cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The radio continuum spectrum of Mira A and Mira B up to submillimeter wavelengths
Creators: name: Planesas, Pere
name: Alcolea, Javier
name: Bachiller, Rafael
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present new measurements of the flux densities at submillimeter wavelengths based on ALMA band 7 (338 GHz) and band 9 (679 GHz) observations to better constrain the origin of the continuum emission of the Mira AB binary system and to check its orbit. We have measured the Mira A and Mira B continuum in ALMA band 7, with a resolution of ~0"31, and for the first time in ALMA band 9, with a resolution of ~0"18. We resolved the binary system at both bands, and derived the continuum spectral index of the stars and their relative position. We also analyzed ALMA SciVer data obtained in bands 6 and 3. Measurements at centimeter wavelengths obtained by other authors have been included in our study of the spectral energy distribution of the Mira components. The Mira A continuum emission has a spectral index of 1.98+-0.04 extending from submillimeter down to centimeter wavelengths. The spectral index of the Mira B continuum emission is 1.93+-0.06 at wavelengths ranging from submillimeter to ~3.1 mm, and a shallower spectral index of 1.22+-0.09 at longer wavelengths. The Mira A continuum emission up to submillimeter wavelengths is consistent with that of a radio photosphere surrounding the evolved star for which models predict a spectral index close to 2. The Mira B continuum emission cannot be described with a single ionized component. An extremely compact and dense region around the star can produce the nearly thermal continuum measured in the 0.4-3.1 mm wavelength range, and an inhomogeneous, less dense, and slightly larger ionized envelope could be responsible for the emission at longer wavelengths. Our results illustrate the potential of ALMA for high precision astrometry of binary systems. We have found a significant discrepancy of ~14 milliarcsec between the ALMA measurements and the predicted orbit positions.
description: 6 pages, 3 figures, 2 tables, accepted for publication in Astronomy and Astrophysics
Sample-efficient Reinforcement Learning Representation Learning with Curiosity Contrastive Forward Dynamics Model
Creators: name: Nguyen, Thanh
name: Luu, Tung M.
name: Vu, Thang
name: Yoo, Chang D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Developing an agent in reinforcement learning (RL) that is capable of performing complex control tasks directly from high-dimensional observation such as raw pixels is yet a challenge as efforts are made towards improving sample efficiency and generalization. This paper considers a learning framework for Curiosity Contrastive Forward Dynamics Model (CCFDM) in achieving a more sample-efficient RL based directly on raw pixels. CCFDM incorporates a forward dynamics model (FDM) and performs contrastive learning to train its deep convolutional neural network-based image encoder (IE) to extract conducive spatial and temporal information for achieving a more sample efficiency for RL. In addition, during training, CCFDM provides intrinsic rewards, produced based on FDM prediction error, encourages the curiosity of the RL agent to improve exploration. The diverge and less-repetitive observations provide by both our exploration strategy and data augmentation available in contrastive learning improve not only the sample efficiency but also the generalization. Performance of existing model-free RL methods such as Soft Actor-Critic built on top of CCFDM outperforms prior state-of-the-art pixel-based RL methods on the DeepMind Control Suite benchmark.
Peripherally automorphic unital completely positive maps
Creators: name: Bhat, B. V. Rajarama
name: Kar, Samir
name: Talwar, Bharat
Publisher: name: arXiv
Year: 2022
Subjects: subject: Operator Algebras (math.OA)
subject: Functional Analysis (math.FA)
subject: Quantum Physics (quant-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 37A55, 46L40, 47A10, 47L40

description: We identify and characterize unital completely positive (UCP) maps on finite dimensional $C^*$-algebras for which the Choi-Effros product extended to the space generated by peripheral eigenvectors matches with the original product. We analyze a decomposition of general UCP maps in finite dimensions into persistent and transient parts. It is shown that UCP maps on finite dimensional $C^*$-algebras with spectrum contained in the unit circle are $\ast$-automorphisms.
description: 16 pages
Lecture on Gauge Gravitation Theory. Gravity as a Higgs Field
Creators: name: Sardanashvily, G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Gravitation theory is formulated as gauge theory on natural bundles with spontaneous symmetry breaking where gauge symmetries are general covariant transformations, gauge fields are general linear connections, and Higgs fields are pseudo-Riemannian metrics.
