cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
On the origin of dual Lax pairs and their $r$-matrix structure
Creators: name: Avan, Jean
name: Caudrelier, Vincent
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Symplectic Geometry (math.SG)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We establish the algebraic origin of the following observations made previously by the authors and coworkers: (i) A given integrable PDE in $1+1$ dimensions within the Zakharov-Shabat scheme related to a Lax pair can be cast in two distinct, dual Hamiltonian formulations; (ii) Associated to each formulation is a Poisson bracket and a phase space (which are not compatible in the sense of Magri); (iii) Each matrix in the Lax pair satisfies a linear Poisson algebra a la Sklyanin characterized by the {\it same} classical $r$ matrix. We develop the general concept of dual Lax pairs and dual Hamiltonian formulation of an integrable field theory. We elucidate the origin of the common $r$-matrix structure by tracing it back to a single Lie-Poisson bracket on a suitable coadjoint orbit of the loop algebra ${\rm sl}(2,\CC) \otimes \CC (λ, λ^{-1})$. The results are illustrated with the examples of the nonlinear Schrödinger and Gerdjikov-Ivanov hierarchies.
description: 36 pages, 1 figure. Final version in line with published article. The latter is available for free at https://authors.elsevier.com/a/1VILr1PNYn24TG (until August 18 2017)
Liu-Nagel phase diagrams in infinite dimension
Creators: name: Biroli, Giulio
name: Urbani, Pierfrancesco
Publisher: name: arXiv
Year: 2017
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We study Harmonic Soft Spheres as a model of thermal structural glasses in the limit of infinite dimensions. We show that cooling, compressing and shearing a glass lead to a Gardner transition and, hence, to a marginally stable amorphous solid as found for Hard Spheres systems. A general outcome of our results is that a reduced stability of the glass favors the appearance of the Gardner transition. Therefore using strong perturbations, e.g. shear and compression, on standard glasses or using weak perturbations on weakly stable glasses, e.g. the ones prepared close to the jamming point, are the generic ways to induce a Gardner transition. The formalism that we discuss allows to study general perturbations, including strain deformations that are important to study soft glassy rheology at the mean field level.
description: 22 pages, 9 figures
Line profile of nuclear de-excitation gamma-ray emission from very hot plasma
Creators: name: Yoneda, Hiroki
name: Aharonian, Felix
name: Coppi, Paolo
name: Siegert, Thomas
name: Takahashi, Tadayuki
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: De-excitation gamma-ray lines, produced by nuclei colliding with protons, provide information about astrophysical environments where particles have kinetic energies of $10-100$ MeV per nucleon. In general, such environments can be categorized into two types: the interaction between non-thermal MeV cosmic rays and ambient gas, and the other is thermal plasma with a temperature above a few MeV. In this paper, we focus on the latter type and investigate the production of de-excitation gamma-ray lines in very hot thermal plasma, especially the dependence of the line profile on the plasma temperature. We have calculated the line profile of prompt gamma rays from $^{12}$C and $^{16}$O and found that when nuclei have a higher temperature than protons, gamma-ray line profiles can have a complex shape unique to each nucleus species. This is caused by anisotropic gamma-ray emission in the nucleus rest frame. We propose that the spectroscopy of nuclear de-excitation gamma-ray lines may enable to probe energy distribution in very hot astrophysical plasmas. This diagnostics can be a new and powerful technique to investigate the physical state of a two-temperature accretion flows onto a black hole, especially the energy distributions of the protons and nuclei, which are difficult to access for any other diagnostics.
description: 12 pages, Accepted for publication in MNRAS
Linear Matrix Inequalities for Physically-Consistent Inertial Parameter Identification: A Statistical Perspective on the Mass Distribution
Creators: name: Wensing, Patrick M.
name: Kim, Sangbae
name: Slotine, Jean-Jacques
Publisher: name: arXiv
Year: 2017
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: With the increased application of model-based whole-body control in legged robots, there has been a resurgence of research interest into methods for accurate system identification. An important class of methods focuses on the inertial parameters of rigid-body systems. These parameters consist of the mass, first mass moment (related to center of mass location), and rotational inertia matrix of each link. The main contribution of this paper is to formulate physical-consistency constraints on these parameters as Linear Matrix Inequalities (LMIs). The use of these constraints in identification can accelerate convergence and increase robustness to noisy data. It is critically observed that the proposed LMIs are expressed in terms of the covariance of the mass distribution, rather than its rotational moments of inertia. With this perspective, connections to the classical problem of moments in mathematics are shown to yield new bounding-volume constraints on the mass distribution of each link. While previous work ensured physical plausibility or used convex optimization in identification, the LMIs here uniquely enable both advantages. Constraints are applied to identification of a leg for the MIT Cheetah 3 robot. Detailed properties of transmission components are identified alongside link inertias, with parameter optimization carried out to global optimality through semidefinite programming.
