cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Research expeditions: routes to knowledge
Creators: name: Die Junge Akademie
Publisher: name: MyCoRe Community
Year: 2014
Subjects: subject: Forschungsreise
subject: Klimaflüchtlinge
subject: Lybien
subject: Mittelalterliche Geschichte
subject: Biodiversität
subject: Klimaänderung
subject: Exzellenzinitiative
subject: Wissenschaftssystem
subject: Popkultur
subject: Speakers’ Corner
subject: Promotionsverfahren
subject: Forschungslaufbahn
subject: Sveriges Unga Akademi
subject: 000

description: What do you take with you when you travel? What do you bring back with you? And, above all, why do you travel in the first place? The members of the Junge Akademie are constantly on the go, doing research or presenting their results in other countries. Some have to cover considerable distances between home and work on a regular basis if they want to have a career as well as a private life (see Junge Akademie Magazin, English Edition, December 2013, pp.4–15). Even going on holiday does not necessarily provide a respite from work – inspiration lurks everywhere. In our Dossier, JA members address the most diverse aspects of research trips. Ethnologist Silja Klepp describes what it means to ‘walk a tightrope between proximity and distance’ in an interview on her undercover research in Libya and her experiences with refugees landing on the shores of Lampedusa. Agricultural and environmental economist Jadwiga R. Ziolkowska, who was recently awarded the Berliner Wissenschaftspreis (an academic prize for young researchers), shares her thoughts on the impact of research trips on the environment. Mediaevalist Klaus Oschema discusses the connection between travel and historical research on travel with his colleague Folker Reichert, arguing in favour of historians travelling to original sites, even in these days of digitisation. Things that members of the Junge Akademie find indispensable on their travels are featured throughout the Dossier. And then there is the story of sinologist Lena Henningsen’s German railcard that did her a great service in China. As usual, the second part of this issue reports on conferences and projects organized by various Research Groups at the Junge Akademie. The street theatre ‘Speakers’ Corner’ shows just how relevant historical texts are to the present day. Cornelis Menke comments on doctorates in Germany, and the RG ‘Science Policy: After the Excellence Initiative’ continues to examine the performance of the German academic system. Europe is the focus of this round of the Junge Akademie’s international ties: JA members got together with members of other European Young Academies to launch joint activities on – exactly! – Europe. The editorial team and I hope you’ll enjoy this issue! Evelyn Runge
description: Junge Akademie Magazin, vol. 17
Alignment and signed-intensity anomalies in WMAP data
Creators: name: Vielva, P.
name: Wiaux, Y.
name: Martinez-Gonzalez, E.
name: Vandergheynst, P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Significant alignment and signed-intensity anomalies of local features of the cosmic microwave background (CMB) are detected on the three-year WMAP data, through a decomposition of the signal with steerable wavelets on the sphere. Firstly, an alignment analysis identifies two mean preferred planes in the sky, both with normal axes close to the CMB dipole axis. The first plane is defined by the directions toward which local CMB features are anomalously aligned. A mean preferred axis is also identified in this plane, located very close to the ecliptic poles axis. The second plane is defined by the directions anomalously avoided by local CMB features. This alignment anomaly provides further insight on recent results (Wiaux et al. 2006). Secondly, a signed-intensity analysis identifies three mean preferred directions in the southern galactic hemisphere with anomalously high or low temperature of local CMB features: a cold spot essentially identified with a known cold spot (Vielva et al. 2004), a second cold spot lying very close to the southern end of the CMB dipole axis, and a hot spot lying close to the southern end of the ecliptic poles axis. In both analyses, the anomalies are observed at wavelet scales corresponding to angular sizes around 10 degress on the celestial sphere, with global significance levels around 1%. Further investigation reveals that the alignment and signed-intensity anomalies are only very partially related. Instrumental noise, foreground emissions, as well as some form of other systematics, are strongly rejected as possible origins of the detections. An explanation might still be envisaged in terms of a global violation of the isotropy of the Universe, inducing an intrinsic statistical anisotropy of the CMB.