description: 46 pages, Invited lecture at the 20th International Summer School on Global Analysis and its Applications. General Relativity: 100 years after Hilbert (Stara Lesna, Slovakia, 2015)
A study on Performance Boost of a 17~m class Cherenkov telescope with a SiPM-based camera
Creators: name: Arcaro, Cornelia
name: Doro, Michele
name: Sitarek, Julian
name: Baack, Dominik
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The current generation of Imaging Atmospheric Cherenkov Telescopes (IACTs), comprised of major installations such as the MAGIC telescopes, H.E.S.S. and VERITAS, is classified as the 3$^{\mathrm{rd}}$ generation of suchs instruments. These telescopes use multipixel cameras composed of thousands of photomultiplier tubes (PMTs). The total light throughput of such instruments depends, besides the PMT photon detection efficiency (PDE), on the mirror dish reflectivity, and the light absorption by the camera window. The supremacy of PMTs is currently being challenged by photon sensors rapidly spreading in popularity, the silicon photomultipliers (SiPMs), that are becoming a valid alternative thanks to their high PDE, low operating voltage and flexibility in installation. In this report, we investigate the performance of an existing 3$^{\mathrm{rd}}$-generation IACT array (taking as an example MAGIC) in which PMTs would be replaced with SiPMs, with minimal further hardware intervention. This would mean that other systems of the telescope responsible for the light collection, in particular the optics, would remain the same, and only the electronic to steer the different photodetectors would be modified. We find an increase of sensitivity up to a factor of 2 for energies below 200~GeV. Interestingly, we also find that the stronger sensitivity of SiPMs in the red part of the spectrum, a source of background for IACTs, does not affect this conclusion.
Quasi-Floquet prethermalization in a disordered dipolar spin ensemble in diamond
Creators: name: He, Guanghui
name: Ye, Bingtian
name: Gong, Ruotian
name: Liu, Zhongyuan
name: Murch, Kater W.
name: Yao, Norman Y.
name: Zu, Chong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Floquet (periodic) driving has recently emerged as a powerful technique for engineering quantum systems and realizing non-equilibrium phases of matter. A central challenge to stabilizing quantum phenomena in such systems is the need to prevent energy absorption from the driving field. Fortunately, when the frequency of the drive is significantly larger than the local energy scales of the many-body system, energy absorption is suppressed. The existence of this so-called prethermal regime depends sensitively on the range of interactions and the presence of multiple driving frequencies. Here, we report the observation of Floquet prethermalization in a strongly interacting dipolar spin ensemble in diamond, where the angular dependence of the dipolar coupling helps to mitigate the long-ranged nature of the interaction. Moreover, we extend our experimental observation to quasi-Floquet drives with multiple incommensurate frequencies. In contrast to a single-frequency drive, we find that the existence of prethermalization is extremely sensitive to the smoothness of the applied field. Our results open the door to stabilizing and characterizing non-equilibrium phenomena in quasi-periodically driven systems.
description: 7+13 pages, 3+8 figures
Trichopria crassifemur Nixon 1980
Creators: name: Notton, David G.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Mymaridae
Trichopria
Trichopria crassifemur

description: Trichopria crassifemur Nixon, 1980: 38, fig. 91.
Valid name
Trichopria crassifemur Nixon, 1980.
Summary of types
Holotype ♂, BMNH number 9.832, by original designation. Paratypes 18 ♂♂.
Primary type data
Surrey:/ Ashtead/ 10.viii.1930 / G.Nixon; Trichopria / crassifemur/ Nixon/ type ♂, 197.
Type locality
England, Surrey, Ashtead.