description: Final author version IEEE RAL / IROS 2017
Spectra of large time-lagged correlation matrices from Random Matrix Theory
Creators: name: Nowak, Maciej A.
name: Tarnowski, Wojciech
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We analyze the spectral properties of large, time-lagged correlation matrices using the tools of random matrix theory. We compare predictions of the one-dimensional spectra, based on approaches already proposed in the literature. Employing the methods of free random variables and diagrammatic techniques, we solve a general random matrix problem, namely the spectrum of a matrix $\frac{1}{T}XAX^{\dagger}$, where $X$ is an $N\times T$ Gaussian random matrix and $A$ is \textit{any} $T\times T$, not necessarily symmetric (Hermitian) matrix. As a particular application, we present the spectral features of the large lagged correlation matrices as a function of the depth of the time-lag. We also analyze the properties of left and right eigenvector correlations for the time-lagged matrices. We positively verify our results by the numerical simulations.
description: 44 pages, 11 figures; v2 typos corrected, final version
Caderno de Resumos do I Workshop Internacional de Pragmática [Proceedings of the Abstracts of the 1st International Workshop on Pragmatics]
Creators: name: Godoi, Elena
name: Et Al.
Publisher: name: Zenodo
Year: 2013

description: [In English below] O I Workshop Internacional de Pragmática: teorias, perspectivas, diálogos e aplicações, promovido pelo Grupo de pesquisa “Linguagem e Cultura” (UFPR/CNPq), teve por escopo criar oportunidades de congregar professores, pesquisadores, estudantes e demais interessados nos temas debatidos. Divulgou novas pesquisas, promoveu o intercâmbio de experiências e conhecimentos entre pesquisadores nacionais e estrangeiros, assim como contribuiu para divulgação e socialização dos conhecimentos produzidos. Visou promover o desenvolvimento dos estudos da Pragmática no Brasil. It was the 1st International Workshop on Pragmatics, promoted by the research group "Language and Culture" (Federal University of Paraná/National Council for Scientific and Technological Development), aiming to gather scholars interested in subject matters within the scope of pragmatics. The event provided an opportunity to both showcase studies being conducted by researchers from different countries and encourage Brazil's research.
description: Uploaded to Zenodo.org on July 3, 2023.
Improving Information Extraction on Business Documents with Specific Pre-Training Tasks
Creators: name: Douzon, Thibault
name: Duffner, Stefan
name: Garcia, Christophe
name: Espinas, Jérémy
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation and Language (cs.CL)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: I.2.7
subject: 68T01

description: Transformer-based Language Models are widely used in Natural Language Processing related tasks. Thanks to their pre-training, they have been successfully adapted to Information Extraction in business documents. However, most pre-training tasks proposed in the literature for business documents are too generic and not sufficient to learn more complex structures. In this paper, we use LayoutLM, a language model pre-trained on a collection of business documents, and introduce two new pre-training tasks that further improve its capacity to extract relevant information. The first is aimed at better understanding the complex layout of documents, and the second focuses on numeric values and their order of magnitude. These tasks force the model to learn better-contextualized representations of the scanned documents. We further introduce a new post-processing algorithm to decode BIESO tags in Information Extraction that performs better with complex entities. Our method significantly improves extraction performance on both public (from 93.88 to 95.50 F1 score) and private (from 84.35 to 84.84 F1 score) datasets composed of expense receipts, invoices, and purchase orders.
description: Conference: Document Analysis Systems. DAS 2022
Centrifugal acceleration in the isotropic photon field
Creators: name: Bakhtadze, G. G.
name: Berezhiani, V. I.
name: Osmanov, Z.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In this paper we study centrifugal acceleration of particles moving along a prescribed rotating curved trajectories. We consider the physical system embedded in an isotropic photon field and study the influence of the photon drag force on the acceleration process. For this purpose we study three major configurations of the field lines: the straight line; the Archimede's spiral and the dipolar field line configuration. By analysing dynamics of particles sliding along the field lines in the equatorial plane we have found several interesting features of motion. In particular, it has been shown that for rectilinear field lines the particles reach the light cylinder (area where the linear velocity of rotation exactly equals the speed of light) zone relatively slowly for bigger drag forces. Considering the Archimede's spiral, we have found that in cases when the field lines lag behind the rotation, the particles achieve the force-free regime of dynamics regardless of the drag force. Unlike this scenario, when the spiral is screwed up in an opposite direction there the particles do not reach the force free regime, but tend to stable equilibrium locations. Such a behaviour has been found for straight field lines as well.
