cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Effect of degree correlations on the loop structure of scale-free networks
Creators: name: Bianconi, Ginestra
name: Marsili, Matteo
Publisher: name: arXiv
Year: 2005
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: In this paper we study the impact of degree correlations in the subgraphs statistics of scale-free networks. In particular we consider loops: a simple case of network subgraphs which encode the redundancy of the paths passing through every two nodes of the network. We provide an understanding of the scaling of the clustering coefficient in modular networks in terms of the eigenvector of the correlation matrix associated with the maximal eigenvalue and we show that correlations affect in a relevant way the average number of Hamiltonian paths in a 3-core of real world networks. We prove our results in the two point correlated hidden variable ensemble and we check the results with exact counting of small loops in real graphs.
description: 6 pages, 1 figure
Population and Agriculture: A General Review
Creators: name: Owen, Wyn F.
name: Owen, Wyn F.
Publisher: name: Unknown
Year: 1948
Subjects: Community/Rural/Urban Development

description: The phenomena known as "drift to the cities" is one which is frequently quoted in relation to problems facing rural industries. Arguments often take the form that this redistribution of population is depleting the rural industry labour force and as such is detrimental to the economy. The cause given or implied, in many cases, is the lack of amenities in the country; the general dullness of farm life in comparison with the life of the city. But while there are many important problems to be faced in relation to income, employment, education and amenities in rural areas, such arguments tend to emphasise symptoms and obscure causes. The purpose of this article is to analyse in a general way some of the fundamental issues involved in the distribution of the working population of a country, with particular reference to Australia.
Sugar: A Commodity Review
Creators: name: Mayne, J.B.
name: Mayne, J.B.
Publisher: name: Unknown
Year: 1948
Subjects: Crop Production/Industries

description: Sugar is one of the many primary products which has been in short supply since the end of the recent war. Present trends in production indicate a return to the productive level of 1939, but certain increases in demand indicate that the supply of this product is unlikely to reach the planned objectives within at least the next two or three seasons.
title: The role of bacteria in paralytic shellfish poisoning
Creators: name: Hold, Georgina Louise
Publisher: name: University of Glasgow
Year: 1999
Subjects: subject: Microbiology, toxicology.

