cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Flat rotation curves using scalar-tensor theories
Creators: name: Cervantes-Cota, Jorge L.
name: Rodriguez-Meza, M. A.
name: Nunez, Dario
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We computed flat rotation curves from scalar-tensor theories in their weak field limit. Our model, by construction, fits a flat rotation profile for velocities of stars. As a result, the form of the scalar field potential and DM distribution in a galaxy are determined. By taking into account the constraints for the fundamental parameters of the theory $(λ, α)$, it is possible to obtain analytical results for the density profiles. For positive and negative values of $α$, the DM matter profile is as cuspy as NFW's.
description: To appear in Journal of Physics: Conference Series: VII Mexican School on Gravitation and Mathematical Physics. 26 November to 1 December 2006, Playa del Carmen, Quintana Roo, Mexico
Transformers: "The End of History" for NLP?
Creators: name: Chernyavskiy, Anton
name: Ilvovsky, Dmitry
name: Nakov, Preslav
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences
subject: F.2.2; I.2.7
subject: 68T50

description: Recent advances in neural architectures, such as the Transformer, coupled with the emergence of large-scale pre-trained models such as BERT, have revolutionized the field of Natural Language Processing (NLP), pushing the state of the art for a number of NLP tasks. A rich family of variations of these models has been proposed, such as RoBERTa, ALBERT, and XLNet, but fundamentally, they all remain limited in their ability to model certain kinds of information, and they cannot cope with certain information sources, which was easy for pre-existing models. Thus, here we aim to shed light on some important theoretical limitations of pre-trained BERT-style models that are inherent in the general Transformer architecture. First, we demonstrate in practice on two general types of tasks -- segmentation and segment labeling -- and on four datasets that these limitations are indeed harmful and that addressing them, even in some very simple and naive ways, can yield sizable improvements over vanilla RoBERTa and XLNet models. Then, we offer a more general discussion on desiderata for future additions to the Transformer architecture that would increase its expressiveness, which we hope could help in the design of the next generation of deep NLP architectures.
description: Transformers, Limitations, Segmentation, Sequence Classification, NLP, BERT, RoBERTa, XLNet
Numerical investigation of internal plasma currents in a magnetic nozzle
Creators: name: Emoto, Kazuma
name: Takahashi, Kazunori
name: Takao, Yoshinori
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Two-dimensional fully kinetic particle-in-cell simulations of an electrodeless plasma thruster, which uses a magnetic nozzle, were conducted to investigate the thrust generation induced by the internal plasma current. The results clearly show that the $\bf{E} \times \bf{B}$ and diamagnetic current densities are the major components of the internal plasma current. The simulated pressure structures reproduced the experimentally observed structures well. The results for various magnetic field strengths reveal that the $\bf{E} \times \bf{B}$ effect decreases and the diamagnetic effect becomes dominant with an increase in the magnetic field strength; this demonstrates the significant contribution of the diamagnetic effect in thrust generation.
description: The following article has been accepted by Physics of Plasmas
New physics searches at the ILC positron and electron beam dumps
Creators: name: Asai, Kento
name: Iwamoto, Sho
name: Sakaki, Yasuhito
name: Ueda, Daiki
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study capability of the ILC beam dump experiment to search for new physics, comparing the performance of the electron and positron beam dumps. The dark photon, axion-like particles, and light scalar bosons are considered as new physics scenarios, where all the important production mechanisms are included: electron-positron pair-annihilation, Primakoff process, and bremsstrahlung productions. We find that the ILC beam dump experiment has higher sensitivity than past beam dump experiments, with the positron beam dump having slightly better performance for new physics particles which are produced by the electron-positron pair-annihilation.
description: 26 pages, 7 figures
Studies of carbamazepine metabolism
Creators: name: Webster, Donald Shaw
Publisher: name: University of British Columbia
Year: 2010

description: The objective of this study was to examine aspects of carbamazepine metabolism, in order to contribute to a long term goal of a thorough examination of how the metabolism of carbamazepine is influenced by other drugs. The first set of experiments were designed with the intent of determining values for the pharmacokinetic parameters of carbamazepine metabolism in male New Zealand white rabbits. Values were obtained for t[sub max] (60-90 min), t[sub ½](90-122 min), clearance (46.2-142.4 ml/min/kg), and the elimination constant (0.0057-0.0077 min⁻¹) in five test cases. In the remainder of cases, unexpected results were observed which did not allow calculation of these parameters. The plasma carbamazepine concentration was either delayed in reaching its peak concentration or it reached an apparent peak, but maintained that level for an extended period of time. It is thought that these differences between rabbits may have been due to differences in the rates of gastric emptying, a factor that may have been influenced by the food eaten by the animals in a period in excess of the 12 hours that some of the rabbits were fasted prior to the experiments. Alternatively, the time period of required sampling may have been underestimated. In addition, it is also possible that some degree of enterohepatic circulation is taking place. The relative positions of the curves for carbamazepine and for carbamazepine-10,11-epoxide suggest that there may be differences in the activities of hepatic monooxygenases and glucuronysyl transferases responsible for the metabolic fates of carbamazepine. The second set of experiments examined the influence of isoniazid and some of its principal metabolites on the conversion of carbamazepine to carbamazepine-10,11-epoxide in the S9 fraction of rat liver homogenate. This study is a prelude to planned in vivo studies of the interaction in rabbits. Three concentrations of each of isoniazid, acetyl hydrazine, acetylisoniazid, hydrazine, and isonicotinic acid were tested in a system containing constant concentrations of carbamazepine and of essential co-factors. The results indicated that there was a concentration dependent inhibition of carbamazepine metabolism by isoniazid, hydrazine, and isonicotinic acid. These types of experiments should expanded to include a range of carbamazepine concentrations so that an evaluation of the type of inhibition can be determined, as can be done Michaelis-Menton kinetics.