Remarks
The holotype is mounted on a card point and its right antenna is lost.
description: Published as part of Notton, David G., 2014, A catalogue of the types of Diapriinae (Hymenoptera, Diapriidae) at the Natural History Museum, London, pp. 1-123 in European Journal of Taxonomy 75 on pages 102-103, DOI: 10.5852/ejt.2014.75, http://zenodo.org/record/3862773
An Ultraviolet Spectrum of the Tidal Disruption Flare ASASSN-14li
Creators: name: Cenko, S. Bradley
name: Cucchiara, Antonino
name: Roth, Nathaniel
name: Veilleux, Sylvain
name: Prochaska, J. Xavier
name: Yan, Lin
name: Guillochon, James
name: Maksym, W. Peter
name: Arcavi, Iair
name: Butler, Nathaniel R.
name: Filippenko, Alexei V.
name: Fruchter, Andrew S.
name: Gezari, Suvi
name: Kasen, Daniel
name: Levan, Andrew J.
name: Miller, Jon M.
name: Pasham, Dheeraj R.
name: Ramirez-Ruiz, Enrico
name: Strubbe, Linda E.
name: Tanvir, Nial R.
name: Tombesi, Francesco
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a Hubble Space Telescope STIS spectrum of ASASSN-14li, the first rest-frame UV spectrum of a tidal disruption flare (TDF). The underlying continuum is well fit by a blackbody with $T_{\mathrm{UV}} = 3.5 \times 10^{4}$ K, an order of magnitude smaller than the temperature inferred from X-ray spectra (and significantly more precise than previous efforts based on optical and near-UV photometry). Super-imposed on this blue continuum, we detect three classes of features: narrow absorption from the Milky Way (probably a high-velocity cloud), and narrow absorption and broad (FWHM $\approx 2000$-8000 km s$^{-1}$) emission lines at/near the systemic host velocity. The absorption lines are blueshifted with respect to the emission lines by $Δv = -(250$-400) km s$^{-1}$. Due both to this velocity offset and the lack of common low-ionization features (Mg II, Fe II), we argue these arise from the same absorbing material responsible for the low-velocity outflow discovered at X-ray wavelengths. The broad nuclear emission lines display a remarkable abundance pattern: N III], N IV], He II are quite prominent, while the common quasar emission lines of C III] and Mg II are weak or entirely absent. Detailed modeling of this spectrum will help elucidate fundamental questions regarding the nature of the emission process(es) at work in TDFs, while future UV spectroscopy of ASASSN-14li would help to confirm (or refute) the previously proposed connection between TDFs and "N-rich" quasars.
description: Accepted for publication in ApJ Letters. 8 pages, 4 figures
Transient Stability of Hybrid Power Systems Dominated by Different Types of Grid-Forming Devices
Creators: name: He, Xiuqiang
name: Geng, Hua
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper investigates the transient stability of power systems co-dominated by different types of grid-forming (GFM) devices. Synchronous generators (SGs and VSGs) and droop-controlled inverters are typical GFM devices in modern power systems. SGs/VSGs are able to provide inertia while droop-controlled inverters are generally inertialess. The transient stability of power systems dominated by homogeneous GFM devices has been extensively studied. Regarding the hybrid system jointly dominated by heterogeneous GFM devices, the transient stability is rarely reported. This paper aims to fill this gap. It is found that the synchronization behavior of the hybrid system can be described by a second-order motion equation, resembling the swing equation of SGs. Moreover, two significant differences from conventional power systems are discovered. The first is that the droop control dramatically enhances the damping effect, greatly affecting the transient stability region. The second is that the frequency state variable exhibits a jump at the moment of fault disturbances, thus impacting the post-fault initial-state location and stability assessment. The underlying mechanism behind the two new characteristics is clarified and the impact on the transient stability performance is analyzed and verified. The findings provide new insights into transient stability of power systems hosting heterogeneous devices.
Efficiently Enabling Block Semantics and Data Updates in DNA Storage
Creators: name: Sharma, Puru
name: Lim, Cheng-Kai
name: Lin, Dehui
name: Pote, Yash
name: Jevdjic, Djordje
Publisher: name: arXiv
Year: 2022
Subjects: subject: Emerging Technologies (cs.ET)
subject: Databases (cs.DB)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: We propose a novel and flexible DNA-storage architecture, which divides the storage space into fixed-size units (blocks) that can be independently and efficiently accessed at random for both read and write operations, and further allows efficient sequential access to consecutive data blocks. In contrast to prior work, in our architecture a pair of random-access PCR primers of length 20 does not define a single object, but an independent storage partition, which is internally blocked and managed independently of other partitions. We expose the flexibility and constraints with which the internal address space of each partition can be managed, and incorporate them into our design to provide rich and functional storage semantics, such as block-storage organization, efficient implementation of data updates, and sequential access. To leverage the full power of the prefix-based nature of PCR addressing, we define a methodology for transforming the internal addressing scheme of a partition into an equivalent that is PCR-compatible. This allows us to run PCR with primers that can be variably elongated to include a desired part of the internal address, and thus narrow down the scope of the reaction to retrieve a specific block or a range of blocks within the partition with sufficiently high accuracy. Our wetlab evaluation demonstrates the practicality of the proposed ideas and a 140x reduction in sequencing cost and latency for retrieval of individual blocks within the partition.
