cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Bayesian model selection on Scalar $ε$-Field Dark Energy
Creators: name: Vázquez, J. Alberto
name: Tamayo, David
name: Sen, Anjan A.
name: Quiros, Israel
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The main aim of this paper is to analyse minimally-coupled scalar-fields -- quintessence and phantom -- as the main candidates to explain the accelerated expansion of the universe and compare its observables to current cosmological observations; as a byproduct we present its python module. This work includes a parameter $ε$ which allows to incorporate both quintessence and phantom fields within the same analysis. Examples of the potentials, so far included, are $V(ϕ)=V_0ϕ^μe^{βϕ^α}$ and $V(ϕ)=V_0(\cosh(αϕ)+β)$ with $α$, $μ$ and $β$ being free parameters, but the analysis can be easily extended to any other scalar field potential. Additional to the field component and the standard content of matter, the study also incorporates the contribution from spatial curvature ($Ω_k$), as it has been the focus in recent studies. The analysis contains the most up-to-date datasets along with a nested sampler to produce posterior distributions along with the Bayesian evidence, that allows to perform a model selection. In this work we constrain the parameter-space describing the two generic potentials, and among several combinations, we found that the best-fit to current datasets is given by a model slightly favouring the quintessence field with potential $V(ϕ)=V_0ϕ^μe^{βϕ}$ with $β=0.22\pm 1.56$, $μ= -0.41\pm 1.90$, and slightly negative curvature $Ω_{k,0}=-0.0016\pm0.0018$, which presents deviations of $1.6σ$ from the standard $Λ$CDM model. Even though this potential contains three extra parameters, the Bayesian evidence $\mathcal{B}_{Λ, ϕ} =2.0$ is unable to distinguish this model compared to the $Λ$CDM with curvature ($Ω_{k,0}=0.0013\pm0.0018$). The potential that provides the minimal Bayesian evidence corresponds to $V(ϕ)=V_0 \cosh(αϕ)$ with $α=-0.61\pm 1.36$.
description: 10 pages
3D architected isotropic materials with tunable stiffness and buckling strength
Creators: name: Wang, Fengwen
name: Sigmund, Ole
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: This paper presents a class of 3D single-scale isotropic materials with tunable stiffness and buckling strength obtained via topology optimization and subsequent shape optimization. Compared to stiffness-optimal closed-cell plate material, the material class reduces the Young's modulus to a range from 79% to 58%, but improves the uniaxial buckling strength to a range from 180% to 767%. Based on small deformation theory, material stiffness is evaluated using the homogenization method. Buckling strength under a given macroscopic stress state is estimated using linear buckling analysis with Block-Floquet boundary conditions to capture both short and long wavelength buckling modes. The 3D isotropic single-scale materials with tunable properties are designed using topology optimization, and are then further simplified using shape optimization. Both topology and shape optimized results demonstrate that material buckling strength can be significantly enhanced by hybrids between truss and variable thickness plate structures.
A Dynamic Model of U.S. Sugar-Related Markets: A Cointegrated Vector Autoregression Approach
Creators: name: Babula, Ronald A.
name: Newman, Douglas
name: Rogowsky, Robert A.
name: Babula, Ronald A.
name: Newman, Douglas
name: Rogowsky, Robert A.
Publisher: name: Unknown
Year: 2006
Subjects: Agribusiness

