cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
MMA Regularization: Decorrelating Weights of Neural Networks by Maximizing the Minimal Angles
Creators: name: Wang, Zhennan
name: Xiang, Canqun
name: Zou, Wenbin
name: Xu, Chen
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The strong correlation between neurons or filters can significantly weaken the generalization ability of neural networks. Inspired by the well-known Tammes problem, we propose a novel diversity regularization method to address this issue, which makes the normalized weight vectors of neurons or filters distributed on a hypersphere as uniformly as possible, through maximizing the minimal pairwise angles (MMA). This method can easily exert its effect by plugging the MMA regularization term into the loss function with negligible computational overhead. The MMA regularization is simple, efficient, and effective. Therefore, it can be used as a basic regularization method in neural network training. Extensive experiments demonstrate that MMA regularization is able to enhance the generalization ability of various modern models and achieves considerable performance improvements on CIFAR100 and TinyImageNet datasets. In addition, experiments on face verification show that MMA regularization is also effective for feature learning. Code is available at: https://github.com/wznpub/MMA_Regularization.
description: NeurIPS2020
Market-Oriented Reforms in Bangladesh and their Impact on Poverty?
Creators: name: Tisdell, Clement A.
name: Alauddin, Mohammad
name: Tisdell, Clement A.
name: Alauddin, Mohammad
Publisher: name: Unknown
Year: 2002
Subjects: subject: International Relations/Trade
subject: Political Economy
subject: Bangladesh
subject: Human Development Index (HDI)
subject: Human Poverty Index (HPI)
subject: Washington Concensus

description: After providing some general background on developments in Bangladesh’s economy, the article indicates the nature of international political pressures, as represented by the Washington consensus, put on Bangladesh to adopt market-oriented reforms. The sequencing and pattern of Bangladesh’s market reforms and their consequences for its external balance are then examined. Particular attention is given to the fact that its macroeconomic reforms preceded its microeconomic ones. The impacts of Bangladesh’s market reforms on the incidence of poverty can be seen as part of the general question of the effects of these reforms on social welfare. The Human Development Index (HDI) for Bangladesh is considered in this context. Poverty may be measured in different ways. Here, the Human Poverty Index (HPI) and the incidence of poverty (based on Bangladesh’s official poverty line) are considered as indicators of the extent of poverty in Bangladesh, and these measures are qualified. The relationships of HDI, of HPI and of the incidence of poverty in rural and urban areas to the progress of Bangladesh’s market reforms (as measured by the openness of its economy) is examined. No strong evidence is found to indicate that the market reforms have reduced the incidence of poverty in Bangladesh.
Final State of Hawking Radiation in Quantum General Relativity
Creators: name: Ward, B. F. L.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We use a new approach to the UV behavior of quantum general relativity, together with some recent results from the phenomenological asymptotic safety analysis of the theory, to discuss the final state of the Hawking radiation for an originally very massive black hole solution of Einstein's theory. We find that, after the black hole evaporates to the Planck mass size, its horizon is obviated by quantum loop effects, rendering the entire mass of the originally massive black hole accessible to our universe.
description: 10 pages, 2 figures; improved text and references; extended text
Non-line-of-sight Imaging
Creators: name: Faccio, D.
name: Velten, A.
name: Wetzstein, G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Image and Video Processing (eess.IV)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Emerging single-photon-sensitive sensors combined with advanced inverse methods to process picosecond-accurate time-stamped photon counts have given rise to unprecedented imaging capabilities. Rather than imaging photons that travel along direct paths from a source to an object and back to the detector, non-line-of-sight (NLOS) imaging approaches analyse photons {scattered from multiple surfaces that travel} along indirect light paths to estimate 3D images of scenes outside the direct line of sight of a camera, hidden by a wall or other obstacles. Here we review recent advances in the field of NLOS imaging, discussing how to see around corners and future prospects for the field.
Adalia simmondsi Kapur & Sudha Rao
Creators: name: POORANI, J.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Coccinellidae
Adalia
Adalia simmondsi

description: Adalia simmondsi Kapur & Sudha Rao
(Fig. 14)
Adalia simmondsi Kapur & Sudha Rao, 1962: 49–51 (Holotype male, ZSIK; Type locality: Kalatop Forest, Chamba, Himachal Pradesh); Poorani 2002a: 320.
Adalia puetzi Iablokoff-Khnzorian, 1986: 80 (Holotype male, Institute de Zoologie, Yerevan; Type locality: NW Murree, Pakistan). New synonym.
