cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Three-dimensional quantum gravity from the quantum pseudo-Kähler plane
Creators: name: Kim, Hyun Kyu
Publisher: name: arXiv
Year: 2021
Subjects: subject: Representation Theory (math.RT)
subject: Mathematical Physics (math-ph)
subject: Geometric Topology (math.GT)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 16T05, 83C45, 46L65

description: A new canonical Hopf algebra called the quantum pseudo-Kähler plane is introduced. This quantum group can be viewed as a deformation quantization of the complex two-dimensional plane $\mathbb{C}^2$ with a pseudo-Kähler metric, or as a complexified version of the well-known quantum plane Hopf algebra. A natural class of nicely-behaved representations of the quantum pseudo-Kähler plane algebra is defined and studied, in the spirit of the previous joint work of the author and I. B. Frenkel. The tensor square of a unique irreducible representation decomposes into the direct integral of the irreducibles, and the unitary decomposition map is expressed by a special function called the modular double compact quantum dilogarithm, used in the recent joint work of the author and C. Scarinci on the quantization of 3d gravity for positive cosmological constant case. Then, from the associativity of the tensor cube, and from the maps between the left and the right duals, we construct unitary operators forming a new representation of Kashaev's group of transformations of dotted ideal triangulations of punctured surfaces, as an analog of Kashaev's quantum Teichmüller theory. The present work thus inspires one to look for a Kashaev-type quantization of 3d gravity for positive cosmological constant.
description: 36 pages. v2 reflects changes made in the reviewing process. To appear in Commun. Math. Phys
Nekhoroshev theorem for perturbations of the central motion
Creators: name: Bambusi, Dario
name: Fuse', Alessandra
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In this paper we prove a Nekhoroshev type theorem for perturbations of Hamiltonians describing a particle subject to the force due to a central potential. Precisely, we prove that under an explicit condition on the potential, the Hamiltonian of the central motion is quasi-convex. Thus, when it is perturbed, two actions (the modulus of the total angular momentum and the action of the reduced radial system) are approximately conserved for times which are exponentially long with the inverse of the perturbation parameter.
Quantum Thermometry with a Dissipative Quantum Rabi System
Creators: name: Xie, Dong
name: Xu, Chunling
name: Wang, An Min
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Dissipative quantum Rabi System, a finite-component system composed of a single two-level atom interacting with an optical cavity field mode, exhibits a quantum phase transition, which can be exploited to greatly enhance the estimation precision of unitary parameters (frequency and coupling strength). Here, using the quantum Langevin equation, standard mean field theory and adiabatic elimination, we investigate the quantum thermometry of a thermal bath surrounding the atom with quantum optical probes. With the increase of coupling strength between the atom and the cavity field, two kinds of singularities can be observed. One type of singularity is the exceptional point (EP) in the anti-parity-time (anti-$\mathcal{PT}$) symmetrical cavity field. The other type of singularity is the critical point (CP) of phase transition from the normal to superradiant phase. We show that the optimal measurement precision occurs at the CP, instead of the EP. And the direct photon detection represents an excellent proxy for the optimal measurement near the CP. In the case where the thermal bath to be tested is independent of the extra thermal bath interacting with the cavity field, the estimation precision of the temperature always increases with the coupling strength. Oppositely, if the thermal bath to be tested is in equilibrium with the extra bath interacting with the cavity field, noises that suppress the information of the temperature will be introduced when increasing the coupling strength unless it is close to the CP.
description: 10pages,5figures
The unrelaxed dynamical structure of the galaxy cluster Abell 85
Creators: name: Yu, Heng
name: Diaferio, Antonaldo
name: Agulli, Irene
name: Aguerri, Jose Alfonso Lopez
name: Tozzi, Paolo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: For the first time, we explore the dynamics of the central region of a galaxy cluster within $r_{500}\sim 600h^{-1}$~kpc from its center by combining optical and X-ray spectroscopy. We use (1) the caustic technique that identifies the cluster substructures and their galaxy members with optical spectroscopic data, and (2) the X-ray redshift fitting procedure that estimates the redshift distribution of the intracluster medium (ICM). We use the spatial and redshift distributions of the galaxies and of the X-ray emitting gas to associate the optical substructures to the X-ray regions. When we apply this approach to Abell 85 (A85), a complex dynamical structure of A85 emerges from our analysis: a galaxy group, with redshift $z=0.0509 \pm 0.0021$ is passing through the cluster center along the line of sight dragging part of the ICM present in the cluster core; two additional groups, at redshift $z=0.0547 \pm 0.0022$ and $z=0.0570 \pm 0.0020$, are going through the cluster in opposite directions, almost perpendicularly to the line of sight, and have substantially perturbed the dynamics of the ICM. An additional group in the outskirts of A85, at redshift $z=0.0561 \pm 0.0023$, is associated to a secondary peak of the X-ray emission, at redshift $z=0.0583^{+0.0039}_{-0.0047}$. Although our analysis and results on A85 need to be confirmed by high-resolution spectroscopy, they demonstrate how our new approach can be a powerful tool to constrain the formation history of galaxy clusters by unveiling their central and surrounding structures.