description: 12 pages, 7 figures. Accepted for publication in MNRAS. Small changes made (including the new subsection 3.4) to match the final version
title: Open Access Policy der Kulturerbe-Einrichtungen in Hessen
Creators: name: Philipps-Universität Marburg
Publisher: name: Philipps-Universität Marburg
Year: 2021
Subjects: Landeskunde
Archiv
Generalities, Science
Allgemeines, Wissenschaft
Urheberrecht
Hochschule
Denkmalpflege
Creative Commons
Open Access
FAIR-Prinzipien
OpenGLAM
Universität
Museum
Hessen
Bibliothek
Kulturerbe

description: Hessische Kultureinrichtungen verfügen über umfangreiche Kulturgüter, die einen universellen und überzeitlichen Wert haben. Die Digitalisierung vereinfacht den Zugang und erweitert und vervielfacht die Nutzbarkeit des von diesen Einrichtungen verwalteten Kulturschatzes. Der offene Zugang wird jedoch häufig durch rechtliche, technische oder finanzielle Beschränkungen stark behindert. Beschränkungen, welche die Nutzung und Fortschreibung von Kunst und Kultur behindern, sollen abgebaut werden. Durch den Ausbau chancengerechter, niederschwelliger Zugänge zu digitalisierten kulturellen Objekten können neue, zielgruppengerechte Angebote entwickelt werden und eine breitere dezentrale Teilhabe ermöglichen – barrierefrei, ortsunabhängig und chancengerecht. Daher haben Mitglieder der AG Digitalisierung, die im Herbst 2018 auf Anregung des Hessischen Ministeriums für Wissenschaft und Kunst als spartenübergreifende Arbeitsgruppe eingerichtet wurde, im Jahr 2021 eine gemeinsame Open Access Policy entwickelt. Sie dient als Handlungsmaxime, um der Öffentlichkeit einen umfassenden, unbeschränkten Einblick in das Kulturerbe Hessens zu ermöglichen. Fast zwanzig Kultureinrichtungen des Landes Hessen gehören zu den Erstunterzeichnenden der Open Access Policy: das Hessische Landesarchiv, die Hochschulen mit ihren Bibliotheken, Museen und Sammlungen, das Hessische Landesamt für geschichtliche Landeskunde, die hessischen Landesmuseen, die Staatlichen Schlösser und Gärten sowie das Landesamt für Denkmalpflege.
Inverse Bayesian Optimization: Learning Human Acquisition Functions in an Exploration vs Exploitation Search Task
Creators: name: Sandholtz, Nathan
name: Miyamoto, Yohsuke
name: Bornn, Luke
name: Smith, Maurice
Publisher: name: arXiv
Year: 2021
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Machine Learning (cs.LG)
subject: Optimization and Control (math.OC)
subject: Applications (stat.AP)
subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: This paper introduces a probabilistic framework to estimate parameters of an acquisition function given observed human behavior that can be modeled as a collection of sample paths from a Bayesian optimization procedure. The methodology involves defining a likelihood on observed human behavior from an optimization task, where the likelihood is parameterized by a Bayesian optimization subroutine governed by an unknown acquisition function. This structure enables us to make inference on a subject's acquisition function while allowing their behavior to deviate around the solution to the Bayesian optimization subroutine. To test our methods, we designed a sequential optimization task which forced subjects to balance exploration and exploitation in search of an invisible target location. Applying our proposed methods to the resulting data, we find that many subjects tend to exhibit exploration preferences beyond that of standard acquisition functions to capture. Guided by the model discrepancies, we augment the candidate acquisition functions to yield a superior fit to the human behavior in this task.
description: 24 pages, 10 figures, 5 appendices
Interpretation of a seismic refraction profile from the Richardson Mountains, Yukon territory
Creators: name: O'Brien, Simon
Publisher: name: University of British Columbia
Year: 2010

description: In March of 1987, the Geologic Survey of Canada conducted a major seismic refraction experiment in the Mackenzie Delta-Southern Beaufort Sea-Northern Yukon area. This study involves the analysis of a portion of the resulting data set. A 2D velocity profile through the Richardson Mountains of the northern Yukon has been constructed using raytracing to model the travel-times and amplitudes. The line is approximately 320 km long, running from a shotpointon the Eagle Plains in the south to one 50 km offshore in Mackenzie Bay to the north, with an average receiver spacing of 3.5 km. An additional shotpoint is located at Shingle Point, on the shore of Mackenzie Bay. A series of four sedimentary basins separated by major structural highs produces a complex basement structure. Two distinct upper crustal layers were modelled, a 5.95 km/s layer overlying a 6.3 km/s layer, as well as a lower crustal layer with a velocity of 7.25 km/s. Crustal velocity gradients are low (≤ 0.005 s⁻¹). The 6.3 km/s layer pinches out beneath the Beaufort-Mackenzie Basin in the north, accompanied by a thinning of the lower crust from a thickness of 20 km in the south to less than 10 km beneath MB. This results in the crust as a whole thinning from a thickness of 50 km under the Richardson Mountains to only 40 km under the Beaufort-Mackenzie Basin. The velocity of the upper mantle is 7.95 km/s. The modelling of shear wave arrivals indicate Poisson's ratios of 0.23 ±0.02 in the upper crust and 0.25 + 0.02 in the lower crust.