description: The methods of the cointegrated vector autoregression (VAR) model are applied to monthly U.S. markets for sugar and for sugar-using markets for confectionary, soft drink, and bakery products. Primarily a methods paper, we apply Johansen and Juselius' advanced procedures to these markets for perhaps the first time, with focus on achievement of a statistically adequate model through analysis of a battery of advanced statistical diagnostic tests and on exploitation of the system's cointegration properties through rank restrictions, statistically supported hypotheses test restrictions, and inference. The VEC model results illuminate the estimates of crucial policy-relevant market parameters that drive these markets, as well as the dynamic nature of the relationships linking these sugar-based markets.
Quark Condensate in Massless QCD from Planar Equivalence
Creators: name: Armoni, Adi
name: Shore, Graham
name: Veneziano, Gabriele
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A previous estimate of the quark condensate in one-flavour massless QCD from the known value of the gluino condensate in super Yang-Mills (SYM) theory is extended to Nf >1 by considering the large-N limit of an SU(N) gauge theory with one flavour in the antisymmetric representation and nf = Nf -1 extra flavours in the fundamental representation. We argue that, even at nf> 0, suitably chosen correlators in this theory can be mapped to those of SYM as N--> infinity. We give arguments why this correspondence should be particularly good for Nf =3 and compare our prediction with available (real and Monte Carlo) data.
description: 18 pages, LaTex. 1 figure
Katoppo, Marianne: mitleiden - mithandeln
Creators: name: Drewes-Siebel, Renate
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 31 Nr. 3 (1982): Ökumenische Rundschau, Band 31, Heft 3
Robust Detection of Non-overlapping Ellipses from Points with Applications to Circular Target Extraction in Images and Cylinder Detection in Point Clouds
Creators: name: Maalek, Reza
name: Lichti, Derek
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Computational Geometry (cs.CG)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: This manuscript provides a collection of new methods for the automated detection of non-overlapping ellipses from edge points. The methods introduce new developments in: (i) robust Monte Carlo-based ellipse fitting to 2-dimensional (2D) points in the presence of outliers; (ii) detection of non-overlapping ellipse from 2D edge points; and (iii) extraction of cylinder from 3D point clouds. The proposed methods were thoroughly compared with established state-of-the-art methods, using simulated and real-world datasets, through the design of four sets of original experiments. It was found that the proposed robust ellipse detection was superior to four reliable robust methods, including the popular least median of squares, in both simulated and real-world datasets. The proposed process for detecting non-overlapping ellipses achieved F-measure of 99.3% on real images, compared to F-measures of 42.4%, 65.6%, and 59.2%, obtained using the methods of Fornaciari, Patraucean, and Panagiotakis, respectively. The proposed cylinder extraction method identified all detectable mechanical pipes in two real-world point clouds, obtained under laboratory, and industrial construction site conditions. The results of this investigation show promise for the application of the proposed methods for automatic extraction of circular targets from images and pipes from point clouds.
The adoption of internet banking : a model of decision factors
Creators: name: Chan, Stan
Publisher: name: University of British Columbia
Year: 2009

description: This paper tests a model of Internet banking adoption, giving insight into issues that banks consider when adopting the Internet as a delivery channel. It also reveals how a bank's perception of these issues is related to the intent to adopt. The study has two parts. The qualitative study involved literature review and interviews with bank executives, leading to the identification of several potential decision factors and the formation of a tentative adoption model. The quantitative research validated the proposed model by conducting a comprehensive survey targeted at senior bank executives in North America. The result has shown that the adoption decision was mainly determined by various issues such as strategic motivation, the perceived value of Internet banking, customer demand, environmental influences, and operational context. However, only a few of them are able to discriminate the level of adoption intent among banks. Keywords: Adoption of IT, Internet Banking, Decision Model, Empirical Study, Literature Review, Theory of Planned Behavior, Factor Analysis, Discriminant Analysis.
Topological Superconductivity from Unconventional Band Degeneracy with Conventional Pairing
Creators: name: Zhang, Zhongyi
name: Wu, Zhenfei
name: Fang, Chen
name: Zhang, Fu-chun
name: Hu, Jiangping
name: Wang, Yuxuan
name: Qin, Shengshan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We present a new scheme for Majorana modes in systems with nonsymmporhic-symmetry-protected band degeneracy. We reveal that when the gapless fermionic excitations are encoded with conventional superconductivity and magnetism, which can be intrinsic or induced by proximity effect, topological superconductivity and Majorana modes can be obtained. We illustrate this outcome in a system which respects the space group P4/nmm and features a fourfold-degenerate fermionic mode at (π, π) in the Brillouin zone. We show that in the presence of conventional superconductivity, different types of topological superconductivity, i.e. first-order and second-order topological superconductivity, with coexisting fragile Wannier obstruction in the latter case, can be generated in accordance with the different types of magnetic orders; Majorana modes are shown to exist on the boundary, at the corner and in the vortices. To further demonstrate the effectiveness of our approach, another example related to the space group P4/ncc based on this scheme is also provided. Our study offers insights into constructing topological superconductors based on bulk energy bands and conventional superconductivity, and helps to find new material candidates and design new platforms for realizing Majorana modes.
Quantum State Reconstruction of Many Body System Based on Complete Set of Quantum Correlations Reduced by Symmetry
Creators: name: Liu, X. F.
name: Sun, C. P.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose and study a universal approach for the reconstruction of quantum states of many body systems from symmetry analysis. The concept of minimal complete set of quantum correlation functions (MCSQCF) is introduced to describe the state reconstruction. As an experimentally feasible physical object, the MCSQCF is mathematically defined through the minimal complete subspace of observables determined by the symmetry of quantum states under consideration. An example with broken symmetry is analyzed in detail to illustrate the idea.
description: 10 pages, n figures, Revtex
The Impact of Cholesterol Information on Meat Demand: Application of an Updated Cholesterol Index
Creators: name: Adhikari, Murali
name: Paudel, Laxmi
name: Houston, Jack E.
name: Paudel, Krishna P.
name: Bukenya, James O.
name: Adhikari, Murali
name: Paudel, Laxmi
name: Houston, Jack E.
name: Paudel, Krishna P.
name: Bukenya, James O.
Publisher: name: Unknown
Year: 2006
Subjects: Demand and Price Analysis
Health Economics and Policy