description: Historically the production of paralytic shellfish toxins (PST), has been attributed to dinoflagellates. However, in the last decade, increasing evidence has been presented to indicate the involvement of a wide range of bacterial species including cyanobacteria and heterotrophic bacteria (Gallacher et al., 1997). Several studies investigating bacteria capable of PST production, have identified bacteria associated with dinoflagellates are capable of autonomous PST production (Gallacher et al., 1997). However, more recent research has focussed on the effects of these bacteria on toxin production by dinoflagellates, for which the production of bacterial-free (axenic) cultures is essential to identify whether dinoflagellates are capable of autonomous toxin production, in the absence of bacteria. Many different methods to produce axenic algal cultures have been published, including washing methods and the addition of bacteriolytic compounds. However, efforts to generate axenic dinoflagellate cultures, have been hampered not only by difficulties in removing associated bacteria, but also by the lack of effective methods for assessing the presence of certain bacteria. Traditionally, the absence of bacterial growth on marine media was considered acceptable proof for axenic status. However, as the numbers of bacteria determined by culture methods falls short of numbers detected using microscopy (Akagi et al., 1977), culture methods alone have been deemed inadequate to determine the axenic status of algal cultures. In this study, the production of an axenic dinoflagellate culture was vital, firstly, to assess the effect on dinoflagellate toxin production following removal of all associated bacteria, and secondly, to identify whether original toxicity was restored when the microflora was replaced. Methods to assess the axenic nature of cultures combined traditional methods of culturing, with epifluorescence microscopy, the method now frequently relied upon for axenic confirmation. However, molecular techniques were also included, which allowed the axenic status of dinoflagellate cultures to be confidently determined. The availability of molecular techniques also enabled an assessment of the bacterial diversity associated with original dinoflagellate cultures to be conducted, with culture-based and non culture-based identification systems adopted. This investigation indicated that a diverse range of bacteria were associated with cultures, although discrepancies between the two detection methods were noted. Results from the assessment of axenic dinoflagellate cultures confirmed the need for molecular methods, as bacterial DNA was identified in cultures which were considered axenic cultures using media assessment and epifluorescence microscopy. (Abstract shortened by ProQuest.).
Scattering length determination from trapped pairs of atoms
Creators: name: Shresta, S.
name: Tiesinga, E.
name: Williams, C. J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A method is described for estimating effective scattering lengths via spectroscopy on a trapped pair of atoms. The method relies on the phenomena that the energy levels of two atoms in a harmonic trap are shifted by their collisional interaction. The amount of shift depends on the strength of the interaction (i.e. scattering length). By combining the spectra of the trap state energy levels and a suitable model for the effective scattering length, an estimate for the latter may be inferred. Two practical methods for measuring the trap spectra are proposed and illustrated in examples. The accuracy of the scheme is analyzed and requirements on measurement precision are given.
description: 10 pages, 10 figures
Symmetry-Resolved Entanglement in AdS${}_3$/CFT${}_2$ coupled to $U(1)$ Chern-Simons Theory
Creators: name: Zhao, Suting
name: Northe, Christian
name: Meyer, René
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider symmetry-resolved entanglement entropy in AdS${}_3$/CFT${}_2$ coupled to $U(1)$ Chern-Simons theory. We identify the holographic dual of the charged moments in the two-dimensional conformal field theory as a charged Wilson line in the bulk of AdS${}_3$, namely the Ryu-Takayanagi geodesic minimally coupled to the $U(1)$ Chern-Simons gauge field. We identify the holonomy around the Wilson line as the Aharonov-Bohm phases which, in the two-dimensional field theory, are generated by charged $U(1)$ vertex operators inserted at the endpoints of the entangling interval. Furthermore, we devise a new method to calculate the symmetry resolved entanglement entropy by relating the generating function for the charged moments to the amount of charge in the entangling subregion. We calculate the subregion charge from the $U(1)$ Chern-Simons gauge field sourced by the bulk Wilson line. We use our method to derive the symmetry-resolved entanglement entropy for Poincaré patch and global AdS${}_3$, as well as for the conical defect geometries. In all three cases, the symmetry resolved entanglement entropy is determined by the length of the Ryu-Takayanagi geodesic and the Chern-Simons level $k$, and fulfills equipartition of entanglement. The asymptotic symmetry algebra of the bulk theory is of $\hat{\mathfrak{u}}{(1)_k}$ Kac-Moody type. Employing the $\hat{\mathfrak{u}}{(1)_k}$ Kac-Moody symmetry, we confirm our holographic results by a calculation in the dual conformal field theory.
description: 28 pages plus appendices, 3 Figures
Self-contained Kondo effect in single molecules
Creators: name: Booth, C. H.
name: Walter, M. D.
name: Daniel, M.
name: Lukens, W. W.
name: Andersen, R. A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Kondo coupling of f and conduction electrons is a common feature of f-electron intermetallics. Similar effects should occur in carbon ring systems(metallocenes). Evidence for Kondo coupling in Ce(C8H8)2 (cerocene) and the ytterbocene Cp*2Yb(bipy) is reported from magnetic susceptibility and L_III-edge x-ray absorption spectroscopy. These well-defined systems provide a new way to study the Kondo effect on the nanoscale, should generate insight into the Anderson Lattice problem, and indicate the importance of this often-ignored contribution to bonding in organometallics.
description: 4 pages, 5 figures (eps)
Elliptic curves with a point of order 13 defined over cyclic cubic fields
Creators: name: Bruin, Peter
name: Derickx, Maarten
name: Stoll, Michael
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11G05, 14G05, 14G25, 14H52

description: We show that there is essentially a unique elliptic curve $E$ defined over a cubic Galois extension $K$ of $\mathbb Q$ with a $K$-rational point of order 13 and such that $E$ is not defined over $\mathbb Q$.
description: 6 pages
Organic Food Marketing and Distribution in the European Union
Creators: name: Canavari, Maurizio
name: Centonze, Roberta
name: Nigro, Gianluca
name: Canavari, Maurizio
name: Centonze, Roberta
name: Nigro, Gianluca
Publisher: name: Unknown
Year: 2007
Subjects: Agribusiness

description: The paper discusses the European organic agricultural sector from a socio-economical point of view and from a EU perspective. In the 1990s organic agriculture has known a strong development and today it is considered as a stable sector and with a certain economic importance inside agricultural sector. If originally organic food was the result of an ideological choice and was set inside the alternative culture in opposition to current models of economic development and social organisation, today it has the feature of an entrepreneurial phenomenon, belonging to a life style and to a finally acknowledged cultural model which is able to attract human and financial resources on its own, to produce profit and to satisfy a steadily increasing market. A description of the data obtained by the main available sources on organic food markets in Europe is provided, trying to analyse the present scenario for organic agriculture with the lenses of the 4Ps marketing management paradigm. The analysis may be useful to shed light on the several facets of the organic sector in Europe, and as a basis for further studies on the topic.
E  A MINHA HISTÓRIA, QUEM VAI CONTAR? (RE) DESCOBRINDO AS  MEMÓRIAS QUE ENTRELAÇAM O PERTENCIMENTO ÉTNICOTERRITORIAL DO POVO GUERÉM COM A COMUNIDADE TUKUM MIRIM,  VALENÇA-BA
Creators: name: Nascimento, Demison dos Santos
Publisher: name: SABEH
Year: 2023
Subjects: Povo Guerém
Territorialidade
Pertencimento étnico-territorial
Tukum Mirim

