex strings in four-dimensional (4D) $\mathcal{N} = 2$ supersymmetric QCD with U$(N=2)$ gauge group and $N_f=4$ flavors of quark hypermultiplets. It has been recently shown that these vortices behave as critical superstrings. The spectrum of closed string states in the associated string theory was found and interpreted as a spectrum of hadrons in 4D $\mathcal{N} = 2$ supersymmetric QCD. In particular, the lowest string state appears to be a massless BPS "baryon." Here we show the occurrence of this stringy baryon using a purely field-theoretic method. To this end we study the conformal world-sheet theory on the non-Abelian string -- the so called weighted $\mathcal{N} = (2,2)$ supersymmetric $\mathbb{CP}$ model. Its target space is given by the six-dimensional non-compact Calabi-Yau space $Y_6$, the conifold. We use mirror description of the model to study the BPS kink spectrum and its transformations on curves (walls) of marginal stability. Then we use the 2D-4D correspondence to show that the deformation of the complex structure of the conifold is associated with the emergence of a non-perturbative Higgs branch in 4D theory which opens up at strong coupling. The modulus parameter on this Higgs branch is the vacuum expectation value of the massless BPS "baryon" previously found in string theory.
description: 53 pages, 9 figures
Adjusting Household Structure: School Enrollment Impacts of Child Fostering in Burkina Faso
Creators: name: Akresh, Richard
name: Akresh, Richard
Publisher: name: Unknown
Year: 2004
Subjects: subject: Labor and Human Capital
subject: human capital investment
subject: child fostering
subject: household structure

description: Researchers claim that children growing up away from their biological parents may be at a disadvantage and have lower human capital investment. This paper measures the impact of child fostering on school enrollment and uses household and child fixed effects regressions to address the endogeneity of fostering. Data collection by the author involved tracking and interviewing the sending and receiving household participating in of foster children with their non-fostered biological siblings. Foster children are equally likely as their host siblings to be enrolled after fostering and are 3.6 percent more likely to be enrolled than their biological siblings. Relative to children from non-fostering households, host siblings, biological siblings, and foster children all experience increased enrollment after the fostering exchange, indicating fostering may help insulate poor households from adverse shocks. This Pareto improvement in schooling translates into a long-run improvement in educational and occupational attainment.
Proposed search for an electric-dipole moment using laser-cooled $^{171}$Yb atoms
Creators: name: Natarajan, Vasant
Publisher: name: arXiv
Year: 2005
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We propose an experiment to search for a permanent atomic electric-dipole moment (EDM) using laser-cooled $^{171}$Yb atoms launched in an atomic fountain. A uniform B field sets the quantization axis, and the Ramsey separated-oscillatory-fields method is used to measure the Zeeman precession frequency of the atoms. Laser beams of appropriate polarization are used for preparation and detection in a given magnetic sublevel. The signature of an EDM is a shift in the Ramsey resonance correlated with application of a large E field. The precision is expected to be at least 20 times better than current limits because the use of a cold atomic beam allows application of E field 10 times larger than in a vapor cell, and the interaction time with the E field is 200 times larger compared to a thermal beam. The leading source of systematic error in beam experiments, the (E x v/c) motional magnetic field, is reduced considerably because of the near-perfect reversal of velocity between up and down trajectories through the E-field region.
description: 7 pages, 3 figures
Social Connections and Group Banking
Creators: name: Karlan, Dean S.
name: Karlan, Dean S.
Publisher: name: Unknown
Year: 2005
Subjects: subject: Institutional and Behavioral Economics
subject: microfinance
subject: group lending
subject: informal savings
subject: social capital

description: Lending to the poor is expensive due to high screening, monitoring, and enforcement costs. Group lending advocates believe lenders overcome this by harnessing social connections. Using data from FINCA-Peru, I exploit a quasi-random group formation process to find evidence of peers successfully monitoring and enforcing joint-liability loans. Individuals with stronger social connections to their fellow group members (i.e., either living closer or being of a similar culture) have higher repayment and higher savings. Furthermore, I observe direct evidence that relationships deteriorate after default, and that through successful monitoring, individuals know who to punish and who not to punish after default.
Im Dienste der georgischen Kultur (1926-1940)
Creators: name: P'eraje, Grigol
name: Kaufhold, Hubert
Publisher: name: Oriens christianus : Hefte für die Kunde des christlichen Orients
Year: 2024