description: 12 pages, 7 figures
title: A critical look into the past – The hidden colonial heritage in mineralogical museums
Creators: name: Bohné, Gero
name: Krag, Raphael
name: Céline, Mertens
name: Rothenhäusler, Marco
name: Zacke, Anne
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
The provenance of objects –in terms of chronology of ownerships – in museums and collections is a cutting-edge topic discussed especially among art historians, historians and ethnologists. Until now, the emphasis is on works of art and cultural objects linked to either Nazi-confiscated art or to objects linked to a colonial context. Discussions about restitutions to legal successors or societies of origin engage scientific communities, feuilletons as well as the public. In geoscientific museums, the provenance of objects usually refers to the exact location of finding. Here, a broader, more critical approach is overdue as many geoscientific objects might have a similar critical background as the above-mentioned groups of objects. As mineralogical museum with several historical collections dating from the end of the 19th and beginning of the 20th century, we shed light on objects with a potentially colonial background. To begin with, we focus on minerals originating from the former German colonies in Africa. Like other museums worldwide, we host hundreds of specimens from Tsumeb in Namibia. The mine got established under German rule in the late 19th century. It did not only supply the German Empire with tons of ores, but also private collectors and museums worldwide with minerals for their collections. We began to review our inventory regarding the number of specimens, historical (previous ownerships) and chronological (moment of exploitation) background. We take a critical look into the past of our 200 years old institution and hence contribute to public and scientific discussions related to the provenance of objects in museums.
Yang-Baxter deformations of $W_{2,4}\times T^{1,1}$ and the associated T-dual models
Creators: name: Sakamoto, Jun-ichi
name: Yoshida, Kentaroh
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Recently, for principal chiral models and symmetric coset sigma models, Hoare and Tseytlin proposed an interesting conjecture that the Yang-Baxter deformations with the homogeneous classical Yang-Baxter equation are equivalent to non-abelian T-dualities with topological terms. It is significant to examine this conjecture for non-symmetric (i.e., non-integrable) cases. Such an example is the $W_{2,4}\times T^{1,1}$ background. In this note, we study Yang-Baxter deformations of type IIB string theory defined on $W_{2,4}\times T^{1,1}$ and the associated T-dual models, and show that this conjecture is valid even for this case. Our result indicates that the conjecture would be valid beyond integrability.
description: 31 pages, no figure, v2: a clarification and a reference added, v3: a further clarification added, v4: published version in NPB
A generalisation of Kani-Rosen decomposition theorem for Jacobian varieties
Creators: name: Reyes-Carocca, Sebastián
name: Rodríguez, Rubí E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14H37, 14H40, 14L30

description: In this short paper we generalise a theorem due to Kani and Rosen on decomposition of Jacobian varieties of Riemann surfaces with group action. This generalisation extends the set of Jacobians for which it is possible to obtain an isogeny decomposition where all the factors are Jacobians.
description: 16 pages
Know What Not To Know: Users' Perception of Abstaining Classifiers
Creators: name: Papenmeier, Andrea
name: Hienert, Daniel
name: Kammerer, Yvonne
name: Seifert, Christin
name: Kern, Dagmar
Publisher: name: arXiv
Year: 2023
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: Machine learning systems can help humans to make decisions by providing decision suggestions (i.e., a label for a datapoint). However, individual datapoints do not always provide enough clear evidence to make confident suggestions. Although methods exist that enable systems to identify those datapoints and subsequently abstain from suggesting a label, it remains unclear how users would react to such system behavior. This paper presents first findings from a user study on systems that do or do not abstain from labeling ambiguous datapoints. Our results show that label suggestions on ambiguous datapoints bear a high risk of unconsciously influencing the users' decisions, even toward incorrect ones. Furthermore, participants perceived a system that abstains from labeling uncertain datapoints as equally competent and trustworthy as a system that delivers label suggestions for all datapoints. Consequently, if abstaining does not impair a system's credibility, it can be a useful mechanism to increase decision quality.
Global well-posedness for the 2D Muskat problem with slope less than 1
Creators: name: Cameron, Stephen
Publisher: name: arXiv
Year: 2017
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We prove the existence of global, smooth solutions to the 2D Muskat problem in the stable regime whenever the product of the maximal and minimal slopes is strictly less than 1. The curvature of these solutions solutions decays to 0 as $t$ goes to infinity, and they are unique when the initial data is $C^{1,ε}$. We do this by constructing a modulus of continuity generated by the equation, just as Kiselev, Nazarov, and Volberg did in their proof of the global well-posedness for the quasi-geostraphic equation.
description: 22 pages
Diffusion-Based Co-Speech Gesture Generation Using Joint Text and Audio Representation
Creators: name: Deichler, Anna
name: Mehta, Shivam
name: Alexanderson, Simon
name: Beskow, Jonas
Publisher: name: arXiv
Year: 2023
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: Human-Computer Interaction (cs.HC)
subject: Machine Learning (cs.LG)
subject: Sound (cs.SD)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: I.2.6; I.2.7
subject: 68T42

description: This paper describes a system developed for the GENEA (Generation and Evaluation of Non-verbal Behaviour for Embodied Agents) Challenge 2023. Our solution builds on an existing diffusion-based motion synthesis model. We propose a contrastive speech and motion pretraining (CSMP) module, which learns a joint embedding for speech and gesture with the aim to learn a semantic coupling between these modalities. The output of the CSMP module is used as a conditioning signal in the diffusion-based gesture synthesis model in order to achieve semantically-aware co-speech gesture generation. Our entry achieved highest human-likeness and highest speech appropriateness rating among the submitted entries. This indicates that our system is a promising approach to achieve human-like co-speech gestures in agents that carry semantic meaning.