The scalar curvature in conical manifolds: some results on existence and obstructions
Creators: name: de Lima, Levi Lopes
Publisher: name: arXiv
Year: 2021
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: We first show that existence results due to Kazdan-Warner and Cruz-Vitório can be extended to the category of manifolds with an isolated conical singularity. More precisely, we check that, under suitable conditions on the link manifold, any bounded and smooth function which is negative somewhere is the scalar curvature of some conical metric (with the boundary being minimal whenever it is non-empty). By way of comparison, we complement this analysis by indicating how index theory, as developed by Albin-Gell-Redman, may be used to transfer to this conical setting some of the classical obstructions to the existence of metrics with positive scalar curvature in the spin context. In particular, we use a version of the notion of infinite $K$-area to obstruct such metrics.
description: 22 pages; rewritten at a few points to conform to the referee's suggestions; one figure added; matches the published version
The phase structure of a chirally invariant lattice Higgs-Yukawa model - numerical simulations
Creators: name: Gerhold, P.
name: Jansen, K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The phase diagram of a chirally invariant lattice Higgs-Yukawa model is explored by means of numerical simulations. The results revealing a rich phase structure are compared to analytical large Nf calculations which we performed earlier. The analytical and numerical results are in excellent agreement at large values of Nf. In the opposite case the large Nf computation still gives a good qualitative description of the phase diagram. In particular we find numerical evidence for the predicted ferrimagnetic phase at intermediate values of the Yukawa coupling constant and for the symmetric phase at strong Yukawa couplings. Emphasis is put on the finite size effects which can hide the existence of the latter symmetric phase.
description: 14 pages, 11 figures
Bernstein-Szego Polynomials Associated with Root Systems
Creators: name: van Diejen, J. F.
name: de la Maza, A. C.
name: Ryom-Hansen, S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05E05, 05E35

description: We introduce multivariate generalizations of the Bernstein-Szego polynomials, which are associated to the root systems of the complex simple Lie algebras. The multivariate polynomials in question generalize Macdonald's Hall-Littlewood polynomials associated with root systems. For the root system of type A1 (corresponding to the Lie algebra SL (2;C)) the classic Bernstein-Szego polynomials are recovered.
description: LaTeX, 12 pages
Non-Gaussianity in D3-brane inflation
Creators: name: Marzouk, Kareem
name: Maraio, Alessandro
name: Seery, David
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We update predictions for observables in the "delicate" D3/anti-D3 inflationary model on the conifold. We use a full CMB likelihood calculation to assess goodness-of-fit, which is necessary because in this model the zeta power spectrum often cannot be modelled as a power-law over observable scales. For the first time we are able to provide accurate forecasts for the amplitude of three-point correlations. In a significant portion of its parameter space the model follows Maldacena's single-field prediction fNL ~ -(5/12)(ns-1) if nt << 1. Therefore |fNL| is usually small when the power spectrum satisfies observational constraints. In a small number of cases the bispectrum is instead dominated by effects from rapid switching between angular minima. The resulting amplitudes are larger, but mostly with unacceptable spectral behaviour. In the most extreme case we obtain |fNLeq| ~ 75 at kt/3 = 0.002/Mpc. It has been suggested that the quasi-single field inflation ("QSFI") mechanism could produce significant 3-point correlations in this model. We do observe rare shifts in amplitude between equilateral and squeezed configurations that could possibly be associated with QSFI effects, but more investigation is needed to establish the full bispectrum shape. There is evidence of "shape" running between equilateral and squeezed configurations that may be inherited from the scale dependence of the spectrum. We explore the dependence of observables on discrete choices such as the truncation point of the potential. Our analysis illustrates the advantages of a standard format for information exchange within the inflationary model-building and testing community.
description: 65 pages plus appendices. See Code & Data tab for data deposit. v2: Minor changes. This is an author-created, un-copyedited version of an article published in JCAP. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at 10.1088/1475-7516/2022/02/013
Spin wave dispersion based on the quasiparticle self-consistent $GW$ method: NiO, MnO and $α$-MnAs
Creators: name: Kotani, Takao
name: van Schilfgaarde, Mark
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We present spin wave dispersions in MnO, NiO, and $α$-MnAs based on the quasiparticle self-consistent $GW$ method (\qsgw), which determines an optimum quasiparticle picture. For MnO and NiO, \qsgw results are in rather good agreement with experiments, in contrast to the LDA and LDA+U description. For $α$-MnAs, we find a collinear ferromagnetic ground state in \qsgw, while this phase is unstable in the LDA.
description: V2: add another figure for SW life time. Formalism is detailed
About two-dimensional fits for the analysis of the scattering rates and renormalization functions from angle-resolved photoelectron spectroscopy data
Creators: name: Kurleto, R.
name: Fink, J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: A new method for the analysis of the scattering rates from angle-resolved photoelectron spectroscopy (ARPES) is presented and described in details. It takes into account experimental instrumental resolution and finite temperature effects. More accurate results are obtained in comparison with a standard, commonly used method. The application of the method is demonstrated for several examples commonly encountered in new quantum materials. Its usefulness is especially apparent in investigations of systems with strongly correlated electrons.
description: 12 pages, 6 figures
A systematic review of physical-digital play technology and developmentally relevant child behaviour
Creators: name: Torres, Pablo E.
name: Ulrich, Philip I. N.