Nonlinear surface waves on the plasma-vacuum interface
Creators: name: Secchi, Paolo
Publisher: name: arXiv
Year: 2015
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 76W05

description: In this paper we study the propagation of weakly nonlinear surface waves on a plasma-vacuum interface. In the plasma region we consider the equations of incompressible magnetohydrodynamics, while in vacuum the magnetic and electric fields are governed by the Maxwell equations. A surface wave propagate along the plasma-vacuum interface, when it is linearly weakly stable. Following the approach of Ali and Hunter, we measure the amplitude of the surface wave by the normalized displacement of the interface in a reference frame moving with the linearized phase velocity of the wave, and obtain that it satisfies an asymptotic nonlocal, Hamiltonian evolution equation. We show the local-in-time existence of smooth solutions to the Cauchy problem for the amplitude equation in noncanonical variables, and we derive a blow up criterion.
description: arXiv admin note: text overlap with arXiv:1305.5327 by other authors
Schubert Products for Permutations with Separated Descents
Creators: name: Huang, Daoji
Publisher: name: arXiv
Year: 2021
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: We say that two permutations $π$ and $ρ$ have separated descents at position $k$ if $π$ has no descents before position $k$ and $ρ$ has no descents after position $k$. We give a counting formula, in terms of reduced word tableaux, for computing the structure constants of products of Schubert polynomials indexed by permutations with separated descents, and recognize that these structure constants are certain Edelman-Greene coefficients. Our approach uses generalizations of Schützenberger's jeu de taquin algorithm and the Edelman-Greene correspondence via bumpless pipe dreams.
description: 26 pages with improved exposition. Viewing in color is recommended
Una generalización de los autómatas celulares
Creators: name: Castillo Ramírez, Alonso
Publisher: name: Zenodo
Year: 2023
Subjects: Autómatas celulares; función; homomorfismo de grupos; Teorema de Curtis-Hedlund; Teorema de composición; Teorema de invertibilidad

description: Resumen Sea G un grupo y A un conjunto con al menos dos elementos. Un autómata celular sobre AG [1] es una función τ : AG → AG definida a través de un conjunto memoria finito S ⊆ G y una función local µ : AS → A. En esta plática presentaremos una generalización de esta definición [2] la cual nos permite considerar ϕ-autómatas celulares τ : AG → AH, donde H es otro grupo arbitrario y ϕ : H → G es un homomorfismo de grupos. La definición clásica de autómata celular se recupera tomando G = H y ϕ = id. Además, esta definición nos permite demostrar análogos a tres teoremas importantes de la teoría de los autómatas celulares clásicos: 1. Teorema de Curtis-Hedlund generalizado: Una función τ : AG → AH es un ϕ-autómata celular si y solo si τ es continua en las topologías prodiscretas y ϕ-equivariante (i.e. h · τ (x) = τ (ϕ(h) · x) para toda x ∈ AG, h ∈ H). 2. Teorema de composición: Consideremos un ψ-autómata celular σ : AH → AK con conjunto memoria S y un ϕ-autómata celular τ : AG → AH con conjunto memoria T. La composición σ ◦ τ : AG → AK es un (ϕ ◦ ψ)-autómata celular con conjunto memoria ϕ(S)T. 3. Teorema de invertibilidad: Un ϕ-autómata celular τ : AG → AH es invertible (en el sentido de que existe un homomorfismo de grupos ψ : G → H y un ψ-autómata celular σ : AH → AG tal que τ ◦ σ = idAH y σ ◦ τ = idAG ) si y sólo si τ es biyectivo.