Generation of Coherence via Gaussian Measurements
Creators: name: Albarelli, Francesco
name: Genoni, Marco G.
name: Paris, Matteo G. A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We address measurement-based generation of quantum coherence in continuous variable systems. We consider Gaussian measurements performed on Gaussian states and focus on two scenarios. In the first one, we assume an initially correlated bipartite state shared by two parties and study how correlations may be exploited to remotely create quantum coherence via measurement back-action. In particular, we focus on conditional states with zero first moments, so as to address coherence due to properties of the covariance matrix. We consider different classes of bipartite states with incoherent marginals and show that the larger the measurement squeezing, the larger the conditional coherence. Homodyne detection is thus the optimal Gaussian measurement to remotely generate coherence. We also show that for squeezed thermal states there exists a threshold value for the generated coherence which separates entangled and separable states at a fixed energy. Finally, we briefly discuss the tripartite case and the relationship between tripartite correlations and the conditional two-mode coherence. In the second scenario, we address the steady state coherence of a system interacting with an environment which is continuously monitored. In particular, we discuss the dynamics of an optical parametric oscillator in order to investigate how the coherence of a Gaussian state may be increased by means of time-continuous Gaussian measurement on the interacting environment.
description: Close to published version
Collective modes of a soliton train in a Fermi superfluid
Creators: name: Dutta, Shovan
name: Mueller, Erich J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We characterize the collective modes of a soliton train in a quasi-one-dimensional Fermi superfluid, using a mean-field formalism. In addition to the expected Goldstone and Higgs modes, we find novel long-lived gapped modes associated with oscillations of the soliton cores. The soliton train has an instability that depends strongly on the interaction strength and the spacing of solitons. It can be stabilized by filling each soliton with an unpaired fermion, thus forming a commensurate Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. We find that such a state is always dynamically stable, which paves the way for realizing long-lived FFLO states in experiments via phase imprinting.
description: Published version: 4-page article + references + supplement. Supplement contains two new sections on (i) protocol to engineer soliton train states and (ii) convention for Bogoliubov operators. Results and conclusions unchanged
Conductance oscillations in Chern insulator junctions: valley-isospin dependence and Aharonov-Bohm effects
Creators: name: Myoung, Nojoon
name: Park, Hee Chul
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The transport properties of Chern insulator junctions generated by bipolar junctions in quantum Hall graphene are theoretically studied in the coherent regime. Coherent transport across the junction exhibits two mesoscopic features: valley-isospin dependence of the quantum Hall conductance, and the Aharonov-Bohm (AB) effects with the interface channels. We demonstrate that the valley-isospin dependence can be measured in a graphene sample with perfect edge terminations, resulting in conductance oscillation for the smallest Chern number case. On the other hand, while conductance plateaus are found to be unclear for larger Chern numbers, the conductance exhibits an oscillatory behavior of which period is relatively longer than the valley-isospin dependent oscillation. This conductance oscillation is ascribed to the AB effect, which is implicitly created by the split metallic channels near the junction interface. We point out that a possible origin of the unclear plateaus previously speculated to be incompleteness in realistic devices is the low-visibility conductance oscillation due to unequal beam splitting.
description: 22 pages (single column), 6 figures
A Lagrangian model for laser-induced fluorescence and its application to measurements of plasma ion temperature and electrostatic waves
Creators: name: Chu, F.
name: Skiff, F.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Extensive information can be obtained on wave-particle interactions and wave fields by direct measurement of perturbed ion distribution functions using laser-induced fluorescence (LIF). For practical purposes, LIF is frequently performed on metastable states that are produced from neutral gas particles and ions in other electronic states. If the laser intensity is increased to obtain a better LIF signal, then optical pumping can produce systematic effects depending on the collision rates which control metastable population and lifetime. We numerically simulate the ion velocity distribution measurement and wave-detection process using a Lagrangian model for the LIF signal for the case where metastables are produced directly from neutrals. This case requires more strict precautions and is important for discharges with energetic primary electrons and a high density of neutrals. Some of the results also apply to metastables produced from pre-existing ions. The simulations show that optical pumping broadening affects the ion velocity distribution function (IVDF) $f_0(v)$ and its first-order perturbation $f_1(v,t)$ when laser intensity is increased above a certain level. The results also suggest that ion temperature measurements are only accurate when the metastable ions can live longer than the ion-ion collision mean free time. For the purposes of wave detection, the wave period has to be significantly shorter than the lifetime of metastable ions for a direct interpretation. It is more generally true that metastable ions may be viewed as test-particles. As long as an appropriate model is available, LIF can be extended to a range of environments.
