cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Scaling and efficiency determine the irreversible evolution of a market
Creators: name: Baldovin, Fulvio
name: Stella, Attilio L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Finance (q-fin.ST)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Economics and business
subject: FOS: Physical sciences

description: In setting up a stochastic description of the time evolution of a financial index, the challenge consists in devising a model compatible with all stylized facts emerging from the analysis of financial time series and providing a reliable basis for simulating such series. Based on constraints imposed by market efficiency and on an inhomogeneous-time generalization of standard simple scaling, we propose an analytical model which accounts simultaneously for empirical results like the linear decorrelation of successive returns, the power law dependence on time of the volatility autocorrelation function, and the multiscaling associated to this dependence. In addition, our approach gives a justification and a quantitative assessment of the irreversible character of the index dynamics. This irreversibility enters as a key ingredient in a novel simulation strategy of index evolution which demonstrates the predictive potential of the model.
description: 5 pages, 4 figures
Optimal Control for Quantum Metrology via Pontryagin's principle
Creators: name: Lin, Chungwei
name: Ma, Yanting
name: Sels, Dries
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum metrology comprises a set of techniques and protocols that utilize quantum features for parameter estimation which can in principle outperform any procedure based on classical physics. We formulate the quantum metrology in terms of an optimal control problem and apply Pontryagin's Maximum Principle to determine the optimal protocol that maximizes the quantum Fisher information for a given evolution time. As the quantum Fisher information involves a derivative with respect to the parameter which one wants to estimate, we devise an augmented dynamical system that explicitly includes gradients of the quantum Fisher information. The necessary conditions derived from Pontryagin's Maximum Principle are used to quantify the quality of the numerical solution. The proposed formalism is generalized to problems with control constraints, and can also be used to maximize the classical Fisher information for a chosen measurement.
description: 10 pages, single column, 4 figures
Determination of intrinsic switching field distributions in perpendicular recording media: numerical study of the $ΔH(M, ΔM)$ method
Creators: name: Liu, Yang
name: Dahmen, Karin A.
name: Berger, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We present a numerical study of the $ΔH(M,ΔM)$ method and its ability to accurately determine intrinsic switching field distributions in interacting granular magnetic materials such as perpendicular recording media. In particular, we study how this methodology fails for large ferromagnetic inter-granular interactions, at which point the associated strongly correlated magnetization reversal cannot be properly represented by the mean-field approximation, upon which the $ΔH(M,ΔM)$ method is based. In this study, we use a 2-dimensional array of symmetric hysterons that have an intrinsic switching field distribution of standard deviation $σ$ and ferromagnetic nearest-neighbor interactions $J$. We find the $ΔH(M,ΔM)$ method to be very accurate for small $J/σ$ values, while substantial errors develop once the effective exchange field becomes comparable with $σ$, corroborating earlier results from micromagnetic simulations. We furthermore demonstrate that this failure is correlated with deviations from data set redundancy, which is a key property of the mean-field approximation. Thus, the $ΔH(M,ΔM)$ method fails in a well defined and quantifiable manner that can be easily assessed from the data sets alone.
description: 13 pages, 9 figures
Stanilov-Tsankov-Videv Theory
Creators: name: Brozos-Vazquez, M.
name: Fiedler, B.
name: Garcia-Rio, E.
name: Gilkey, P.
name: Nikcevic, S.
name: Stanilov, G.
name: Tsankov, Y.
name: Vazquez-Lorenzo, R.
name: Videv, V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53B20

description: We survey some recent results concerning Stanilov-Tsankov-Videv theory, conformal Osserman geometry, and Walker geometry which relate algebraic properties of the curvature operator to the underlying geometry of the manifold.
description: This is a contribution to the Proceedings of the 2007 Midwest Geometry Conference in honor of Thomas P. Branson, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA/
Thermodynamics of hydrogen in electroslag remelting
Creators: name: Chattopadhyay, Subrata
Publisher: name: University of British Columbia
Year: 2010

description: Oxide ion activities in binary CaF₂ - CaO and ternary, CaF₂ -CaO - Al₂O₃ and CaF₂ - CaO -SiO₂, slags were determined by CO₂-slag equilibrium experiments at 1400°C. The carbonate capacity of these slags was computed and compared with the sulfide1 capacity data available in the literature. The similarity in their trends suggests the possibility of characterizing carbonate capacity as an alternative basicity index for fluoride-based slags. The optical basicity of these slags is difficult to define, and with the assumption of CaF₂ as an inert diluent, this parameter did not show any distinct relationship with carbonate capacity. Slag-D20 equilibrium experiments were performed at 1400°C with binary ( CaF₂ - CaO ) and ternary ( CaF₂ - CaO - Al₂O₃ and CaF₂ - CaO -SiO₂) slags to determine water solubility at two different partial pressures of D₂O. A new technique of slag sampling was employed using a quartz tube. A new and reliable method of water analysis in ESR slags was developed. The new water solubility data were higher than the previous data by an order of magnitude, however, the solubility data showed a linear relationship with the square root of water vapour partial pressure. Also, the solubility was at a maximum in binary slags and a minimum in ternary slags containing SiO₂ with N[sub CaO]/N[sub SiO₂]≤2. These experimental findings were used along with literature data to generate a new equilibrium ratio for hydrogen distributed between the slag and the metal during an ESR process. This information was further extended to compute the maximum permissible water content in an initial ESR slag for the production of an ESR ingot with an acceptable level of hydrogen.