name: Cucuiat, Veronica
name: Cukurova, Mutlu
name: De la Presa, Maria Fercovic
name: Luckin, Rose
name: Carr, Amanda
name: Dylan, Thomas
name: Durrant, Abigail
name: Vines, John
name: Lawson, Shaun
Publisher: name: arXiv
Year: 2021
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: New interactive physical-digital play technologies are shaping the way children plan. These technologies refer to digital play technologies that engage children in analogue forms of behaviour, either alone or with others. Current interactive physical-digital play technologies include robots, digital agents, mixed or augmented reality devices, and smart-eye based gaming. Little is known, however, about the ways in which these technologies could promote or damage child development. This systematic review was aimed at understanding if and how these physical-digital play technologies promoted developmentally relevant behaviour in typically developing 0 to 12 year-olds. Psychology, Education, and Computer Science databases were searched producing 635 paper. A total of 31 papers met the inclusion criteria, of which 17 were of high enough quality to be included for synthesis. Results indicate that these new interactive play technologies could have a positive effect on children's developmentally relevant behaviour. The review indicated specific ways in which different behaviour were promoted. Providing information about own performance promoted self-monitoring. Slowing interactivity, play interdependency, and joint object accessibility promoted collaboration. Offering delimited choices promoted decision making. Problem solving and physical activity were promoted by requiring children to engage in them to keep playing. Four principles underpinned the ways in which physical digital play technologies afforded child behaviour. These included social expectations framing play situations, the directiveness of action regulations (inviting, guiding or forcing behaviours), the technical features of play technologies (digital play mechanics and physical characteristics), and the alignment between play goals, play technology and the play behaviours promoted.
description: 11 Tables, 1 Figure, 4 Appendices; Keywords: Systematic review, digital play, child development, child behaviour, child-computer interactions *Corresponding author info: Faculty of Education, University of Cambridge. Email: pelt2@cam.ac.uk; torresp.uk@gmail.com
Two-loop world-sheet corrections in AdS_5 x S^5 superstring
Creators: name: Roiban, R.
name: Tirziu, A.
name: Tseytlin, A. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We initiate the computation of the 2-loop quantum AdS_5 x S^5 string corrections on the example of a certain string configuration in S^5 related by an analytic continuation to a folded rotating string in AdS_5 in the ``long string'' limit. The 2-loop term in the energy of the latter should represent the subleading strong-coupling correction to the cusp anomalous dimension and thus provide a further check of recent conjectures about the exact structure of the Bethe ansatz underlying the AdS/CFT duality. We use the conformal gauge and several choices of the κ-symmetry gauge. While we are unable to verify the cancellation of 2d UV divergences we compute the bosonic contribution to the effective action and also determine the non-trivial finite part of the fermionic contribution. Both the bosonic and the fermionic contributions to the string energy happen to be proportional to the Catalan's constant. The resulting value for 2-loop superstring prediction for the subleading coefficient a_2 in the scaling function matches the numerical value found in hep-th/0611135 from the BES equation.
description: 48 pages, 1 Figure. v3: several mistakes corrected, the finite result for the 2-loop coefficient is found to agree with the numerical value found by Benna et al in hep-th/0611135
Grazing sheep under walnut trees - O pastoreio de ovelhas sob o coberto de nogueiras
Creators: name: MORENO, María Lourdes LÓPEZ Gerardo
Publisher: name: Zenodo
Year: 2017
Subjects: pasture
Juglans nigra x J. regia
J. major x J. regia
forage legumes
livestock
high quality wood
agroforestry management
pastagens
leguminosas forrageiras
pecuária
madeira de alta qualidade
gestão agroflorestal

description: Tradução de leaflet do Projeto AGFORWARD - Na UE a procura de madeiras nobres de folhosas, como a nogueira híbrida, é elevada. Para satisfazer esta procura, as plantações de espécies produtoras de madeiras nobres têm vindo a aumentar substancialmente na última década, em muitas regiões de Espanha. Frequentemente é necessária uma gestão intensiva para garantir a produção com revoluções de curta duração, incluindo irrigação, fertilização e controlo químico de infestantes. No entanto, este nível de gestão tem custos económicos e ambientais elevados. A gestão da plantação custa mais de 45% do investimento total. Além disso, estas operações podem ter impactos ambientais elevados, semelhantes aos efeitos dos sistemas de agricultura intensiva. A introdução de gado e a sementeira de leguminosas pode reduzir os custos financeiros destas plantações e otimizar as suas funções ambientais, configurando um sistema silvopastoril.
Luminous Red Galaxy Clustering at z~0.7 - First Results using AAOmega
Creators: name: Ross, Nicholas P.
name: Shanks, T.
name: Cannon, Russell D.
name: Wake, D. A.
name: Sharp, R. G.
name: Croom, S. M.