Order Effects in Bayesian Updates
Creators: name: Moreira, Catarina
name: de Barros, Jose Acacio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Probability (math.PR)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Order effects occur when judgments about a hypothesis's probability given a sequence of information do not equal the probability of the same hypothesis when the information is reversed. Different experiments have been performed in the literature that supports evidence of order effects. We proposed a Bayesian update model for order effects where each question can be thought of as a mini-experiment where the respondents reflect on their beliefs. We showed that order effects appear, and they have a simple cognitive explanation: the respondent's prior belief that two questions are correlated. The proposed Bayesian model allows us to make several predictions: (1) we found certain conditions on the priors that limit the existence of order effects; (2) we show that, for our model, the QQ equality is not necessarily satisfied (due to symmetry assumptions); and (3) the proposed Bayesian model has the advantage of possessing fewer parameters than its quantum counterpart.
Interaction of the axionic dark matter, dynamic aether, spinor and gravity fields as an origin of oscillations of the fermion effective mass
Creators: name: Balakin, Alexander B.
name: Efremova, Anna O.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In the framework of the Einstein-Dirac-axion-aether theory we consider the quartet of self-interacting cosmic fields, which includes the dynamic aether, presented by the unit timelike vector field, the axionic dark mater, described by the pseudoscalar field, the spinor field associated with fermion particles, and the gravity field. The key, associated with the mechanism of self-interaction, is installed into the modified periodic potential of the pseudoscalar (axion) field constructed on the base of a guiding function, which depends on one invariant, one pseudo-invariant and two cross-invariants containing the spinor and vector fields. The total system of the field equations related to the isotropic homogeneous cosmological model is solved; we have found the exact solutions for the guiding function for three cases: nonzero, vanishing and critical values of the cosmological constant. Based on these solutions, we obtained the expressions for the effective mass of spinor particles, interacting with the axionic dark matter and dynamic aether. This effective mass is shown to bear imprints of the cosmological epoch and of the state of the cosmic dark fluid in that epoch.
description: 12 pages, 0 figures; revised version published in The European Physical Journal C
On the squashed seven-sphere operator spectrum
Creators: name: Ekhammar, Simon
name: Nilsson, Bengt E. W.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We derive major parts of the eigenvalue spectrum of the operators on the squashed seven-sphere that appear in the compactification of eleven-dimensional supergravity. These spectra determine the mass spectrum of the fields in $AdS_4$ and are important for the corresponding ${\mathcal N} =1$ supermultiplet structure. This work is a continuation of the work in [1] where the complete spectrum of irreducible isometry representations of the fields in $AdS_4$ was derived for this compactification. Some comments are also made concerning the $G_2$ holonomy and its implications on the structure of the operator equations on the squashed seven-sphere.
description: 28 pages, v2: typos corrected, a footnote added
Towards Understanding IT Security Professionals and Their Tools
Creators: name: Botta, David
name: Werlinger, Rodrigo
name: Gagné, André
name: Beznosov, Konstantin
name: Fels, Sid
name: Iverson, Lee
name: Fisher, Brian
Publisher: name: Zenodo
Year: 2007
Subjects: HOT Admin
Field Study
Usable Security
IT Security Management

description: It is estimated that organizations worldwide will spend around $100 Billion USD on IT Security in 2007. A notable size of this will be spent on tools but little is known how effective IT security tools, and what works and what does not. "Human, Organization, and Technology Centred Improvement of the IT Security Administration" (HOT Admin for short) is a three year long research project funded by the Canadian government and headed by Konstantin Beznosov at the University of British Columbia. It aims to investigate methodologies and techniques for evaluating and developing better tools for managing IT security in organizations. The project is in its first stage, which is a field study of IT professionals who are involved in security management. In conducting 14 interviews with IT professionals from 5 different organizations, we focused on the interactions of technological, organizational, and human factors. Our results suggest that the job of IT security management is distributed across multiple employees, often affiliated with different organizational units or groups within a unit and responsible for different aspects of it. Our participants had to meet three disjoint responsibilities: design, response, and maintenance of IT security systems. To meet these responsibilities, security practitioners had to perform several tasks, such as: monitor systems, verify notifications, correlate different sources of information, and report. Three skills stand out as significant to perform the tasks: inferential analysis, pattern recognition, and bricolage. In this presentation we will report our preliminary findings. We will discuss the similarities found across the organizations in the areas of the organization structure, the responsibilities of a practitioner, the skills needed. We will also discuss what our participants liked and did not like about their tools and possible directions for improving security tools.