Refractive Index Enhancement with Vanishing Absorption in an Atomic Vapor
Creators: name: Proite, N. A.
name: Unks, B. E.
name: Green, J. T.
name: Yavuz, D. D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report a proof-of-principle experiment where the refractive index of an atomic vapor is enhanced while maintaining vanishing absorption of the beam. The key idea is to drive alkali atoms in a vapor with appropriate control lasers and induce a gain resonance and an absorption resonance for a probe beam in a two-photon Raman configuration. The strength and the position of these two resonances can be manipulated by changing the parameters of the control lasers. By using the interference between these two resonances, we obtain an enhanced refractive index without an increase in the absorption.
description: 11 pages, 4 figures
Multi-Feature Semi-Supervised Learning for COVID-19 Diagnosis from Chest X-ray Images
Creators: name: Qi, Xiao
name: Nosher, John L.
name: Foran, David J.
name: Hacihaliloglu, Ilker
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Computed tomography (CT) and chest X-ray (CXR) have been the two dominant imaging modalities deployed for improved management of Coronavirus disease 2019 (COVID-19). Due to faster imaging, less radiation exposure, and being cost-effective CXR is preferred over CT. However, the interpretation of CXR images, compared to CT, is more challenging due to low image resolution and COVID-19 image features being similar to regular pneumonia. Computer-aided diagnosis via deep learning has been investigated to help mitigate these problems and help clinicians during the decision-making process. The requirement for a large amount of labeled data is one of the major problems of deep learning methods when deployed in the medical domain. To provide a solution to this, in this work, we propose a semi-supervised learning (SSL) approach using minimal data for training. We integrate local-phase CXR image features into a multi-feature convolutional neural network architecture where the training of SSL method is obtained with a teacher/student paradigm. Quantitative evaluation is performed on 8,851 normal (healthy), 6,045 pneumonia, and 3,795 COVID-19 CXR scans. By only using 7.06% labeled and 16.48% unlabeled data for training, 5.53% for validation, our method achieves 93.61\% mean accuracy on a large-scale (70.93%) test data. We provide comparison results against fully supervised and SSL methods. Code: https://github.com/endiqq/Multi-Feature-Semi-Supervised-Learning-for-COVID-19-CXR-Images
Variational Graph Normalized Auto-Encoders
Creators: name: Ahn, Seong Jin
name: Kim, Myoung Ho
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Link prediction is one of the key problems for graph-structured data. With the advancement of graph neural networks, graph autoencoders (GAEs) and variational graph autoencoders (VGAEs) have been proposed to learn graph embeddings in an unsupervised way. It has been shown that these methods are effective for link prediction tasks. However, they do not work well in link predictions when a node whose degree is zero (i.g., isolated node) is involved. We have found that GAEs/VGAEs make embeddings of isolated nodes close to zero regardless of their content features. In this paper, we propose a novel Variational Graph Normalized AutoEncoder (VGNAE) that utilize L2-normalization to derive better embeddings for isolated nodes. We show that our VGNAEs outperform the existing state-of-the-art models for link prediction tasks. The code is available at https://github.com/SeongJinAhn/VGNAE.
Large enhancement of Edelstein effect in Weyl semimetals from Fermi-arc surface states
Creators: name: Limtragool, Kridsanaphong
name: Pasanai, Krisakron
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: One remarkable feature of Weyl semimetals is the manifestation of their topological nature in the form of the Fermi-arc surface states. In a recent calculation by \cite{Johansson2018}, the current-induced spin polarization or Edelstein effect has been predicted, within the semiclassical Boltzmann theory, to be strongly amplified in a Weyl semimetal TaAs due to the existence of the Fermi arcs. Motivated by this result, we calculate the Edelstein response of an effective model for an inversion-symmetry-breaking Weyl semimetal in the presence of an interface using linear response theory. The scatterings from scalar impurities are included and the vertex corrections are computed within the self-consistent ladder approximation. At chemical potentials close to the Weyl points, we find the surface states have a much stronger response near the interface than the bulk states by about one to two orders of magnitude. At higher chemical potentials, the surface states' response near the interface decreases to be about the same order of magnitude as the bulk states' response. We attribute this phenomenon to the decoupling between the Fermi arc states and bulk states at energies close to the Weyl points. The surface states which are effectively dispersing like a one-dimensional chiral fermion become nearly nondissipative. This leads to a large surface vertex correction and, hence, a strong enhancement of the surface states' Edelstein response.
