cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Magnetic structure of divalent europium compound EuGa$_4$ studied by single crystal time-of-flight neutron diffraction
Creators: name: Kawasaki, Takuro
name: Kaneko, Koji
name: Nakamura, Ai
name: Aso, Naofumi
name: Hedo, Masato
name: Nakama, Takao
name: Ohhara, Takashi
name: Kiyanagi, Ryoji
name: Oikawa, Kenichi
name: Tamura, Itaru
name: Nakao, Akiko
name: Munakata, Koji
name: Hanashima, Takayasu
name: Ōnuki, Yoshichika
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The magnetic structure of the intermetallic compound EuGa$_4$ was investigated using single-crystal neutron diffraction with the time-of-flight (TOF) Laue technique on the new diffractometer SENJU at MLF of J-PARC. In spite of high neutron absorption of Eu, a vast number of diffraction spots were observed without isotope enrichment. The magnetic reflections were appeared at the positions with the diffraction indices of $h+k+l{\neq}2n$ below 16 K, indicating that the ordering vector is ${\bf q}=(0~0~0)$. Continuous evolution of magnetic reflection intensity below $T_{\rm N}$ follows a squared Brillouin function for $S$=7/2. By adopting a wavelength-dependent absorption collection, the magnetic structure of EuGa$_4$ was revealed that a nearly full magnetic moment of 6.4$~μ_{\rm B}$ of Eu lies within the basal plane of the lattice. The present study reveals a well-localized divalent Eu magnetism in EuGa$_4$ and demonstrates a high ability of SENJU to investigate materials with high neutron absorption.
description: 5 pages, 5 figures, 2 Tables. submitted to J. Phys. Soc. Jpn
On the one-sided boundedness of the local discrepancy of $\{nα\}$-sequences
Creators: name: Ying, Jiangang
name: Zheng, Yushu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: Primary 11K06, 11K50

description: The main interest of this article is the one-sided boundedness of the local discrepancy of $α\in\mathbb{R}\setminus\mathbb{Q}$ on the interval $(0,c)\subset(0,1)$ defined by \[D_n(α,c)=\sum_{j=1}^n 1_{\{\{jα\}
description: 15 pages
Quantum prey-predator dynamics: a gaussian ensemble analysis
Creators: name: Bernardini, Alex E.
name: Bertolami, Orfeu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Quantum frameworks for modeling competitive ecological systems and self-organizing structures have been investigated under multiple perspectives yielded by quantum mechanics. These comprise the description of the phase-space prey-predator competition dynamics in the framework of the Weyl-Wigner quantum mechanics. In this case, from the classical dynamics described by the Lotka-Volterra (LV) Hamiltonian, quantum states convoluted by statistical gaussian ensembles can be analytically evaluated. Quantum modifications on the patterns of equilibrium and stability of the prey-predator dynamics can then be identified. These include quantum distortions over the equilibrium point drivers of the LV dynamics which are quantified through the Wigner current fluxes obtained from an onset Hamiltonian background. In addition, for gaussian ensembles highly localized around the equilibrium point, stability properties are shown to be affected by emergent topological quantum domains which, in some cases, could lead either to extinction and revival scenarios or to the perpetual coexistence of both prey and predator agents identified as quantum observables in microscopic systems. Conclusively, quantum and gaussian statistical driving parameters are shown to affect the stability criteria and the time evolution pattern for such microbiological-like communities.
description: 12 pages, 3 figures (This version includes some short text modifications and additional references)
Topological Phase Transition and Chiral-Anomaly Driven Negative Magneto-Resistance in Bulk Black Phosphorus
Creators: name: Li, Chun-Hong
name: Long, Yu-Jia
name: Zhao, Ling-Xiao
name: Shan, Lei
name: Ren, Zhi-An
name: Zhao, Jian-Zhou
name: Weng, Hong-Ming
name: Dai, Xi
name: Fang, Zhong
name: Chen, Gen-Fu
name: Ren, Cong
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report the anisotropic magneto-transport measurement on a non-compound band semiconductor black phosphorus (BP) with magnetic field B up to 16 Tesla applied in both perpendicular and parallel to electric current I under hydrostatic pressures. The BP undergoes a topological Lifshitz transition from band semiconductor to a zero-gap Dirac semimetal state, characterized by a weak localization-weak antilocaliation transition at low magnetic fields and the emergence of a nontrivial Berry Phase of detected by SdH magneto-oscillations in magnetoresistance curves. In the transition region, we observe a pressure-dependent negative MR only in the B//I configuration. This negative longitudinal MR is attributed to the Adler-Bell-Jackiw anomaly (topological E$\cdot$B term) in the presence of weak antilocalization corrections.
Twisted Hilbert modular surfaces, arithmetic intersections and the Jacquet-Langlands correspondence
Creators: name: Montplet, Gerard Freixas i
name: Sankaran, Siddarth
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 11G18, 11F41, 11F67