description: We estimate an almost ideal-demand system (AIDS) to assess the impacts of cholesterol information on the market demand of meats in the U.S. Our study indicates a significant negative impact of cholesterol information on the market demand of beef and pork and a significant positive influence on chicken demand. The study further demonstrated that the flow of carbohydrate information lessened the magnitude of cholesterol health information elasticities.
Influence of water models on water movement through AQP1
Creators: name: Gonzalez, Miguel A.
name: Zaragoza, Alberto
name: Lynch, Charlotte I.
name: Sansom, Mark S. P.
name: Valeriani, Chantal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Water diffusion through membrane proteins is a key aspect of cellular function. Essential processes of cellular metabolism are driven by osmotic pressure, which depends on water channels. Membrane proteins such as aquaporins (AQPs) are responsible for enabling water transport through the cell membrane. AQPs are highly selective, allowing only water and relatively small polar molecules to cross the membrane. Experimentally, estimation of water flux through membrane proteins is still a challenge, and hence accurate simulations of water transport are of particular importance. We present a numerical study of water diffusion through AQP1 comparing three water models: TIP3P, OPC and TIP4P/2005. Bulk diffusion, diffusion permeability and osmotic permeability are computed and compared among all models. The results show that there are significant differences between TIP3P (a particularly widespread model for simulations of biological systems), and the more recently developed TIP4P/2005 and OPC models. We demonstrate that OPC and TIP4P/2005 reproduce protein-water interactions and dynamics in excellent agreement with experimental data. From this study, we find that the choice of the water model has a significant effect on the computed water dynamics as well as its molecular behaviour within a biological nanopore.
Departure from the conical dispersion in epitaxial graphene
Creators: name: Zhou, S. Y.
name: Siegel, D. A.
name: Fedorov, A. V.
name: Lanzara, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The pi bands of epitaxially grown graphene are studied by using high resolution angle resolved photoemission spectroscopy. Clear deviations from the conical dispersion expected for massless Dirac fermions and an anomalous increase of the scattering rate are observed in the vicinity of the Dirac point energy. Possible explanations for such anomalies are discussed in terms of many-body interactions and the opening of a gap. We present detailed experimental evidences in support of the gap scenario. This finding reveals a fundamental intrinsic property of epitaxial graphene and demonstrates the possibility of engineering the band gap in epitaxial graphene.
description: 5 pages, 5 figures
Child labour and schooling decision of the marginal farmer households: An empirical evidence from the East Medinipur district of West Bengal, India
Creators: name: Das, Sangita
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Economics (econ.GN)
subject: FOS: Economics and business

description: Based on the field investigation of West Bengal, this paper investigates whether the school-aged children of the marginal farmer households are full-time paid labourers or unpaid domestic labourers along with schooling or regular students. Probit Regression analysis is applied here to assess the influencing factors for reducing the size of the child labour force in practice. The result shows that the higher is the earning of the adult members of the households, the lower is the incidence of child labour. Moreover, the credit accessibility of the mother from the Self-help group and more person-days of the father in work in a reference year are also responsible for reducing the possibility of a child turning into labour. The study further suggests that the younger age of the father, education of fathers, and low operational landholdings are positive and significant determinants to decide on a child education by restricting their excessive domestic work burden.
description: 12 pages
A semi-relativistic approach to the circular restricted three body problem and a numerical experiment around the 3:2 resonance
Creators: name: Gueron, Eduardo
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A Hamiltonian that approaches the study of the three-body problem in general relativity is obtained. We use it to study the relativistic version of the circular restricted three-body problem in which the first body is the heaviest and the third body is a test-particle. We focus on the orbits around the 3:2 resonance. We show that, in spite of the notable difference between the relativistic and Newtonian orbits, most of the resonant region is preserved. Nevertheless, differently from the Newtonian case, the frequencies between the second and the third body are no longer commensurable.
description: 6 eps figures, accepted to Class. Quant. Grav
Modeling Product Flow Through a Generic Post-Harvest Distribution System
Creators: name: Tollner, Ernest W.
name: Prussia, Stanley E.
name: Florkowski, Wojciech J.
name: Tollner, Ernest W.
name: Prussia, Stanley E.
name: Florkowski, Wojciech J.
Publisher: name: Unknown
Year: 2006
Subjects: Agribusiness