description: 24 pages, 9 figures
KM3NeT/ARCA expectations in view of a novel multimessenger study of starburst galaxies
Creators: name: Marinelli, Antonio
name: Ambrosone, Antonio
name: Ibnsalih, Walid Idrissi
name: Miele, Gennaro
name: Migliozzi, Pasquale
name: Pisanti, Ofelia
name: Sharma, Ankur
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Starburst galaxies (SBGs) and more in general starforming galaxies represent a class of galaxies with a high star formation rate (up to 100 solar masses/year). Despite their low luminosity, they can 19 be considered as guaranteed "factories" of high energy neutrinos, being "reservoirs" of accelerated 20 cosmic rays and hosting a high density target gas in the central region. In this contribution 21 we present a novel multimessenger study of these sources and the possibility of observing their 22 neutrino signals with the KM3NeT/ARCA telescope. The differential sensitivity for different SBG 23 scenarios is reported considering track-like neutrino events in the 100 GeV-100 PeV energy range.
description: Presented at the 9th Very Large Volume Neutrino Telescope Workshop (VLVnT 2021), Prepared for submission to JINST
An exterior-algebraic derivation of the symmetric stress-energy-momentum tensor in flat space-time
Creators: name: Martinez, Alfonso
name: Font-Segura, Josep
name: Colombaro, Ivano
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Physics (physics.gen-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: This paper characterizes the symmetric rank-2 stress-energy-momentum tensor associated with fields whose Lagrangian densities are expressed as the dot product of two multivector fields, e. g., scalar or gauge fields, in flat space-time. The tensor is derived by a direct application of exterior-algebraic methods to deal with the invariance of the action to infinitesimal space-time translations; this direct derivation avoids the use of the canonical tensor. Formulas for the tensor components and for the tensor itself are derived for generic values of the multivector grade $s$ and of the number of time and space dimensions, $k$ and $n$, respectively. A simple, coordinate-free, closed-form expression for the interior derivative (divergence) of the symmetric stress-energy-momentum tensor is also obtained: this expression provides a natural generalization of the Lorentz force that appears in the context of the electromagnetic theory. Applications of the formulas derived in this paper to the cases of generalized electromagnetism, Proca action, Yang-Mills fields and conformal invariance are briefly discussed.
description: 21 pages
NNLO QCD corrections to diphoton production with an additional jet at the LHC
Creators: name: Chawdhry, Herschel A.
name: Czakon, Michal
name: Mitov, Alexander
name: Poncelet, Rene
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We calculate the NNLO QCD corrections to diphoton production with an additional jet at the LHC. Our calculation represents the first NNLO-accurate prediction for the transverse momentum distribution of the diphoton system. The improvement in the accuracy of the theoretical prediction is significant, by a factor of up to four relative to NLO QCD. Our calculation is exact except for the finite remainder of the two-loop amplitude which is included at leading color. The numerical impact of this approximated contribution is small. The results of this work are expected to further our understanding of the Higgs boson sector and of the behavior of higher-order corrections to LHC processes.
description: 12 pages, 7 figures
แผ่นเจลประดิษฐ์จากแป้งมันสำปะหลังสำหรับการประคบร้อน–เย็น
Creators: name: ภัทิรา สุขทนารักษ์
Publisher: name: หน่วยวิจัยวิทยาศาสตร์ เทคโนโลยี และสิ่งแวดล้อมเพื่อการเรียนรู้ คณะวิทยาศาสตร์ มหาวิทยาลัยศรีนครินทรวิโรฒ
Year: 2564
Subjects: แผ่นเจลประคบร้อน–เย็น
แป้งมันสำปะหลัง
ประสิทธิภาพในการเก็บกักอุณหภูมิ

description: วารสารหน่วยวิจัยวิทยาศาสตร์ เทคโนโลยี และสิ่งแวดล้อมเพื่อการเรียนรู้ (JSTEL), 12, 2, 316-329
Spinors of Spin-one-half Fields
Creators: name: Cahill, Kevin
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Physics (physics.gen-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: This paper reviews how a two-state, spin-one-half system transforms under rotations. It then uses that knowledge to explain how momentum-zero, spin-one-half annihilation and creation operators transform under rotations. The paper then explains how a spin-one-half field transforms under rotations. The momentum-zero spinors are found from the way spin-one-half systems transform under rotations and from the Dirac equation. Once the momentum-zero spinors are known, the Dirac equation immediately yields the spinors at finite momentum. The paper then shows that with these spinors, a Dirac field transforms appropriately under charge conjugation, parity, and time reversal. The paper also describes how a Dirac field may be decomposed either into two 4-component Majorana fields or into a 2-component left-handed field and a 2-component right-handed field. Wigner rotations and Weinberg's derivation of the properties of spinors are also discussed.