Diagnosis. Length: 3.80–4.30 mm; width: 2.60–2.80 mm. Form (Fig. 14a) elongate oval, weakly convex. Head yellowish testaceous, with a black marking covering most of middle and lateral sides. Pronotum pale yellowish to ochreous, with at least 5 and a maximum of 11 black maculae of varying size and shape, sometimes fused to form larger markings. Scutellar shield light yellowish brown or with darker borders. Elytra uniformly pale ochreous to yellowish brown, elytral punctation somewhat coarse, clearly dual and dense. Ventral side more or less dark pitchy brown, except outer half of prothoracic hypomeron, elytral epipleura and posterior abdominal ventrites pale ochreous to yellowish brown. Male genitalia (Fig. 14c–e) and spermatheca (Fig. 14b) as illustrated.
Distribution: India: Northwestern Himalayas (Himachal Pradesh). It appears to be endemic to this region and extremely rare.
Prey/associated habitat. Adelgidae: Adelges spp. on silver fir (label data).
Seasonal occurrence. Collected during July, November, and January, in northwestern India (label data).
Notes. Adalia puetzi Iablokoff-Khnzorian (new synonym) is conspecific with this species and the specimens identified by Dr Roger Booth as A. puetzi in the collections of BMNH (examined) match A. simmondsi and in both, elytral punctation is somewhat coarse, clearly dual and dense and the interspaces are not smooth and shiny as in A. bipunctata and A. tetraspilota. In general, A. simmondsi appears to be smaller in size and museum specimens are dull yellow. Kovář (2007: 605) wrongly listed it as a synonym of A. tetraspilota (Hope). Kapur & Sudha Rao (1962) described it in detail with illustrations.
description: Published as part of POORANI, J., 2023, An illustrated guide to lady beetles (Coleoptera: Coccinellidae) of the Indian Subcontinent. Part 1. Tribe Coccinellini, pp. 1-307 in Zootaxa 5332 (1) on page 29, DOI: 10.11646/zootaxa.5332.1.1, http://zenodo.org/record/8261502
S^3-Rec: Self-Supervised Learning for Sequential Recommendation with Mutual Information Maximization
Creators: name: Zhou, Kun
name: Wang, Hui
name: Zhao, Wayne Xin
name: Zhu, Yutao
name: Wang, Sirui
name: Zhang, Fuzheng
name: Wang, Zhongyuan
name: Wen, Ji-Rong
Publisher: name: arXiv
Year: 2020
Subjects: subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Recently, significant progress has been made in sequential recommendation with deep learning. Existing neural sequential recommendation models usually rely on the item prediction loss to learn model parameters or data representations. However, the model trained with this loss is prone to suffer from data sparsity problem. Since it overemphasizes the final performance, the association or fusion between context data and sequence data has not been well captured and utilized for sequential recommendation. To tackle this problem, we propose the model S^3-Rec, which stands for Self-Supervised learning for Sequential Recommendation, based on the self-attentive neural architecture. The main idea of our approach is to utilize the intrinsic data correlation to derive self-supervision signals and enhance the data representations via pre-training methods for improving sequential recommendation. For our task, we devise four auxiliary self-supervised objectives to learn the correlations among attribute, item, subsequence, and sequence by utilizing the mutual information maximization (MIM) principle. MIM provides a unified way to characterize the correlation between different types of data, which is particularly suitable in our scenario. Extensive experiments conducted on six real-world datasets demonstrate the superiority of our proposed method over existing state-of-the-art methods, especially when only limited training data is available. Besides, we extend our self-supervised learning method to other recommendation models, which also improve their performance.
description: Accepted as CIKM2020 long paper
A Chandra Observation of the Diffuse Emission Centered on the Low Mass X-ray Binary 4U 1755-33
Creators: name: Park, Shinae Q.
name: Miller, Jon M.
name: McClintock, Jeffrey E.
name: Murray, Stephen S.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present an analysis of a Chandra observation of the field surrounding the low-mass X-ray binary 4U 1755-33, which has been in quiescence since 1996. In 2003, Angelini and White reported the appearance of a narrow 7 arcmin long jetlike feature centered on the position of 4U 1755-33 using the XMM-Newton telescope. Though the source and jet are not visibly apparent in our Chandra/ACIS-S image, there is a significant excess (4-6 sigma) of counts in a region that encloses the jet when compared to adjacent regions. We examined a knot of emission in the jet that was detected by XMM-Newton but not by Chandra and calculated that if the knot flux observed by XMM-Newton was concentrated in a point source, Chandra would have easily detected it; we therefore conclude that this knot of emission is diffuse. In summary, we suggest that the jetlike feature found previously in the XMM-Newton data is quite diffuse and likely a true jet, and is not due to a chance alignment of discrete point sources or point-like regions of emission associated with internal shocks.