description: O texto busca debater, analisar e avaliar os dilemas e entraves que interferem no processo de reconhecimento e pertencimento étnico-territorial da comunidade Tukum Mirim com o povo Guerém, localizada em Valença – BA. Ambas têm como prática cotidiana as territorialidades indígenas, observando e narrando as características que remetem a uma identidade ancestral na contemporaneidade. Para tais análises e debates decorreu a realização de uma pesquisa autobiográfica de cunho qualitativo: a pesquisa de campo foi desenvolvida em formato de entrevistas semiestruturadas na comunidade Tukum Mirim e oficinas temáticas em duas escolas públicas: Escola Municipal do Jiquiriçá, localizada na comunidade do Jiquiriçá e o Colégio Estadual do Campo Hermínio Manoel de Jesus situado na comunidade do Bonfim. O trabalho se organiza em uma proposta decolonial, para tanto, a escrita se estrutura na circularidade do corpo-território e as seções estão organizadas no processo de ritualística do Toré, prática cultural e ancestral dos povos originários a exemplo do povo da etnia Guerém.
FINANCIAL CHARACTERISTICS OF NORTH DAKOTA FARMS 2005-2006
Creators: name: Swenson, Andrew L.
name: Swenson, Andrew L.
Publisher: name: Unknown
Year: 2007
Subjects: subject: Agricultural Finance
subject: Farm financial management
subject: farm management
subject: farm income
subject: liquidity
subject: solvency
subject: profitability
subject: repayment capacity
subject: financial efficiency
subject: financial benchmarks
subject: tenure
subject: North Dakota.

description: The performance of over 500 North Dakota farms, 2005-2006, is summarized using 16 financial measures. Farms are categorized by geographic region, farm type, farm size, gross cash sales, farm tenure, net farm income, debt-to-asset, and age of farmer to analyze relationships between financial performance and farm characteristics. Five-year averages, 2001-2005, and farm financial trends for the 1997-2006 period are also presented. In 2006, median and average acreage per farm was 1,966 and 2,386, respectively. Median and average cash farm revenue was $281,751 and $361,418, respectively. Financial performance is volatile. Year-to-year changes in median net farm income within regions and farm types averaged 50 percent from 1997 to 2006. Median net farm income in 2006 was the lowest in five years, $35,980, and ranged from $83,970 in the Red River Valley to only $689 in the west region which was the lowest for any region over the 1997-2006 period. In 1999, 2000, 2003 and 2004 the rate of return on equity exceeded the rate of return on assets, which indicates that debt capital was employed profitably. Interest expense as a percent of gross revenue improved from 1997-2004, but increased in 2005 and 2006 because of higher debt and interest rates. The Red River Valley and crop farms had stronger profitability, solvency and repayment capacity from 1997 to 2006 than other regions and farm types, respectively, except in 2005 when the south central region and livestock farms had better performance. Farms with sales less than $100,000 were over twice as likely to have debt-to-asset higher than 70 percent than were farms with sales greater than $500,000. Farms that own some crop land, but less than 40 percent are more likely to be crop farms, farm more acreage, have larger sales, and be more profitable. As expected, solvency and percent of crop land owned increased with farmer age.
Optical Gaze Tracking with Spatially-Sparse Single-Pixel Detectors
Creators: name: Li, Richard
name: Whitmire, Eric
name: Stengel, Michael
name: Boudaoud, Ben
name: Kautz, Jan
name: Luebke, David
name: Patel, Shwetak
name: Akşit, Kaan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Gaze tracking is an essential component of next generation displays for virtual reality and augmented reality applications. Traditional camera-based gaze trackers used in next generation displays are known to be lacking in one or multiple of the following metrics: power consumption, cost, computational complexity, estimation accuracy, latency, and form-factor. We propose the use of discrete photodiodes and light-emitting diodes (LEDs) as an alternative to traditional camera-based gaze tracking approaches while taking all of these metrics into consideration. We begin by developing a rendering-based simulation framework for understanding the relationship between light sources and a virtual model eyeball. Findings from this framework are used for the placement of LEDs and photodiodes. Our first prototype uses a neural network to obtain an average error rate of 2.67° at 400Hz while demanding only 16mW. By simplifying the implementation to using only LEDs, duplexed as light transceivers, and more minimal machine learning model, namely a light-weight supervised Gaussian process regression algorithm, we show that our second prototype is capable of an average error rate of 1.57° at 250 Hz using 800 mW.
description: 10 pages, 8 figures, published in IEEE International Symposium on Mixed and Augmented Reality (ISMAR) 2020
Diffusion correction to the avalanche--to--streamer transition
Creators: name: Montijn, C.
name: Ebert, U.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Space-charge dominated streamer discharges can emerge in free space from single electrons. We reinvestigate the Raether-Meek criterion and show that streamer emergence depends not only on ionization and attachment rates and gap length, but also on electron diffusion. Motivated by simulation results, we derive an explicit quantitative criterion for the avalanche-to-streamer transition both for pure non-attaching gases and for air, under the assumption that the avalanche emerges from a single free electron and evolves in a homogenous field.
description: 24 pages, 8 figures, submitted to J. Phys. D: Appl. Phys
Determinants of the U.S. Trade Balance in Consumer-Oriented Agricultural Products
Creators: name: Zhuang, Renan
name: Koo, Won W.
name: Mattson, Jeremy W.
name: Zhuang, Renan
name: Koo, Won W.
name: Mattson, Jeremy W.
Publisher: name: Unknown
Year: 2007
Subjects: subject: International Relations/Trade
subject: Consumer-oriented products
subject: trade balance
subject: trade deficit
subject: exchange rate