description: A pedagogical paper of 34 pages
Experimental Investigation of the Fluid-Structure Interaction during the Water Impact of Thin Aluminium Plates at High Horizontal Speed
Creators: name: Spinosa, Emanuele
name: Iafrati, Alessandro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The water impact of an inclined flat plate and at high horizontal velocity is experimentally investigated with focus on the fluid-structure interaction aspects. Several test conditions have been examined by varying the vertical to horizontal velocity ratio, the pitch angle and the plate thickness. Measurements are performed in terms of strains, loads and local pressure. The study highlights the significant changes in the strains and, more in general, in the structural behaviour when varying the plate stiffness and the test conditions. For some of the test presented, permanent deformations are also found. The strong fluid-structure interaction is analysed by comparing the simultaneous measurements of strains and pressures, and it is shown that the deformation of the plate leads to a reduction of the pressure peak and to a corresponding pressure rise behind it. The variation in the shape of the spray root caused by the structural deformation are discussed based on both pressure measurements and underwater images. Despite the reduction of the pressure peak intensity, it is shown that the structural deformation leads to an increase in the total loading up to 50% for the test conditions examined in this study. It is also observed that in presence of large structural deformations the hydrodynamic loads do not obey the scaling that works in the case of the thick plates, and some practical conclusions about the scaling of tests in presence of a strong fluid-structure interaction are provided.
A panoramic view of the Local Group dwarf galaxy NGC 6822
Creators: name: Zhang, Shumeng
name: Mackey, Dougal
name: Da Costa, Gary
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a panoramic survey of the isolated Local Group dwarf irregular galaxy NGC 6822. Our photometry reaches $\sim2-3$ magnitudes deeper than most previous studies and spans the widest area around the dwarf compared to any prior work. We observe no stellar over-densities in the outskirts of NGC 6822 to $V\sim 30$ mag$\,$arcsec$^{-2}$ and a projected radius of $16.5$ kpc. This indicates that NGC 6822 has not experienced any recent interaction with a companion galaxy, despite previous suggestions to the contrary. Similarly, we find no evidence for any dwarf satellites of NGC 6822 to a limiting luminosity $M_V\approx -5$. NGC 6822 contains a disk of HI gas and young stars, oriented at $\sim 60$ degrees to an extended spheroid composed of old stellar populations. We observe no correlation between the distribution of young stars and spheroid members. Our imaging allows us to trace the spheroid to nearly $11$ kpc along its major axis, commensurate with the extent of the NGC 6822 globular cluster system. We find that the spheroid becomes increasingly flattened at larger radii, and its position angle twists by up to $40$ degrees. We use Gaia EDR3 astrometry to measure a proper motion for NGC 6822, and then sample its orbital parameter space. While this galaxy has spent the majority of its life in isolation, we find that it likely passed within the virial radius of the Milky Way $\sim3-4$ Gyr ago. This may explain the apparent flattening and twisting observed in the outskirts of its spheroid.
description: Accepted for publication in MNRAS
Anisotropic effective redshift and evolving clustering amplitude
Creators: name: Obuljen, Andrej
name: Percival, Will J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: A typical galaxy survey geometry results in galaxy pairs of different separation and angle to the line-of-sight having different distributions in redshift and consequently a different effective redshift. However, clustering measurements are analysed assuming that the clustering is representative of that at a single effective redshift. We investigate the impact of variations in the galaxy-pair effective redshift on the large-scale clustering measured in galaxy surveys. We find that galaxy surveys spanning a large redshift range have different effective redshifts as a function of both pair separation and angle. Furthermore, when considering tracers whose clustering amplitude evolves strongly with redshift, this combination can result in an additional scale-dependent clustering anisotropy. We demonstrate the size of this effect on the eBOSS DR16 Quasar sample and show that, while the impact on monopole is negligible, neglecting this effect can result in a large-scale tilt of $\sim 4\%$ and $\sim40\%$ in quadrupole and hexadecapole, respectively. We discuss strategies to mitigate this effect when making measurements.
description: 7 pages, 7 figures. Comments welcome
Integrated photonics enables continuous-beam electron phase modulation
Creators: name: Henke, J. -W.
name: Raja, A. S.
name: Feist, A.
name: Huang, G.
name: Arend, G.
name: Yang, Y.
name: Kappert, J.
name: Wang, R. N.
name: Möller, M.
name: Pan, J.
name: Liu, J.
name: Kfir, O.
name: Ropers, C.