Fabry-Pérot interferometry with gate-tunable 3D topological insulator nanowires
Creators: name: Osca, Javier
name: Moors, Kristof
name: Sorée, Bart
name: Serra, Llorenç
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Three-dimensional topological insulator (3D TI) nanowires display various interesting magnetotransport properties that can be attributed to their spin-momentum-locked surface states such as quasiballistic transport and Aharonov-Bohm oscillations. Here, we focus on the transport properties of a 3D TI nanowire with a gated section that forms an electronic Fabry-Pérot (FP) interferometer that can be tuned to act as a surface-state filter or energy barrier. By tuning the carrier density and length of the gated section of the wire, the interference pattern can be controlled and the nanowire can become fully transparent for certain topological surface-state input modes while completely filtering out others. We also consider the interplay of FP interference with an external magnetic field, with which Klein tunneling can be induced, and transverse asymmetry of the gated section, e.g., due to a top-gated structure, which displays an interesting analogy with Rashba nanowires. Due to its rich conductance phenomenology, we propose a 3D TI nanowire with gated section as an ideal setup for a detailed transport-based characterization of 3D TI nanowire surface states near the Dirac point, which could be useful towards realizing 3D TI nanowire-based topological superconductivity and Majorana bound states.
description: 22 pages, 11 figures
The deceleration parameter in `tilted' Friedmann universes: Newtonian vs relativistic treatment
Creators: name: Tsagas, C. G.
name: Kadiltzoglou, M. I.
name: Asvesta, K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Although bulk peculiar motions are commonplace in the universe, most theoretical studies either bypass them, or take the viewpoint of the idealised Hubble-flow observers. As a result, the role of these peculiar flows remains largely unaccounted for, despite the fact that relative-motion effects have led to the misinterpretation of the observations in a number of occasions. Here, we examine the implications of large-scale peculiar flows for the interpretation of the deceleration parameter. We compare, in particular, the deceleration parameters measured by the Hubble-flow observers and by their bulk-flow counterparts. In so doing, we use Newtonian theory and general relativity and employ closely analogous theoretical tools, which allows for the direct and transparent comparison of the two studies. We find that the Newtonian relative-motion effects are generally too weak to make a difference between the two measurements. In relativity, however, the deceleration parameters measured in the two frames differ considerably, even at the linear level. This could deceive the unsuspecting observers to a potentially serious misinterpretation of the universe's global kinematic status. We also discuss the implications and the observational viability of the relativistic study.
description: Revised version. References added. Matches published manuscript
Topological Lattice Defects by Groupoid Methods and Kasparov's KK-Theory
Creators: name: Prodan, Emil
Publisher: name: arXiv
Year: 2021
Subjects: subject: Operator Algebras (math.OA)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The bulk-boundary and a new bulk-defect correspondence principles are formulated using groupoid algebras. The new strategy relies on the observation that the groupoids of lattices with boundaries or defects display spaces of units with invariant accumulation manifolds, hence they can be naturally split into disjoint unions of open and closed invariant sub-sets. This leads to standard exact sequences of groupoid $C^\ast$-algebras that can be used to associate a Kasparov element to a lattice defect and to formulate an extremely general bulk-defect correspondence principle. As an application, we establish a correspondence between topological defects of a 2-dimensional square lattice and Kasparov's group $KK^1 (C^\ast(\mathbb Z^3),\mathbb C)$. Numerical examples of non-trivial bulk-defect correspondences are supplied.