description: This study investigates the factors behind the growing U.S. trade deficit in consumer-oriented agricultural and food products by using reliable panel data and an empirical trade model derived from international trade theory. The results indicate that per capita income in the United States appears to be the most important determinant for the growing U.S. trade deficit. Increases in per capita income and trade liberalization in foreign countries improve the U.S. trade balance. U.S. foreign direct investment abroad in food processing, a strong U.S. dollar, and NAFTA are found to have negative effects on the U.S. trade balance.
Examining Difference : the case of women and men in municipal politics
Creators: name: Begley, Christopher G.
Publisher: name: University of British Columbia
Year: 2009

description: Currently, the Greater Vancouver Regional District has one of the highest rates of female participation in North America. Of 153 elected councillors and mayors, 55 are women. Token theory predicts that as women become less of a minority, they will have more influence over affairs and will be more willing to assert themselves. To a large degree, in the GVRD this proves to be the case. Women form dissenting blocs on council with greater regularity than men and women seem more willing to challenge the prevailing ideology of Canadian municipal politics than do men. While in many areas, particularly in what the priorities o f municipal government should be, female councillors in the GVRD are virtually indistinguishable from their male colleagues, in other, more openly ideological areas of municipal governance, women form a sharply distinctive group. Overall, women do seem to make a difference in the operation of municipal councils.
A holed membrane at finite equibiaxial stretch
Creators: name: Friedberg, Idan Z.
name: deBotton, Gal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The deformation and stress distribution in a stretched thin neo-Hookean circular membrane with a hole at its center are analyzed within the framework of finite deformation elasticity. Initially, we derive a simple form for the differential governing equation to the problem. This enables us to introduce a closed-form solution in the limit of infinite stretch. Subsequently, we propose approximate solutions for intermediate and large deformations. These approximations approach the exact solutions in the limits of small and infinite stretches. The transition stretch at which the membrane behavior switches from the intermediate to the large deformation approximation is determined too. Comparison of our solution and approximations to corresponding numerical results reveal a neat agreement for any stretch and ratio between the hole to the membrane radii. In the limit of large stretches and a small hole, the ratio of the hoop stress at the hole boundary to the nominal stress is 4, which is twice the corresponding ratio in the small deformation limit. Comparison of the strain energy stored in the membrane to the one in a membrane without a hole reveals that only at finite stretches the difference between these energies becomes meaningful. This implies that it is likely that a flaw in a membrane will tear out only at a finite level of stretches.
Dynamical Landscape and Multistability of a Climate Model
Creators: name: Margazoglou, Georgios
name: Grafke, Tobias
name: Laio, Alessandro
name: Lucarini, Valerio
Publisher: name: arXiv
Year: 2020
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: Machine Learning (stat.ML)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We apply two independent data analysis methodologies to locate stable climate states in an intermediate complexity climate model and analyze their interplay. First, drawing from the theory of quasipotentials, and viewing the state space as an energy landscape with valleys and mountain ridges, we infer the relative likelihood of the identified multistable climate states, and investigate the most likely transition trajectories as well as the expected transition times between them. Second, harnessing techniques from data science, specifically manifold learning, we characterize the data landscape of the simulation output to find climate states and basin boundaries within a fully agnostic and unsupervised framework. Both approaches show remarkable agreement, and reveal, apart from the well known warm and snowball earth states, a third intermediate stable state in one of the two climate models we consider. The combination of our approaches allows to identify how the negative feedback of ocean heat transport and entropy production via the hydrological cycle drastically change the topography of the dynamical landscape of Earth's climate.
description: 28 pages, 12 figures plus Supplementary Material. Revised version
Grain Shipments on the Mississippi River System: A Long-Term Projection
Creators: name: Wilson, William W.
name: Dahl, Bruce L.
name: Taylor, Richard D.
name: Koo, Won W.
name: Wilson, William W.
name: Dahl, Bruce L.
name: Taylor, Richard D.
name: Koo, Won W.
Publisher: name: Unknown
Year: 2007
Subjects: Agribusiness
International Relations/Trade