description: 12 pages, 11 figures, accepted by ApJ
The Infrared Imaging Spectrograph (IRIS) for TMT: motion planning with collision avoidance for the on-instrument wavefront sensors
Creators: name: Chapin, Edward L.
name: Dunn, Jennifer
name: Weiss, Jason
name: Gillies, Kim
name: Hayano, Yutaka
name: Johnson, Chris
name: Larkin, James
name: Moore, Anna
name: Riddle, Reed L.
name: Sohn, Ji Man
name: Smith, Roger
name: Suzuki, Ryuji
name: Walth, Gregory
name: Wright, Shelley
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The InfraRed Imaging Spectrograph (IRIS) will be a first-light client instrument for the Narrow Field Infrared Adaptive Optics System (NFIRAOS) on the Thirty Meter Telescope. IRIS includes three configurable tip/tilt (TT) or tip/tilt/focus (TTF) On-Instrument Wavefront Sensors (OIWFS). These sensors are positioned over natural guide star (NGS) asterisms using movable polar-coordinate pick-off arms (POA) that patrol an approximately 2-arcminute circular field-of-view (FOV). The POAs are capable of colliding with one another, so an algorithm for coordinated motion that avoids contact is required. We have adopted an approach in which arm motion is evaluated using the gradient descent of a scalar potential field that includes an attractive component towards the goal configuration (locations of target stars), and repulsive components to avoid obstacles (proximity to adjacent arms). The resulting vector field is further modified by adding a component transverse to the repulsive gradient to avoid problematic local minima in the potential. We present path planning simulations using this computationally inexpensive technique, which exhibit smooth and efficient trajectories.
description: 10 pages, 5 figures, SPIE (2016) 9913-29
Robust and Efficient Hamiltonian Learning
Creators: name: Yu, Wenjun
name: Sun, Jinzhao
name: Han, Zeyao
name: Yuan, Xiao
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: With the fast development of quantum technology, the sizes of both digital and analog quantum systems increase drastically. In order to have better control and understanding of the quantum hardware, an important task is to characterize the interaction, i.e., to learn the Hamiltonian, which determines both static and dynamic properties of the system. Conventional Hamiltonian learning methods either require costly process tomography or adopt impractical assumptions, such as prior information on the Hamiltonian structure and the ground or thermal states of the system. In this work, we present a robust and efficient Hamiltonian learning method that circumvents these limitations based only on mild assumptions. The proposed method can efficiently learn any Hamiltonian that is sparse on the Pauli basis using only short-time dynamics and local operations without any information on the Hamiltonian or preparing any eigenstates or thermal states. The method has a scalable complexity and a vanishing failure probability regarding the qubit number. Meanwhile, it performs robustly given the presence of state preparation and measurement errors and resiliently against a certain amount of circuit and shot noise. We numerically test the scaling and the estimation accuracy of the method for transverse field Ising Hamiltonian with random interaction strengths and molecular Hamiltonians, both with varying sizes and manually added noise. All these results verify the robustness and efficacy of the method, paving the way for a systematic understanding of the dynamics of large quantum systems.
description: 41 pages, 6 figures, Open source implementation available at https://github.com/zyHan2077/HamiltonianLearning
Are There Nuclear Structure Effects on the Isoscalar Giant Monopole Resonance and Nuclear Incompressibility near A~90?
Creators: name: Gupta, Y. K.
name: Garg, U.
name: Howard, K. B.
name: Matta, J. T.
name: Senyigit, M.
name: Itoh, M.
name: Ando, S.
name: Aoki, T.
name: Uchiyama, A.
name: Adachi, S.
name: Fujiwara, M.
name: Iwamoto, C.
name: Tamii, A
name: Akimune, H.
name: Kadono, C.
name: Matsuda, Y.
name: Nakahara, T.
name: Furuno, T.
name: Kawabata, T.
name: Tsumura, M.
name: Harakeh, M. N.
name: Kalantar-Nayestanaki, N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: "Background-free" spectra of inelastic $α$-particle scattering have been measured at a beam energy of 385 MeV in $^{90, 92}$Zr and $^{92}$Mo at extremely forward angles, including 0$^{\circ}$. The ISGMR strength distributions for the three nuclei coincide with each other, establishing clearly that nuclear incompressibility is not influenced by nuclear shell structure near $A\sim$90 as was claimed in recent measurements.
description: 5 pages, 4 figures; accepted for publication in Phys. Lett. B
Localization for one-dimensional Anderson-Dirac models
Creators: name: Zalczer, Sylvain
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: Classical Analysis and ODEs (math.CA)
subject: Spectral Theory (math.SP)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: Primary 34L40, Secondary 81Q10, 37H15

description: We prove spectral and dynamical localization for a one-dimensional Dirac operator to which is added an ergodic random potential, with a discussion on the different types of potential. We use scattering properties to prove the positivity of the Lyapunov exponent through Fürstenberg theorem. We get then the Hölder regularity of the integrated density of states through a new version of Thouless formula, and thus the Wegner estimate necessary for the multiscale analysis.