description: 9 pages, 15 figures
Global phase diagram and quantum spin liquids in spin-1/2 triangular antiferromagnet
Creators: name: Gong, Shou-Shu
name: Zhu, W.
name: Zhu, J. -X.
name: Sheng, D. N.
name: Yang, Kun
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the spin-$1/2$ Heisenberg model on the triangular lattice with the nearest-neighbor $J_1 > 0$, the next-nearest-neighobr $J_2 > 0$ Heisenberg interactions, and the additional scalar chiral interaction $J_χ(\vec{S}_i \times \vec{S}_j) \cdot \vec{S}_k$ for the three spins in all the triangles using large-scale density matrix renormalization group calculation on cylinder geometry. With increasing $J_2$ ($J_2/J_1 \leq 0.3$) and $J_χ$ ($J_χ/J_1 \leq 1.0$) interactions, we establish a quantum phase diagram with the magnetically ordered $120^{\circ}$ phase, stripe phase, and non-coplanar tetrahedral phase. In between these magnetic order phases, we find a chiral spin liquid (CSL) phase, which is identified as a $ν= 1/2$ bosonic fractional quantum Hall state with possible spontaneous rotational symmetry breaking. By switching on the chiral interaction, we find that the previously identified spin liquid in the $J_1 - J_2$ triangular model ($0.08 \lesssim J_2/J_1 \lesssim 0.15$) shows a phase transition to the CSL phase at very small $J_χ$. We also compute spin triplet gap in both spin liquid phases, and our finite-size results suggest large gap in the odd topological sector but small or vanishing gap in the even sector. We discuss the implications of our results to the nature of the spin liquid phases.
description: 10 pages, 14 figures
Towards Intuitive HMI for UAV Control
Creators: name: Zoric, Filip
name: Vasiljevic, Goran
name: Orsag, Matko
name: Kovacic, Zdenko
Publisher: name: arXiv
Year: 2023
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: In the last decade, UAVs have become a widely used technology. As they are used by both professionals and amateurs, there is a need to explore different control modalities to make control intuitive and easier, especially for new users. In this work, we compared the most widely used joystick control with a custom human pose control. We used human pose estimation and arm movements to send UAV commands in the same way that operators use their fingers to send joystick commands. Experiments were conducted in a simulation environment with first-person visual feedback. Participants had to traverse the same maze with joystick and human pose control. Participants' subjective experience was assessed using the raw NASA Task Load Index.
description: 2022 International Conference on Smart Systems and Technologies (SST)
Ultra-fast Vapor Generation by a Graphene Nano-ratchet
Creators: name: Ding, Hongru
name: Peng, Guilong
name: Ma, Dengke
name: Sharshir, S. W.
name: Yang, Nuo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Vapor generation is of prime importance for a broad range of applications: domestic water heating, desalination and wastewater treatment, etc. However, the slow and low efficiency evaporation limits their development. In this paper, we proposed a nano-ratchet, multilayer graphene with cone-shaped nanopores (MGCN), to accelerate the vapor generation. By performing molecular dynamics simulations, we found that the air molecules spontaneously transport across MGCN and form a remarkable pressure difference, 21kPa, between the two sides of MGCN. Besides, we studied the dependence of pressure difference on the ambient temperature and the geometry of MGCN in detail. By further analysis of the diffusive transport, we identified that the pressure difference relates to the competition between ratchet transport and Knudsen diffusion. The significant pressure difference could lead to 15 times enhancement of vapor generation at least, which shows the wide applications of this nano-ratchet.
On the galaxy-halo connection in the EAGLE simulation
Creators: name: Desmond, Harry
name: Mao, Yao-Yuan
name: Wechsler, Risa
name: Crain, Robert
name: Schaye, Joop
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Empirical models of galaxy formation require assumptions about the correlations between galaxy and halo properties. These may be calibrated against observations or inferred from physical models such as hydrodynamical simulations. In this Letter, we use the EAGLE simulation to investigate the correlation of galaxy size with halo properties. We motivate this analysis by noting that the common assumption of angular momentum partition between baryons and dark matter in rotationally supported galaxies overpredicts both the spread in the stellar mass-size relation and the anticorrelation of size and velocity residuals, indicating a problem with the galaxy-halo connection it implies. We find the EAGLE galaxy population to perform significantly better on both statistics, and trace this success to the weakness of the correlations of galaxy size with halo mass, concentration and spin at fixed stellar mass. Using these correlations in empirical models will enable fine-grained aspects of galaxy scalings to be matched.