description: 5 pages, color figures, uses emulateapj.cls and apjfonts.sty, submitted to ApJ Letters
Tractability Beyond $β$-Acyclicity for Conjunctive Queries with Negation
Creators: name: Lanzinger, Matthias
Publisher: name: arXiv
Year: 2020
Subjects: subject: Databases (cs.DB)
subject: FOS: Computer and information sciences
subject: H.2.4

description: Numerous fundamental database and reasoning problems are known to be NP-hard in general but tractable on instances where the underlying hypergraph structure is $β$-acyclic. Despite the importance of many of these problems, there has been little success in generalizing these results beyond acyclicity. In this paper, we take on this challenge and propose nest-set width, a novel generalization of hypergraph $β$-acyclicity. We demonstrate that nest-set width has desirable properties and algorithmic significance. In particular, evaluation of boolean conjunctive queries with negation is tractable for classes with bounded nest-set width. Furthermore, propositional satisfiability is fixed-parameter tractable when parameterized by nest-set width.
Economics and Tourism Development: Structural Features of Tourism and Economic Influences on its Vulnerability
Creators: name: Tisdell, Clement A.
name: Tisdell, Clement A.
Publisher: name: Unknown
Year: 2002
Subjects: subject: International Relations/Trade
subject: Public Economics
subject: tourism industry
subject: tourism

description: To a large extent, economic factors explain the global growth of the tourism industry, the concentration of tourism in high-income countries, and the high degree of cross-border tourism between higher income countries themselves. This is discussed. In doing so, shortcomings of tourism statistics reported by the World Tourism Organisation are examined. These statistics can be quite misleading as a means of identifying the relative importance of tourism to different nations. This is shown by rank correlations and conceptually. Economics not only influences the geographical spread of tourism but it is a major determinant of market structures in the tourism industry. These industrial market structures, such as those involving monopolistic competition, combined with high overhead costs experienced by pivotal sectors of the modern tourism industry, make this industry highly vulnerable to sudden declines in demand for its services. These supply-side vulnerability factors are additional to those that contribute to volatility in the demand for tourism itself. Combined supply-side and demand factors have, in particular, made the international tourism industry highly vulnerable to shocks, such as terrorist attacks, unexpected political events and so on. Economic analysis can enhance our understanding of the factors involved.
A western perspective on Kautilya's 'Arthasastra': Does it provide a basis for economic science?
Creators: name: Tisdell, Clement A.
name: Tisdell, Clement A.
Publisher: name: Unknown
Year: 2003
Subjects: subject: Teaching/Communication/Extension/Profession
subject: Arthasastra
subject: agent-and-principle problems
subject: market-making
subject: urban-bias

description: In Arthasastra, Kautilya shows a knowledge of basic economics that had no parallels in Western economic thought until the publication of Adam Smith’s Wealth of Nations in 1776. Although the king was at the centre of the body politic in Kautilya’s time, Kautilya makes it clear that the king is bound by an implicit social contract and that the ultimate objective of the king, in economic and other affairs, should be to benefit his subjects. Their happiness or welfare should be the prime objective of State policy. As pointed out here, Kautilya’s conception of economics was superior to that of the Mercantilists and the Physiocrats. Given the central position of the Mauryan State in directing economic activity and providing security, the importance of adequate receipts for the Treasury was stressed. In doing so, Kautilya develops principles of taxation that are to be found in modern texts. His discussion of public economics and finance is extensive. However, he was keenly aware that the fortunes of the Treasury and the prosperity of the nation depended on its development of agriculture, industry, trade and commerce and the efficient functioning of these economic sectors. He suggests various policies that the State should follow to foster their development. Many modern concepts of economics underlie much of Kautilya’s discussion is Arthasastra. Good governance is one of his central concerns and he gives much attention to agent-and-principal problems and asymmetry of information in relation to public administration. Other modern issues that can be identified in Arthasastra include urban-bias, the importance for State revenue of ‘market-making’ and the significance of adequate transport infrastructure for exchanging produce, as well as for defence purposes. At the heart of Kautilyan economics is the obligation of the State to provide for the social security and welfare of the people. The State was required to help the poor and helpless and to be proactive in contributing to the welfare of its citizens. This basic social principle appears to have appealed to many Indians over the centuries. Arthasastra provides much basic knowledge about economics, and several of its conceptions are still relevant. Overall, however, the political economy emphasized in it, or the economic system described, is one relevant to Mauryan period. Kautilya did not believe that it would be applicable for all times nor to all social settings. In that, as in many other respects, he displayed great wisdom.
The Efficient Public Provision of Commodities: Transaction Cost, Bounded Rationality and Other Considerations
Creators: name: Tisdell, Clement A.
name: Tisdell, Clement A.