Graphs with convex balls
Creators: name: Chalopin, Jérémie
name: Chepoi, Victor
name: Giocanti, Ugo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Discrete Mathematics (cs.DM)
subject: Combinatorics (math.CO)
subject: Group Theory (math.GR)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: In this paper, we investigate the graphs in which all balls are convex and the groups acting on them geometrically (which we call CB-graphs and CB-groups). These graphs have been introduced and characterized by Soltan and Chepoi (1983) and Farber and Jamison (1987). CB-graphs and CB-groups generalize systolic (alias bridged) and weakly systolic graphs and groups, which play an important role in geometric group theory. We present metric and local-to-global characterizations of CB-graphs. Namely, we characterize CB-graphs $G$ as graphs whose triangle-pentagonal complexes $X(G)$ are simply connected and balls of radius at most $3$ are convex. Similarly to systolic and weakly systolic graphs, we prove a dismantlability result for CB-graphs $G$: we show that their squares $G^2$ are dismantlable. This implies that the Rips complexes of CB-graphs are contractible. Finally, we adapt and extend the approach of Januszkiewicz and Swiatkowski (2006) for systolic groups and of Chalopin et al. (2020) for Helly groups, to show that the CB-groups are biautomatic.
Deterministic all-versus-nothing proofs of Bell nonlocality based on non-stabilizer states
Creators: name: Tang, Weidong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The all-versus-nothing proof of Bell nonlocality is a kind of mainstream demonstration of Bell's theorem without inequalities. Two kinds of such proofs, called the deterministic all-versus-nothing proof and the probabilistic all-versus-nothing proof, are both widely investigated. So far, all previous deterministic all-versus-nothing proofs of Bell nonlocality are constructed based on stabilizer states. To break with this tradition, some deterministic all-versus-nothing proofs induced from non-stabilizer states are firstly presented in this work. These results not only can greatly enrich the family of the demonstration of Bell nonlocality without inequalities, but also may provide us some useful resources in certain quantum information processing.
description: 16 pages and 4 figures
Universal structural estimator and dynamics approximator for complex networks
Creators: name: Chen, Yu-Zhong
name: Lai, Ying-Cheng
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Revealing the structure and dynamics of complex networked systems from observed data is of fundamental importance to science, engineering, and society. Is it possible to develop a universal, completely data driven framework to decipher the network structure and different types of dynamical processes on complex networks, regardless of their details? We develop a Markov network based model, sparse dynamical Boltzmann machine (SDBM), as a universal network structural estimator and dynamics approximator. The SDBM attains its topology according to that of the original system and is capable of simulating the original dynamical process. We develop a fully automated method based on compressive sensing and machine learning to find the SDBM. We demonstrate, for a large variety of representative dynamical processes on model and real world complex networks, that the equivalent SDBM can recover the network structure of the original system and predicts its dynamical behavior with high precision.
Measurement Error Models for Spatial Network Lattice Data: Analysis of Car Crashes in Leeds
Creators: name: Gilardi, Andrea
name: Borgoni, Riccardo
name: Presicce, Luca
name: Mateu, Jorge
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Road casualties represent an alarming concern for modern societies. During the last years, several authors proposed sophisticated approaches to help authorities implement new policies. These models were usually developed considering a set of socioeconomic variables and ignoring the measurement error, which can bias the statistical inference. This paper presents a Bayesian model to analyse car crashes occurrences at the network-lattice level, taking into account measurement error in the spatial covariate. The suggested methodology is exemplified by considering the collisions in the road network of Leeds (UK) during 2011-2019. Traffic volumes are approximated using an extensive set of counts obtained from mobile devices and the estimates are adjusted using a spatial measurement error correction.
Interprofessional team-based simulation training for undergraduate medical, midwifery and paramedical students during their obstetric rotation to improve understanding of professional roles.
Creators: name: Siddharth, Aditi
name: Gbemisola  David West
name: Carpenter, Jane
name: Burns, Ethel
name: Catterall, Matthew
name: Moore, Jane
Publisher: name: F1000 Research Limited
Year: 2023

description: Background
 Training for the medical, midwives and paramedical students has traditionally been in silos though the three professional groups are expected to work together in a hospital setting. Evidence shows training together improves communication and shared leadership (Kenaszchuk et al., 2011, Kyrkjebø et al., 2006, Foronda et al., 2016). This simulation training was embedded into the patient safety day for Oxford medical and Oxford Brookes midwifery and paramedical students with the aim to gain an understanding of the strengths of the different professional groups through team-based simulation of obstetric emergencies.