description: We study arithmetic intersections on twisted (quaternionic) Hilbert modular surfaces and Shimura curves over a real quadratic field. Our first main result is the determination of the degree of the top arithmetic Todd class of an arithmetic twisted Hilbert modular surface. This quantity is then related to the arithmetic volume of a Shimura curve, via the arithmetic Grothendieck-Riemann-Roch theorem and the Jacquet-Langlands correspondence.
description: 71 pp
Independent operation of two waveguide-integrated quantum emitters
Creators: name: Papon, Camille
name: Wang, Ying
name: Uppu, Ravitej
name: Scholz, Sven
name: Wieck, Andreas Dirk
name: Ludwig, Arne
name: Lodahl, Peter
name: Midolo, Leonardo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We demonstrate the resonant excitation of two quantum dots in a photonic integrated circuit for on-chip single-photon generation in multiple spatial modes. The two quantum dots are electrically tuned to the same emission wavelength using a pair of isolated $p$-$i$-$n$ junctions and excited by a resonant pump laser via dual-mode waveguides. We demonstrate two-photon quantum interference visibility of $(79\pm2)\%$ under continuous-wave excitation of narrow-linewidth quantum dots. Our work solves an outstanding challenge in quantum photonics by realizing the key enabling functionality of how to scale-up deterministic single-photon sources.
description: 7 pages 3 figures, Supplementary materials 7 pages 9 figures
Ghost Imaging with Atoms
Creators: name: Khakimov, R. I.
name: Henson, B. M.
name: Shin, D. K.
name: Hodgman, S. S.
name: Dall, R. G.
name: Baldwin, K. G. H.
name: Truscott, A. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Ghost imaging is a technique -- first realized in quantum optics -- in which the image emerges from cross-correlation between particles in two separate beams. One beam passes through the object to a bucket (single-pixel) detector, while the second beam's spatial profile is measured by a high resolution (multi-pixel) detector but never interacts with the object. Neither detector can reconstruct the image independently. However, until now ghost imaging has only been demonstrated with photons. Here we report the first realisation of ghost imaging of an object using massive particles. In our experiment, the two beams are formed by correlated pairs of ultracold metastable helium atoms, originating from two colliding Bose-Einstein condensates (BECs) via $s$-wave scattering. We use the higher-order Kapitza-Dirac effect to generate the large number of correlated atom pairs required, enabling the creation of a ghost image with good visibility and sub-millimetre resolution. Future extensions could include ghost interference as well as tests of EPR entantlement and Bell's inequalities.
Fractonic Luttinger Liquids and Supersolids in a Constrained Bose-Hubbard Model
Creators: name: Zechmann, Philip
name: Altman, Ehud
name: Knap, Michael
name: Feldmeier, Johannes
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum many-body systems with fracton constraints are widely conjectured to exhibit unconventional low-energy phases of matter. In this work, we demonstrate the existence of a variety of such exotic quantum phases in the ground states of a dipole-moment conserving Bose-Hubbard model in one dimension. For integer boson fillings, we perform a mapping of the system to a model of microscopic local dipoles, which are composites of fractons. We apply a combination of low-energy field theory and large-scale tensor network simulations to demonstrate the emergence of a dipole Luttinger liquid phase. At non-integer fillings our numerical approach shows an intriguing compressible state described by a quantum Lifshitz model in which charge density-wave order coexists with dipole long-range order and superfluidity - a `dipole supersolid'. While this supersolid state may eventually be unstable against lattice effects in the thermodynamic limit, its numerical robustness is remarkable. We discuss potential experimental implications of our results.
description: 17 pages, 11 figures
Interference control of perfect photon absorption in cavity quantum electrodynamics
Creators: name: Wang, Liyong
name: Di, Ke
name: Zhu, Yifu