description: The costs of delays for shipping commodities on the Mississippi River are important and adversely impact growth in shipments. Lock and dam expansion requires substantial capital investment and an extended time period to complete. This study analyzes delay costs and the competitive position of grain shipments on the Mississippi River system. A spatial optimization model of the world grain trade was developed. Results indicated that without expansion in barge capacity, delay costs in 2020 would increase on each reach, with some up to $1.08/mt. Expansion results in reduced delay costs. Barge demand is also impacted by rail capacity. Finally, expanding the locks would result in a re-allocation of shipments among modes, reaches, and ports, notwithstanding minor adjustments in production.
A Physical Axiomatic Approach to Schrodinger's Equation
Creators: name: Parwani, Rajesh R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The Schrodinger equation for non-relativistic quantum systems is derived from some classical physics axioms within an ensemble hamiltonian framework. Such an approach enables one to understand the structure of the equation, in particular its linearity, in intuitive terms. Furthermore it allows for a physically motivated and systematic investigation of potential generalisations which are briefly discussed.
description: Extended version. 14 pages
Fair Asynchronous Session Subtyping
Creators: name: Bravetti, Mario
name: Lange, Julien
name: Zavattaro, Gianluigi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Programming Languages (cs.PL)
subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: Session types are widely used as abstractions of asynchronous message passing systems. Refinement for such abstractions is crucial as it allows improvements of a given component without compromising its compatibility with the rest of the system. In the context of session types, the most general notion of refinement is asynchronous session subtyping, which allows message emissions to be anticipated w.r.t. a bounded amount of message consumptions. In this paper we investigate the possibility to anticipate emissions w.r.t. an unbounded amount of consumptions: to this aim we propose to consider fair compliance over asynchronous session types and fair refinement as the relation that preserves it. This allows us to propose a novel variant of session subtyping that leverages the notion of controllability from service contract theory and that is a sound characterisation of fair refinement. In addition, we show that both fair refinement and our novel subtyping are undecidable. We also present a sound algorithm which deals with examples that feature potentially unbounded buffering. Finally, we present an implementation of our algorithm and an empirical evaluation of it on synthetic benchmarks.
Direct prediction of phonon density of states with Euclidean neural networks
Creators: name: Chen, Zhantao
name: Andrejevic, Nina
name: Smidt, Tess
name: Ding, Zhiwei
name: Chi, Yen-Ting
name: Nguyen, Quynh T.
name: Alatas, Ahmet
name: Kong, Jing
name: Li, Mingda
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Machine learning has demonstrated great power in materials design, discovery, and property prediction. However, despite the success of machine learning in predicting discrete properties, challenges remain for continuous property prediction. The challenge is aggravated in crystalline solids due to crystallographic symmetry considerations and data scarcity. Here we demonstrate the direct prediction of phonon density of states using only atomic species and positions as input. We apply Euclidean neural networks, which by construction are equivariant to 3D rotations, translations, and inversion and thereby capture full crystal symmetry, and achieve high-quality prediction using a small training set of $\sim 10^{3}$ examples with over 64 atom types. Our predictive model reproduces key features of experimental data and even generalizes to materials with unseen elements,and is naturally suited to efficiently predict alloy systems without additional computational cost. We demonstrate the potential of our network by predicting a broad number of high phononic specific heat capacity materials. Our work indicates an efficient approach to explore materials' phonon structure, and can further enable rapid screening for high-performance thermal storage materials and phonon-mediated superconductors.
description: 21 pages total, 5 main figures + 16 supplementary figures. To appear in Advanced Science (2021)
High Energy Emission from Supernova Remnants
Creators: name: Vink, Jacco
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: This paper discusses several aspects of current research on high energy emission from supernova remnants, covering the following main topics: 1) The recent evidence for magnetic field amplification near supernova remnant shocks, which makes that cosmic rays are more efficiently accelerated than previously thought. 2) The evidence that ions and electrons in some remnants have very different temperatures, and only equilibrate through Coulomb interactions. 3) The evidence that the explosion that created Cas A was asymmetric, and seems to have involved a jet/counter jet structure. And finally, 4), I will argue that the unremarkable properties of supernova remnants associated with magnetars candidates, suggest that magnetars are not formed from rapidly (P ~ 1 ms) rotating proto-neutron stars, but that it is more likely that they are formed from massive progenitors stars with high magnetic fields.
description: Invited review, to be published in the proceedings of IAUS230: "Populations of High Energy Sources in Galaxies", 14-19 August 2005, Dublin, Eds E.J.A. Meurs and G. Fabbiano
Distortion of wreath products in some finitely presented groups
Creators: name: Cleary, Sean
Publisher: name: arXiv
Year: 2005
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 20F65