 Methods
 The students from the three professional groups were divided into teams of 7 supervised by 2 faculty members. Roles of patient, partner and professionals were assigned. Each team managed two emergency scenarios (eclampsia and postpartum haemorrhage) with the aid of simulation equipment (mannequins, algorithms etc) followed by a 20 minute debrief. Pre and post simulation questions via mentimeter helped document changes in attitudes towards the professional groups. We have run these simulations for one year (6 iterations)

 Results:
 Pre and Post simulation discussion and reflection via mentimeter clearly demonstrated the change in attitude towards the other professional groups with qualitative feedback such as ‘midwives know a lot’, ‘medical students have a deeper understanding’ and ‘paramedics are reassuring’. Post-simulation confidence scores have always demonstrated an improvement.
Role of Capacity Building on Economic Development of Women in Mogadishu Somalia
Creators: name: ohamud Dahir Hilif
Publisher: name: Zenodo
Year: 2024

description: The capacity building of women is crucial for its significant contribution to society and sustainable economicdevelopment in Somalia. These institutions prioritize not only their business interests but also their socio-economicdevelopment objectives. The capacity building play role reducing poverty by increasing employment and income,thereby enhancing women's capacity for sustainable development and eco-comic growth. This research aims to examinethe influence of capacity building on economic development of women in Somalia. The study utilized a correlationalresearch design to investigate the relationship between capacity building provision and women's economicadvancement. The data was analyzed using SPSS software after being collected from 135 responded. The study found asignificant positive correlation between capacity building services and women's economic development. The studyindicates that capacity building and overall economic progress significantly enhance the economic progress of women inSomalia.The research findings suggest that a higher degree of adoption of capacity building has the potential to enhancewomen's financial status, self-assurance, and improve their chances for uplifting themselves from poverty. Theseoutcomes can significantly contribute to the overall progress and well-being of society as a whole.
Signatures of a topological phase transition in a planar Josephson junction
Creators: name: Banerjee, A.
name: Lesser, O.
name: Rahman, M. A.
name: Wang, H. -R.
name: Li, M. -R.
name: Kringhøj, A.
name: Whiticar, A. M.
name: Drachmann, A. C. C.
name: Thomas, C.
name: Wang, T.
name: Manfra, M. J.
name: Berg, E.
name: Oreg, Y.
name: Stern, Ady
name: Marcus, C. M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: A growing body of work suggests that planar Josephson junctions fabricated using superconducting hybrid materials provide a highly controllable route toward one-dimensional topological superconductivity. Among the experimental controls are in-plane magnetic field, phase difference across the junction, and carrier density set by electrostatic gate voltages. Here, we investigate planar Josephson junctions with an improved design based on an epitaxial InAs/Al heterostructure, embedded in a superconducting loop, probed with integrated quantum point contacts (QPCs) at both ends of the junction. For particular ranges of in-plane field and gate voltages, a closing and reopening of the superconducting gap is observed, along with a zero-bias conductance peak (ZBCP) that appears upon reopening of the gap. Consistency with a simple theoretical model supports the interpretation of a topological phase transition. While gap closings and reopenings generally occurred together at the two ends of the junction, the height, shape, and even presence of ZBCPs typically differed between the ends, presumably due to disorder and variation of couplings to local probes.
The Infrared Imaging Spectrograph (IRIS) for TMT: Data Reduction System
Creators: name: Walth, Gregory
name: Wright, Shelley A.
name: Weiss, Jason
name: Larkin, James E.
name: Moore, Anna M.
name: Chapin, Edward L.
name: Do, Tuan
name: Dunn, Jennifer
name: Ellerbroek, Brent
name: Gillies, Kim
name: Hayano, Yutaka
name: Johnson, Chris
name: Marshall, Daniel
name: Riddle, Reed L.
name: Simard, Luc
name: Sohn, Ji Man
name: Suzuki, Ryuji
name: Wincensten, James
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: IRIS (InfraRed Imaging Spectrograph) is the diffraction-limited first light instrument for the Thirty Meter Telescope (TMT) that consists of a near-infrared (0.84 to 2.4 $μ$m) imager and integral field spectrograph (IFS). The IFS makes use of a lenslet array and slicer for spatial sampling, which will be able to operate in 100's of different modes, including a combination of four plate scales from 4 milliarcseconds (mas) to 50 mas with a large range of filters and gratings. The imager will have a field of view of 34$\times$34 arcsec$^{2}$ with a plate scale of 4 mas with many selectable filters. We present the preliminary design of the data reduction system (DRS) for IRIS that need to address all of these observing modes. Reduction of IRIS data will have unique challenges since it will provide real-time reduction and analysis of the imaging and spectroscopic data during observational sequences, as well as advanced post-processing algorithms. The DRS will support three basic modes of operation of IRIS; reducing data from the imager, the lenslet IFS, and slicer IFS. The DRS will be written in Python, making use of open-source astronomical packages available. In addition to real-time data reduction, the DRS will utilize real-time visualization tools, providing astronomers with up-to-date evaluation of the target acquisition and data quality. The quicklook suite will include visualization tools for 1D, 2D, and 3D raw and reduced images. We discuss the overall requirements of the DRS and visualization tools, as well as necessary calibration data to achieve optimal data quality in order to exploit science cases across all cosmic distance scales.