name: Agarwal, G. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We propose and analyze a scheme for controlling coherent photon transmission and reflection in a cavity-quantum-electrodynamics (CQED) system consisting of an optical resonator coupled with three-level atoms coherently prepared by a control laser from free space. When the control laser is off and the cavity is excited by two identical light fields from two ends of the cavity, the two input light fields can be completely absorbed by the CQED system and the light energy is converted into the excitation of the polariton states, but no light can escape from the cavity. Two distinct cases of controlling the perfect photon absorption are analyzed: (a) when the control laser is tuned to the atomic resonance and creates electromagnetically induced transparency, the prefect photon absorption is suppressed and the input light fields are nearly completely transmitted through the cavity; (b) when the control laser is tuned to the polariton state resonance and inhibits the polariton state excitation, the perfect photon absorption is again suppressed and the input light fields are nearly completely reflected from the cavity. Thus, the CQED system can act as a perfect absorber or near perfect transmitter/reflector by simply turning off or on of the control laser. Such interference control of the coherent photon-atom interaction in the CQED system should be useful for a variety of applications in optical logical devices.
description: 14 pages, 9 figures
Gravitational waves from eccentric extreme mass-ratio inspirals as probes of scalar fields
Creators: name: Zhang, Chao
name: Gong, Yungui
name: Liang, Dicong
name: Wang, Bin
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study eccentric orbits of the Schwarzschild spacetime for extreme mass ratio system (EMRI) in modified gravity theories with additional scalar fields. Due to the additional energy and angular momentum carried away by the scalar field, the orbit of the EMRI in modified gravity decays faster than that in general relativity. The time that it takes the eccentricity $e$ to reach the minimum is smaller and the values of the semi-latus rectum $p$ and $e$ at the turning point when $e$ reaches the minimum are bigger for larger scalar charge $d$. In addition to the calculation of energy fluxes with numerical method, we also use the Post-Newtonian expansion of the rate of energy carried away by the scalar field in eccentric orbits to understand the behaviors of the energy emission. By adding the scalar flux to the open code FastEMRIWaveforms of the Black Hole Perturbation Toolkit, we numerically generate fast gravitational waveforms for eccentric EMRIs with scalar fields and use the faithfulness between waveforms with and without the scalar charge to discuss the detection of scalar charge $d$. The detection error of the scalar charge is also estimated with method of Fisher information matrix.
description: 26 pages, 13 figures, 1 table; accepted for publication by JCAP
Numerical Investigation of Triexciton Stabilization in Diamond with Multiple Valleys and Bands
Creators: name: Katow, Hiroki
name: Usukura, Junko
name: Akashi, Ryosuke
name: Várga, Kálman
name: Tsuneyuki, Shinji
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The existence of polyexcitons, the $N$-body complexes of excitons for $N > 2$ in 3D bulk systems, has been controversial for more than 40 years since its first theoretical suggestion. We investigated the stability of fundamental excitonic complexes in diamond numerically with the stochastic variational method (SVM) and an explicitly correlated Gaussian (ECG) basis. The electron-hole many-body system is described by an effective mass Hamiltonian. Our model includes the effective mass anisotropy and multiple valley and band degrees of freedom. We show that the excitons, trions, biexcitons, charged biexcitons, and triexcitons are stable in diamond. Numerical calculations reproduce from 81% to 86% of the experimentally reported binding energies for neutral bound states.
Global Fits of Dirac Dark Matter Effective Field Theories
Creators: name: Beniwal, Ankit
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: In this proceeding, we present results from a global fit of Dirac fermion dark matter (DM) effective field theory (EFT) based on arXiv:2106.02056 using the GAMBIT framework. Here we show results only for the dimension-6 operators that describe the interactions between a gauge-singlet Dirac fermion and Standard Model quarks. Our global fit combines the latest constraints from \textit{Planck}, direct and indirect DM detection, and the LHC. For DM mass below 100 GeV, it is impossible to simultaneously satisfy all constraints while maintaining the EFT validity at high energies. For higher masses, however, large regions of parameter space remain viable where the EFT is valid and saturates the observed DM abundance.
description: 6 pages, 1 figure. Contribution to the proceeding of 14th International Conference on Identification of Dark Matter, Vienna, Austria (18-22 July, 2022). Submitted to SciPost Physics Proceedings
Selective Unsupervised Feature Learning with Convolutional Neural Network (S-CNN)
Creators: name: Ghaderi, Amir
name: Athitsos, Vassilis