name: Peacock, John A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on the AAT-AAOmega LRG Pilot observing run to establish the feasibility of a large spectroscopic survey using the new AAOmega instrument. We have selected Luminous Red Galaxies (LRGs) using single epoch SDSS riz-photometry to i<20.5 and z<20.2. We have observed in 3 fields including the COSMOS field and the COMBO-17 S11 field, obtaining a sample of ~600 redshift z>=0.5 LRGs. Exposure times varied from 1 - 4 hours to determine the minimum exposure for AAOmega to make an essentially complete LRG redshift survey in average conditions. We show that LRG redshifts to i<20.5 can measured in approximately 1.5hr exposures and present comparisons with 2SLAQ and COMBO-17 (photo-)redshifts. Crucially, the riz selection coupled with the 3-4 times improved AAOmega throughput is shown to extend the LRG mean redshift from z=0.55 for 2SLAQ to z=0.681+/- 0.005 for riz-selected LRGs. This extended range is vital for maximising the S/N for the detection of the baryon acoustic oscillations (BAOs). Furthermore, we show that the amplitude of LRG clustering is s_0 = 9.9+/-0.7 h^-1 Mpc, as high as that seen in the 2SLAQ LRG Survey. Consistent results for the real-space amplitude are found from projected and semi-projected correlation functions. This high clustering amplitude is consistent with a long-lived population whose bias evolves as predicted by a simple ``high-peaks'' model. We conclude that a redshift survey of 360 000 LRGs over 3000deg^2, with an effective volume some 4 times bigger than previously used to detect BAO with LRGs, is possible with AAOmega in 170 nights.
description: 12 pages, 7 figures, 8 tables, minor changes, matches published version
Six-point functions and collisions in the black hole interior
Creators: name: Haehl, Felix M.
name: Streicher, Alexandre
name: Zhao, Ying
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In the eternal AdS black hole geometry, we consider two signals sent from the boundaries into the black hole interior shared between the two asymptotic regions. We compute three different out-of-time-order six-point functions to quantify various properties of the collision of these signals behind the horizons: (i) We diagnose the strength of the collision by probing the two-signal state on a late time slice with boundary operators. (ii) We quantify two-sided operator growth, which provides a dual description of the signals meeting in the black hole interior, in terms of the quantum butterfly effect and quantum circuits. (iii) We consider an explicit coupling between the left and right CFTs to make the wormhole traversable and extract information about the collision product from behind the horizon. At a technical level, our results rely on the method of eikonal resummation to obtain the relevant gravitational contributions to Lorentzian six-point functions at all orders in the $G_N$-expansion. We observe that such correlation functions display an intriguing factorization property. We corroborate these results with geodesic computations of six-point functions in two- and three-dimensional gravity.
description: 26 pages, 11 figures + 4 appendices; v2: minor improvements
A comparison of satellite winds and surface buoy winds
Creators: name: Bepple, Nancy
Publisher: name: University of British Columbia
Year: 2010

description: This thesis investigates the relationship between open hexagonal cell cloud motion and surface winds in the northeast Pacific Ocean. Cloud targets are tracked using an automatic scheme fashioned after Barnea and Silverman's (1972) Sequential Similarity Detection Algorithm. The cloud motion vectors obtained are comparable to results obtained by tracking the same cloud targets manually. The well-organized character of open hexagonal cells permits a comparison of various methods of estimating the height of the cloud motion vectors. One method, which uses the minimum infrared pixel value, and a second method, which establishes an arbitrary minimum cloud top temperature, are both found to be unsuitable because of cirrus contamination and partially cloud filled pixels. The cloud motion winds for open hexagonal cells and disorganized cumulus clouds are compared with winds measured at collocated surface buoys. The lack of directional shears between open hexagonal cell movements and surface winds, and directional shears of 14° to 27° for the disorganized cumulus clouds, agree with other observations for the two types of clouds. The differences between the two cloud types suggests that any estimate of surface winds from cloud motion should include cloud type information.
Notes on Superconformal Chern-Simons-Matter Theories
Creators: name: Gaiotto, Davide
name: Yin, Xi
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The three dimensional N=2 supersymmetric Chern-Simons theory coupled to matter fields, possibly deformed by a superpotential, give rise to a large class of exactly conformal theories with Lagrangian descriptions. These theories can be arbitrarily weakly coupled, and hence can be studied perturbatively. We study the theories in the large N limit, and compute the two-loop anomalous dimension of certain long operators. Our result suggests that various N=2 U(N) Chern-Simons theories coupled to suitable matter fields are dual to open or closed string theories in AdS4, which are not yet constructed.
description: 47 pages, 20 figures
An Infinite Set of Integral Formulae for Polar, Nematic, and Higher Order Structures at the Interface of Motility-Induced Phase Separation
Creators: name: Lee, Chiu Fan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Motility-induced phase separation (MIPS) is a purely non-equilibrium phenomenon in which self-propelled particles phase separate without any attractive interactions. One surprising feature of MIPS is the emergence of polar, nematic, and higher order structures at the interfacial region, whose underlying physics remains poorly understood. Starting with a model of MIPS in which all many-body interactions are captured by an effective speed function and an effective pressure function that depend solely on the local particle density, I derive analytically an infinite set of integral formulae (IF) for the ordering structures at the interface. I then demonstrate that half of these IF are in fact exact for a wide class of active Brownian particle systems. Finally, I test the IF by applying them to numerical data from direct particle dynamics simulation and find that all the IF remain valid to a great extent.