name: Kippenberg, T. J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The ability to tailor laser light on a chip using integrated photonics has allowed for extensive control over fundamental light-matter interactions in manifold quantum systems including atoms, trapped ions, quantum dots, and defect centers. Free electrons, enabling high-resolution microscopy for decades, are increasingly becoming the subject of laser-based quantum manipulation. Using free-space optical excitation and intense laser pulses, this has led to the observation of free-electron quantum walks, attosecond electron pulses, and imaging of electromagnetic fields. Enhancing the interaction with electron beams through chip-based photonics promises unique applications in nanoscale quantum control and sensing, but has yet to enter electron microscopy. Here, we merge integrated photonics with electron microscopy, demonstrating coherent phase modulation of an electron beam using a silicon nitride microresonator driven by a continuous-wave laser. The high-Q factor (~$10^6$) cavity enhancement and a waveguide designed for phase matching lead to efficient electron-light scattering at unprecedentedly low, few-microwatt optical powers. Specifically, we fully deplete the initial electron state at a cavity-coupled power of 6 $μ$W and create >500 photon sidebands for only 38 mW in the bus waveguide. Moreover, we demonstrate $μ$eV electron energy gain spectroscopy (EEGS). Providing simultaneous optical and electronic spectroscopy of the resonant cavity, the fiber-coupled photonic structures feature single-mode electron-light interaction with full control over the input and output channels. This approach establishes a versatile framework for exploring free-electron quantum optics, with future developments in strong coupling, local quantum probing, and electron-photon entanglement. Our results highlight the potential of integrated photonics to efficiently interface free electrons and light.
A physics-informed variational DeepONet for predicting the crack path in brittle materials
Creators: name: Goswami, Somdatta
name: Yin, Minglang
name: Yu, Yue
name: Karniadakis, George
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Numerical Analysis (math.NA)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Failure trajectories, identifying the probable failure zones, and damage statistics are some of the key quantities of relevance in brittle fracture applications. High-fidelity numerical solvers that reliably estimate these relevant quantities exist but they are computationally demanding requiring a high resolution of the crack. Moreover, independent intensive simulations need to be carried out even for a small change in domain parameters and/or material properties. Therefore, fast and generalizable surrogate models are needed to alleviate the computational burden but the discontinuous nature of fracture mechanics presents a major challenge to developing such models. We propose a physics-informed variational formulation of DeepONet (V-DeepONet) for brittle fracture analysis. V-DeepONet is trained to map the initial configuration of the defect to the relevant fields of interests (e.g., damage and displacement fields). Once the network is trained, the entire global solution can be rapidly obtained for any initial crack configuration and loading steps on that domain. While the original DeepONet is solely data-driven, we take a different path to train the V-DeepONet by imposing the governing equations in variational form and we also use some labelled data. We demonstrate the effectiveness of V-DeepOnet through two benchmarks of brittle fracture, and we verify its accuracy using results from high-fidelity solvers. Encoding the physical laws and also some data to train the network renders the surrogate model capable of accurately performing both interpolation and extrapolation tasks, considering that fracture modeling is very sensitive to fluctuations. The proposed hybrid training of V-DeepONet is superior to state-of-the-art methods and can be applied to a wide array of dynamical systems with complex responses.
Radiative corrections of order $O(αE_e/m_N)$ to Sirlin's radiative corrections of order $O(α/π)$, induced by the hadronic structure of the neutron
Creators: name: Ivanov, A. N.
name: Höllwieser, R.
name: Troitskaya, N. I.
name: Wellenzohn, M.
name: Berdnikov, Ya. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We investigate the contributions of the hadronic structure of the neutron to radiative $O(αE_e/m_N)$ corrections (or the inner $O(αE_e/m_N)$ RC) to the neutron beta decay, where $α$, $E_e$ and $m_N$ are the fine-structure constant, the electron energy and the nucleon mass, respectively. We perform the calculation within the effective quantum field theory of strong low-energy pion-nucleon interactions described by the linear $σ$-model with chiral $SU(2) \times SU(2)$ symmetry and electroweak hadron-hadron, hadron-lepton and lepton-lepton interactions for the electron-lepton family with $SU(2)_L \times U(1)_Y$ symmetry of the Standard Electroweak Theory (Ivanov et al., Phys. Rev. D99, 093006 (2019)). We show that after renormalization, carried out in accordance with Sirlin's prescription (Sirlin, Phys. Rev. 164, 1767 (1967)), the inner $O(αE_e/m_N)$ RC are of the order of a few parts of $10^{-5} - 10^{-4}$. This agrees well with the results obtained in (Ivanov et al., Phys. Rev. D99, 093006 (2019)).