description: 5 pages, 4 figures; revised to match MNRAS Letters accepted version
K2-139 b: a low-mass warm Jupiter on a 29-day orbit transiting an active K0 V star
Creators: name: Barragán, O.
name: Gandolfi, D.
name: Smith, A. M. S.
name: Deeg, H. J.
name: Fridlund, M. C. V.
name: Persson, C. M.
name: Donati, P.
name: Endl, M.
name: Csizmadia, Sz.
name: Grziwa, S.
name: Nespral, D.
name: Hatzes, A. P.
name: Cochran, W. D.
name: Fossati, L.
name: Brems, S. S.
name: Cabrera, J.
name: Cusano, F.
name: Eigmüller, Ph.
name: Eiroa, C.
name: Erikson, A.
name: Guenther, E.
name: Korth, J.
name: Lorenzo-Oliveira, D.
name: Mancini, L.
name: Pätzold, M.
name: Prieto-Arranz, J.
name: Rauer, H.
name: Rebollido, I.
name: Saario, J.
name: Zakhozhay, O. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We announce the discovery of K2-139 b (EPIC 218916923 b), a transiting warm-Jupiter ($T_\mathrm{eq}$=547$\pm$25 K) on a 29-day orbit around an active (log $R^\prime_\mathrm{HK}$ = $-$4.46 $\pm$ 0.06) K0 V star in K2 Campaign 7. We derive the system's parameters by combining the K2 photometry with ground-based follow-up observations. With a mass of~$0.387 _{ - 0.075 } ^ {+ 0.083 } M_{\rm J}$ and radius of $0.808 _{ - 0.033 } ^ {+ 0.034 } R_{\rm J}$, K2-139 b is one of the transiting warm Jupiters with the lowest mass known to date. The planetary mean density of $0.91 _{ - 0.20} ^ { + 0.24 }$ $\mathrm{g cm^{-3}}$ can be explained with a core of $\sim$50 $M_\oplus$. Given the brightness of the host star ($V$ = 11.653 mag), the relatively short transit duration ($\sim$5 hours), and the expected amplitude of the Rossiter-McLaughlin effect ($\sim25 {\rm m s^{-1}}$ ), K2-139 is an ideal target to measure the spin-orbit angle of a planetary system hosting a warm Jupiter.
description: 12 pages, 5 tables, 5 figures, accepted for publication in MNRAS
Real-Time dynamics and phase separation in a holographic first order phase transition
Creators: name: Janik, Romuald A.
name: Jankowski, Jakub
name: Soltanpanahi, Hesam
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study the fully nonlinear time evolution of a holographic system possessing a first order phase transition. The initial state is chosen in the spinodal region of the phase diagram, and includes an inhomogeneous perturbation in one of the field theory directions. The final state of the time evolution shows a clear phase separation in the form of domain formation. The results indicate the existence of a very rich class of inhomogeneous black hole solutions.
description: 4 pages,4 figures, one reference added
A "Gauged" $U(1)$ Peccei-Quinn Symmetry
Creators: name: Fukuda, Hajime
name: Ibe, Masahiro
name: Suzuki, Motoo
name: Yanagida, Tsutomu T.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Peccei-Quinn (PQ) solution to the strong $CP$ problem requires an anomalous global $U(1)$ symmetry, the PQ symmetry. The origin of such a convenient global symmetry is quite puzzling from the theoretical point of view in many aspects. In this paper, we propose a simple prescription which provides an origin of the PQ symmetry. There, the global $U(1)$ PQ symmetry is virtually embedded in a gauged $U(1)$ PQ symmetry. Due to its simplicity, this mechanism can be implemented in many conventional models with the PQ symmetry.
description: 5 pages, 1 figures
Machine learning the dimension of a Fano variety
Creators: name: Coates, Tom
name: Kasprzyk, Alexander M.
name: Veneziale, Sara
Publisher: name: arXiv
Year: 2023
Subjects: subject: Algebraic Geometry (math.AG)
subject: Machine Learning (cs.LG)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 14J45 (Primary), 68T07 (Secondary)

description: Fano varieties are basic building blocks in geometry - they are `atomic pieces' of mathematical shapes. Recent progress in the classification of Fano varieties involves analysing an invariant called the quantum period. This is a sequence of integers which gives a numerical fingerprint for a Fano variety. It is conjectured that a Fano variety is uniquely determined by its quantum period. If this is true, one should be able to recover geometric properties of a Fano variety directly from its quantum period. We apply machine learning to the question: does the quantum period of X know the dimension of X? Note that there is as yet no theoretical understanding of this. We show that a simple feed-forward neural network can determine the dimension of X with 98% accuracy. Building on this, we establish rigorous asymptotics for the quantum periods of a class of Fano varieties. These asymptotics determine the dimension of X from its quantum period. Our results demonstrate that machine learning can pick out structure from complex mathematical data in situations where we lack theoretical understanding. They also give positive evidence for the conjecture that the quantum period of a Fano variety determines that variety.