Low-rank matrix decompositions for ab initio nuclear structure
Creators: name: Tichai, A.
name: Arthuis, P.
name: Hebeler, K.
name: Heinz, M.
name: Hoppe, J.
name: Schwenk, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The extension of ab initio quantum many-body theory to higher accuracy and larger systems is intrinsically limited by the handling of large data objects in form of wave-function expansions and/or many-body operators. In this work we present matrix factorization techniques as a systematically improvable and robust tool to significantly reduce the computational cost in many-body applications at the price of introducing a moderate decomposition error. We demonstrate the power of this approach for the nuclear two-body systems, for many-body perturbation theory calculations of symmetric nuclear matter, and for non-perturbative in-medium similarity renormalization group simulations of finite nuclei. Establishing low-rank expansions of chiral nuclear interactions offers possibilities to reformulate many-body methods in ways that take advantage of tensor factorization strategies.
description: 7 pages, 5 figures, published in Phys. Lett. B
Correspondence of eikonal quasinormal modes and unstable fundamental photon orbits for Kerr-Newman black hole
Creators: name: Li, Peng-Cheng
name: Lee, Tsai-Chen
name: Guo, Minyong
name: Chen, Bin
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work, we study the relation of the eikonal quasinormal modes (EQNMs) and the unstable fundamental photon orbits (UFPOs) in the Kerr-Newman spacetime. We find that in the eikonal limit the gravitational and electromagnetic perturbations of the Kerr-Newman black hole are naturally decoupled, and a single one-dimensional Schrödinger-like equation encoding the QNM spectrum can be derived. We then show that the decoupled Teukolsky master equation and the Klein-Gordon equation for the massless scalar field in the Kerr-Newman spacetime are of the same form in the eikonal limit. As a direct consequence, taking into account of the boundary conditions for EQNMs we show an exact correspondence between EQNMs and UFPOs, that is, EQNM/UFPO correspondence. More precisely, similar to the Kerr case, the real part of EQNM's frequency is a linear combination of the precessional and (polar) orbital frequencies, while the imaginary part of the frequency is proportional to the Lyapunov exponent of the UFPO.
description: 26 papges, accepted in PRD
Leptonic anomalous magnetic moments in $ν$SMEFT
Creators: name: Cirigliano, Vincenzo
name: Dekens, Wouter
name: de Vries, Jordy
name: Fuyuto, Kaori
name: Mereghetti, Emanuele
name: Ruiz, Richard
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 investigate contributions to the anomalous magnetic moments of charged leptons in the neutrino-extended Standard Model Effective Field Theory ($ν$SMEFT). We discuss how $ν$SMEFT operators can contribute to a lepton's magnetic moment at one- and two-loop order. We show that only one operator can account for existing electronic and muonic discrepancies, assuming new physics appears above $1$ TeV. In particular, we find that a right-handed charged current in combination with minimal sterile-active mixing can explain the discrepancy for sterile neutrino masses of $\mathcal O(100)$ GeV while avoiding direct and indirect constraints. We discuss how searches for sterile neutrino production at the (HL-)LHC, measurements of $h\rightarrow μ^+ μ^-$ and searches for $h\rightarrow e^+ e^-$, neutrinoless double beta decay experiments, and improved unitarity tests of the CKM matrix can further probe the relevant parameter space.
description: Journal version. 37 pages (incl. references), 6 figures, 4 tables. vSMEFT FeynRules UFO available from https://feynrules.irmp.ucl.ac.be/wiki/HeavyN
Binary lattice-gases of particles with soft exclusion: Exact phase diagrams for tree-like lattices
Creators: name: Shapoval, Dmytro
name: Dudka, Maxym
name: Bénichou, Olivier
name: Oshanin, Gleb
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study equilibrium properties of binary lattice-gases comprising $A$ and $B$ particles, which undergo continuous exchanges with their respective reservoirs, maintained at chemical potentials $μ_A = μ_B = μ$. The particles interact via on-site hard-core exclusion and also between the nearest-neighbours: there are a soft repulsion for $AB$ pairs and interactions of arbitrary strength $J$, positive or negative, for $AA$ and $BB$ pairs. For tree-like Bethe and Husimi lattices, we determine the full phase diagram of such a ternary mixture of particles and voids. We show that for $J$ being above a lattice-dependent threshold value, the critical behaviour is similar: the system undergoes a transition at $μ= μ_c$ from a phase with equal mean densities of species into a phase with a spontaneously broken symmetry, in which the mean densities are no longer equal. Depending on the value of $J$, this transition can be either continuous or of the first order. For sufficiently big negative $J$, the behaviour on the two lattices becomes markedly different: while for the Bethe lattice there exists a continuous transition into a phase with an alternating order followed by a continuous re-entrant transition into a disordered phase, an alternating order phase is absent on the Husimi lattice due to strong frustration effects.
description: 38 pages, 16 figures
Correlations break homogenization
Creators: name: Comar, Naim Elias
name: Landi, Gabriel T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The standard collisional model paradigm consists of a system that interacts sequentially with identically prepared ancillas. After infinitely many collisions, and under appropriate conditions, the system may converge to the same state as the ancillas. This process, known as homogenization, is independent of the ancilla initial state, being a property only of the underlying dynamics. In this paper we extend this idea to locally identical, but globally correlated, ancillas, and show that correlations break homogenization. This is done numerically using a minimal qubit model, and analytically using an exactly soluble Gaussian model. In both cases, we use Hamiltonian graph states with cyclic graphs as the prototypical method for building scalable many-body entangled ancillary states.