description: Half of the Integral Formulae are now shown to be exact in this new version
Mesoscopic order and the dimentionality of long-range resonance energy transfer in supramolecular semiconductors
Creators: name: Daniel, Clement
name: Makereel, Francois
name: Herz, Laura M.
name: Hoeben, Freek J. M.
name: Jonkheijm, Pascal
name: Schenning, Albertus P. H. J.
name: Meijer, E. W.
name: Silva, Carlos
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present time-resolved photoluminescence measurements on two series of oligo-p-phenylenevinylene materials that self-assemble into supramolecular nanostructures with thermotropic reversibility in dodecane. One set of derivatives form chiral, helical stacks while the second set form less organised, frustrated stacks. Here we study the effects of supramolecular organisation on the resonance energy transfer rates. We measure these rates in nanoassemblies formed with mixed blends of oligomers and compare them with the rates predicted by Foerster theory. Our results and analysis show that control of supramolecular order in the nanometre lengthscale has a dominant effect on the efficiency and dimentionality of resonance energy transfer.
description: 17 Pages, 5 Figures, Submitted to J. Chem. Phys
eta photoproduction and N* resonances
Creators: name: Choi, Ki-Seok
name: Nam, Seung-il
name: Hosaka, Atsushi
name: Kim, Hyun-Chul
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate the eta photoproduction using the effective Lagrangian approach at the tree level. We focus on the new nucleon resonance N*(1675), which was reported by the GRAAL, CB-ELSA and Tohoku LNS, testing its possible spin and parity states theoretically (J^P=1/2^+-,3/2^+-). In addition, we include six nucleon resonances, D_13(1520), S_11(1535), S_11(1650), D_15(1675), P_11(1710), P_13(1720) as well as the possible background contributions. We calculate various cross sections including beam asymmetries for the neutron and proton targets. We find noticeable isospin asymmetry in transition amplitudes for photon and neutron targets. This observation may indicate that the new resonance can be identified as a non-strangeness member of the baryon antidecuplet.
description: 18 pages, 8 figures
Learning to agree over large state spaces
Creators: name: Crescenzi, Michele
Publisher: name: arXiv
Year: 2021
Subjects: subject: Theoretical Economics (econ.TH)
subject: FOS: Economics and business

description: We study how a consensus emerges in a finite population of like-minded individuals who are asymmetrically informed about the realization of the true state of the world. Agents observe a private signal about the state and then start exchanging messages. Generalizing the classical model of rational dialogues of Geanakoplos and Polemarchakis (1982) and its subsequent extensions, we dispense with the standard assumption that the state space is a probability space and we do not put any bound on the cardinality of the state space itself or the information partitions. We show that a class of rational dialogues can be found that always lead to consensus provided that three main conditions are met. First, everybody must be able to send messages to everybody else, either directly or indirectly. Second, communication must be reciprocal. Finally, agents need to have the opportunity to engage in dialogues of transfinite length.
Entropy of Open Lattice Systems
Creators: name: Derrida, B.
name: Lebowitz, J. L.
name: Speer, E. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate the behavior of the Gibbs-Shannon entropy of the stationary nonequilibrium measure describing a one-dimensional lattice gas, of L sites, with symmetric exclusion dynamics and in contact with particle reservoirs at different densities. In the hydrodynamic scaling limit, L to infinity, the leading order (O(L)) behavior of this entropy has been shown by Bahadoran to be that of a product measure corresponding to strict local equilibrium; we compute the first correction, which is O(1). The computation uses a formal expansion of the entropy in terms of truncated correlation functions; for this system the k-th such correlation is shown to be O(L^{-k+1}). This entropy correction depends only on the scaled truncated pair correlation, which describes the covariance of the density field. It coincides, in the large L limit, with the corresponding correction obtained from a Gaussian measure with the same covariance.
description: Latex, 28 pages, 4 figures as eps files
Special Relativity and Theory of Gravity via Maximum Symmetry and Localization -- In Honor of the 80th Birthday of Professor Qikeng Lu
Creators: name: Guo, Han-Ying
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Like Euclid, Riemann and Lobachevsky geometries on an almost equal footing, based on the principle of relativity of maximum symmetry proposed by Lu and the postulate on invariant universal constants, dS/AdS SR can be set up on an almost equal footing with Einstein's SR. For dS-case, there is a coin-like relation: A law of inertia in Beltrami atlas with Beltrami time simultaneity for the PoR on one side. The proper-time simultaneity and a RW-like dS-space with entropy and an accelerated expanding S^3 fitting the cosmological principle on another. If our universe is asymptotic to the RW-like dS-space, it should be slightly closed with an entropy bound. Contrarily, via its asymptotic behavior, it can fix on Beltrami frames without `an argument in a circle' and acts as the origin of inertia. There is a triality of conformal extensions of three kinds of SR and their null physics on the projective boundary of a 5-d AdS-space. Thus there is a dS-spacetime on the boundary of a vacuum of supergravity. Gravity should be based on the localized PoR of full maximum symmetry with a gauge-like dynamics. Thus, this may lead to theory of gravity of corresponding local maximum symmetry. A simple model of dS-gravity characterized by a dimensionless constant shows the features. Our universe may already indicate that the dS SR and the dS-gravity be the foundation of large scale physics.