description: {"references": ["Ceccherini-Silberstein, T., Coornaert, M.: Cellular Automata and Groups. Springer Monographs in Mathematics, Springer-Verlag Berlin Heidelberg, 2010.", "Castillo-Ramirez, A., Sanchez-Alvarez, M., Vazquez-Aceves, A., Zaldivar-Corichi, A.: A generalization of cellular automata over groups, Communications in Algebra 51.7 (2023) 3114- 3123. https://doi.org/10.1080/00927872.2023.2177663"]}
title: Применение метода пространства состояний для обобщенной системы типа «один вход – один выход»
title: Application of the State Space Method for a Generalized Single Input Single Output System
Creators: name: Музылева, Инна Васильевна
name: Языкова, Любовь Николаевна
name: Мещеряков, Виктор Николаевич
Publisher: name: Издательский центр СурГУ
Year: 2022

description: Объектом исследования являются аналитические и топологические методы расчета систем автоматического управления. Целью работы является построение практико-ориентированного способа применения метода пространства состояний раздела неметрической математики для исследования систем типа «один вход – один выход». Исследована обобщенная система n-го порядка
в виде «вход – выход», разработана структурная схема ее моделирования согласно методу пространства состояний, апробированная на примере системы второго порядка с проверкой методом контрольного моделирования. Исследуемая система n-го порядка преобразована к виду «вход – внутреннее состояние – выход», разработана структурная схема ее моделирования по методу пространства состояний
в различных системах визуальной симуляции, апробированная на примере системы третьего порядка
с проверкой методом контрольного моделирования. Критерием правильности является тождественность графиков выходных сигналов исследуемой системы, полученных методом пространства состояний, методом структурного моделирования и заданием передаточной функции. Разработанный универсальный математический инструментарий позволяет проводить исследование систем типа «один
вход – один выход» любой степени сложности.
description: The object of the study is analytical and topological methods for automatic control systems
engineering. The aim of the study is to build a practice-oriented approach for applying the state space method,
which is part of nonmetric mathematics, to analyze the single input single output systems. A generalized n
th
-
order input output system is investigated. A structural scheme for such system modeling is developed according to the state space method. The scheme was tested on the example of the second order system using verification of the control modeling method. The n
th
-order system is transformed into “input ‒ internal state ‒ output”
type. The structural scheme of its modeling is developed according to the state space method in various visual  simulation systems and tested on the example of the third order system using verification of the control modeling method. The criterion of correctness is equality of graphs of output signals of the system analyzed, which
were obtained by the state space method, the structural modeling method and the assignment of the transfer
function. The developed universal mathematical tools make it possible to study single input single output systems of any complexity.
Dynamical scaling of Loschmidt echo in non-Hermitian systems
Creators: name: Tang, Jia-Chen
name: Kou, Su-Peng
name: Sun, Gaoyong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show that non-Hermitian biorthogonal many-body phase transitions can be characterized by the enhanced decay of Loschmidt echo. The quantum criticality is numerically investigated in a non-Hermitian transverse field Ising model by performing the finite-size dynamical scaling of Loschmidt echo. We determine the equilibrium correlation length critical exponents that are consistent with previous results from the exact diagonalization. More importantly, we introduce a simple method to detect quantum phase transitions with the short-time average of rate function motivated by the critically enhanced decay behavior of Loschmidt echo. Our studies show how to detect equilibrium many-body phase transitions with biorthogonal Loschmidt echo that can be observed in future experiments via quantum dynamics after a quench.
description: 6 pages, 3 figures
SU Lyncis, a hard X-ray bright M giant: Clues point to a large hidden population of symbiotic stars
Creators: name: Mukai, K.
name: Luna, G. J. M.
name: Cusumano, G.
name: Segreto, A.
name: Munari, U.
name: Sokoloski, J. L.
name: Lucy, A. B.
name: Nelson, T.
name: Nunez, N. E.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Symbiotic star surveys have traditionally relied almost exclusively on low resolution optical spectroscopy. However, we can obtain a more reliable estimate of their total Galactic population by using all available signatures of the symbiotic phenomenon. Here we report the discovery of a hard X-ray source, 4PBC J0642.9+5528, in the Swift hard X-ray all-sky survey, and identify it with a poorly studied red giant, SU Lyn, using pointed Swift observations and ground-based optical spectroscopy. The X-ray spectrum, the optical to UV spectrum, and the rapid UV variability of SU Lyn are all consistent with our interpretation that it is a symbiotic star containing an accreting white dwarf. The symbiotic nature of SU Lyn went unnoticed until now, because it does not exhibit emission lines strong enough to be obvious in low resolution spectra. We argue that symbiotic stars without shell-burning have weak emission lines, and that the current lists of symbiotic stars are biased in favor of shell-burning systems. We conclude that the true population of symbiotic stars has been underestimated, potentially by a large factor.