description: A spreadsheet-based stochastic model was developed to track fruit numbers and fruit value for 1,000 individual items grown in a farmer's field, sorted at a packinghouse with and without advanced inspection technology, distributed with and without repack, and sold at a retail store. The quantities generated at each step are value per unit volume in the production field and the respective price multipliers and passing fractions at the packinghouse, distribution center, and retail store. Values of these coefficients were set to reflect experience with the onion industry. It was assumed that about 30% (with repackaging) to 40% (without repackaging) of the fruit leaving the farmer's field would reach the consumer. The initial price per unit volume and pricing multipliers were configured to give representative prices at the production field and representative price per unit fruit at steps through the system to the consumer. The pass-through percentage was decreased an extra 10% to 15% with technology and up to 20% with repack, with corresponding increases in subsequent steps to maintain the 25% to 25% total pass-through. Repacking and technology addition in the packinghouse tended to result in increased value at the retail level. Placing technology in the packinghouse did not result in increased value for the packinghouse. Vertical integration that included the packinghouse would be required to make it profitable to add sorting technology that increases quality by removing defective items. Both technology addition and repackaging reduce the total number of fruits reaching the consumer. The model suggests that the notion of early removal of fruits with latent damage to avoid increased distribution costs does not really benefit the consumer for the conditions modeled. Additional considerations such as food security are required for one to expect additional equipment adoption under current scenarios.
Joint Scene and Object Tracking for Cost-Effective Augmented Reality Assisted Patient Positioning in Radiation Therapy
Creators: name: Sarmadi, Hamid
name: Muñoz-Salinas, Rafael
name: Berbís, M. Álvaro
name: Luna, Antonio
name: Medina-Carnicer, R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: BACKGROUND AND OBJECTIVE: The research done in the field of Augmented Reality (AR) for patient positioning in radiation therapy is scarce. We propose an efficient and cost-effective algorithm for tracking the scene and the patient to interactively assist the patient's positioning process by providing visual feedback to the operator. Up to our knowledge, this is the first framework that can be employed for mobile interactive AR to guide patient positioning. METHODS: We propose a point cloud processing method that combined with a fiducial marker-mapper algorithm and the generalized ICP algorithm tracks the patient and the camera precisely and efficiently only using the CPU unit. The alignment between the 3D reference model and body marker map is calculated employing an efficient body reconstruction algorithm. RESULTS: Our quantitative evaluation shows that the proposed method achieves a translational and rotational error of 4.17 mm/0.82 deg at 9 fps. Furthermore, the qualitative results demonstrate the usefulness of our algorithm in patient positioning on different human subjects. CONCLUSION: Since our algorithm achieves a relatively high frame rate and accuracy employing a regular laptop (without the usage of a dedicated GPU), it is a very cost-effective AR-based patient positioning method. It also opens the way for other researchers by introducing a framework that could be improved upon for better mobile interactive AR patient positioning solutions in the future.
description: 16 pages, 7 figures
Realizing convex codes with axis-parallel boxes
Creators: name: Benitez, Miguel
name: Chen, Siran
name: Han, Tianhui
name: Jeffs, R. Amzi
name: Paguyo, Kinapal
name: Zhou, Kevin A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 52C99, 52A20

description: Every ordered collection of sets in Euclidean space can be associated to a combinatorial code, which records the regions cut out by the sets in space. Given two ordered collections of sets, one can form a third collection in which the $i$-th set is the Cartesian product of the corresponding sets from the original collections. We prove a general "product theorem" which characterizes the code associated to the collection resulting from this operation, in terms of the codes associated to the original collections. We use this theorem to characterize the codes realizable by axis-parallel boxes, and exhibit differences between this class of codes and those realizable by convex open or closed sets. We also use our theorem to prove that a "monotonicity of open convexity" result of Cruz, Giusti, Itskov, and Kronholm holds for closed sets when some assumptions are slightly weakened.
description: 15 pages, 6 figures
Spectral faux trees
Creators: name: Butler, Steve
name: D'Avanzo, Elena
name: Heikkinen, Rachel
name: Jeffries, Joel
name: Kruczek, Alyssa
name: Niergarth, Harper
Publisher: name: arXiv
Year: 2022
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C50

description: A spectral faux tree with respect to a given matrix is a graph which is not a tree but is cospectral with a tree for the given matrix. We consider the existence of spectral faux trees for several matrices, with emphasis on constructions.
 For the Laplacian matrix, there are no spectral faux trees. For the adjacency matrix, almost all trees are cospectral with a faux tree. For the signless Laplacian matrix, spectral faux trees can only exist when the number of vertices is of the form $n=4k$. For the normalized adjacency, spectral faux trees exist when the number of vertices $n\ge 4$, and we give an explicit construction for a family whose size grows exponentially with $k$ for $n=αk+1$ where $α$ is fixed.
description: 17 pages
Urban transportation networks and optimal transport-based infrastructures: similarity and economy of scale
Creators: name: Leite, Daniela
name: De Bacco, Caterina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: Designing and optimizing the structure of urban transportation networks is a challenging task. In this study, we propose a method inspired by optimal transport theory and the principle of economy of scale that uses little information in input to generate structures that are similar to those of public transportation networks. Contrarily to standard approaches, it does not assume any initial backbone network infrastructure, but rather extracts this directly from a continuous space using only a few origin and destination points. Analyzing a set of urban train, tram and subway networks, we find a noteworthy degree of similarity in several of the studied cases between simulated and real infrastructures. By tuning one parameter, our method can simulate a range of different subway, tram and train networks that can be further used to suggest possible improvements in terms of relevant transportation properties. Outputs of our algorithm provide naturally a principled quantitative measure of similarity between two networks that can be used to automatize the selection of similar simulated networks.
Perceived Risks of Agro-Biotechnology and Organic Food Purchases in the United States
Creators: name: Rimal, Arbindra
name: Moon, Wanki
name: Balasubramanian, Siva K.
name: Rimal, Arbindra
name: Moon, Wanki
name: Balasubramanian, Siva K.
Publisher: name: Unknown
Year: 2006
Subjects: Food Consumption/Nutrition/Food Safety