description: Comments are welcome
Uhlmann Fidelity and Fidelity Susceptibility for Integrable Spin Chains at Finite Temperature: Exact Results
Creators: name: Białończyk, Michał
name: Gómez-Ruiz, Fernando Javier
name: del Campo, Adolfo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We derive the exact expression for the Uhlmann fidelity between arbitrary thermal Gibbs states of the quantum XY model in a transverse field with finite system size. Using it, we conduct a thorough analysis of the fidelity susceptibility of thermal states for the Ising model in a transverse field. We compare the exact results with a common approximation that considers only the positive-parity subspace, which is shown to be valid only at high temperatures. The proper inclusion of the odd parity subspace leads to the enhancement of maximal fidelity susceptibility in the intermediate range of temperatures. We show that this enhancement persists in the thermodynamic limit and scales quadratically with the system size. The correct low-temperature behavior is captured by an approximation involving the two lowest many-body energy eigenstates, from which simple expressions are obtained for the thermal susceptibility and specific heat.
description: 25 pages, 5 figures, 1 Appendix + 1 Figure. Accepted Version
Formation of Close Double White Dwarfs: model results VS observation
Creators: name: LI Huaju
Publisher: name: Zenodo
Year: 2019

description: We do a binary population synthesis (BPS) simulation about the close double white dwarfs (CDWDs), two main BPS modifications are as follows.

1.The mass–orbital period relation after stable RLOF is implemented into our BPS code;

2.The mass transfer stability criterionis obtained from adiabatic mass loss model(Ge, H et al. 2015).
Quantization and Deployment of Deep Neural Networks on Microcontrollers
Creators: name: Novac, Pierre-Emmanuel
name: Hacene, Ghouthi Boukli
name: Pegatoquet, Alain
name: Miramond, Benoît
name: Gripon, Vincent
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Embedding Artificial Intelligence onto low-power devices is a challenging task that has been partly overcome with recent advances in machine learning and hardware design. Presently, deep neural networks can be deployed on embedded targets to perform different tasks such as speech recognition,object detection or Human Activity Recognition. However, there is still room for optimization of deep neural networks onto embedded devices. These optimizations mainly address power consumption,memory and real-time constraints, but also an easier deployment at the edge. Moreover, there is still a need for a better understanding of what can be achieved for different use cases. This work focuses on quantization and deployment of deep neural networks onto low-power 32-bit microcontrollers. The quantization methods, relevant in the context of an embedded execution onto a microcontroller, are first outlined. Then, a new framework for end-to-end deep neural networks training, quantization and deployment is presented. This framework, called MicroAI, is designed as an alternative to existing inference engines (TensorFlow Lite for Microcontrollers and STM32CubeAI). Our framework can indeed be easily adjusted and/or extended for specific use cases. Execution using single precision 32-bit floating-point as well as fixed-point on 8- and 16-bit integers are supported. The proposed quantization method is evaluated with three different datasets (UCI-HAR, Spoken MNIST and GTSRB). Finally, a comparison study between MicroAI and both existing embedded inference engines is provided in terms of memory and power efficiency. On-device evaluation is done using ARM Cortex-M4F-based microcontrollers (Ambiq Apollo3 and STM32L452RE).
description: 34 pages, 14 figures. Published in MDPI Sensors 2021, special issue "Embedded Artificial Intelligence (AI) for Smart Sensing and IoT Applications": https://www.mdpi.com/1424-8220/21/9/2984 . v2: add reference for MicroAI software and link to source code repository; fix Eq. 3 according to implementation; improve English grammar and spelling; improve page layout
Fast MILP-based Task and Motion Planning for Pick-and-Place with Hard/Soft Constraints of Collision-Free Route
Creators: name: Kogo, Takuma
name: Takaya, Kei
name: Oyama, Hiroyuki
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: We present new models of optimization-based task and motion planning (TAMP) for robotic pick-and-place (P&P), which plan action sequences and motion trajectory with low computational costs. We improved an existing state-of-the-art TAMP model integrated with the collision avoidance, which is formulated as a mixed-integer linear programing (MILP) problem. To enable the MILP solver to search for solutions efficiently, we introduced two approaches leveraging features of collision avoidance in robotic P&P. The first approach reduces number of binary variables, which are related to the collision avoidance of delivery objects, by reformulating them as continuous variables with additional hard constraints. These hard constraints maintain consistency by conditionally propagating binary values, which are related to the carry action state and collision avoidance of robots, to the reformulated continuous variables. The second approach is more aware of the branch-and-bound method, which is the fundamental algorithm of modern MILP solvers. This approach guides the MILP solver to find integer solutions with shallower branching by adding a soft constraint, which softly restricts a robot's routes around delivery objects. We demonstrate the effectiveness of the proposed approaches with a modern MILP solver.