Publisher: name: Unknown
Year: 2003
Subjects: subject: Public Economics
subject: bounded rationality
subject: competence
subject: economic efficiency
subject: transaction costs
subject: user charges

description: After briefly reviewing recent economic theories about the economic welfare consequences of public provision of private commodities, this article examines the cost efficient supply of publicly provided commodities. In the light of the presence of transaction costs and bounded rationality, and consequences for the competence of public bodies, it considers whether the following are cost effective: (1) increased out-sourcing of government funded work and supplies using market and competitive mechanisms; (2) greater contestability of employment in the public sector; (3) more widespread imposition of user charges for publicly supplied commodities; and (4) the increased use of performance budgeting and accounting in the public sector. These measures are often favoured by proponents of structural adjustment policies as means to increase the economic efficiency of the public sector. However, it is argued here that such measures can potentially reduce the economic efficiency of the public sector rather than increase it.
Leptonic CP Violation and Neutrino Mass Models
Creators: name: Branco, Gustavo C.
name: Rebelo, M. N.
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss leptonic mixing and CP violation at low and high energies, emphasizing possible connections between leptogenesis and CP violation at low energies, in the context of lepton flavour models. Furthermore we analyse weak basis invariants relevant for leptogenesis and for CP violation at low energies. These invariants have the advantage of providing a simple test of the CP properties of any lepton flavour model.
description: 26 pages, no figures, submitted to the Focus Issue on `Neutrino Physics` edited by F. Halzen, M. Lindner and A. Suzuki, to be published in New Journal of Physics
Translating Workflow Nets to Process Trees: An Algorithmic Approach
Creators: name: van Zelst, Sebastiaan J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: Since their recent introduction, process trees have been frequently used as a process modeling formalism in many process mining algorithms. A process tree is a tree-based model of a process, in which internal vertices represent behavioral control-flow relations and leaves represent process activities. A process tree is easily translated into a sound Workflow net (WF-net), however, the reverse is not the case. Yet, an algorithm that translates a WF-net into a process tree is of great interest, e.g., the explicit knowledge of the control-flow hierarchy in a WF-net allows one to more easily reason on its behavior. Hence, in this paper, we present such an algorithm, i.e., it detects whether a WF-net corresponds to a process tree, and, if so, constructs it. We prove that, if a process tree is discovered, the language of the process tree equals the language of the original WF-net. Conducted experiments show, that the algorithm's corresponding implementation has a quadratic time-complexity in the size of the WF-net. Furthermore, the experiments show strong evidence of process tree rediscoverability.
Globalization, Social Welfare and Labor Market Inequalities
Creators: name: Tisdell, Clement A.
name: Svizzero, Serge
name: Tisdell, Clement A.
name: Svizzero, Serge
Publisher: name: Unknown
Year: 2003
Subjects: subject: Labor and Human Capital
subject: Public Economics
subject: fiscal competition
subject: globalization
subject: income inequality
subject: labor markets
subject: public economics

description: Income inequality has increased sharply in higher income countries. Theories attributing this to bifurcation of labor markets are examined. Some theorists attribute this bifurcation primarily to technical change with influence from globalization. Others take an opposite viewpoint. A contrasting view presented here is that globalization is strongly linked with technological change more significantly even if globalization increases economic efficiency and growth in high-income countries, it can raise income inequality and reduce social welfare. International fiscal competitiveness may, it is argued, contribute to income inequality and make all nations worse off. Trends in public social expenditure and in taxation receipts in higher income countries, including Singapore, are examined to determine the empirical support for the theory.
title: Learning Sequential Force Interaction Skills
Creators: name: Manschitz, Simon
name: Gienger, Michael
name: Kober, Jens
name: Peters, Jan
Publisher: name: MDPI
Year: 2024

description: Learning skills from kinesthetic demonstrations is a promising way of minimizing the gap between human manipulation abilities and those of robots. We propose an approach to learn sequential force interaction skills from such demonstrations. The demonstrations are decomposed into a set of movement primitives by inferring the underlying sequential structure of the task. The decomposition is based on a novel probability distribution which we call Directional Normal Distribution. The distribution allows infering the movement primitive’s composition, i.e., its coordinate frames, control variables and target coordinates from the demonstrations. In addition, it permits determining an appropriate number of movement primitives for a task via model selection. After finding the task’s composition, the system learns to sequence the resulting movement primitives in order to be able to reproduce the task on a real robot. We evaluate the approach on three different tasks, unscrewing a light bulb, box stacking and box flipping. All tasks are kinesthetically demonstrated and then reproduced on a Barrett WAM robot.