description: 28 pages, 5 tables, 23 figures. This version of the article has been accepted for publication, after peer review but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections
Topologies of $L^p_{loc}$ type for Carathéodory functions with applications in non-autonomous differential equations
Creators: name: Longo, Iacopo P.
name: Novo, Sylvia
name: Obaya, Rafael
Publisher: name: arXiv
Year: 2017
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 34A34, 37B55, 34A12, 34F05

description: Metric topological vector spaces of Carathéodory functions and topologies of $L^p_{loc}$ type are introduced, depending on a suitable set of moduli of continuity. Theorems of continuous dependence on initial data for the solutions of non-autonomous Carathéodory differential equations are proved in such new topological structures. As a consequence, new families of continuous linearized skew-product semiflows are provided in the Carathéodory spaces.
description: 28 pages, 2 figures
Modeling the dynamical sinking of biogenic particles in oceanic flow
Creators: name: Monroy, Pedro
name: Hernández-García, Emilio
name: Rossi, Vincent
name: López, Cristóbal
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We study the problem of sinking particles in a realistic oceanic flow, with major energetic structures in the mesoscale, focussing in the range of particle sizes and densities appropriate for marine biogenic particles. Our aim is to unify the theoretical investigations with its applications in the oceanographic context and considering a mesoscale simulation of the oceanic velocity field. By using the equation of motion of small particles in a fluid flow, we assess the influence of physical processes such as the Coriolis force and the inertia of the particles, and we conclude that they represent negligible corrections to the most important terms, which are passive motion with the velocity of the flow, and a constant added vertical velocity due to gravity. Even if within this approximation three-dimensional clustering of particles can not occur, two-dimensional cuts or projections of the evolving three-dimensional density can display inhomogeneities similar to the ones observed in sinking ocean particles.
description: 13 pages, 7 figures
Video Salient Object Detection via Fully Convolutional Networks
Creators: name: Wang, Wenguan
name: Shen, Jianbing
name: Shao, Ling
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This paper proposes a deep learning model to efficiently detect salient regions in videos. It addresses two important issues: (1) deep video saliency model training with the absence of sufficiently large and pixel-wise annotated video data, and (2) fast video saliency training and detection. The proposed deep video saliency network consists of two modules, for capturing the spatial and temporal saliency information, respectively. The dynamic saliency model, explicitly incorporating saliency estimates from the static saliency model, directly produces spatiotemporal saliency inference without time-consuming optical flow computation. We further propose a novel data augmentation technique that simulates video training data from existing annotated image datasets, which enables our network to learn diverse saliency information and prevents overfitting with the limited number of training videos. Leveraging our synthetic video data (150K video sequences) and real videos, our deep video saliency model successfully learns both spatial and temporal saliency cues, thus producing accurate spatiotemporal saliency estimate. We advance the state-of-the-art on the DAVIS dataset (MAE of .06) and the FBMS dataset (MAE of .07), and do so with much improved speed (2fps with all steps).
description: W. Wang, J. Shen, and L. Shao, Video salient object detection via fully convolutional networks, IEEE Trans. on Image Processing, 27(1):38-49, 2018 Code and results: https://github.com/wenguanwang/deepvideosaliency
Femtoscopy with identified charged pions in proton-lead collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with ATLAS
Creators: name: ATLAS Collaboration
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Bose-Einstein correlations between identified charged pions are measured for $p$+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV using data recorded by the ATLAS detector at the LHC corresponding to a total integrated luminosity of $28$ $\mathrm{nb}^{-1}$. Pions are identified using ionization energy loss measured in the pixel detector. Two-particle correlation functions and the extracted source radii are presented as a function of collision centrality as well as the average transverse momentum ($k_{\mathrm{T}}$) and rapidity ($y^{\star}_{ππ}$) of the pair. Pairs are selected with a rapidity $-2 < y^{\star}_{ππ} < 1$ and with an average transverse momentum $0.1 < k_{\mathrm{T}} < 0.8$ GeV. The effect of jet fragmentation on the two-particle correlation function is studied, and a method using opposite-charge pair data to constrain its contributions to the measured correlations is described. The measured source sizes are substantially larger in more central collisions and are observed to decrease with increasing pair $k_{\mathrm{T}}$. A correlation of the radii with the local charged-particle density is demonstrated. The scaling of the extracted radii with the mean number of participating nucleons is also used to compare a selection of initial-geometry models. The cross-term $R_\mathrm{ol}$ is measured as a function of rapidity, and a nonzero value is observed with $5.1σ$ combined significance for $-1 < y^{\star}_{ππ} < 1$ in the most central events.