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Supervised learning of convolutional neural networks (CNNs) can require very large amounts of labeled data. Labeling thousands or millions of training examples can be extremely time consuming and costly. One direction towards addressing this problem is to create features from unlabeled data. In this paper we propose a new method for training a CNN, with no need for labeled instances. This method for unsupervised feature learning is then successfully applied to a challenging object recognition task. The proposed algorithm is relatively simple, but attains accuracy comparable to that of more sophisticated methods. The proposed method is significantly easier to train, compared to existing CNN methods, making fewer requirements on manually labeled training data. It is also shown to be resistant to overfitting. We provide results on some well-known datasets, namely STL-10, CIFAR-10, and CIFAR-100. The results show that our method provides competitive performance compared with existing alternative methods. Selective Convolutional Neural Network (S-CNN) is a simple and fast algorithm, it introduces a new way to do unsupervised feature learning, and it provides discriminative features which generalize well.
Unruh Effect and Takagi's Statistics Inversion in Strained Graphene
Creators: name: Bhardwaj, Anshuman
name: Sheehy, Daniel E.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present a theoretical study of how a spatially-varying quasiparticle velocity in honeycomb lattices, achievable using strained graphene or in engineered cold-atom optical lattices that have a spatial dependence to the local tunneling amplitude, can yield the Rindler Hamiltonian embodying an observer accelerating in Minkowski spacetime. Within this setup, a sudden switch-on of the spatially-varying tunneling (or strain) yields a spontaneous production of electron-hole pairs, an analogue version of the Unruh effect characterized by the Unruh temperature. We discuss how this thermal behavior, along with Takagi's statistics inversion, can manifest themselves in photo-emission and scanning tunneling microscopy experiments. We also calculate the average electronic conductivity and find that it grows linearly with frequency $ω$. Finally, we find that the total system energy at zero environment temperature looks like Planck's blackbody result for photons due to the aforementioned statistics inversion, whereas for an initial thermally excited state of fermions, the total internal energy undergoes stimulated particle reduction.
description: 25 pages, 5 figures
Optimal control of a cavity-mediated iSWAP gate between silicon spin qubits
Creators: name: Young, Steve M.
name: Jacobson, N. Tobias
name: Petta, Jason R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Semiconductor spin qubits may be coupled through a superconducting cavity to generate an entangling two-qubit gate. However, the fidelity of such an operation will be reduced by a variety of error mechanisms such as charge and magnetic noise, phonons, cavity loss, transitions to non-qubit states and, for electrons in silicon, excitation into other valley eigenstates. Here, we model the effects of these error sources and the valley degree of freedom on the performance of a cavity-mediated two-qubit iSWAP gate. For valley splittings inadequately large relative to the interdot tunnel coupling within each qubit, we find that valley excitation may be a limiter to the fidelity of this two-qubit gate. In addition, we show tradeoffs between gating times and exposure to various error sources, identifying optimal operating regimes and device improvements that would have the greatest impact on the fidelity of the cavity-mediated spin iSWAP. Importantly, we find that while the impact of charge noise and phonon relaxation favor operation in the regime where the qubits are most spin-like to reduce sensitivity to these sources of noise, the combination of hyperfine noise and valley physics shifts the optimal regime to charge-like qubits with stronger effective spin-photon coupling so that gate times can be made as short as possible. In this regime, the primary limitation is the need to avoid Landau-Zener transitions as the gate is implemented.
Advances in the implementation of a UT contactless inspection system in the manufacturing process of thermoplastic components for aeronautical use, within the framework of the H2020-DOMMINIO project.
Creators: name: Giacchetta, Roberto
name: Gonzales, Ricardo
name: Sánchez, David
name: Morales, Alfredo
name: Ansedes, Francisco
name: Moreno, Eduardo
Publisher: name: Zenodo
Year: 2023
Subjects: Aircraft Ultrasonic NDT
Thermoplastic plate elements
Lamb waves
Air contactless ultrasonic technology