description: 13 pages, 2 figures, 6 tables, Proceeding 9913-165 of the SPIE Astronomical Telescopes + Instrumentation 2016
The role of density in the energy conservation for the isentropic compressible Euler equations
Creators: name: Wang, Yanqing
name: Ye, Yulin
name: Yu, Huan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper, we study Onsager's conjecture on the energy conservation for the isentropic compressible Euler equations via establishing the energy conservation criterion involving the density $\varrho\in L^{k}(0,T;L^{l}(\mathbb{T}^{d}))$. The motivation is to analysis the role of the integrability of density of the weak solutions keeping energy in this system, since almost all known corresponding results require $\varrho\in L^{\infty}(0,T;L^{\infty}(\mathbb{T}^{d}))$. Our results imply that the lower integrability of the density $\varrho$ means that more integrability of the velocity $v$ are necessary in energy conservation and the inverse is also true. The proof relies on the Constantin-E-Titi type and Lions type commutators on mollifying kernel.
description: 17 pages
Localization of matter waves in lattice systems with moving disorder
Creators: name: Guo, Chenyue
name: Cai, Zi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We study the localization phenomena in a one-dimensional lattice system with a uniformly moving disordered potential. At a low moving velocity, we find a sliding localized phase in which the initially localized matter wave adiabatically follows the moving potential without diffusion, thus resulting in an initial state memory in the many-body dynamics. Such an intriguing localized phase distinguishes itself from the standard Anderson localization in two aspects: it is not robust against interaction, but persists in the presence of slowly varying perturbations. Such a sliding localized phase can be understood as a consequence of interference between the wavepacket paths under moving quasi-periodic potentials with various periods that are incommensurate with the lattice constant. The experimental realization and detection were also discussed..
description: 11 pages
The Weyl bound for triple product L-functions
Creators: name: Blomer, Valentin
name: Jana, Subhajit
name: Nelson, Paul D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: Let $π_1, π_2, π_3$ be three cuspidal automorphic representations for the group ${\rm SL}(2, \Bbb{Z})$, where $π_1$ and $π_2$ are fixed and $π_3$ has large conductor. We prove a subconvex bound for $L(1/2, π_1 \otimes π_2 \otimes π_3)$ of Weyl-type quality. Allowing $π_3$ to be an Eisenstein series we also obtain a Weyl-type subconvex bound for $L(1/2 + it, π_1 \otimes π_2)$.
description: minor updates; to appear in Duke Math. J
Noether currents and generators of local gauge transformations in the covariant canonical formalism
Creators: name: Nakajima, Satoshi
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We investigate generators of local transformations in the covariant canonical formalism (CCF). The CCF treats space and time on an equal footing regarding the differential forms as the basic variables. The conjugate forms $π_A$ are defined as derivatives of the Lagrangian $d$-form $L(ψ^A, dψ^A)$ with respect to $dψ^A$, namely $π_A := \partial L/\partial dψ^A$, where $ψ^A $ are $p$-form dynamical fields. The form-canonical equations are derived from the form-Legendre transformation of the Lagrangian form $H:=dψ^A \wedge π_A - L$. We show that the Noether current form is the generator of an infinitesimal transformation $ψ^A \to ψ^A + δψ^A$ if the transformation of the Lagrangian form is given by $δL=dl$ and $δψ^A$ and $l$ depend on only $ψ^A$ and the parameters. As an instance, we study the local gauge transformation for the gauge field and the local Lorentz transformation for the second order formalism of gravity.
description: 9 pages, no figure. arXiv admin note: substantial text overlap with arXiv:1909.06779
Global gradients for cosmic-ray protons in the heliosphere during the solar minimum of cycle 23/24
Creators: name: Vos, E. E.
name: Potgieter, M. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Global gradients for cosmic-ray (CR) protons in the heliosphere are computed with a comprehensive modulation model for the recent prolonged solar minimum of Cycle 23/24. Fortunately, the PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) and Ulysses/KET (Kiel Electron Telescope) instruments simultaneously observed proton intensities for the period between July 2006 and June 2009. Radial and latitudinal gradients are calculated from measurements, with the latter possible because Ulysses changed its position significantly in the heliocentric meridional plane during this period. The modulation model is set up for the conditions that prevailed during this unusual solar minimum period to gain insight into the role role that particle drifts played in establishing the observed gradients for this period. Four year-end PAMELA proton spectra were reproduced with the model, from 2006 to 2009, followed by corresponding radial profiles that were computed along the Voyager-1 trajectory, and compared to available observations. It is found that the computed intensity levels are in agreement with solar minimum observations from Voyager-1 at multiple energies. The model also reproduces the steep intensity increase observed when Voyager-1 crossed the heliopause region. Good agreement is found between computed and observed latitudinal gradients so that we conclude that the model gives a most reasonable representation of modulation conditions from the Earth to the heliopause for the period from 2006 to 2009. As a characteristic feature of CR drifts, the most negative latitudinal gradient is computed for 2009, with a value of -0.15%/degree around 600 MV. The maximum radial gradient in the inner heliosphere (as covered by Ulysses) also occurs in this range, with the highest value of 4.25%/AU in 2009.