Modular Invariant Quark and Lepton Models in Double Covering of $S_4$ Modular Group
Creators: name: Liu, Xiang-Gan
name: Yao, Chang-Yuan
name: Ding, Gui-Jun
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We perform a comprehensive analysis of the homogeneous finite modular group $Γ'_4\equiv S'_4$ which is the double covering of $S_4$ group. The weight 1 modular forms of level 4 are constructed in terms of Dedekind eta function, and they transform as a triplet $\mathbf{\hat{3}'}$ of $S'_4$. The integral weight modular forms until weight 6 are built from the tensor products of weight 1 modular forms. We perform a systematical classification of $S'_4$ modular models for lepton masses and mixing with/without generalized CP, where the left-handed leptons are assigned to triplet of $S'_4$ and right-handed charged leptons transform as singlets under $S'_4$, and we consider both scenarios where the neutrino masses arise from Weinberg operator or type I seesaw mechanism. The phenomenological implications of the minimal models for lepton masses, mixing angles, CP violation phases and neutrinoless double decay are discussed. The $S'_4$ modular symmetry is extended to quark sector, we present several predictive models which use nine or ten free parameters including real and imaginary parts of $τ$ to describe quark masses and Cabibbo-Kobayashi-Maskawa mixing matrix. We give a quark-lepton unified model which can explain the flavor structure of quarks and leptons simultaneously for a common value of $τ$.
description: 54 pages, 8 figures
Spectral denoising for unsupervised analysis of correlated ionic transport
Creators: name: Molinari, Nicola
name: Xie, Yu
name: Leifer, Ian
name: Marcolongo, Aris
name: Kornbluth, Mordechai
name: Kozinsky, Boris
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Computation of correlated ionic transport properties from molecular dynamics in the Green-Kubo formalism is expensive as one cannot rely on the affordable mean square displacement approach. We use spectral decomposition of the short-time ionic displacement covariance to learn a set of diffusion eigenmodes that encode the correlation structure and form a basis for analyzing the ionic trajectories. This allows to systematically reduce the uncertainty and accelerate computations of ionic conductivity in systems with a steady-state correlation structure. We provide mathematical and numerical proofs of the method's robustness, and demonstrate it on realistic electrolyte materials.
Next-to-next-to-next-to-leading-order soft-gluon corrections in hard-scattering processes near threshold
Creators: name: Kidonakis, Nikolaos
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: I present a unified calculation of soft-gluon corrections to hard-scattering cross sections through next-to-next-to-next-to-leading order (NNNLO). Master formulas are derived, from a threshold resummation formalism, that can be applied to total and differential cross sections for hard-scattering processes in hadron colliders. I also present numerical results for charged Higgs production at the LHC where these corrections are large, and for top quark production at the Tevatron where these corrections greatly reduce the scale dependence of the cross section.
description: 22 pages, 3 figures
Accelerating bianchi type dark energy cosmological model with cosmic string in f(T) Gravity
Creators: name: Shekh, S. H.
name: Chirde, V. R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: In this paper, we have investigated some features of anisotropic accelerating Bianchi type-I cosmological model in the presence of two non-interacting fluids, i.e. one usual string and other dark energy fluid towards the gravitational field equations for the linear form of $f(T)$ gravity, where \textit{T }be the torsion. To achieve a physically realistic solution of the field equations, we have considered an exact matter dominated volumetric power law expansion. The aspects of derived model are discussed with the help of solution and make the model at late times turn out to be flat Universe. Also, observed that the model has initially non-singular and stable while for whole expansion it is unstable. At an initial expansion $0.01\le t\le 0.05$ when the Universe start to expand to infinite expansion $t>1.73$ (break away from for small interval of cosmic time $0.06\le t\le 1.73$), there is a matter dominated era while for $0.06\le t\le 1.73$ it approaches the quintessence region. Also, the string exists in the early universe which is in agreement with constraints of CMBR data but with the expansion the string phase of the Universe disappears, i.e. we have an anisotropic fluid of particles.
description: 13 pages, 8 figures. arXiv admin note: text overlap with arXiv:1209.4859, arXiv:1308.2962, arXiv:1007.1411 by other authors
The milliQan experiment: search for milli-charged particles at the LHC
Creators: name: Zaraket, H.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Charge quantization has always been enigmatic. Theoretically, Millicharged particles can be an answer. The use of existing detectors, without affecting their initial mandate, is a very promising low cost new physics detector for millicharged particles. The Milliqan collaboration has installed a 1/100th version of the full detector at LHC point 5 in CMS. Data collected in 2018 is now under investigation/analysis. Some results are presented in this paper.