description: Oriens christianus : Hefte für die Kunde des christlichen Orients, Bd. 83 (1999): Oriens christianus, Band 83
Highway Franchising and Real Estate Values
Creators: name: Engel, Eduardo M.R.A.
name: Fischer, Ronald
name: Galetovic, Alexander
name: Engel, Eduardo M.R.A.
name: Fischer, Ronald
name: Galetovic, Alexander
Publisher: name: Unknown
Year: 2002
Subjects: subject: Land Economics/Use
subject: Demsetz auctions
subject: highway concessions
subject: private participation in infrastructure

description: It has become increasingly common to allocate highway franchises to the bidder that offers to charge the lowest toll. Often, building a highway increases the value of land held by a small group of developers, an effect that is more pronounced with lower tolls. We study the welfare implications of highway franchises that benefit large developers, focusing on the incentives developers have to internalize the effect of the toll they bid on the value of their land. We study how participation by developers in the auction affects equilibrium tolls and welfare. We find that large developers bid more aggressively than construction companies that own no land. As long as land ownership is sufficiently concentrated, allowing developers in the auction leads to lower tolls and higher welfare. Moreover, collusion among developers is socially desirable. We also analyze the case when the franchise holder can charge lower tolls to those buying her land ('toll discrimination'). Relative to uniform tolls, discrimination decreases welfare when land is highly concentrated, but increases welfare otherwise. Finally, we consider the welfare implications of subsidies and bonuses for proposing new highway projects.
Behavioural concern modelling for software change tasks
Creators: name: Lai, Albert Yee-Hang
Publisher: name: University of British Columbia
Year: 2009

description: Many modification tasks on an existing software system result in changes to code that crosscuts the system's structure. Making these changes is difficult because a developer must understand large parts of the system and must reason about how the modification will interact with the existing behaviour. Most of the time, developers attempt to make a change use an ad-hoc process with tools that help in gaining some understanding of the existing system, but which do not provide any specific support for reasoning about, implementing, or analyzing the modification. This thesis presents the Behavioural Concern Modelling (BCM) approach and tool that provide direct support for a systematic approach to modification tasks. This approach helps a developer create a partial, abstract, grounded behavioural model of a concern or concerns. The model is grounded in that the relationship between the model and the code is explicit: A developer describes which code contributes to each part of the model. The examples described use a finite state machine as a model and show how the approach can help a developer capture a concern, reason about design options, and implement modifications.
Turbulent magnetic dynamo excitation at low magnetic Prandtl number
Creators: name: Mininni, P. D.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Planetary and stellar dynamos likely result from turbulent motions in magnetofluids with kinematic viscosities that are small compared to their magnetic diffusivities. Laboratory experiments are in progress to produce similar dynamos in liquid metals. This work reviews recent computations of thresholds in critical magnetic Reynolds number above which dynamo amplification can be expected for mechanically-forced turbulence (helical and non-helical, short wavelength and long wavelength) as a function of the magnetic Prandtl number $P_M$. New results for helical forcing are discussed, for which a dynamo is obtained at $P_M=5\times10^{-3}$. The fact that the kinetic turbulent spectrum is much broader in wavenumber space than the magnetic spectrum leads to numerical difficulties which are bridged by a combination of overlapping direct numerical simulations and subgrid models of magnetohydrodynamic turbulence. Typically, the critical magnetic Reynolds number increases steeply as the magnetic Prandtl number decreases, and then reaches an asymptotic plateau at values of at most a few hundred. In the turbulent regime and for magnetic Reynolds numbers large enough, both small and large scale magnetic fields are excited. The interactions between different scales in the flow are also discussed.
description: 8 pages, 8 figures, to appear in Physics of Plasmas
Inside the 'Black Box' of Project Star: Estimation of Peer Effects Using Experimental Data
Creators: name: Boozer, Michael A.
name: Cacciola, Stephen E.
name: Boozer, Michael A.
name: Cacciola, Stephen E.
Publisher: name: Unknown
Year: 2001
Subjects: subject: Teaching/Communication/Extension/Profession
subject: peer effects
subject: data with a group structure
subject: organization of schooling
subject: experimental evidence