description: 17 pages, 9 figures. To be published in Solar Physics
Near Infrared Counterpart of 2E 1613.5-5053, the Central Source in Supernova Remnant RCW 103
Creators: name: Tendulkar, Shriharsh P.
name: Kaspi, Victoria M.
name: Archibald, Robert F.
name: Scholz, Paul
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: On 2016 June 22, 2E 1613.5-5053, the puzzling central compact object in supernova remnant RCW 103, emitted a magnetar-like burst. Using Director's Discretionary Time, we observed 2E 1613.5-5053 with the Hubble Space Telescope (WFC3/IR) and we report here on the detection of a previously unseen infrared counterpart. In observations taken on 2016 July 4 and August 11, we detect a new source ($m_\mathrm{F110W} = 26.3$ AB mag and $m_\mathrm{F160W} = 24.2$ AB mag) at the Chandra position of 2E 1613.5-5053 which was not detected in HST/NICMOS images from 2002 August 15 and October 8 to a depth of 24.5 AB mag (F110W) and 25.5 AB mag (F160W). We show that these deep IR observations rule out the possibility of an accreting binary but mimic IR emission properties of magnetars and isolated neutron stars. The presence or absence of a low-mass fallback disk cannot be confirmed from our observations.
description: 7 pages, 3 figures. Submitted to ApJ
On-board monitoring of 2-D spatially-resolved temperatures in cylindrical lithium-ion batteries: Part I. Low-order thermal modelling
Creators: name: Richardson, Robert R.
name: Zhao, Shi
name: Howey, David A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: 93

description: Estimating the temperature distribution within Li-ion batteries during operation is critical for safety and control purposes. Although existing control-oriented thermal models - such as thermal equivalent circuits (TEC) - are computationally efficient, they only predict average temperatures, and are unable to predict the spatially resolved temperature distribution throughout the cell. We present a low-order 2D thermal model of a cylindrical battery based on a Chebyshev spectral-Galerkin (SG) method, capable of predicting the full temperature distribution with a similar efficiency to a TEC. The model accounts for transient heat generation, anisotropic heat conduction, and non-homogeneous convection boundary conditions. The accuracy of the model is validated through comparison with finite element simulations, which show that the 2-D temperature field (r, z) of a large format (64 mm diameter) cell can be accurately modelled with as few as 4 states. Furthermore, the performance of the model for a range of Biot numbers is investigated via frequency analysis. For larger cells or highly transient thermal dynamics, the model order can be increased for improved accuracy. The incorporation of this model in a state estimation scheme with experimental validation against thermocouple measurements is presented in the companion contribution (Part II).
description: 13 pages, 6 figures, submitted to the Journal of Power Sources, 2016
SCEI: A Smart-Contract Driven Edge Intelligence Framework for IoT Systems
Creators: name: Xu, Chenhao
name: Ge, Jiaqi
name: Li, Yong
name: Deng, Yao
name: Gao, Longxiang
name: Zhang, Mengshi
name: Xiang, Yong
name: Zheng, Xi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Federated learning (FL) enables collaborative training of a shared model on edge devices while maintaining data privacy. FL is effective when dealing with independent and identically distributed (iid) datasets, but struggles with non-iid datasets. Various personalized approaches have been proposed, but such approaches fail to handle underlying shifts in data distribution, such as data distribution skew commonly observed in real-world scenarios (e.g., driver behavior in smart transportation systems changing across time and location). Additionally, trust concerns among unacquainted devices and security concerns with the centralized aggregator pose additional challenges. To address these challenges, this paper presents a dynamically optimized personal deep learning scheme based on blockchain and federated learning. Specifically, the innovative smart contract implemented in the blockchain allows distributed edge devices to reach a consensus on the optimal weights of personalized models. Experimental evaluations using multiple models and real-world datasets demonstrate that the proposed scheme achieves higher accuracy and faster convergence compared to traditional federated and personalized learning approaches.
Associative submanifolds in Joyce's generalised Kummer constructions
Creators: name: Dwivedi, Shubham
name: Platt, Daniel
name: Walpuski, Thomas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: This article constructs examples of associative submanifolds in $G_2$-manifolds obtained by resolving $G_2$-orbifolds using Joyce's generalised Kummer construction. As the $G_2$-manifolds approach the $G_2$-orbifolds, the volume of the associative submanifolds tends to zero. This partially verifies a prediction due to Halverson and Morrison.