description: Accepted for publication in MNRAS Letters; 6 pages (in arXiv version, 5 with proper fonts) including 5 figures and 2 tables
Additional file 8 of Healthcare use attributable to COVID-19: a propensity-matched national electronic health records cohort study of 249,390 people in Wales, UK
Creators: name: Kennedy, J
name: Parker, M
name: Seaborne, M
name: Mhereeg, M
name: Walker, A
name: Walker, V
name: Denaxas, S
name: Kennedy, N
name: Katikireddi, S. V
name: Brophy, S
Publisher: name: figshare
Year: 2023
Subjects: subject: Medicine
subject: Neuroscience
subject: Sociology
subject: FOS: Sociology
subject: Immunology
subject: FOS: Clinical medicine

description: Additional file 8: Table S5. Underlying life table data for death outcome only.
Numerical simulations of the random angular momentum in convection II: delayed explosions of red supergiants following "failed'' supernovae
Creators: name: Antoni, Andrea
name: Quataert, Eliot
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: When collapse of the iron core in a massive red or yellow supergiant does not lead to an energetic supernova, a significant fraction of the convective hydrogen envelope will fall in towards the black hole formed from the collapsing core. The random velocity field in the convective envelope results in finite specific angular momentum in each infalling shell. Using 3D hydrodynamical simulations, we follow the infall of this material to small radii, resolving the circularization radii of the flow. We show that infall of the convective envelope leads to nearly complete envelope ejection in a $\gtrsim$ 10$^{48}$ erg explosion with outflow speeds of $\gtrsim$ 200 km/s. The light curve of such an explosion would show a characteristic, red plateau as the ejecta cools and a hydrogen recombination front recedes through the expanding ejecta. Adopting supernova IIp scalings, the event would have a plateau luminosity of $\gtrsim$ 10$^{40}$ erg/s and a duration of several hundreds of days. These events would appear quite similar to luminous red novae with red or yellow supergiant progenitors; some luminous red novae may, in fact, be signposts of black hole formation. The mechanism studied here produces more energetic explosions than the weak shock generated from the radiation of neutrino energy during the proto-neutron star phase. Because we cannot simulate all the way to the horizon, our results are likely lower limits on the energy and luminosity of transients produced during the collapse of a red or yellow supergiant to form a black hole.
description: MNRAS published version. Minor updates (a few references added)
Comparing real-time coupled cluster methods through simulation of collective Rabi oscillations
Creators: name: Skeidsvoll, Andreas S.
name: Koch, Henrik
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The time-dependent equation-of-motion coupled cluster (TD-EOM-CC) and time-dependent coupled cluster (TDCC) methods are compared by simulating Rabi oscillations for different numbers of non-interacting atoms in a classical electromagnetic field. While the TD-EOM-CC simulations are numerically stable, the oscillating time-dependent energy scales unreasonably with the number of subsystems resonant with the field. The TDCC simulations give the correct scaling of the time-dependent energy in the initial stages of the Rabi cycle, but the numerical solution breaks down when the multi-atom system approaches complete population inversion. We present a general theoretical framework in which the two methods can be described, where the cluster amplitude time derivatives are taken as auxiliary conditions, leading to a shifted time-dependent Hamiltonian matrix. In this framework, TDCC has a shifted Hamiltonian with a block upper triangular structure, explaining the correct scaling properties of the method.
description: 9 pages and 4 figures
A Polynomial-time, Truthful, Individually Rational and Budget Balanced Ridesharing Mechanism
Creators: name: Iwase, Tatsuya
name: Stein, Sebastian
name: Gerding, Enrico H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: FOS: Computer and information sciences

description: Ridesharing has great potential to improve transportation efficiency while reducing congestion and pollution. To realize this potential, mechanisms are needed that allocate vehicles optimally and provide the right incentives to riders. However, many existing approaches consider restricted settings (e.g., only one rider per vehicle or a common origin for all riders). Moreover, naive applications of standard approaches, such as the Vickrey-Clarke-Groves or greedy mechanisms, cannot achieve a polynomial-time, truthful, individually rational and budget balanced mechanism. To address this, we formulate a general ridesharing problem and apply mechanism design to develop a novel mechanism which satisfies all four properties and whose social cost is within 8.6% of the optimal on average.