description: 5 pages, 5 figures, EPS-HEP2019
Advanced data analysis procedure for hard x-ray resonant magnetic reflectivity discussed for Pt thin film samples of various complexity
Creators: name: Krieft, Jan
name: Graulich, Dominik
name: Moskaltsova, Anastasiia
name: Bouchenoire, Laurence
name: Francoual, Sonia
name: Kuschel, Timo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: X-ray resonant magnetic reflectivity (XRMR) is a powerful method to determine the optical, structural and magnetic depth profiles of a variety of thin films. Here, we investigate samples of different complexity all measured at the Pt L$_3$ absorption edge to determine the optimal procedure for the analysis of the experimental XRMR curves, especially for nontrivial bi- and multilayer samples that include differently bonded Pt from layer to layer. The software tool ReMagX is used to fit these data and model the magnetooptic depth profiles based on a highly adaptable layer stack which is modified to be a more precise and physically consistent representation of the real multilayer system. Various fitting algorithms, iterative optimization approaches and a detailed analysis of the asymmetry ratio features as well as $χ^2$ (goodness of fit) landscapes are utilized to improve the agreement between measurements and simulations. We present a step-by-step analysis procedure tailored to the Pt thin film systems to take advantage of the excellent magnetic sensitivity and depth resolution of XRMR.
description: 16 pages, 14 figures
Transition to zero resistance in a two dimensional electron gas driven with microwaves
Creators: name: Alicea, J.
name: Balents, L.
name: Fisher, M. P. A.
name: Paramekanti, A.
name: Radzihovsky, L.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: High-mobility 2D electron systems in a perpendicular magnetic field exhibit zero resistance states (ZRS) when driven with microwave radiation. We study the nonequilibrium phase transition into this ZRS using phenomenological equations of motion to describe the current and density fluctuations. We focus on two models for the transition into a time-independent steady state. Model-I assumes rotational invariance, density conservation, and symmetry under shifting the density globally by a constant. This model is argued to describe physics on small length scales where the density does not vary appreciably from its mean. The ordered state that arises in this case breaks rotational invariance and consists of a uniform current and transverse Hall field. We discuss some properties of this state, such as stability to fluctuations and the appearance of a Goldstone mode associated with the continuous symmetry breaking. Using dynamical renormalization group techniques, we find that with short-range interactions this model can admit a continuous transition described by mean-field theory, whereas with long-range interactions the transition is driven first-order. Model-II, which assumes only rotational invariance and density conservation and is argued to be appropriate on longer length scales, is shown to predict a first-order transition with either short- or long-range interactions. We discuss implications for experiments, including scaling relations and a possible way to detect the Goldstone mode in the case of a continuous transition into the ZRS, as well as possible signatures of a first-order transition in larger samples. We also point out the connection of our work to the well-studied phenomenon of `flocking'.
description: 13 pages, 2 figs
Evaluation of association schemes in the CPA and PC-SAFT equations of state in modeling VLE of organic acids + water systems
Creators: name: Román-Ramírez, Luis A.
name: García-Sánchez, Fernando
name: Leeke, Gary A.
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Space Science
subject: Medicine
subject: Physiology
subject: FOS: Biological sciences
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: Cancer
subject: Science Policy

description: The performance of various association schemes was evaluated in modeling isothermal and isobaric vapor–liquid equilibria of mixtures of organic acids and water with the CPA and the PC-SAFT equations of state. The organic acids considered were formic, acetic, propanoic and butanoic acid. Combinations of the 1A and 2B association schemes for the acids and the 2B, 3B, and 4C for water were tested. Polar contributions were also studied in PC-SAFT. The case in which no association contribution is included in the thermodynamic model was also assessed. It is concluded that the chosen association scheme greatly affects the performance of the equation of state. It was not possible to identify a single association scheme combination that would work well for all the systems and conditions studied. On average, PC-SAFT with the organic acid modeled as 1A and water as 4C showed the greatest accuracy. Interestingly, for some of the mixtures the nonassociation case gave considerably better representations than when the association term was used. When a binary interaction parameter is used the performance of the equations studied is comparable to the classic PR.
Mechanical unfolding of RNA hairpins
Creators: name: Hyeon, Changbong
name: Thirumalai, D.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Biomolecules (q-bio.BM)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Biological sciences

description: Mechanical unfolding trajectories, generated by applying constant force in optical tweezer experiments, show that RNA hairpins and the P5abc subdomain of the group I intron unfold reversibly. We use coarse-grained Go-like models for RNA hairpins to explore forced-unfolding over a broad range of temperatures. A number of predictions that are amenable to experimental tests are made. At the critical force the hairpin jumps between folded and unfolded conformations without populating any discernible intermediates. The phase diagram in the force-temperature (f,T) plane shows that the hairpin unfolds by an all-or-none process. The cooperativity of the unfolding transition increases dramatically at low temperatures. Free energy of stability, obtained from time averages of mechanical unfolding trajectories, coincide with ensemble averages which establishes ergodicity. The hopping time between the the native basin of attraction (NBA) and the unfolded basin increases dramatically along the phase boundary. Thermal unfolding is stochastic whereas mechanical unfolding occurs in "quantized steps" with great variations in the step lengths. Refolding times, upon force quench, from stretched states to the NBA is "at least an order of magnitude" greater than folding times by temperature quench. Upon force quench from stretched states the NBA is reached in at least three stages. In the initial stages the mean end-to-end distance decreases nearly continuously and only in the last stage there is a sudden transition to the NBA. Because of the generality of the results we propose that similar behavior should be observed in force quench refolding of proteins.
description: 23 pages, 6 Figures. in press (Proc. Natl. Acad. Sci.)