description: In recent decades, the aeronautical industry has undergone a drastic transformation in the manufacturing philosophy in response to the growth of aircraft production (by 60% in the last 10 years), due to the increase in passenger transport demand. Although the pandemic has contracted the sector 66% during the last years 2020-2021, it is expected to normalize by 2024. The transition to the use of more advanced composite materials, together with the increase in aircraft performance and the rate of productivity is a challenge. Also, the necessity to produce effective structures and components using ecological materials and technologies have been increased, with the consequence of reducing cost, weight and fuel consumption. The DOMMINIO project from the European H2020 program, aims to develop new integrated design methodologies and knowledge based on manufacturing and optimization for the production of new multifunctional fuselage parts. A new technology is applied manufacturing by Laser ATL (Automatic Tape Layout) technique, using the automated deposit of thermoplastic tapes on a mold. Additionally, the DOMMINIO project deals with ensuring the quality of the components during the manufacturing process by a novel non-destructive control based on Ultrasound contactless technologies. To this end, DASEL has developed non-contact transducers that are coupled to the technological process of layer deposition, performing a non-contact quality control. This paper presents the results of the first year of the project, emphasizing the detection of delamination or lack of consolidation in real time
Crustal failure as a tool to probe hybrid stars
Creators: name: Pereira, Jonas P.
name: Bejger, Michał
name: Haensel, Paweł
name: Zdunik, Julian Leszek
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: It is currently unknown if neutron stars (NSs) are composed of nucleons only or are hybrid stars, i.e., in addition to nucleonic crusts and outer cores, they also possess quark cores. Quantum chromodynamics allows for such a possibility, but accurate calculations relevant for compact stars are still elusive. Here we investigate some crust-breaking aspects of hybrid stars. We show that the crust-breaking frequency and maximum fiducial ellipticity are sensitive to the quark-hadron density jump and equation of state stiffness. Remarkably, the crust-breaking frequency related to static tides scales linearly with the mass of the star (for a given companion's mass), and its slope encompasses information about the microphysics of the star. However, for precise crust-breaking frequency predictions, relativistic corrections to Kepler's third law and the Newtonian tidal field should not be ignored. When a liquid quark core touches an elastic hadronic phase (the result of a significant energy-density jump), the maximum ellipticity can increase around an order of magnitude when compared to a liquid quark core touching a liquid hadronic phase. That is relevant because it would increase the odds of detecting continuous gravitational waves from NSs. Our order-of-magnitude analysis also suggests that a given upper limit to the ellipticity(crust-breaking frequency) could have representatives in stars with either small or intermediate(large) energy-density jumps. Therefore, when upper limits to the ellipticity for isolated stars are better constrained or electromagnetic radiation (e.g., gamma-ray precursors) is detected along with gravitational waves in inspiraling binary systems, they may help constrain some aspects of phase transitions in NSs.
description: 12 pages, 6 figures. Improved discussions on boundary conditions, maximum fiducial ellipticities, crust-breaking frequencies, error estimation due to relativistic corrections to some Newtonian quantities used (orbital frequency and tidal field). Accepted for publication in ApJ
The mass-loss rates of red supergiants at low metallicity: Detection of rotational CO emission from two red supergiants in the Large Magellanic Cloud
Creators: name: Matsuura, Mikako
name: Sargent, B.
name: Swinyard, Bruce
name: Yates, Jeremy
name: Royer, P.
name: Barlow, M. J.
name: Boyer, Martha
name: Decin, L.
name: Khouri, Theo
name: Meixner, Margaret
name: van Loon, Jacco Th.
name: Woods, Paul M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Using the PACS and SPIRE spectrometers on-board the Herschel Space Observatory, we obtained spectra of two red supergiants (RSGs) in the Large Magellanic Cloud (LMC). Multiple rotational CO emission lines (J=6-5 to 15-14) and 15 H2O lines were detected from IRAS 05280-6910, and one CO line was detected from WOH G64. This is the first time CO rotational lines have been detected from evolved stars in the LMC. Their CO line intensities are as strong as those of the Galactic RSG, VY CMa. Modelling the CO lines and the spectral energy distribution results in an estimated mass-loss rate for IRAS 05280-6910 of 3x10^-4 Msun per yr. The model assumes a gas-to-dust ratio and a CO-to-H2 abundance ratio is estimated from the Galactic values scaled by the LMC metallicity ([Fe/H]~-0.3), i.e., that the CO-to-dust ratio is constant for Galactic and LMC metallicities within the uncertainties of the model. The key factor determining the CO line intensities and the mass-loss rate found to be the stellar luminosity.
description: 11 pages; accepted by MNRAS
Sample-based Uncertainty Quantification with a Single Deterministic Neural Network
Creators: name: Kanazawa, Takuya
name: Gupta, Chetan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Development of an accurate, flexible, and numerically efficient uncertainty quantification (UQ) method is one of fundamental challenges in machine learning. Previously, a UQ method called DISCO Nets has been proposed (Bouchacourt et al., 2016), which trains a neural network by minimizing the energy score. In this method, a random noise vector in $\mathbb{R}^{10\text{--}100}$ is concatenated with the original input vector in order to produce a diverse ensemble forecast despite using a single neural network. While this method has shown promising performance on a hand pose estimation task in computer vision, it remained unexplored whether this method works as nicely for regression on tabular data, and how it competes with more recent advanced UQ methods such as NGBoost. In this paper, we propose an improved neural architecture of DISCO Nets that admits faster and more stable training while only using a compact noise vector of dimension $\sim \mathcal{O}(1)$. We benchmark this approach on miscellaneous real-world tabular datasets and confirm that it is competitive with or even superior to standard UQ baselines. Moreover we observe that it exhibits better point forecast performance than a neural network of the same size trained with the conventional mean squared error. As another advantage of the proposed method, we show that local feature importance computation methods such as SHAP can be easily applied to any subregion of the predictive distribution. A new elementary proof for the validity of using the energy score to learn predictive distributions is also provided.