description: 39 pages. Invited talk at the 2006 International Conference on Several Complex Variables, June 5 - 9, 2006; Beijing, China
The Suzaku Observation of the Nucleus of the Radio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material
Creators: name: Markowitz, A.
name: Takahashi, T.
name: Watanabe, S.
name: Nakazawa, K.
name: Fukazawa, Y.
name: Kokubun, M.
name: Makishima, K.
name: Awaki, H.
name: Bamba, A.
name: Isobe, N.
name: Kataoka, J.
name: Madejski, G.
name: Mushotzky, R.
name: Okajima, T.
name: Ptak, A.
name: Reeves, J. N.
name: Ueda, Y.
name: Yamasaki, T.
name: Yaqoob, T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A Suzaku observation of the nucleus of the radio-loud AGN Centaurus A in 2005 has yielded a broadband spectrum spanning 0.3 to 250 keV. The net exposure times after screening were: 70 ks per X-ray Imaging Spectrometer (XIS) camera, 60.8 ks for the Hard X-ray Detector (HXD) PIN, and 17.1 ks for the HXD-GSO. The hard X-rays are fit by two power-laws of the same slope, absorbed by columns of 1.5 and 7 * 10^{23} cm^{-2} respectively. The spectrum is consistent with previous suggestions that the power-law components are X-ray emission from the sub-pc VLBI jet and from Bondi accretion at the core, but it is also consistent with a partial covering interpretation. The soft band is dominated by thermal emission from the diffuse plasma and is fit well by a two-temperature VAPEC model, plus a third power-law component to account for scattered nuclear emission, jet emission, and emission from X-ray Binaries and other point sources. Narrow fluorescent emission lines from Fe, Si, S, Ar, Ca and Ni are detected. The Fe K alpha line width yields a 200 light-day lower limit on the distance from the black hole to the line-emitting gas. Fe, Ca, and S K-shell absorption edges are detected. Elemental abundances are constrained via absorption edge depths and strengths of the fluorescent and diffuse plasma emission lines. The high metallicity ([Fe/H]=+0.1) of the circumnuclear material suggests that it could not have originated in the relatively metal-poor outer halo unless enrichment by local star formation has occurred. Relative abundances are consistent with enrichment from Type II and Ia supernovae.
description: Accepted for publication to ApJ. 22 pages, 11 figures (3 color). Uses emulateapj5.sty. Grammatical errors corrected; some references updated
Exact solution of a model of qubit dephasing due to telegraph noise
Creators: name: Cheng, Bin
name: Wang, Qiang-Hua
name: Joynt, Robert
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a general and exact formalism for finding the evolution of a quantum system subject to external telegraph noise. The various qubit decoherence rates are determined by the eigenvalues of a transfer matrix. The formalism can be applied to a qubit subject to an arbitrary combination of dephasing and relaxational telegraph noise, in contrast to existing non-perturbative methods that treat only one or the other of these limits. We present 3 applications: 1) We obtain the full qubit dynamics on time scales short compared with the enviromental correlation times. In the strong coupling cases this reveals unexpected oscillations and induced magnetization components; 2) We find in strong coupling case strong violations of the widely used relation 1/T$_2$ = 1/2T$_1$ + 1/T$_ϕ$, which is a result of perturbation theory; 3) We discuss the effects of bang-bang and spin-echo controls of the qubit dynamics in general settings of the telegraph noises. %The result shows that these methods are not very effective in %reducing decoherence arising from a single telegraph noise. Finally, we discuss the extension of the method to the cases of many telegraph noise sources and multiple qubits. The method still works when white noise is also present.
description: 7 pages, 6 figures, revised and extended
The quantum sinh-Gordon model in noncommutative (1+1) dimensions
Creators: name: Vaidya, Sachindeo
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Using twisted commutation relations we show that the quantum sinh-Gordon model on noncommutative space is integrable, and compute the exact two-particle scattering matrix. The model possesses a strong-weak duality, just like its commutative counterpart.
description: 7 pages, 2 figures, LaTex. References added
MR Imaging of Reynolds Dilatancy in the Bulk of Smooth Granular Flows
Creators: name: Sakaie, Ken
name: Fenistein, Denis
name: Carroll, Timothy J.
name: van Hecke, Martin
name: Umbanhowar, Paul
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Dense granular matter has to expand in order to flow, a phenomenon known as dilatancy. Here we perform, by means of Magnetic Resonance Imaging, direct measurements of the evolution of the local packing density of a slow and smooth granular shear flow generated in a split-bottomed geometry. The dilatancy is found to be surprisingly strong. The dilated zone follow the region of large strain rate and slowly spreads as a function of time. This suggests that the local packing density is governed by the total amount of local strain experienced since the start of the experiment.