description: 60 pages in total, author list starting page 44, 35 figures, 1 table, published version, all figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2015-11/
New Observations Needed to Advance Our Understanding of Coronal Mass Ejections
Creators: name: Palmerio, Erika
name: Lynch, Benjamin J.
name: Lee, Christina O.
name: Jian, Lan K.
name: Nieves-Chinchilla, Teresa
name: Davies, Emma E.
name: Wood, Brian E.
name: Lugaz, Noé
name: Winslow, Réka M.
name: Török, Tibor
name: Al-Haddad, Nada
name: Regnault, Florian
name: Jin, Meng
name: Scolini, Camilla
name: Carcaboso, Fernando
name: Farrugia, Charles J.
name: Ledvina, Vincent E.
name: Downs, Cooper
name: Kay, Christina
name: Pal, Sanchita
name: Salman, Tarik M.
name: Allen, Robert C.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Coronal mass ejections (CMEs) are large eruptions from the Sun that propagate through the heliosphere after launch. Observational studies of these transient phenomena are usually based on 2D images of the Sun, corona, and heliosphere (remote-sensing data), as well as magnetic field, plasma, and particle samples along a 1D spacecraft trajectory (in-situ data). Given the large scales involved and the 3D nature of CMEs, such measurements are generally insufficient to build a comprehensive picture, especially in terms of local variations and overall geometry of the whole structure. This White Paper aims to address this issue by identifying the data sets and observational priorities that are needed to effectively advance our current understanding of the structure and evolution of CMEs, in both the remote-sensing and in-situ regimes. It also provides an outlook of possible missions and instruments that may yield significant improvements into the subject.
description: White Paper submitted to the Heliophysics 2024-2033 Decadal Survey, 9 pages, 4 figures
British Gallup Poll CQ 592-3
Creators: name: Social Surveys (Gallup Poll) Limited
Publisher: name: Roper Center for Public Opinion Research
Year: 2022

description: Opinion of people 10-25 (1); opinion of people over 45 (1); separate grammar schools (1); air pollution (1); national resources (1); social services (4); personal freedom (1); crime (2); moral opinion of people (18); trade unions (1); Reader's Digest (311).
Coherent control in quantum transport: amplification, filtering and switching at finite bias
Creators: name: Thethi, Rajpal
name: Emary, Clive
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider coherent feedback control of quantum transport and focus on the application of simple controllers and the effects of a finite bias voltage. We show that simple single-parameter controllers can give rise to a range of useful effects such as amplification of changes in plant transmission, increased resolution of energy filtration, and the detection of differences between otherwise indistinguishable plants. We explore how these effects are impacted by the phase-averaging effects associated with the application of a finite bias and identify important voltage scales for the maintenance of the functionalities achieved through feedback control.
description: 18 pages; 6 figs
title: Hydrothermal alteration of pyrochlore from carbonatite: An experimental study
Creators: name: Valsera Moreno, Pilar
name: Berndt, Jasper
name: Sanchez-Valle, Carmen
name: Louvel, Marion
name: Klemme, Stephan
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
Niobium is a critical metal used in various superconducting materials and alloys. It is predominantly mined from ores rich in pyrochlore-group minerals with the general formula A2B2O6Y (B ≥ 50% Nb). Fluorcalciopyrochlore, (Ca,Na)2Nb2O6F, is considered as primary magmatic pyrochlore. However, metasomatism by hydrothermal fluids, amongst other processes, can lead to a wide range of chemical compositions (Mitchell 2015). Different stages of pyrochlore alteration were assigned to specific p-T-ranges using associated minerals in the host rock ores. Enrichment in Ba for example is documented in low-temperature hydrothermal environments (Lumpkin & Ewing 1995).

However, it is difficult to unravel the role of temperature, pressure, fluid composition or time in alteration processes of primary fluorcalciopyrochlore in natural carbonatite systems. Therefore, alteration experiments using an autoclave are necessary to identify and quantify alteration mechanisms. To our knowledge, such experiments have only been conducted for microlite and betafite (Geisler et al. 2005), but not for pyrochlore sensu stricto.

Hence, we studied the interaction of natural fluorcalciopyrochlore with Cl-rich, acidic hydrothermal fluids of varying composition in teflon-lined hydrothermal reactor vessels at 200 °C. Here we will present preliminary results of our experiments and discuss consequences of hydrothermal alteration of pyrochlores, with application to Nb-rich carbonatite ores.

R. H. Mitchell, Ore Geology Reviews, 64, 2015; G. R. Lumpkin & R. C. Ewing, American Mineralogist, 80, 1995; T. Geisler et al., American Mineralogist, 90, 2005