description: This study examines the role of consumers' perceived risks and benefits of agro-biotechnology in shaping purchase patterns for organic food among U.S. consumers. Perceived risks and benefits of biotechnology, general purchase behavior, knowledge of GM technology, and socio-demographic variables are examined in relation to their impact on organic food purchases. Consumers who are concerned about negative attributes of agro-biotechnology, including long-term health and environmental hazards, inequity in the distribution of benefits from the technology, and adverse effects to small and medium farms, are the potential organic food consumers. Growth in the organic food market is largely dependent on continued reinforcement of consumers' belief that organic foods are safer than conventional foods.
Spatial Limits of the TCM revisited: Island Effects
Creators: name: Loomis, John B.
name: Gonzalez-Sepulveda, Juan Marcos
name: Gonzalez-Caban, Armando
name: Loomis, John B.
name: Gonzalez-Sepulveda, Juan Marcos
name: Gonzalez-Caban, Armando
Publisher: name: Unknown
Year: 2007
Subjects: subject: Marketing
subject: FOS: Economics and business

description: The purpose of this paper is to address a problem that may arise with the assumption of a continuous spatial market in the TCM model. We find that this assumption can be challenged by geographical limitations that an area of study might have. Particularly for islands (or isolated island-like areas) that have a valuable non-market resource or good, the spatial market characteristic of the TCM model might be limited or truncated. The geographical truncation limits the observed maximum travel cost of the demand curve falsely implying a lower WTP than otherwise. The study uses a dichotomous choice CVM to confirm that the resulting demand schedules from the TCM underestimates WTP for day trips to the Caribbean National Forest in Puerto Rico. This results in a considerably smaller TCM WTP for the value of recreation sites at $17 to $29 versus $109 per day trip from the dichotomous choice CVM.
U.S. Fresh Produce Wholesale Sector Trade Practices: Initial Survey Results
Creators: name: Martinez, Lourdes R.
name: Thornsbury, Suzanne
name: Martinez, Lourdes R.
name: Thornsbury, Suzanne
Publisher: name: Unknown
Year: 2006
Subjects: Agribusiness

description: The wholesale sector is an intermediate stage in the supply chain of fresh produce. In general, business operations in this sector do not transform a specific product, but rather provide services related to the sale of the product. The term 'wholesaler' refers to all merchants that are part of this intermediate stage in the supply chain; namely, wholesale merchants, distributors, jobbers, shippers, import/export merchants, agents, brokers, commission merchants, and other types of intermediaries (US Census 2004). This definition of wholesalers, however, does not accurately depict all the activities and relationships participants in this supply chain sector develop. Hence, in order to be consistent with a correct terminology and to understand the results presented in this report, the use of 'intermediaries' throughout this paper refers to all participants including grower-shipper/distributors, brokers, custom service providers and wholesalers.
Direct Characterization of Quantum Dynamics
Creators: name: Mohseni, M.
name: Lidar, D. A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The characterization of quantum dynamics is a fundamental and central task in quantum mechanics. This task is typically addressed by quantum process tomography (QPT). Here we present an alternative "direct characterization of quantum dynamics" (DCQD) algorithm. In contrast to all known QPT methods, this algorithm relies on error-detection techniques and does not require any quantum state tomography. We illustrate that, by construction, the DCQD algorithm can be applied to the task of obtaining partial information about quantum dynamics. Furthermore, we argue that the DCQD algorithm is experimentally implementable in a variety of prominent quantum information processing systems, and show how it can be realized in photonic systems with present day technology.
description: 4 pages, 2 figures, published version
On the Optimal Linear Contraction Order of Tree Tensor Networks, and Beyond
Creators: name: Stoian, Mihail
name: Milbradt, Richard
name: Mendl, Christian B.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Databases (cs.DB)
subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The contraction cost of a tensor network depends on the contraction order. However, the optimal contraction ordering problem is known to be NP-hard. We show that the linear contraction ordering problem for tree tensor networks admits a polynomial-time algorithm, by drawing connections to database join ordering. The result relies on the adjacent sequence interchange property of the contraction cost, which enables a global decision of the contraction order based on local comparisons. Based on that, we specify a modified version of the IKKBZ database join ordering algorithm to find the optimal tree tensor network linear contraction order. Finally, we extend our algorithm as a heuristic to general contraction orders and arbitrary tensor network topologies.
description: Journal version: 16 pages, 14 figures
Kontsevich's star-product up to order 7 for affine Poisson brackets: where are the Riemann zeta values?
Creators: name: Buring, Ricardo
name: Kiselev, Arthemy V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Algebra (math.QA)
subject: Mathematical Physics (math-ph)
subject: Combinatorics (math.CO)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 05C22, 53D55, 68R10, also 11M32, 16Z05, 53D17. 81R60, 81Q30