description: 4 pages, 3 figs, submitted to PRE
Distributed Algorithms for Spectrum Allocation, Power Control, Routing, and Congestion Control in Wireless Networks
Creators: name: Xi, Yufang
name: Yeh, Edmund M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: We develop distributed algorithms to allocate resources in multi-hop wireless networks with the aim of minimizing total cost. In order to observe the fundamental duplexing constraint that co-located transmitters and receivers cannot operate simultaneously on the same frequency band, we first devise a spectrum allocation scheme that divides the whole spectrum into multiple sub-bands and activates conflict-free links on each sub-band. We show that the minimum number of required sub-bands grows asymptotically at a logarithmic rate with the chromatic number of network connectivity graph. A simple distributed and asynchronous algorithm is developed to feasibly activate links on the available sub-bands. Given a feasible spectrum allocation, we then design node-based distributed algorithms for optimally controlling the transmission powers on active links for each sub-band, jointly with traffic routes and user input rates in response to channel states and traffic demands. We show that under specified conditions, the algorithms asymptotically converge to the optimal operating point.
description: 14 pages, 5 figures, submitted to IEEE/ACM Transactions on Networking
Light-Front Dynamics and AdS/QCD Correspondence: The Pion Form Factor in the Space- and Time-Like Regions
Creators: name: Brodsky, Stanley J.
name: de Teramond, Guy F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The AdS/CFT correspondence between string theory in AdS space and conformal field theories in physical space-time leads to an analytic, semi-classical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. The AdS/CFT correspondence also provides insights into the inherently non-perturbative aspects of QCD such as the orbital and radial spectra of hadrons and the form of hadronic wavefunctions. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of anti-de Sitter (AdS) space $z$ and a specific light-front impact variable $ζ$ which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions of mesons and baryons, the fundamental entities which encode hadron properties and which allow the computation of decay constants, form factors and other exclusive scattering amplitudes. Relativistic light-front equations in ordinary space-time are found which reproduce the results obtained using the fifth-dimensional theory. As specific examples we compute the pion coupling constant $f_π$, the pion charge radius $< r_π^2 >$ and examine the propagation of the electromagnetic current in AdS space, which determines the space and time-like behavior of the pion form factor and the pole of the $ρ$ meson.
description: 21 pages, 7 figures. Title adjusted to PRD title. Typo corrected in Eq (B3)
Chaînes de Markov Constructives Indexées par Z
Creators: name: Brossard, Jean
name: Leuridan, Christophe
Publisher: name: arXiv
Year: 2007
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60J05 (Primary)

description: Nous étudions les cha\^{ı}nes de Markov $(X_n)_{n\in\mathbf{Z}}$ gouvernées par une relation de récurrence de la forme $X_{n+1}=f(X_n,V_{n+1})$, où $(V_n)_{n\in\mathbf{Z}}$ est une suite de variables aléatoires indépendantes et de même loi telle pour tout $n\in \mathbf{Z}$, $V_{n+1}$ est indépendante de la suite $((X_k,V_k))_{k\le n}$. L'objet de l'article est de donner une condition nécessaire et suffisante pour que les innovations $(V_n)_{n\in\mathbf{Z}}$ déterminent complètement la suite $(X_n)_{n\in \mathbf{Z}}$ et de décrire l'information manquante dans le cas contraire.
description: Published at http://dx.doi.org/10.1214/009117906000000430 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Ultradilute quantum liquid of dipolar atoms in a bilayer
Creators: name: Guijarro, G.
name: Astrakharchik, G. E.
name: Boronat, J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We show that ultradilute quantum liquids can be formed with ultracold bosonic dipolar atoms in a bilayer geometry. Contrary to previous realizations of ultradilute liquids, there is no need for stabilizing the system with an additional repulsive short-range potential. The advantage of the proposed system is that dipolar interactions on their own are sufficient for creation of a self-bound state and no additional short-range potential is needed for the stabilization. We perform quantum Monte Carlo simulations and find a rich ground-state phase diagram that contains quantum phase transitions between liquid, solid, atomic gas, and molecular gas phases. The stabilization mechanism of the liquid phase is consistent with the microscopic scenario in which the effective dimer-dimer attraction is balanced by an effective three-dimer repulsion. The equilibrium density of the liquid, which is extremely small, can be controlled by the interlayer distance. From the equation of state, we extract the spinodal density, below which the homogeneous system breaks into droplets. Our results offer a new example of a two-dimensional interacting dipolar liquid in a clean and highly controllable setup.
description: 7 pages, 5 figures; Supplemental Materials included
Lattice QCD thermodynamics with Wilson quarks
Creators: name: Ejiri, Shinji
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We review studies of QCD thermodynamics by lattice QCD simulations with dynamical Wilson quarks. After explaining the basic properties of QCD with Wilson quarks at finite temperature including the phase structure and the scaling properties around the chiral phase transition, we discuss the critical temperature, the equation of state and heavy-quark free energies.
description: Talk at Yukawa International Seminar 2006 (Kyoto), 8 pages, 8 figures