description: accepted by Phys.Rev.D
A complete ab initio view of Orbach and Raman spin-lattice relaxation in a Dysprosium coordination compound
Creators: name: Briganti, Matteo
name: Santanni, Fabio
name: Tesi, Lorenzo
name: Totti, Federico
name: Sessoli, Roberta
name: Lunghi, Alessandro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The unique electronic and magnetic properties of Lanthanides molecular complexes place them at the forefront of the race towards high-temperature single-ion magnets and magnetic quantum bits. The design of compounds of this class has so far been almost exclusively driven by static crystal field considerations, with emphasis on increasing the magnetic anisotropy barrier. This guideline has now reached its maximum potential and new progress can only come from a deeper understanding of spin-phonon relaxation mechanisms. In this work we compute relaxation times fully ab initio and unveil the nature of all spin-phonon relaxation mechanisms, namely Orbach and Raman pathways, in a prototypical Dy single-ion magnet. Computational predictions are in agreement with the experimental determination of spin relaxation time and crystal field anisotropy, and show that Raman relaxation, dominating at low temperature, is triggered by low-energy phonons and little affected by further engineering of crystal field axiality. A comprehensive analysis of spin-phonon coupling mechanism reveals that molecular vibrations beyond the ion's first coordination shell can also assume a prominent role in spin relaxation through an electrostatic polarization effect. Therefore, this work shows the way forward in the field by delivering a novel and complete set of chemically-sound design rules tackling every aspect of spin relaxation at any temperature
Mean-Squared Accuracy of Good-Turing Estimator
Creators: name: Skorski, Maciej
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (stat.ML)
subject: Cryptography and Security (cs.CR)
subject: Information Theory (cs.IT)
subject: Machine Learning (cs.LG)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: The brilliant method due to Good and Turing allows for estimating objects not occurring in a sample. The problem, known under names "sample coverage" or "missing mass" goes back to their cryptographic work during WWII, but over years has found has many applications, including language modeling, inference in ecology and estimation of distribution properties. This work characterizes the maximal mean-squared error of the Good-Turing estimator, for any sample \emph{and} alphabet size.
Reducing alarm fatigue for optimal performance: analysis of a multi-unit health system process improvement
Creators: name: Roberts, Laura D.
Publisher: name: No Publisher Supplied
Year: 2021

description: Technology in healthcare greatly enhances service delivery, safety, and efficacy yet when systems are not optimized any benefits of the technology are lost. This dissertation examines remote temperature monitoring systems and the inefficiencies of the alarms generated. Using Six Sigma methodology for performance improvement in healthcare, this dissertation focuses process improvement, specifically, reducing alarm/alert fatigue in healthcare generated by temperature monitoring systems. Extant research fails to examine non-patient alarms as distractions endured by healthcare professionals. Temperature and humidity control of the environment is critically important in clinical environments for infection control, pharmaceutical and food storage, and equipment function, among other reasons. Manual monitoring is resource-laden and error-prone, and automated environmental monitoring offers significant time-savings and reallocation of resources to other job tasks. However, without a robust infrastructure and implementation rules problems may arise. The case analysis of a multi-unit health system redesign of automated environmental monitoring highlights the complexity and inherent failures related to alarm management. Further, this case study examines alarm redeployment following11,000 environmental excursion alerts occurred each month with only 22% of those alerts being addressed. Using qualitative data from stakeholders, three research hypotheses were developed and examined relative to an end user:1. The presence of user policies or procedures for use impacted the number of alarms generated;2. Regular review of monitoring requirements and consistent system interaction impacted the number of alarms generated; and3. Alert parameters determined by expert definition or empirically based system use impacted the number of alerts with corrections documented.Baseline data is compared to post-improvement data to validate hypotheses and determine efficacy of real-time improvements. Continued improvement throughout the course of the project is measurable and sustainable. The author also proposes enhancements and improvements can be realized using six sigma methodology for technology installations that become out-moded to provide optimal performance.
The Intrinsic Scatter of Galaxy Scaling Relations
Creators: name: Stone, Connor
name: Courteau, Stéphane
name: Arora, Nikhil
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a compendium of disk galaxy scaling relations and a detailed characterization of their intrinsic scatter. Observed scaling relations are typically characterized by their slope, intercept, and scatter; however, these parameters are a mixture of observational errors and astrophysical processes. We introduce a novel Bayesian framework for computing the intrinsic scatter of scaling relations that accounts for nonlinear error propagation and covariant uncertainties. Bayesian intrinsic scatters are ~25percent more accurate than those obtained with a first-order classical method, which systematically underestimates the true intrinsic scatter. Structural galaxy scaling relations based on velocity (V23.5), size (R23.5), luminosity (L23.5), colour (g-z), central stellar surface density (Sigma1), stellar mass (M*), dynamical mass (Mdyn), stellar angular momentum (j*), and dynamical angular momentum (jdyn), are examined to demonstrate the power and importance of the Bayesian formalism. Our analysis is based on a diverse selection of over 1000 late-type galaxies from the Photometry and Rotation Curve Observations from Extragalactic Surveys compilation with deep optical photometry and extended rotation curves. We determine the tightest relation for each parameter by intrinsic orthogonal scatter, finding M*-V23.5, R23.5-j*, and L23.5-jdyn to be especially tight. The scatter of the R23.5-L23.5, V23.5-(g-z), and R23.5-jdyn relations is mostly intrinsic, making them ideal for galaxy formation and evolutionary studies. Our code to compute the Bayesian intrinsic scatter of any scaling relation is also presented. We quantify the correlated nature of many uncertainties in galaxy scaling relations and scrutinize the uncertain nature of disk inclination corrections and their effect on scatter estimates.