Shallow vs. deep : bilingual contrast processing
Creators: name: Yoshida, Katherine Aya
Publisher: name: University of British Columbia
Year: 2009

description: Languages differ in the range of phones that cluster together to carry the same meaning, forming phonemic categories (e.g. all the possible manifestations of /l/ in English). These phonemes then contrast with one another to denote differences of meaning (e.g. /l/ vs. /r/, a valid contrast in English but not in Japanese). Infants are born with the ability to discriminate contrasts belonging to their native language, as well as those that are non-native contrasts. However, by 10-12 months of age they refine their repertoire, leaving only those utilized in the language input (Werker & Tees, 1984). The subsequent formation of non-native phonemes belonging to an ensuing second language (L2) is less clearly understood. This work uses Cantonese-native ESL speakers to investigate the distinction between "shallow" knowledge of non-native (Englishspecific) isolated phonemes and "deep" knowledge of the phonemes embedded within a linguistic context (Werker et al, 2001). Deep knowledge of the non-native contrasts is tested using a lexical decision task (Pallier, Colomé & Sebastián-Gallés, 2001) and compared to shallow knowledge, operationalized as ability to perceive differences between pairs of isolated phones. Results indicated that the bilinguals had difficulty perceiving the English-specific contrasts within the deep context, but not within the shallow context. Thus, support is found for a shallow-deep distinction within L2 speakers of a language. This helps explain previous divergent findings of L2 perception, and may potentially have implications for hypotheses of interference and a critical period.
Superfluid Density in a Highly Underdoped YBCO Superconductor
Creators: name: Broun, D. M.
name: Huttema, W. A.
name: Turner, P. J.
name: Ozcan, S.
name: Morgan, B.
name: Liang, Ruixing
name: Hardy, W. N.
name: Bonn, D. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The superfluid density rho_s(T) = 1/lambda^2(T) has been measured at 2.64 GHz in highly underdoped YBCO, at 37 dopings with T_c between 3 K and 17 K. Within limits set by the transition width Delta T_c ~ 0.4 K, rho_s(T) shows no evidence of critical fluctuations as T goes to T_c, with a mean-field-like transition and no indication of vortex unbinding. Instead, we propose that rho_s displays the behaviour expected for a quantum phase transition in the (3 + 1)-dimensional XY universality class, with rho_s0 ~ (p - p_c), T_c ~ (p - p_c)^1/2 and rho_s(T) ~ (T_c - T)^1 as T goes to T_c.
description: 4 pages, 5 figures; final version of paper
Dual spheres have the same girth
Creators: name: Paiva, Juan Carlos Alvarez
Publisher: name: arXiv
Year: 2004
Subjects: subject: Metric Geometry (math.MG)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: 46B20, 53D25

description: Symplectic and Finsler geometry are used to settle a conjecture of Schäffer stating that the girth of a normed space--the infimum of the lengths of all closed, rectifiable, centrally symmetric curves on its unit sphere--equals the girth of its dual.
description: 10 pages
Double Cover of Modular $S_4$ for Flavour Model Building
Creators: name: Novichkov, P. P.
name: Penedo, J. T.
name: Petcov, S. T.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We develop the formalism of the finite modular group $Γ'_4 \equiv S'_4$, a double cover of the modular permutation group $Γ_4 \simeq S_4$, for theories of flavour. The integer weight $k>0$ of the level 4 modular forms indispensable for the formalism can be even or odd. We explicitly construct the lowest-weight ($k=1$) modular forms in terms of two Jacobi theta constants, denoted as $\varepsilon(τ)$ and $θ(τ)$, $τ$ being the modulus. We show that these forms furnish a 3D representation of $S'_4$ not present for $S_4$. Having derived the $S'_4$ multiplication rules and Clebsch-Gordan coefficients, we construct multiplets of modular forms of weights up to $k=10$. These are expressed as polynomials in $\varepsilon$ and $θ$, bypassing the need to search for non-linear constraints. We further show that within $S'_4$ there are two options to define the (generalised) CP transformation and we discuss the possible residual symmetries in theories based on modular and CP invariance. Finally, we provide two examples of application of our results, constructing phenomenologically viable lepton flavour models.