description: IEEE International Conference on Systems, Man, and Cybernetics (SMC) 2021 - accepted
Quantum Hall Superconductivity from Moir{é} Landau Levels
Creators: name: Chaudhary, Gaurav
name: MacDonald, A. H.
name: Norman, M. R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: It has long been speculated that quasi-two-dimensional superconductivity can reappear above its semiclassical upper critical field due to Landau quantization, yet this reentrant property has never been observed. Here, we argue that twisted bilayer graphene at a magic angle (MATBG) is an ideal system in which to search for this phenomenon because its Landau levels are doubly degenerate, and its superconductivity appears already at carrier densities small enough to allow the quantum limit to be reached at relatively modest magnetic fields. We study this problem theoretically by combining a simplified continuum model for the electronic structure of MATBG with a phenomenological attractive pairing interaction, and discuss obstacles to the observation of quantum Hall superconductivity presented by disorder, thermal fluctuations, and competing phases.
description: Published version
Manipulation and readout of spin states of a single-molecule magnet by a spin-polarized current
Creators: name: Xue, Hai-Bin
name: Liang, Jiu-Qing
name: Liu, Wu-Ming
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Single-molecule memory device based on a single-molecule magnet (SMM) is one of the ultimate goals of semiconductor nanofabrication technologies. Here, we study how to manipulate and readout the SMM's two spin-state of stored information that characterized by the maximum and minimum average value of the $Z$-component of the total spin of the SMM and the conduction-electron, which are recognized as the information bits "$1$" and "$0$". We demonstrate that the switching time depends on both the sequential tunneling gap $\varepsilon_{se}$ and the spin-selection-rule allowed transition-energy $\varepsilon_{trans}$, which can be tuned by the gate voltage. In particular, when the external bias voltage is turned off, in the cases of the unoccupied and doubly-occupied ground eigenstates, the time derivative of the transport current can be used to read out the SMM's two spin-state of stored information. Moreover, the tunneling strength of and the asymmetry of the SMM-electrode coupling have a strong influence on the switching time, but that have a slight influence on the readout time that being on the order of nanoseconds. Our results suggest a SMM-based memory device, and provide fundamental insight into the electrical controllable manipulation and readout of the SMM's two spin-state of stored information.
description: 15 pages, 10 figures
Functional design and swimming energetics of the freshwater pufferfish, Tetraodon fluviatilis
Creators: name: Varley, Robert Mark
Publisher: name: University of British Columbia
Year: 2010

description: Measurements of morphometric characteristics pertinent to hydromechanical analysis were recorded, transformed where necessary and regression analysis was performed to relate the morphometric characteristics to standard body length. Terminal velocity measurements were recorded for a series of drop tank experiments. The data was converted into drag coefficients and Reynolds numbers and regression analysis was performed- to establish the specific relationships between those two hydromechanical parameters which were compared to theoretical estimates calculated from hydromechanical theory. High speed cinefilms of pufferfish fin and body motions made during forward swirriming were recorded and subsequently digitized onto a computer with a frame analyzer. The data was converted to distance and time from which the kinematic parameters of fins and body motions were calculated and compared to values found for other aquatic propulsive systems. A modified Actuator-Disc model was employed to estimate propulsive power and efficiency during steady forward swimming based on the morphometric, kinematic and hydromechanical parameters calculated for the pufferfish. Comparisons of the experimental estimates for drag and power were made with theoretical estimates and with estimates found for other aquatic propulsive systems. The efficacy of the modified Actuator-Disc model was discussed with respect to negating factors found during this study for the application of the model to multiple fin aquatic propulsive systems.
Fixed and partial-node approximations in Slater determinant space for molecules
Creators: name: Blunt, Nick S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a study of fixed and partial-node approximations in Slater determinant basis sets, using full configuration interaction quantum Monte Carlo (FCIQMC) to perform sampling. Walker annihilation in the FCIQMC method allows partial-node simulations to be performed, relaxing the nodal constraint to converge to the FCI solution. This is applied to ab initio molecular systems, using symmetry-projected Jastrow mean-field wave functions for complete active space (CAS) problems. Convergence and the sign problem within the partial-node approximation are studied, which is shown to eventually be limited in its use due to the large walker populations required. However the fixed-node approximation results in an accurate and practical method. We apply these approaches to various molecular systems and active spaces, including ferrocene and acenes. This also provides a test of symmetry-projected Jastrow mean-field wave functions in variational Monte Carlo (VMC) for a new set of problems. For trans-polyacetylene molecules and acenes we find that the time to perform a constant number of fixed-node FCIQMC iterations scales as O(N^{1.44}) and O(N^{1.75}) respectively, resulting in an efficient method for CAS-based problems that can be applied accurately to large active spaces.