description: 16 pages, 17 figures, 2 tables. Accepted by the 14th International Conference on Neural Computation Theory and Applications (NCTA 2022) held as part of IJCCI 2022, October 24-26, 2022, Valletta, Malta
Controllable optical response by modifying the gain and loss of a mechanical resonator and cavity mode in an optomechanical system
Creators: name: Liu, Yu-Long
name: Wu, Rebing
name: Zhang, Jing
name: Özdemir, Şahin Kaya
name: Yang, Lan
name: Nori, Franco
name: Liu, Yu-xi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We theoretically study a strongly-driven optomechanical system which consists of a passive optical cavity and an active mechanical resonator. When the optomechanical coupling strength is varied, phase transitions, which are similar those observed in $\mathcal{PT}$-symmetric systems, are observed. We show that the optical transmission can be controlled by changing the gain of the mechanical resonator and loss of the optical cavity mode. Especially, we find that: (i) for balanced gain and loss, optical amplification and absorption can be tuned by changing the optomechanical coupling strength through a control field; (ii) for unbalanced gain and loss, even with a tiny mechanical gain, both optomechanically-induced transparency and anomalous dispersion can be observed around a critical point, which exhibits an ultra-long group delay. The time delay $τ$ can be optimized by regulating the optomechanical coupling strength through the control field and improved up to several orders of magnitude ($τ\sim2$ $\mathrm{ms}$) compared to that of conventional optomechanical systems ($τ\sim1$ $μ\mathrm{s}$). The presence of mechanical gain makes the group delay more robust to environmental perturbations. Our proposal provides a powerful platform to control light transport using a $\mathcal{PT}$-symmetric-like optomechanical system.
Energy-Aware Relay Selection and Power Allocation for Multiple-User Cooperative Networks
Creators: name: Gupta, Sabyasachi
name: Bose, Ranjan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: This paper investigates the relay assignment and power allocation problem for two different network power management policies: group lifetime maximization (GLM) and minimum weighted total power (MWTP), with the aim of lifetime maximization in symbol error rate (SER) constrained multipleuser cooperative network. With optimal power allocation solution obtained for each policy, we show that the optimal relay assignment can be obtained using bottleneck matching (BM) algorithm and minimum weighted matching (MWM) algorithm for GLM and MWTP policies, respectively. Since relay assignment with BM algorithm is not power efficient, we propose a novel minimum bottleneck matching (MBM) algorithm to solve the relay assignment problem optimally for GLM policy. To further reduce the complexity of the relay assignment, we propose suboptimal relay selection (SRS) algorithm which has linear complexity in number of source and relay nodes. Simulation results demonstrate that the proposed relay selection and power allocation strategies based on GLM policy have better network lifetime performance over the strategies based on MWTP policy. Compared to the MBM and SRS algorithm, relay assignment based on BM algorithm for GLM policy has inferior network lifetime performance at low update interval. We show that relay assignment based on MBM algorithm achieves maximum network lifetime performance and relay assignment with SRS algorithm has performance very close to it.
description: 7 pages, 6 figures, presented in part at the IEEE Wireless Communications and Networking Conference (WCNC), Doha, Qatar, April 2016
Diffuse Gas in Retired Galaxies: Nebular Emission Templates and Constraints on the Sources of Ionization
Creators: name: Johansson, Jonas
name: Woods, Tyrone E.
name: Gilfanov, Marat
name: Sarzi, Marc
name: Chen, Yan-Mei
name: Oh, Kyuseok
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present emission line templates for passively evolving ("retired") galaxies, useful for investigation of the evolution of the ISM in these galaxies, and characterization of their high-temperature source populations. The templates are based on high signal-to-noise ($>800$) co-added spectra ($3700-6800$Å) of $\sim11500$ gas-rich Sloan Digital Sky Survey galaxies devoid of star-formation and active galactic nuclei. Stacked spectra are provided for the entire sample and sub-samples binned by mean stellar age. In Johansson~et al (2014), these spectra provided the first measurements of the He II 4686Å line in passively-evolving galaxies, and the observed He II/H$β$ ratio constrained the contribution of accreting white dwarfs (the "single-degenerate" scenario) to the type Ia supernova rate. In this paper, the full range of unambiguously detected emission lines are presented. Comparison of the observed [O I] 6300Å/H$α$ ratio with photoionization models further constrains any high-temperature single-degenerate scenario for type Ia supernovae (with 1.5 $\lesssim$ T/$10^{5}K$ $\lesssim$ 10) to $\lesssim$3-6\% of the observed rate in the youngest age bin (i.e. highest SN Ia rate). Hence, for the same temperatures, in the presence of an ambient population of post-AGB stars, we exclude additional high-temperature sources with a combined ionizing luminosity of $\approx 1.35\times 10^{30} L_{\odot}/M_{\odot,*}$ for stellar populations with mean ages of 1 - 4 Gyrs. Furthermore, we investigate the extinction affecting both the stellar and nebular continuum. The latter shows about five times higher values. This contradicts isotropically distributed dust and gas that renders similar extinction values for both cases.
description: Accepted for publication in MNRAS, 16 pages, 12 figures
D1.1 Report on the analysis of existing training activities and quality assessment
Creators: name: Lagido, Cristina
name: Kragh, Gitte
name: Nielsen, Kristian
Publisher: name: Zenodo
Year: 2024
Subjects: Open Responsible Research Innovation
Trainings
Open Science