description: 28 pages, 6 figures, 8 tables, accepted for publication in the Astrophysical Journal
Bilingual Argumentative Discourse Unit Detection for Argument Mining on French and German Proceedings of the European Parliament
Creators: name: Graf, Franziska
Publisher: name: Zenodo
Year: 2021

description: Argumentation Mining aims at automatically extracting structured arguments from unstructured textual documents. This work addresses the conduction of a cross-lingual argumentation mining task, the detection of argumentative discourse units (ADU)s. Our contribution is two-fold: firstly, we extract a German and French ADU-annotated parallel corpus for further research, secondly, we thereupon compare five state-of-the-art language models (LM)s. Following the CRISP-DM framework for data mining, we prepare the data from the popular Europarl corpus by conducting a topic modeling to semantically trim corpus size. On the French and German subcorpus, annotations are made, distinguishing between the labels non-argumentative, claim and premise. Given the human baseline, in the modeling phase, the five LMs German BERT, German DistilBERT, CamemBERT, mBERT and mDistilBERT are compared on the sentence classification task. The task is performed by the LMs with moderate success. There is a performance difference between German and French models, leading to the insight that considering the input language as a feature and not only a parameter is crucial. Other than that, the beneficial influence of multilingual pretraining is discussed, triggering a need for further research. Find attached the results of this work!
The Jet-Disk Boundary Layer in Black Hole Accretion
Creators: name: Wong, George N.
name: Du, Yufeng
name: Prather, Ben S.
name: Gammie, Charles F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Magnetic fields lines are trapped in black hole event horizons by accreting plasma. If the trapped field lines are lightly loaded with plasma, then their motion is controlled by their footpoints on the horizon and thus by the spin of the black hole. In this paper, we investigate the boundary layer between lightly loaded polar field lines and a dense, equatorial accretion flow. We present an analytic model for aligned prograde and retrograde accretion systems and argue that there is significant shear across this "jet-disk boundary" at most radii for all black hole spins. Specializing to retrograde aligned accretion, where the model predicts the strongest shear, we show numerically that the jet-disk boundary is unstable. The resulting mixing layer episodically loads plasma onto trapped field lines where it is heated, forced to rotate with the hole, and permitted to escape outward into the jet. In one case we follow the mass loading in detail using Lagrangian tracer particles and find a time-averaged mass-loading rate ~ 0.01 Mdot.
description: 17 pages, 13 figures, accepted for publication in ApJ
Focusing of high-energy particles in the electrostatic field of a homogeneously charged sphere and the effective momentum approximation
Creators: name: Aste, Andreas
name: Trautmann, Dirk
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The impact of the strongly attractive electromagnetic field of heavy nuclei on electrons in quasi-elastic (e,e') scattering is often accounted for by the effective momentum approximation. This method is a plane wave Born approximation which takes the twofold effect of the attractive nucleus on initial and final state electrons into account, namely the modification of the electron momentum in the vicinity of the nucleus, and the focusing of electrons towards the nuclear region leading to an enhancement of the corresponding wave function amplitudes. The focusing effect due to the attractive Coulomb field of a homogeneously charged sphere on a classical ensemble of charged particles incident on the field is calculated in the highly relativistic limit and compared to results obtained from exact solutions of the Dirac equation. The result is relevant for the theoretical foundation of the effective momentum approximation and describes the high energy behavior of the amplitude of continuum Dirac waves in the potential of a homogeneously charged sphere. Our findings indicate that the effective momentum approximation is a useful approximation for the calculation of Coulomb corrections in (e,e') scattering off heavy nuclei for sufficiently high electron energies and momentum transfer.