description: Supporting information is included
The gas flow pattern through a small size Resistive Plate Chamber with 2mm gap
Creators: name: Pezeshkian, Yousef
name: Kiyoumarsioskouei, Amir
name: Ahmadpouri, Majid
name: Ghorbani, Ghasem
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: A prototype of a single-gap glass Resistive Plate Chamber (RPC) is constructed by the authors. To find the considerations required for better operation of the detector's gas system, we have simulated the flow of the Ar gas through the detector by using computational fluid dynamic methods. Simulations show that the pressure inside the chamber linearly depends on the gas flow rate and the chamber's output hose length. The simulation results were compatible with experiments. We have found that the pressure-driven speed of the gas molecules is two orders of magnitude larger in the inlet and outlet regions than the blocked corners of a 14x14 cm2 chamber, and most likely seems to be higher for larger detectors and different geometries.
Narrow-band giant pulses from the Crab pulsar
Creators: name: Thulasiram, Parasar
name: Lin, Hsiu-Hsien
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We used a new spectral-fitting technique to identify a subpopulation of 6 narrow-band giant pulses from the Crab pulsar out of a total of 1578. These giant pulses were detected in 77 minutes of observations with the 46-m dish at the Algonquin Radio Observatory at 400-800 MHz. The narrow-band giant pulses consist of both main- and inter-pulses, thereby being more likely to be caused by an intrinsic emission mechanism as opposed to a propagation effect. Fast Radio Bursts (FRBs) have demonstrated similar narrow-band features while only little has been observed in the giant pulses of pulsars. We report the narrow-band giant pulses with $Δν/ ν$ on the order of 0.1, which is close to the value of 0.05 reported for the repeater FRB 20190711A. Hence, the connection between FRBs and giant pulses of pulsars is further established.
description: 7 pages, 3 figures
Quasitopological electromagnetism: Reissner-Nordström black strings in Einstein and Lovelock gravities
Creators: name: Cisterna, Adolfo
name: Henríquez-Báez, Carla
name: Mora, Nicolás
name: Sanhueza, Leonardo
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: In this work, we provide consistent compactifications of Einstein-Maxwell and Einstein-Maxwell-Lovelock theories on direct product spacetimes of the form $\mathcal{M}_D=\mathcal{M}_d\times\mathcal{K}^{p}$, where $\mathcal{K}^p$ is a Euclidean internal manifold of constant curvature. For these compactifications to take place, it is required the distribution of a precise flux of $p$-forms over the internal manifold. The dynamic of the $p$-forms are demanded to be controlled by two types of interaction. First, by specific couplings with the curvature tensor and, second, by a suitable interaction with the electromagnetic field of the $d$-dimensional brane, the latter being dictated by a modification of the recently proposed theory of Quasitopological Electromagnetism. The field equations of the corresponding compactified theories, which are of second order, are solved and general homogenous charged black p-branes are constructed. We explicitly provide homogenous Reissner-Nordström black strings and black p-branes in Einstein-Maxwell theory and homogenous charged Boulware-Deser black p-branes for quadratic and cubic Maxwell-Lovelock gravities.
description: References added. Matches published version
First-year ion-acoustic wave observations in the solar wind by the RPW/TDS instrument onboard Solar Orbiter
Creators: name: Píša, D.
name: Souček, J.
name: Santolík, O.
name: Hanzelka, M.
name: Nicolaou, G.
name: Maksimovic, M.
name: Bale, S. D.
name: Chust, T.
name: Khotyaintsev, Y.
name: Krasnoselskikh, V.
name: Kretzschmar, M.
name: Lorfèvre, E.
name: Plettemeier, D.
name: Steller, M.
name: Štverák, Š.
name: Trávníček, P.
name: Vaivads, A.
name: Vecchio, A.
name: Horbury, T.
name: O'Brien, H.
name: Evans, V.
name: Angelini, V.
name: Owen, C. J.