description: Wreath products such as Z wr Z are not finitely-presentable yet can occur as subgroups of finitely presented groups. Here we compute the distortion of Z wr Z as a subgroup of Thompson's group F and as a subgroup of Baumslag's metabelian group G. We find that Z wr Z is undistorted in F but is at least exponentially distorted in G.
description: 9 pages, 5 figures
Anisotropic dressing of electrons in electron-doped cuprate superconductors
Creators: name: Tan, Shuning
name: Liu, Yiqun
name: Mou, Yingping
name: Feng, Shiping
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The recent experiments revealed a remarkable possibility for the absence of the disparity between the phase diagrams of the electron- and hole-doped cuprate superconductors, while such an aspect should be also reflected in the dressing of the electrons. Here the phase diagram of the electron-doped cuprate superconductors and the related exotic features of the anisotropic dressing of the electrons are studied based on the kinetic-energy driven superconductivity. It is shown that although the optimized Tc in the electron-doped side is much smaller than that in the hole-doped case, the electron- and hole-doped cuprate superconductors rather resemble each other in the doping range of the superconducting dome, indicating an absence of the disparity between the phase diagrams of the electron- and hole-doped cuprate superconductors. In particular, the anisotropic dressing of the electrons due to the strong electron's coupling to a strongly dispersive spin excitation leads to that the electron Fermi surface is truncated to form the disconnected Fermi arcs centered around the nodal region. Concomitantly, the dip in the peak-dip-hump structure of the quasiparticle excitation spectrum is directly associated with the corresponding peak in the quasiparticle scattering rate, while the dispersion kink is always accompanied by the corresponding inflection point in the total self-energy, as the dip in the peak-dip-hump structure and dispersion kink in the hole-doped counterparts. The theory also predicts that both the normal and anomalous self-energies exhibit the well-pronounced low-energy peak-structures.
description: 13 pages, 9 figures,added figure, references, and discussions; accepted for publication in Physical Review B
Empirical determination of the energy loss of heavy quarks in nuclear collisions at RHIC and LHC energies
Creators: name: De, Somnath
name: De, Sudipan
name: Shukla, Prashant
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Heavy quarks produced in the heavy ion collisions loose energy while propagting in the hot partonic matter which finally fragment to heavy ($D$ or $B$) mesons. The energy loss suffered by the heavy quarks is imprinted in the nuclear modification factor as a function of transverse momenta ($p_T$) of these heavy mesons. An alternate measure of in-medium energy loss comes through the effective shift in transverse momentum spectra of hadrons recorded in nucleus-nucleus collisions when it is compared to the same in proton-proton collisions. We start by parametrizing invariant momentum yields of heavy mesons in p+p collisions. The fit function from p+p collisions and measured nuclear modification factor in heavy ion collisions are then utilised to obtain the shift in the transeverse mass $Δm_T$ of heavy mesons produced at the RHIC and LHC experiments.The energy loss $Δm_T$ so obtained is found to scale with the transverse mass ($m_T$) of heavy mesons through a power law at different energies and centralities of collisions. We have also calculated using theoretical formalism, the total energy loss suffered by a charm quark in quark-gluon plasma produced in Pb~+~Pb collisions at the LHC energies. The evolution of the plasma is described by (2+1) dimensional longitudinal boost-invariant ideal hydrodynamics. It is found that the total energy loss of charm quarks scales with the transverse mass of charm quarks through a similar power law which supports our empirical analysis of energy loss.
description: 11 pages, 4 figures
Super-exponential scrambling of Out-of-time-ordered correlators
Creators: name: Zhao, Wen-Lei
name: Hu, Yue
name: Li, Zhi
name: Wang, Qian
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Out-of-time-ordered correlators (OTOCs) are an effective tool in characterizing black hole chaos, many-body thermalization and quantum dynamics instability. Previous research findings have shown that the OTOCs' exponential growth (EG) marks the limit for quantum systems. However, we report in this letter a periodically-modulated nonlinear Schrödinger system, in which we interestingly find a novel way of information scrambling: super-EG. We show that the quantum OTOCs' growth, which stems from the quantum chaotic dynamics, will increase in a super-exponential way. We also find that in the classical limit, the hyper-chaos revealed by a linearly-increasing Lyapunov exponent actually triggers the super-EG of classical OTOCs. The results in this paper break the restraints of EG as the limit for quantum systems, which give us new insight into the nature of information scrambling in various fields of physics from black hole to many-body system.
description: 6 pages, 3 figures
Conformation and market effects of corporate cereal farms in Hungary
Creators: name: Jambor, Attila
name: Jambor, Attila
Publisher: name: Unknown
Year: 2007
Subjects: Agribusiness

description: Functions and existence of agricultural corporate farms have concerned agricultural economists for a long time. It is worth examining in a given market how these forms of companies evolve, work, what effects they have on supply chain, land market or natural environment, etc. Importance of the topic is also underpinned by western experts arguing that a totally different pattern of agricultural structure developed in former socialist states (superlarge farms) than in West-Europe (family farms). The aim of this paper is to present how superlarge companies affect their environment in the Hungarian cereal market, which is one of the leading sectors of the national agriculture. Moreover, growing cereals are suitable for large scale companies, especially in Hungary, where 84% of the total agricultural land was arable land in 2005.
Graphic Bernstein Results in Curved Pseudo-Riemannian Manifolds
Creators: name: Li, Guanghan
name: Salavessa, Isabel M. C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C21; 53C42; 53C50