description: The credible identification of endogenous peer group effects- i.e. social multiplier or feedback effects -has long eluded social scientists. We argue that such effects are most credibly identified by a randomly assigned social program which operates at differing intensities within and between peer groups. The data we use are from Project STAR, a class size reduction experiment conducted in Tennessee elementary schools. In these data, classes were comprised of varying fractions of students who had previously been exposed to the Small class treatment, creating class groupings of varying experimentally induced quality. We use this variation in class group quality to estimate the spillover effect. We find that when allowance is made for this 'feedback' effect of prior exposure to the Small class treatment, the peer effects account for much of the total experimental effects in the later grades, and the direct class size effects are rendered substantially smaller.
Acceleration and vortex filaments in turbulence
Creators: name: Toschi, F.
name: Biferale, L.
name: Boffetta, G.
name: Celani, A.
name: Devenish, B. J.
name: Lanotte, A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We report recent results from a high resolution numerical study of fluid particles transported by a fully developed turbulent flow. Single particle trajectories were followed for a time range spanning more than three decades, from less than a tenth of the Kolmogorov time-scale up to one large-eddy turnover time. We present some results concerning acceleration statistics and the statistics of trapping by vortex filaments.
description: 10 pages, 5 figures
Chinese Manufacturing Performance in Comparative Perspective, 1980-2002
Creators: name: Szirmai, Adam
name: Ren, Ruoen
name: Bai, Manyin
name: Szirmai, Adam
name: Ren, Ruoen
name: Bai, Manyin
Publisher: name: Unknown
Year: 2005
Subjects: subject: Industrial Organization
subject: China
subject: manufacturing
subject: productivity growth
subject: catch up
subject: unit value ratios
subject: international comparisons

description: This paper uses the detailed information in the 1995 Census of Industrial Production as a benchmark for analysing the coverage, concepts and consistency of published statistical series. On the basis of the analysis, the paper proposes a series of adjustments which result in more consistent long-run series of labour productivity for 21 manufacturing sectors from 1980-2002. For purposes of international comparisons with the USA, the paper subsequently presents industry of origin unit value ratios for the benchmark year 1995. These are used to convert Chinese value added into US dollars. In 2002, value added for the statistically well-covered sectors of Chinese manufacturing was 43 per cent of US value added, against 12 per cent in 1980. The comparative analysis of labour productivity points to a long period of Chinese growth without catch up from 1980-1992. After 1992, there was a rapid and accelerating process of catch up. In comparative terms labour productivity increased from 5.3 per cent of the US level in 1995 to 13.7 per cent in 2002.
Chandra's X-ray study confirms that the magnetic standard Ap star KQ Vel hosts a neutron star companion
Creators: name: Oskinova, Lidia M.
name: Ignace, Richard
name: Leto, Paolo
name: Postnov, Konstantin A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: KQ Vel is a peculiar A0p star with a strong surface magnetic field of about 7.5 kG. It has a slow rotational period of nearly 8 years. Bailey et al. (2015) detected a binary companion of uncertain nature, and suggested it could be a neutron star or a black hole. In this Letter we analyze X-ray data obtained by the Chandra telescope to ascertain information about the stellar magnetic field and interaction between the star and its companion. We confirm previous X-ray detection of KQ Vel with a relatively large X-ray luminosity of 2\times 10^{30} erg/s. X-ray spectra suggest the presence of hot gas at > 20MK and, possibly, of a non-thermal component. X-ray light curves are variable, but better quality data are needed to determine periodicity if any. We interpret X-ray spectra as a combination of two components: the non-thermal emission arising from the aurora on the A0p star and the hot thermal plasma filling the extended shell surrounding the "propelling" neutron star. We explore various alternatives, but a hybrid model involving the stellar magnetosphere along with a hot shell around the propelling neutron star seems most plausible. We speculate that KQ Vel was originally a triple system, and the Ap star is a merger product. We conclude that KQ Vel is an intermediate-mass binary consisting of a strongly magnetic main sequence star and a neutron star.
description: accepted to A&AL. 8 pages including the appendix where the formalism describing the X-ray emission from a hot shell around a propelling neutron star in settling accretion regime is presented
Spectral properties of disordered fully-connected graphs
Creators: name: Taraskin, S. N.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The spectral properties of disordered fully-connected graphs with a special type of the node-node interactions are investigated. The approximate analytical expression for the ensemble-averaged spectral density for the Hamiltonian defined on the fully-connected graph is derived and analysed both for the electronic and vibrational problems which can be related to the contact process and to the problem of stochastic diffusion, respectively. It is demonstrated how to evaluate the extreme eigenvalues and use them for finding the lower bound estimates of the critical parameter for the contact process on the disordered fully-connected graphs.
description: to be published in Phys. Rev. E, 2005