name: Louarn, P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Space Physics (physics.space-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Electric field measurements of the Time Domain Sampler (TDS) receiver, part of the Radio and Plasma Waves (RPW) instrument on board Solar Orbiter, often exhibit very intense broadband wave emissions at frequencies below 20~kHz in the spacecraft frame. In this paper, we present a year-long study of electrostatic fluctuations observed in the solar wind at an interval of heliocentric distances from 0.5 to 1~AU. The RPW/TDS observations provide a nearly continuous data set for a statistical study of intense waves below the local plasma frequency. The on-board and continuously collected and processed properties of waveform snapshots allow for the mapping plasma waves at frequencies between 200~Hz and 20~kHz. We used the triggered waveform snapshots and a Doppler-shifted solution of the dispersion relation for wave mode identification in order to carry out a detailed spectral and polarization analysis. Electrostatic ion-acoustic waves are the common wave emissions observed between the local electron and proton plasma frequency in the soler wind. The occurrence rate of ion-acoustic waves peaks around perihelion at distances of 0.5~AU and decreases with increasing distances, with only a few waves detected per day at 0.9~AU. Waves are more likely to be observed when the local proton moments and magnetic field are highly variable. A more detailed analysis of more than 10000 triggered waveform snapshots shows the mean wave frequency at about 3 kHz and wave amplitude about 2.5 mV/m. The wave amplitude varies as 1/R^(1.38) with the heliocentric distance. The relative phase distribution between two components of the E-field shows a mostly linear wave polarization. Electric field fluctuations are closely aligned with the directions of the ambient field lines. Only a small number (3%) of ion-acoustic waves are observed at larger magnetic discontinuities.
description: 9 pages, 8 figures
Measurements of $^{160}$Dy($p,γ$) at energies relevant for astrophysical $γ$ process
Creators: name: Cheng, Hao
name: Sun, Bao-Hua
name: Zhu, Li-Hua
name: Kusakabe, Motohiko
name: Zheng, Yun
name: He, Liu-Chun
name: Kajino, Toshitaka
name: Niu, Zhong-Ming
name: Li, Tian-Xiao
name: Li, Cong-Bo
name: Wang, Dong-Xi
name: Wang, Meng
name: Li, Guang-Shuai
name: Wang, Kang
name: Song, Lin
name: Guo, Ge
name: Huang, Zhi-Yong
name: Wei, Xiu-Lin
name: Zhao, Fu-WeI
name: Wu, Xiao-Guang
name: Abulikemu, Yimuran
name: Liu, Jian-Cheng
name: Fan, Ping
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Rare information on photodisintegration reactions of nuclei with mass numbers $A \approx 160$ at astrophysical conditions impedes our understanding of the origin of $p$-nuclei. Experimental determination of the key ($p,γ$) cross sections has been playing an important role to verify nuclear reaction models and to provide rates of relevant ($γ,p$) reactions in $γ$-process. In this paper we report the first cross section measurements of $^{160}$Dy($p,γ$)$^{161}$Ho and $^{161}$Dy($p,n$)$^{161}$Ho in the beam energy range of 3.4 - 7.0 MeV, partially covering the Gamow window. Such determinations are possible by using two targets with various isotopic fractions. The cross section data can put a strong constraint on the nuclear level densities and gamma strength functions for $A \approx$ 160 in the Hauser-Feshbach statistical model. Furthermore, we find the best parameters for TALYS that reproduce the A $\thicksim$ 160 data available, $^{160}$Dy($p,γ$)$^{161}$Ho and $^{162}$Er($p,γ$)$^{163}$Tm, and recommend the constrained $^{161}$Ho($γ,p$)$^{160}$Dy reaction rates over a wide temperature range for $γ$-process network calculations. Although the determined $^{161}$Ho($γ$, p) stellar reaction rates at the temperature of 1 to 2 GK can differ by up to one order of magnitude from the NON-SMOKER predictions, it has a minor effect on the yields of $^{160}$Dy and accordingly the $p$-nuclei, $^{156,158}$Dy. A sensitivity study confirms that the cross section of $^{160}$Dy($p$, $γ$)$^{161}$Ho is measured precisely enough to predict yields of $p$-nuclei in the $γ$-process.
description: 12 pages,9 figures
Spontaneous Symmetry Breaking and Frustrated Phases
Creators: name: Casasola, Heitor
name: Hernaski, Carlos A.
name: Gomes, Pedro R. S.
name: Bienzobaz, Paula F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study a system involving a single quantum degree of freedom per site of the lattice interacting with a few neighbors (up to second neighbors), with the interactions chosen as to produce frustration. At zero temperature, this system undergoes several quantum phase transitions from both gapped-to-gapless and gapless-to-gapless phases, providing a very rich phase structure with disordered, homogeneous and modulated ordered phases meeting in a quantum Lifshitz point. The gapless phases spontaneously break spatial lattice translations as well as internal symmetries of the form $U(1)^{\mathsf{N}_c}$, where $\mathsf{N}_c$ is the number of independent pitch vectors that arise in the homogeneous and modulated ordered phases. We carry out a detailed analysis of the quantum critical behavior discussing the mechanism leading to the phase transitions. We also discuss a proper characterization of all the gapless phases as well as the nature of the Goldstone excitations. We study the behavior of the correlation functions and identify regions in the phase diagram where the system exhibits generalized symmetries, such as polynomial shift symmetry. This type of symmetry plays an important role in the so-called fractonic phases, which is an exotic form of matter recently discovered.
description: 50 pages, 8 figures, clarifications added, typos fixed, refs. added, published version (Editors' Suggestion)