description: The current document, titled ‘State of the art of Open and Responsible trainings’ has been developed within the PATTERN project, which receives funding from the European Union’s Horizon Europe Research and Innovation Programme (grant agreement No 101094416).

Our main objectives in this report are as follows:

·        Mapping Open Science (OS) and Responsible Research and Innovation (RRI) training opportunities for researchers at all stages of their careers, with a focus on Europe;

·        Identifying gaps and opportunities in OS and RRI skills training;

·        Conveying current trends and insights into OS and RRI skills training in Europe and beyond.  

The PATTERN consortium includes partners from across Europe that possess extensive expertise in the following eight Open RRI transferable skill areas: Open Access; Findable, Accessible, Interoperable and Reusable (FAIR) Data Management; Citizen Science; Research Integrity; Gender, non-discrimination and inclusion in research; Dissemination and Exploitation of Results; Science Communication (towards media and policy makers); and Management and Leadership. Through collective knowledge gathering in the consortium, desk research, and a survey, PATTERN has mapped over 500 training resources covering these eight areas.  Moreover, this work was complemented by three mutual learning events and interviews to understand gaps, needs and opportunities, as well as current trends and best practices in training.

The training resources span course-type activities, such as courses, workshops, and e-learning, as well as static resources potentially useful in training, including guides, reports, recordings of webinars, etc. Both in-person and online or blended formats, and both informal and formal training, were mapped. We analysed the content themes of all training and resources mapped to identify gaps and opportunities. A subset of trainings and resources, around 250, that are digitally and freely available were quality-assessed based on their relevance, accessibility, ease of implementation and adaption, adequate structure and description of aims, goals and methods, and clear language.  We identified their strengths and weaknesses, along with gaps in training addressed, to evaluate their suitability for reuse and the opportunities for new training in the eight Open RRI themes.
Robust Classification of Digitally Modulated Signals Using Capsule Networks and Cyclic Cumulant Features
Creators: name: Snoap, John A.
name: Latshaw, James A.
name: Popescu, Dimitrie C.
name: Spooner, Chad M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The paper studies the problem of robust classification of digitally modulated signals using capsule networks and cyclic cumulant (CC) features extracted by cyclostationary signal processing (CSP). Two distinct datasets that contain similar classes of digitally modulated signals but that have been generated independently are used in the study, which reveals that capsule networks trained using CCs achieve high classification accuracy while also outperforming other deep learning-based approaches in terms of classification accuracy as well as generalization abilities.
description: 6 pages, 5 figures, to be published in IEEE MILCOM 2022: IEEE Military Communications Conference 2022
D1.1 State of the art of Open and Responsible trainings
Creators: name: Lagido, Cristina
name: Kragh, Gitte
name: Nielsen, Kristian
Publisher: name: Zenodo
Year: 2023
Subjects: Open Responsible Research Innovation
Trainings
Open Science

description: The current document, titled ‘State of the art of Open and Responsible trainings’ has been developed within the PATTERN project, which receives funding from the European Union’s Horizon Europe Research and Innovation Programme (grant agreement No 101094416).

Our main objectives in this report are as follows:

·        Mapping Open Science (OS) and Responsible Research and Innovation (RRI) training opportunities for researchers at all stages of their careers, with a focus on Europe;

·        Identifying gaps and opportunities in OS and RRI skills training;

·        Conveying current trends and insights into OS and RRI skills training in Europe and beyond.  

The PATTERN consortium includes partners from across Europe that possess extensive expertise in the following eight Open RRI transferable skill areas: Open Access; Findable, Accessible, Interoperable and Reusable (FAIR) Data Management; Citizen Science; Research Integrity; Gender, non-discrimination and inclusion in research; Dissemination and Exploitation of Results; Science Communication (towards media and policy makers); and Management and Leadership. Through collective knowledge gathering in the consortium, desk research, and a survey, PATTERN has mapped over 500 training resources covering these eight areas.  Moreover, this work was complemented by three mutual learning events and interviews to understand gaps, needs and opportunities, as well as current trends and best practices in training.

The training resources span course-type activities, such as courses, workshops, and e-learning, as well as static resources potentially useful in training, including guides, reports, recordings of webinars, etc. Both in-person and online or blended formats, and both informal and formal training, were mapped. We analysed the content themes of all training and resources mapped to identify gaps and opportunities. A subset of trainings and resources, around 250, that are digitally and freely available were quality-assessed based on their relevance, accessibility, ease of implementation and adaption, adequate structure and description of aims, goals and methods, and clear language.  We identified their strengths and weaknesses, along with gaps in training addressed, to evaluate their suitability for reuse and the opportunities for new training in the eight Open RRI themes.