Non-linear propagation effects of intense femtosecond pulses on low order harmonics in solids
Creators: name: Hussain, Mukhtar
name: Williams, Gareth O
name: Imran, Tayyab
name: Fajardo, Marta
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The non-linear propagation of the intense near-infrared (NIR) driving field in wide bandgap materials pose a challenge and an opportunity to control the spectral properties of high harmonic generation (HHG) in solids. Here, we have investigated the non-linear propagation effects of the ultrafast intense near-infrared (NIR) driving field at 800 nm of 40 fs pulse duration operating at a repetition rate of 1 kHz focused on the wide bandgap dielectrics such as MgO, Chromium (Cr) doped MgO (Cr: MgO), Sapphire (Sa) crystals and fused silica (FS). Furthermore, we have generated second and third harmonic (TH) in these materials to explore the non-linear response at a strong field. To quantify the non-linear propagation effects, low-order harmonics have been generated in reflection and compared with the harmonics generated in transmission. We observe spectral shifts and broadening of the driving field spectrum which is imprinted on the harmonics. We attribute these effects to strong photoionization, generation of free-carrier density and self-phase modulation effects. We have also studied the polarization dependence of second harmonic generation (SHG) and TH in FS. The linear polarization dependence of below bandgap harmonics in FS and Sa generated in reflection demonstrated the sharp anisotropy than in transmission. This work shows the sensitivity to control the spectral profile of harmonics by manipulating the driving field, showing the possibility of new tailored solid-state XUV sources for optical diagnostics.
Zoology of non-Hermitian spectra and their graph topology
Creators: name: Tai, Tommy
name: Lee, Ching Hua
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We uncover the very rich graph topology of generic bounded non-Hermitian spectra, distinct from the topology of conventional band invariants and complex spectral winding. The graph configuration of complex spectra are characterized by the algebraic structures of their corresponding energy dispersions, drawing new intimate links between combinatorial graph theory, algebraic geometry and non-Hermitian band topology. Spectral graphs that are conformally related belong to the same equivalence class, and are characterized by emergent symmetries not necessarily present in the physical Hamiltonian. The simplest class encompasses well-known examples such as the Hatano-Nelson and non-Hermitian SSH models, while more sophisticated classes represent novel multi-component models with interesting spectral graphs resembling stars, flowers, and insects. With recent rapid advancements in metamaterials, ultracold atomic lattices and quantum circuits, it is now feasible to not only experimentally realize such esoteric spectra, but also investigate the non-Hermitian flat bands and anomalous responses straddling transitions between different spectral graph topologies.
description: 32 pages, 22 figures
On a question of Moshe Roitman and Euler class of stably free module
Creators: name: Keshari, Manoj K.
name: Tikader, Soumi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Commutative Algebra (math.AC)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics
subject: 13C10, 13B25, 19A13

description: Let $A$ be a ring of dimension $d$ containing an infinite field $k$, $T_1,\ldots,T_r$ be variables over $A$ and $P$ be a projective $A[T_1,\ldots,T_r]$-module of rank $n$. Assume one of the following conditions hold. (1) $2n\geq d+3$ and $P$ is extended from $A$. (2) $2n\geq d+2$, $A$ is an affine $\overline {\mathbb F}_p$-algebra and $P$ is extended from $A$. (3) $2n\geq d+3$ and singular locus of $Spec(A)$ is a closed set $V(\mathcal J)$ with ht $\mathcal J\geq d-n+2$. Assume $Um(P_f)\neq \varnothing$ for some monic polynomial $f(T_r)\in A[T_1,\ldots,T_r]$. Then $Um(P)\neq \varnothing$.
description: 16 pages
Tabulation of knots up to five triple-crossings and moves between oriented diagrams
Creators: name: Jabłonowski, Michał
Publisher: name: arXiv
Year: 2021
Subjects: subject: Geometric Topology (math.GT)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: We enumerate and show tables of minimal diagrams for all prime knots up to the triple-crossing number equal to five. We derive a minimal generating set of oriented moves connecting triple-crossing diagrams of the same oriented knot. We also present a conjecture about a strict lower bound of the triple-crossing number of a knot related to the breadth of its Alexander polynomial.
description: 15 pages, many TikZ figures
Asymptotic Completeness in a Class of Massive Wedge-Local Quantum Field Theories in any Dimension
Creators: name: Duell, Maximilian
name: Dybalski, Wojciech
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: A recently developed n-particle scattering theory for wedge-local quantum field theories is applied to a class of models described and constructed by Grosse, Lechner, Buchholz, and Summers. In the BLS-deformation setting we establish explicit expressions for n-particle wave operators and the S-matrix of ordered asymptotic states, and we show that ordered asymptotic completeness is stable under the general BLS-deformation construction. In particular the (ordered) Grosse-Lechner S-matrices are non-trivial also beyond two-particle scattering and factorize into 2-particle scattering processes, which is an unusual feature in space-time dimension d > 1 + 1. Most notably, the Grosse-Lechner models provide the first examples of relativistic (wedge-local) QFT in space-time dimension d > 1 + 1 which are interacting and asymptotically complete.