description: The Kontsevich star-product admits a well-defined restriction to the class of affine -- in particular, linear -- Poisson brackets; its graph expansion consists only of Kontsevich's graphs with in-degree $\leqslant 1$ for aerial vertices. We obtain the formula $\star_{\text{aff}}\text{ mod }\bar{o}(\hbar^7)$ with harmonic propagators for the graph weights (over $n\leqslant 7$ aerial vertices); we verify that all these weights satisfy the cyclic weight relations by Shoikhet--Felder--Willwacher, that they match the computations using the $\textsf{kontsevint}$ software by Panzer, and the resulting affine star-product is associative modulo $\bar{o}(\hbar^7)$.
 We discover that the Riemann zeta value $ζ(3)^2/π^6$, which enters the harmonic graph weights (up to rationals), actually disappears from the analytic formula of $\star_{\text{aff}}\text{ mod }\bar{o}(\hbar^7)$ \textit{because} all the $\mathbb{Q}$-linear combinations of Kontsevich graphs near $ζ(3)^2/π^6$ represent differential consequences of the Jacobi identity for the affine Poisson bracket, hence their contribution vanishes. We thus derive a ready-to-use shorter formula $\star_{\text{aff}}^{\text{red}}$ mod~$\bar{o}(\hbar^7)$ with only rational coefficients.
description: This paper is an extract from the PhD thesis of R.B. and is based on a series of talks and posters in Banff and Strasbourg; contains 44 pages, 2 tables, 2 appendices. Old chapter 3 and old appendices 3--6 were extracted from original version 1 and, in expanded form, published separately, see arXiv:2309.16664 [math.QA]
The contact angle in inviscid fluid mechanics
Creators: name: Shankar, P N
name: Kidambi, R
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 76B07, 76B15, 76B45

description: We show that in general, the specification of a contact angle condition at the contact line in inviscid fluid motions is incompatible with the classical field equations and boundary conditions generally applicable to them. The limited conditions under which such a specification is permissible are derived; however, these include cases where the static meniscus is not flat. In view of this situation, the status of the many `solutions' in the literature which prescribe a contact angle in potential flows comes into question. We suggest that these solutions which attempt to incorporate a phenomenological, but incompatible, condition are in some, imprecise sense `weak-type solutions'; they satisfy or are likely to satisfy, at least in the limit, the governing equations and boundary conditions everywhere except in the neighbourhood of the contact line. We discuss the implications of the result for the analysis of inviscid flows with free surfaces.
description: 13 pages, no figures, no tables
title: Identifying and prioritising important areas for biodiversity and conservation in Mozambique
Creators: name: Matimele, Hermenegildo Alfredo
name: Royal Botanic Gardens, KewDarwin Initiative
Publisher: name: University of Kent
Year: 2024

description: It has long been recognised that biodiversity has been heavily impacted by ongoing human activities which has led to massive losses of species and habitats. The consequences of this are profound, as it compromises the functioning of ecosystems services, such as the provision of clean air, water and food, and exacerbates poverty levels and inequality, particularly in developing countries where climate change events are frequent and severe. Nearly the entire world recognises that this trend needs to change now and the inspiration comes from the Convention on Biological Diversity’s vision of “living in harmony with nature by 2050”. A key part of achieving this vision involves establishing conservation areas to halt biodiversity loss. However, there is growing recognition that, as well as creating protected areas (PAs), we need to account for other area-based conservation measures (OECMs), with a focus on putting local communities at the forefront of conservation initiatives to enhance their well-being and livelihoods. This approach is largely welcomed as conservation will be used as a tool to promote social cohesion and higher potential to achieve national and local targets. There is also a recognition that these new conservation areas need to focus on sites that are important for biodiversity, as many species and ecosystems are under-represented in current PA network. 