description: 16 pages, 9 figures, LATEX, some references added
The elastic vacuum
Creators: name: Mathur, Samir D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The quantum gravity vacuum must contain virtual fluctuations of black hole microstates. These extended-size fluctuations get `crushed' when a closed trapped surface forms, and turn into on-shell `fuzzball' states that resolve the information puzzle. We argue that these same fluctuations can get `stretched' by the anti-trapped surfaces in an expanding cosmology, and that this stretching generates vacuum energy. The stretching happen when the Hubble deceleration reduces quickly, which happens whenever the pressure drops quickly. We thus get an inflation-scale vacuum energy when the heavy GUTS particles become nonrelativistic, and again a small vacuum energy when the radiation phase turns to dust. The expansion law in the radiation phase does not allow stretching, in agreement with the observed irrelevance of vacuum energy in that phase. The extra energy induced when the radiation phase changes to dust may explain the tension in the Hubble constant between low and high redshift data.
description: 6 pages, 5 figures (Slightly expanded version of essay awarded first prize in the 2021 Gravity Research Foundation essay competition)
Role models for complex networks
Creators: name: Reichardt, Joerg
name: White, Douglas R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: We present a framework for automatically decomposing ("block-modeling") the functional classes of agents within a complex network. These classes are represented by the nodes of an image graph ("block model") depicting the main patterns of connectivity and thus functional roles in the network. Using a first principles approach, we derive a measure for the fit of a network to any given image graph allowing objective hypothesis testing. From the properties of an optimal fit, we derive how to find the best fitting image graph directly from the network and present a criterion to avoid overfitting. The method can handle both two-mode and one-mode data, directed and undirected as well as weighted networks and allows for different types of links to be dealt with simultaneously. It is non-parametric and computationally efficient. The concepts of structural equivalence and modularity are found as special cases of our approach. We apply our method to the world trade network and analyze the roles individual countries play in the global economy.
New criteria for the equation of state development: Simple model fluids
Creators: name: Duda, Yurko
name: Orea, Pedro
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Recently we have proposed (J. Chem. Phys. 128 (2008) 134508) a new rescaling of fluid density $ρ$ by its critical value $ρ_c^{2/3}$ to apply the corresponding states law for the attractive Yukawa fluids study. Analysis of precise simulation results allows us to generalize this concept to the case of simple fluids with different interparticle interactions, like Mie (n,m) and Sutherland pair potentials. It is shown, that there is a linear relationship between the critical pressure and critical temperature, as well as the critical density and inverse critical temperature for these frequently used pair potentials. As a consequence, the critical compressibility factor of these model fluids is close to its universal value measured experimentally for different real substances.
description: 5 pages, 3 figures
Supporting data for Raman tensor of zinc-phosphide (Zn3P2): from polarization measurements to simulation of Raman spectra
Creators: name: Dimitrievska, Mirjana
Publisher: name: Zenodo
Year: 2021
Subjects: Raman spectrscopy
Zn3P2
DFT

description: Supporting data for Raman tensor of zinc-phosphide (Zn3P2): from polarization measurements to simulation of Raman spectra containing figures, raw data and origin files.
World-line Path integral for the Propagator expressed as an ordinary integral: Concept and Applications
Creators: name: Padmanabhan, T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The (Feynman) propagator $G(x_2,x_1)$ encodes the entire dynamics of a massive, free scalar field propagating in an arbitrary curved spacetime. The usual procedures for computing the propagator -- either as a time ordered correlator or from a partition function defined through a path integral -- requires introduction of a field $ϕ(x)$ and its action functional $A[ϕ(x)]$. An alternative, more geometrical, procedure is to define a propagator in terms of the world-line path integral which only uses curves, $x^i(s)$, defined on the manifold. I show how the world-line path integral can be reinterpreted as an ordinary integral by introducing the concept of effective number of quantum paths of a given length. Several manipulations of the world-line path integral become algebraically tractable in this approach. In particular, I derive an explicit expression for the propagator $G_{\rm QG}(x_2,x_1)$, which incorporates the quantum structure of spacetime through a zero-point-length, in terms of the standard propagator $G_{\rm std}(x_2,x_1)$, in an arbitrary curved spacetime. This approach also helps to clarify the interplay between the path integral amplitude and the path integral measure in determining the form of the propagator. This is illustrated with several explicit examples.
description: 22 pages; no figures
Can QFT on Moyal-Weyl spaces look as on commutative ones?
Creators: name: Fiore, Gaetano
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We sketch a natural affirmative answer to the question based on a joint work [11] with J. Wess. There we argue that a proper enforcement of the "twisted Poincare'" covariance makes any differences $(x-y)^μ$ of coordinates of two copies of the Moyal-Weyl deformation of Minkowski space like undeformed. Then QFT in an operator approach becomes compatible with (minimally adapted) Wightman axioms and time-ordered perturbation theory, and physically equivalent to ordinary QFT, as observables involve only coordinate differences.
description: Talk given at the 21st Nishinomiya-Yukawa Memorial Symposium on Theoretical Physics "Noncommutative Geometry and Spacetime in Physics", Nishinomiya-Kyoto, Nov. 2006