description: 47 pages, 7 figures, 11 tables; several comments and a reference added to match the version published in NPB; sign in eq.(3.5) fixed
Exploring Critical Points of Energy Landscapes: From Low-Dimensional Examples to Phase Field Crystal PDEs
Creators: name: Subramanian, Priya
name: Kevrekidis, Ioannis G.
name: Kevrekidis, Panayotis G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: In the present work we explore the application of a few root-finding methods to a series of prototypical examples. The methods we consider include: (a) the so-called continuous-time Nesterov (CTN) flow method; (b) a variant thereof referred to as the squared-operator method (SOM); and (c) the the joint action of each of the above two methods with the so-called deflation method. More traditional methods such as Newton's method (and its variant with deflation) are also brought to bear. Our toy examples start with a naive one degree-of-freedom (dof) system to provide the lay of the land. Subsequently, we turn to a 2-dof system that is motivated by the reduction of an infinite-dimensional, phase field crystal (PFC) model of soft matter crystallisation. Once the landscape of the 2-dof system has been elucidated, we turn to the full PDE model and illustrate how the insights of the low-dimensional examples lead to novel solutions at the PDE level that are of relevance and interest to the full framework of soft matter crystallization.
description: 17 pages, 16 figures
Heavy Ion Physics and Quark-Gluon Plasma
Creators: name: Nagle, J. L.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: These proceedings represent a brief overview of the exciting physics coming out from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The experimental results from BRAHMS, PHOBOS, PHENIX and STAR indicate a strongly-coupled state of matter that can only be described on the partonic level. Here we review some of the latest experimental results as presented at the meeting of the Division of Particles and Fields of the American Physical Society in Riverside, CA in August 2004.
description: 12 pages, 10 figures, Proceedings from the meeting of the Division of Particles and Fields (DPF) of the APS, August 2004, Riverside CA
Search for continuous gravitational waves from Fomalhaut b in the second Advanced LIGO observing run with a hidden Markov model
Creators: name: Jones, Dana
name: Sun, Ling
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Results are presented from a semicoherent search for continuous gravitational waves from a nearby neutron star candidate, Fomalhaut b, using data collected in the second observing run of Advanced LIGO. The search is based on a hidden Markov model scheme, capable of tracking signal frequency evolution from the star's secular spin down and stochastic timing noise simultaneously. The scheme is combined with a frequency domain matched filter ($\mathcal{F}$-statistic), calculated coherently over five-day time stretches. The frequency band 100-1000 Hz is searched. After passing the above-threshold candidates through a hierarchy of vetoes, one candidate slightly above the 1% false alarm probability threshold remains for further scrutiny. No strong evidence of continuous waves is found. We present the strain upper limits in the full frequency band searched at 90% confidence level.
Dissipative neutrino oscillations in randomly fluctuating matter
Creators: name: Benatti, F.
name: Floreanini, R.
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The generalized dynamics describing the propagation of neutrinos in randomly fluctuating media is analyzed: it takes into account matter-induced, decoherence phenomena that go beyond the standard MSW effect. A widely adopted density fluctuation pattern is found to be physically untenable: a more general model needs to be instead considered, leading to flavor changing effective neutrino-matter interactions. They induce new, dissipative effects that modify the neutrino oscillation pattern in a way amenable to a direct experimental analysis.
description: 14 pages, plain-TeX
Easing cosmic tensions with an open and hotter universe
Creators: name: Bose, Benjamin
name: Lombriser, Lucas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Despite the great observational success of the standard cosmological model some discrepancies in the inferred parameter constraints have manifested among a number of cosmological data sets. These include a tension between the expansion rate of our Cosmos as inferred from the cosmic microwave background (CMB) and as found from local measurements, the preference for an enhanced amplitude of CMB lensing, a somewhat low quadrupole moment of the CMB fluctuations as well as a preference for a lower amplitude of matter fluctuations in large-scale structure surveys than inferred from the CMB. We analyse these observational tensions under the addition of spatial curvature and a free CMB background temperature that may deviate from its locally measured value. With inclusion of these parameters, we observe a trend in the parameter constraints from CMB and baryon acoustic oscillation data towards an open and hotter universe with larger current expansion rate, standard CMB lensing amplitudes, lower amplitude of matter fluctuations, and marginally lower CMB quadrupole moment, consistently reducing the individual tensions among the cosmological data sets. Combining this data with local distance measurements, we find a preference for an open and hotter universe beyond the 99.7% confidence level. Finally, we briefly discuss a local void as a possible source for a deviation of the locally measured CMB temperature from its background value and as mimic of negative spatial curvature for CMB photons. This interpretation implies a $\sim$20% underdensity in our local neighbourhood of $\sim$10-100 Mpc in diameter, which is well within cosmic variance.
description: 5 pages, 2 figures. Updated discussion on local void interpretation