This thesis consists of four chapters that use spatial conservation prioritisation analysis to identify important sites for biodiversity and people at the national and transfrontier levels in Mozambique. I tested the Important Plant Area (IPA) and the Key Biodiversity Area (KBA) criteria and provided a novel way of delineating their boundaries. Building from this, I applied systematic conservation planning to identify the best places to establish new OECMs in the Maputaland transfrontier biodiversity hotspot then I scaled this up to a national level of Mozambique based on meeting conservation targets. Next, I described a process I co-led to identify KBAs for the whole of Mozambique. Finally, I used national KBA and IPA data to identify priority areas for conservation at a national level, assessing the effectiveness of the current conservation area network for meeting biodiversity targets. This thesis provides insights into how Mozambique’s network of PAs and OECMs could be developed but implementing these plans will require governments and civil society to develop and implement context-specific projects that are led by local communities.
Factor Graph Fusion of Raw GNSS Sensing with IMU and Lidar for Precise Robot Localization without a Base Station
Creators: name: Beuchert, Jonas
name: Camurri, Marco
name: Fallon, Maurice
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Accurate localization is a core component of a robot's navigation system. To this end, global navigation satellite systems (GNSS) can provide absolute measurements outdoors and, therefore, eliminate long-term drift. However, fusing GNSS data with other sensor data is not trivial, especially when a robot moves between areas with and without sky view. We propose a robust approach that tightly fuses raw GNSS receiver data with inertial measurements and, optionally, lidar observations for precise and smooth mobile robot localization. A factor graph with two types of GNSS factors is proposed. First, factors based on pseudoranges, which allow for global localization on Earth. Second, factors based on carrier phases, which enable highly accurate relative localization, which is useful when other sensing modalities are challenged. Unlike traditional differential GNSS, this approach does not require a connection to a base station. On a public urban driving dataset, our approach achieves accuracy comparable to a state-of-the-art algorithm that fuses visual inertial odometry with GNSS data -- despite our approach not using the camera, just inertial and GNSS data. We also demonstrate the robustness of our approach using data from a car and a quadruped robot moving in environments with little sky visibility, such as a forest. The accuracy in the global Earth frame is still 1-2 m, while the estimated trajectories are discontinuity-free and smooth. We also show how lidar measurements can be tightly integrated. We believe this is the first system that fuses raw GNSS observations (as opposed to fixes) with lidar in a factor graph.
description: 7 pages, 4 figures, accompanying video: https://youtu.be/55BLjt6ce1Y, accepted to the 2023 IEEE International Conference on Robotics and Automation (ICRA)
On differential equation on four-point correlation function in the Conformal Toda Field Theory
Creators: name: Fateev, V. A.
name: Litvinov, A. V.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The properties of completely degenerate fields in the Conformal Toda Field Theory are studied. It is shown that a generic four-point correlation function that contains only one such field does not satisfy ordinary differential equation in contrast to the Liouville Field Theory. Some additional assumptions for other fields are required. Under these assumptions we write such a differential equation and solve it explicitly. We use the fusion properties of the operator algebra to derive a special set of three-point correlation function. The result agrees with the semiclassical calculations.
description: 5 pages
Polynomial representations of the Witt Lie algebra
Creators: name: Sam, Steven V
name: Snowden, Andrew
name: Tosteson, Philip
Publisher: name: arXiv
Year: 2022
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics

description: The Witt algebra W_n is the Lie algebra of all derivations of the n-variable polynomial ring V_n=C[x_1, ..., x_n] (or of algebraic vector fields on A^n). A representation of W_n is polynomial if it arises as a subquotient of a sum of tensor powers of V_n. Our main theorems assert that finitely generated polynomial representations of W_n are noetherian and have rational Hilbert series. A key intermediate result states polynomial representations of the infinite Witt algebra are equivalent to representations of Fin^op, where Fin is the category of finite sets. We also show that polynomial representations of W_n are equivalent to polynomial representations of the endomorphism monoid of A^n. These equivalences are a special case of an operadic version of Schur--Weyl duality, which we establish.
description: 25 pages
RELICS: Properties of z>5.5 Galaxies Inferred from Spitzer and Hubble Imaging Including A Candidate z~6.8 Strong [OIII] Emitter
Creators: name: Strait, Victoria
name: Bradac, Marusa
name: Coe, Dan
name: Lemaux, Brian C.
name: Carnall, Adam
name: Bradley, Larry
name: Pelliccia, Debora
name: Sharon, Keren
name: Zitrin, Adi
name: Acebron, Ana
name: Neufeld, Chloe
name: Andrade-Santos, Felipe
name: Avila, Roberto J.
name: Frye, Brenda L.
name: Mahler, Guillaume
name: Nonino, Mario
name: Ogaz, Sara
name: Oguri, Masamune
name: Ouchi, Masami
name: Paterno-Mahler, Rachel
name: Stark, Daniel P.
name: Mainali, Ramesh
name: Oesch, Pascal A.
name: Trenti, Michele
name: Carrasco, Daniela
name: Dawson, William A.
name: Jones, Christine
name: Umetsu, Keiichi
name: Vulcani, Benedetta
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present constraints on the physical properties (including stellar mass, age, and star formation rate) of 207 $6\lesssim z \lesssim8$ galaxy candidates from the Reionization Lensing Cluster Survey (RELICS) and companion Spitzer-RELICS surveys. We measure photometry using T-PHOT and perform spectral energy distribution fitting using EA$z$Y and BAGPIPES. Of the 207 candidates for which we could successfully measure Spitzer fluxes, 23 were demoted to likely low redshift ($z<4$). Among the remaining high redshift candidates, we find intrinsic stellar masses between $1\times10^6\rm{M_{\odot}}$ and $4\times10^9\rm{M_\odot}$, and rest-frame UV absolute magnitudes between $-22.6$ and $-14.5$ mag. While our sample is mostly comprised of $L_{UV}/L^*_{UV}<1$ galaxies, there are a number of brighter objects in the sample, extending to $L_{UV}/L^*_{UV}\sim2$. The galaxies in our sample span approximately four orders of magnitude in stellar mass and star-formation rates, and exhibit ages ranging from maximally young to maximally old. We highlight 11 galaxies which have detections in Spitzer/IRAC imaging and redshift estimates $z\geq6.5$, several of which show evidence for some combination of evolved stellar populations, large contributions of nebular emission lines, and/or dust. Among these is PLCKG287+32-2013, one of the brightest $z\sim7$ candidates known (AB mag 24.9) with a Spitzer 3.6$μ$m flux excess suggesting strong [OIII] + H-$β$ emission ($\sim$1000Å rest-frame equivalent width). We discuss the possible uses and limits of our sample and present a public catalog of Hubble 0.4--1.6$μ$m + Spitzer 3.6$μ$m and 4.5$μ$m photometry along with physical property estimates for all 207 objects in the sample. Because of their apparent brightnesses, high redshifts, and variety of stellar populations, these objects are excellent targets for follow-up with James Webb Space Telescope.
description: 20 pages, 9 figures
Ignorability for categorical data
Creators: name: Jaeger, Manfred
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62A01, 62N01 (Primary)

description: We study the problem of ignorability in likelihood-based inference from incomplete categorical data. Two versions of the coarsened at random assumption (car) are distinguished, their compatibility with the parameter distinctness assumption is investigated and several conditions for ignorability that do not require an extra parameter distinctness assumption are established. It is shown that car assumptions have quite different implications depending on whether the underlying complete-data model is saturated or parametric. In the latter case, car assumptions can become inconsistent with observed data.
description: Published at http://dx.doi.org/10.1214/009053605000000363 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Quantum-classical tradeoffs and multi-controlled quantum gate decompositions in variational algorithms
Creators: name: Tomesh, Teague
name: Allen, Nicholas
name: Dilley, Daniel
name: Saleem, Zain
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The computational capabilities of near-term quantum computers are limited by the noisy execution of gate operations and a limited number of physical qubits. Hybrid variational algorithms are well-suited to near-term quantum devices because they allow for a wide range of tradeoffs between the amount of quantum and classical resources used to solve a problem. This paper investigates tradeoffs available at both the algorithmic and hardware levels by studying a specific case -- applying the Quantum Approximate Optimization Algorithm (QAOA) to instances of the Maximum Independent Set (MIS) problem. We consider three variants of the QAOA which offer different tradeoffs at the algorithmic level in terms of their required number of classical parameters, quantum gates, and iterations of classical optimization needed. Since MIS is a constrained combinatorial optimization problem, the QAOA must respect the problem constraints. This can be accomplished by using many multi-controlled gate operations which must be decomposed into gates executable by the target hardware. We study the tradeoffs available at this hardware level, combining the gate fidelities and decomposition efficiencies of different native gate sets into a single metric called the gate decomposition cost.
description: 21 pages, 11 figures, 5 tables
Non-admissible irreducible representations of $p$-adic $\mathrm{GL}_{n}$ in characteristic $p$
Creators: name: Ghate, Eknath
name: Le, Daniel
name: Sheth, Mihir
Publisher: name: arXiv
Year: 2022
Subjects: subject: Representation Theory (math.RT)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 22E50, 11S37

description: Let $p>3$ and $F$ be a non-archimedean local field with residue field a proper finite extension of $\mathbb{F}_p$. We construct smooth absolutely irreducible non-admissible representations of $\mathrm{GL}_2(F)$ defined over the residue field of $F$ extending the earlier results of the authors for $F$ unramified over $\mathbb{Q}_{p}$. This construction uses the theory of diagrams of Breuil and Paskunas. By parabolic induction, we obtain smooth absolutely irreducible non-admissible representations of $\mathrm{GL}_n(F)$ for $n>2$.
description: 15 pages, this version contains the erratum to the published version: the statement of Prop 3.1, its proof, and the proof of Thm 1.2 is corrected