description: We generalize a Bernstein-type result due to Albujer and Alías, for maximal surfaces in a curved Lorentzian product 3-manifold of the form $Σ_1\times \mathbb{R}$, to higher dimension and codimension. We consider $M$ a complete spacelike graphic submanifold with parallel mean curvature, defined by a map $f: Σ_1\to Σ_2$ between two Riemannian manifolds $(Σ_1^m, g_1)$ and $(Σ^n_2, g_2)$ of sectional curvatures $K_1$ and $K_2$, respectively. We take on $Σ_1\times Σ_2$ the pseudo-Riemannian product metric $g_1-g_2$. Under the curvature conditions, $\mathrm{Ricci}_1 \geq 0$ and $K_1\geq K_2$, we prove that, if the second fundamental form of $M$ satisfies an integrability condition, then $M$ is totally geodesic, and it is a slice if $\mathrm{Ricci}_1(p)>0$ at some point. For bounded $K_1$, $K_2$ and hyperbolic angle $θ$, we conclude $M$ must be maximal. If $M$ is a maximal surface and $K_1\geq K_2^+$, we show $M$ is totally geodesic with no need for further assumptions. Furthermore, $M$ is a slice if at some point $p\in Σ_1$, $K_1(p)> 0$, and if $Σ_1$ is flat and $K_2<0$ at some point $f(p)$, then the image of $f$ lies on a geodesic of $Σ_2$.
description: Accepted for publication in the Journal of Geometry and Physics. Final version: Some simplifications, improvements and reorganization. In version 3, we replace the condition $K_1\geq 0$ by the weaker condition $Ricci_1\geq 0$. The proofs are essentially the same
Matrix Rearrangement Inequalities Revisited
Creators: name: Chayes, Victoria M
Publisher: name: arXiv
Year: 2020
Subjects: subject: Functional Analysis (math.FA)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics

description: Let $||X||_p=\text{Tr}[(X^\ast X)^{p/2}]^{1/p}$ denote the $p$-Schatten norm of a matrix $X\in M_{n\times n}(\mathbb{C})$, and $σ(X)$ the singular values with $\uparrow$ $\downarrow$ indicating its increasing or decreasing rearrangements. We wish to examine inequalities between $||A+B||_p^p+||A-B||_p^p$, $||σ_\downarrow(A)+σ_\downarrow(B)||_p^p+||σ_\downarrow(A)-σ_\downarrow(B)||_p^p$, and $||σ_\uparrow(A)+σ_\downarrow(B)||_p^p+||σ_\uparrow(A)-σ_\downarrow(B)||_p^p$ for various values of $1\leq p
The Millennium Galaxy Catalogue: On the natural sub-division of galaxies
Creators: name: Ellis, S. C.
name: Driver, S. P.
name: Allen, P. D.
name: Liske, J.
name: Bland-Hawthorn, J.
name: De Propris, R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The distribution of global photometric, spectroscopic, structural and morphological parameters for a well defined sample of 350 nearby galaxies has been examined. The usual trends were recovered demonstrating that E/S0 galaxies are redder, more quiescent, more centrally concentrated and possess larger Sersic indices than later type galaxies. Multivariate statistical analyses were performed to examine the distribution of all parameters simultaneously. The main result of these analyses was the existence of only two classes of galaxies, corresponding closely to early and late types. Linear discriminant analysis was able to reproduce the classifications of early and late types galaxies with high success, but further refinement of galaxy types was not reproduced in the distribution of observed galaxy properties. A principal components analysis showed that the major variance of the parameter set corresponded to a distinction between early and late types, highlighting the importance of the distinction. A hierarchical clustering analysis revealed only two clear natural classes within the parameter set, closely corresponding to early and late types. Early and late types are clearly distinct and the distinction is of fundamental importance. In contrast, late types from Sa to Irr are smoothly distributed throughout the parameter space. A population of galaxies classified by eye as elliptical/lenticular, and exhibiting concentration indices similar to early-types were found to have a significant star-formation activity. These galaxies are preferentially faint, suggesting they are low-mass systems.
description: Accepted for publication in MNRAS. 17 pages, 12 figures
Testing of the new JOREK stellarator-capable model in the tokamak limit
Creators: name: Nikulsin, Nikita
name: Hoelzl, Matthias
name: Zocco, Alessandro
name: Lackner, Karl
name: Guenter, Sibylle
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: In preparation for extending the JOREK nonlinear MHD code to stellarators, a hierarchy of stellarator-capable reduced and full MHD models has been derived and tested. The derivation was presented at the EFTC 2019 conference. Continuing this line of work, we have implemented the reduced MHD model (arXiv:1907.12486) as well as an alternative model which was newly derived using a different set of projection operators for obtaining the scalar momentum equations from the full MHD vector momentum equation. With the new operators, the reduced model matches the standard JOREK reduced models for tokamaks in the tokamak limit and conserves energy exactly, while momentum conservation is less accurate than in the original model whenever field-aligned flow is present.
description: 23 pages, 1 table, 7 figures. Submitted to Journal of Plasma Physics
Description of the two-nucleon system on the basis of the Bargmann representation of the S matrix
Creators: name: Babenko, V. A.
name: Petrov, N. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: For the effective-range function $k\cot δ$, a pole approximation that involves a small number of parameters is derived on the basis of the Bargmann representation of the $S$ matrix. The parameters of this representation, which have a clear physical meaning, are related to the parameters of the Bargmann $S$ matrix by simple equations. By using a polynomial least-squares fit to the function $k\cot δ$ at low energies, the triplet low-energy parameters of neutron-proton scattering are obtained for the latest experimental data of Arndt et al. on phase shifts. The results are $a_{t}=5.4030 $fm, $r_{t}=1.7494 $fm, and $v_{2}=0.163 $fm$^{3}$. With allowance for the values found for the low-energy scattering parameters and for the pole parameter, the pole approximation of the function $k\cot δ$ provides an excellent description of the triplet phase shift for neutron-proton scattering over a wide energy range ($T_{\text{lab}}\lesssim 1000 $MeV), substantially improving the description at low energies as well. For the experimental phase shifts of Arndt et al., the triplet shape parameters $v_{n}$ of the effective-range expansion are obtained by using the pole approximation. The description of the phase shift by means of the effective-range expansion featuring values found for the low-energy scattering parameters proves to be fairly accurate over a broad energy region extending to energy values approximately equal to the energy at which this phase shift changes sign, this being indicative of a high accuracy and a considerable value of the effective-range expansion in describing experimental data on nucleon-nucleon scattering. The properties of the deuteron that were calculated by using various approximations of the effective-range function comply well with their experimental values.
description: 39 pages, 3 figures
On the SU(3) parametrization of qutrits
Creators: name: Bolukbasi, A. T.
name: Dereli, T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Parametrization of qutrits on the complex projective plane CP^2 = SU(3)/U(2) is given explicitly. A set of constraints that characterize mixed state density matrices is found.
description: Paper presented at 12th Central European Workshop on Quantum Optics, 6-9 June 2005, Bilkent Univ., Ankara, Turkey
The impact of a random metric upon a diffusing particle
Creators: name: Haba, Z.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We show that if the singularity of the quantized gravity propagator is $\vert {\bf x}\vert^{-2γ}$ then the mean value of the fourth power of the distance achieved in time $t$ by a diffusing particle behaves as $t^{2(1-γ)}$ for a small $t$.
description: 12 pages, journal version
Corporate farm size determinants in transitional economy: the case of the Moscow region
Creators: name: Svetlov, Nikolai M.
name: Svetlov, Nikolai M.
Publisher: name: Unknown
Year: 2007
Subjects: subject: Agribusiness
subject: Farm Management
subject: Productivity Analysis
subject: farm size
subject: return to scale
subject: dynamic DEA
subject: Moscow region
subject: transitional economy
subject: corporate farms.