**This version of the document is still under approval of the EC
Quantifying coherence in terms of Fisher information
Creators: name: Yu, Deng-hui
name: Yu, Chang-shui
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Information Theory (cs.IT)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: In quantum metrology, the parameter estimation accuracy is bounded by quantum Fisher information. In this paper, we present coherence measures in terms of (quantum) Fisher information by directly considering the post-selective non-unitary parametrization process. This coherence measure demonstrates the apparent operational meaning by the exact connection between coherence and parameter estimation accuracy. We also discuss the distinction between our coherence measure and the quantum Fisher information subject to unitary parametrization. The analytic coherence measure is given for qubit states.
The detection of possible transient Quasi-Periodic Oscillations in the $γ$-ray light curve of PKS 0244-470 and 4C+38.41
Creators: name: Das, Avik Kumar
name: Prince, Raj
name: Gupta, Alok C.
name: Kushwaha, Pankaj
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The continuous monitoring capability of Fermi-LAT has enabled the exploration of Quasi-Periodic Oscillations (QPOs) in the $γ$-ray light curve of blazar that has given a new perspective to probe these sources over a wide range of time scales. We report the presence of transient QPOs in the long-term $γ$-ray light curve of blazars PKS 0244-470 and 4C +38.41. We first identified different flux states using the Bayesian Block algorithm and then explored the possible transient QPOs in the segments of each flux phase where the flux level changes over fairly regular intervals. Combining this with the source's intrinsic variance, we identified two flux phases for PKS 0244-470: one activity (AP-1) and one quiescent phase (QP-1). For 4C+38.41, we similarly identified four activity (AP-1, AP-2, AP-3, AP-4) and two quiescent (QP-1, QP-2) phases. AP-1 phase of PKS 0244-470 shows QPO of $\sim$225 days persisting for 8 cycles ($\sim$ 4.1$σ$). In 4C+38.41, AP-1 and AP-2 phases show QPO-like behavior of $\sim$110 days and $\sim$ 60 days, respectively, persisting for 5 cycles. In AP-3, we identified three sub-phases, and all show a $\sim$ week scale possible recurrent rise with five complete cycles, while in QP-1, we could identify 2 sub-phases (Q1, and Q2). Q1 phase shows a period of $\sim$ 104 days with six complete cycles. Q2 phase also shows QPO but with only $\sim$3.7 cycles. We discuss the possible origin and argue that the current driven kink instability and curved jet model seem the most likely cause for shorter and longer QPOs.
description: Accepted for publication in ApJ
Unrolled Compressed Blind-Deconvolution
Creators: name: Tolooshams, Bahareh
name: Mulleti, Satish
name: Ba, Demba
name: Eldar, Yonina C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: The problem of sparse multichannel blind deconvolution (S-MBD) arises frequently in many engineering applications such as radar/sonar/ultrasound imaging. To reduce its computational and implementation cost, we propose a compression method that enables blind recovery from much fewer measurements with respect to the full received signal in time. The proposed compression measures the signal through a filter followed by a subsampling, allowing for a significant reduction in implementation cost. We derive theoretical guarantees for the identifiability and recovery of a sparse filter from compressed measurements. Our results allow for the design of a wide class of compression filters. We, then, propose a data-driven unrolled learning framework to learn the compression filter and solve the S-MBD problem. The encoder is a recurrent inference network that maps compressed measurements into an estimate of sparse filters. We demonstrate that our unrolled learning method is more robust to choices of source shapes and has better recovery performance compared to optimization-based methods. Finally, in data-limited applications (fewshot learning), we highlight the superior generalization capability of unrolled learning compared to conventional deep learning.
description: Accepted to IEEE TSP
Magnetically Dominated Disks in Tidal Disruption Events and Quasi-Periodic Eruptions
Creators: name: Kaur, Karamveer
name: Stone, Nicholas C.
name: Gilbaum, Shmuel
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The classical radiation pressure instability has been a persistent theoretical feature of thin, radiatively efficient accretion disks with accretion rates 1 to 100 per cent of the Eddington rate. But there is only limited evidence of its occurrence in nature: rapid heartbeat oscillations of a few X-ray binaries and now, perhaps, the new class of hourly X-ray transients called quasi-periodic eruptions (QPEs). The accretion disks formed in tidal disruption events (TDEs) have been observed to peacefully trespass through the range of unstable accretion rates without exhibiting any clear sign of the instability. We try to explain the occurrence or otherwise of this instability in these systems, by constructing steady state 1D models of thin magnetic accretion disks. The local magnetic pressure in the disk is assumed to be dominated by toroidal fields arising from a dynamo sourced by magneto-rotational instability (MRI). We choose a physically motivated criterion of MRI saturation, validated by recent magnetohydrodynamic simulations, to determine the strength of magnetic pressure in the disk. The resulting magnetic pressure support efficiently shrinks: (1) the parameter space of unstable mass accretion rates, explaining the absence of instability in systems such as TDEs and (2) the range of unstable radii in the inner accretion disk, which can shorten the quasi-periods of instability limit-cycles by more than three orders of magnitude, explaining the observed periods ( a few hrs) of QPEs. In addition to examining stability properties of strongly magnetized disks, we predict other observational signatures such as spectral hardening factors and jet luminosities to test the compatibility of our disk models with observations of apparently stable TDE disks.
description: Submitted to MNRAS