description: 28 pages. Typos corrected and linguistic improvements
SAITS: Self-Attention-based Imputation for Time Series
Creators: name: Du, Wenjie
name: Cote, David
name: Liu, Yan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Missing data in time series is a pervasive problem that puts obstacles in the way of advanced analysis. A popular solution is imputation, where the fundamental challenge is to determine what values should be filled in. This paper proposes SAITS, a novel method based on the self-attention mechanism for missing value imputation in multivariate time series. Trained by a joint-optimization approach, SAITS learns missing values from a weighted combination of two diagonally-masked self-attention (DMSA) blocks. DMSA explicitly captures both the temporal dependencies and feature correlations between time steps, which improves imputation accuracy and training speed. Meanwhile, the weighted-combination design enables SAITS to dynamically assign weights to the learned representations from two DMSA blocks according to the attention map and the missingness information. Extensive experiments quantitatively and qualitatively demonstrate that SAITS outperforms the state-of-the-art methods on the time-series imputation task efficiently and reveal SAITS' potential to improve the learning performance of pattern recognition models on incomplete time-series data from the real world. The code is open source on GitHub at https://github.com/WenjieDu/SAITS.
description: This paper has been published in the journal Expert Systems with Applications. The DOI link is https://doi.org/10.1016/j.eswa.2023.119619/
CIRCE Code of conduct
Creators: name: Calamai, Silvia
Publisher: name: Zenodo
Year: 2023
Subjects: code of conduct
ethical principles
accent discrimination

description: Counteracting accent dIscrimination pRactiCes in Education (CIRCE) is an ERASMUS+ project co-funded by European Commission under the programme “Cooperation partnerships in school education” (KA220-SCH). The CIRCE Code of Conduct provides general ethical principles on how CIRCE Members should operate during fieldwork, meetings, publication, conferences, events, committee and other work, mentoring relationships, and in all online spaces including (but not limited to) CIRCE social media accounts and website.
description: Counteracting accent dIscrimination pRactiCes in Education (CIRCE) is an ERASMUS+ project co-funded by European Union under Grant Agreement no. 2022-1-IT02-KA220-SCH-000087602. Views and opinions expressed are however those of the authors only and do not necessarily reflect those of the European Union or the European Education and Culture Executive Agency (EACEA). Neither the European Union nor EACEA can be held responsible for them. Further information about the project is available at https://www.circe-project.eu/.
Tutorial: Topology, waves, and the refractive index
Creators: name: Horsley, S. A. R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: This tutorial is divided into two parts: the first examines the application of topology to problems in wave physics. The origins of the Chern number are reviewed, where it is shown that this counts the number of critical points of a complex tangent vector field on the surface. We then show that this quantity arises naturally when calculating the dispersion of modes in any linear system, and give examples of its application to find one--way propagating interface modes in both continuous and periodic materials. The second part offers a physical interpretation for the Chern number, based on the idea that the critical points which it records can be understood as points where the refractive index vanishes. Using the theory of crystal optics, we show that when the refractive index vanishes in a complex valued direction, the wave is forced to circulate in only one sense, and this is the origin of the one-way propagation of topological interface states. We conclude by demonstrating that this idea of `zero refractive index in a complex direction' can be used as a shortcut to find acoustic and electromagnetic materials supporting one-way interface states.
description: 82 pages, 20 figures
U-shape Transformer for Underwater Image Enhancement
Creators: name: Peng, Lintao
name: Zhu, Chunli
name: Bian, Liheng
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The light absorption and scattering of underwater impurities lead to poor underwater imaging quality. The existing data-driven based underwater image enhancement (UIE) techniques suffer from the lack of a large-scale dataset containing various underwater scenes and high-fidelity reference images. Besides, the inconsistent attenuation in different color channels and space areas is not fully considered for boosted enhancement. In this work, we constructed a large-scale underwater image (LSUI) dataset including 5004 image pairs, and reported an U-shape Transformer network where the transformer model is for the first time introduced to the UIE task. The U-shape Transformer is integrated with a channel-wise multi-scale feature fusion transformer (CMSFFT) module and a spatial-wise global feature modeling transformer (SGFMT) module, which reinforce the network's attention to the color channels and space areas with more serious attenuation. Meanwhile, in order to further improve the contrast and saturation, a novel loss function combining RGB, LAB and LCH color spaces is designed following the human vision principle. The extensive experiments on available datasets validate the state-of-the-art performance of the reported technique with more than 2dB superiority.
description: under review