description: A set of dynamic DEA models is applied to investigate size determinants on the Moscow region corporate farms during 1996-2004. The institutional theoretical framework is found to be relevant to explaining corporate farm sizes and their changes in the Moscow region, unlike the neo-classical framework. Farms' opportunities to utilize returns to scale for improving performance are minor. Rank correlation between performance and size indicators is positive. This cannot be comprehensively explained by wider opportunities to grow that are available to best-practice farms. The theoretical expectation of pursuing lower transaction costs as a motivation for a large-scale farm business complies with the estimations.
"Singing Duvalier", singing the nation : masculinity in the discourse of nation formation in Haiti
Creators: name: Burnham, Thorald M.
Publisher: name: University of British Columbia
Year: 2009

description: This thesis argues that no discussion of nationalism is possible without addressing the subject of masculinity. In the case of Haiti, masculinity is the privileged category of an oppositional national discourse, or "discent" narrative, and, therefore, orders and ranks constructions of race, class, language, colour, religion and sexuality. With the election of Francois Duvalier in September of 1957, the Black urban middle-classes expressed their interest in changing a national discourse that excluded them both literally and metaphorically, primarily on the basis of their colour. One year after his election as President of Haiti, the Musical Institute of Haiti held a song competition in honour of the new "Father" of the nation. A compilation of the songs was printed and released to the public. It is through a critical analysis of this booklet, as a site of discursive deployment of power and the national discourse, that the depth of the masculine narrative can be seen. Indeed, I argue that the songs of the competition reveal how in "singing Duvalier" they are in fact singing an oppositional, or "discenting" masculinity. This idea of competing masculinities is traceable to the origins of Haitian Independence and the establishment of a national, Black inclusive masculinity lasting until the U.S. occupation in 1915. The invasion imposed a "marine masculinity" which excluded Black Haitians and destroyed colour and power sharing etiquettes. Duvalier's election in 1957 was the articulation of the Black middle-classes' opposition to this new national discourse which had been perpetuated by the Mulatre elites after the marine's departure in 1934. Indeed, in "Singing Duvalier", the songs express a new, inclusionary national discourse by articulating race, class, colour, religion, and sexuality through a rubric of masculinity.