Nonclassical light from a large number of independent single-photon emitters
Creators: name: Lachman, Lukáš
name: Slodička, Lukáš
name: Filip, Radim
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Nonclassical quantum effects gradually reach domains of physics of large systems previously considered as purely classical. We derive a hierarchy of operational criteria suitable for a reliable detection of nonclassicality of light from an arbitrarily large ensemble of independent single-photon emitters. We show, that such large ensemble can always emit nonclassical light without any phase reference and under realistic experimental conditions including incoherent background noise. The nonclassical light from the large ensemble of the emitters can be witnessed much better than light coming from a single or a few emitters.
description: 7 pages, 3 figures
Singmaster's conjecture in the interior of Pascal's triangle
Creators: name: Matomäki, Kaisa
name: Radziwiłł, Maksym
name: Shao, Xuancheng
name: Tao, Terence
name: Teräväinen, Joni
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: Singmaster's conjecture asserts that every natural number greater than one occurs at most a bounded number of times in Pascal's triangle; that is, for any natural number $t \geq 2$, the number of solutions to the equation $\binom{n}{m} = t$ for natural numbers $1 \leq m < n$ is bounded. In this paper we establish this result in the interior region $\exp(\log^{2/3+\varepsilon} n) \leq m \leq n-\exp(\log^{2/3 + \varepsilon} n)$ for any fixed $\varepsilon > 0$. Indeed, when $t$ is sufficiently large depending on $\varepsilon$, we show that there are at most four solutions (or at most two in either half of Pascal's triangle) in this region. We also establish analogous results for the equation $(n)_m = t$, where $(n)_m := n(n-1)\ldots(n-m+1)$ denotes the falling factorial.
description: 33 pages
Quantum Computing Techniques for Multi-Knapsack Problems
Creators: name: Awasthi, Abhishek
name: Bär, Francesco
name: Doetsch, Joseph
name: Ehm, Hans
name: Erdmann, Marvin
name: Hess, Maximilian
name: Klepsch, Johannes
name: Limacher, Peter A.
name: Luckow, Andre
name: Niedermeier, Christoph
name: Palackal, Lilly
name: Pfeiffer, Ruben
name: Ross, Philipp
name: Safi, Hila
name: Schönmeier-Kromer, Janik
name: von Sicard, Oliver
name: Wenger, Yannick
name: Wintersperger, Karen
name: Yarkoni, Sheir
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Optimization problems are ubiquitous in various industrial settings, and multi-knapsack optimization is one recurrent task faced daily by several industries. The advent of quantum computing has opened a new paradigm for computationally intensive tasks, with promises of delivering better and faster solutions for specific classes of problems. This work presents a comprehensive study of quantum computing approaches for multi-knapsack problems, by investigating some of the most prominent and state-of-the-art quantum algorithms using different quantum software and hardware tools. The performance of the quantum approaches is compared for varying hyperparameters. We consider several gate-based quantum algorithms, such as QAOA and VQE, as well as quantum annealing, and present an exhaustive study of the solutions and the estimation of runtimes. Additionally, we analyze the impact of warm-starting QAOA to understand the reasons for the better performance of this approach. We discuss the implications of our results in view of utilizing quantum optimization for industrial applications in the future. In addition to the high demand for better quantum hardware, our results also emphasize the necessity of more and better quantum optimization algorithms, especially for multi-knapsack problems.
description: 20 pages
Quantum Hall effect and Landau levels without spatial long-range correlations
Creators: name: Sahlberg, Isac
name: Ivaki, Moein N.
name: Pöyhönen, Kim
name: Ojanen, Teemu
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The spectrum of charged particles in translation-invariant systems in a magnetic field is characterized by the Landau levels, which play a fundamental role in the thermodynamic and transport properties of solids. The topological nature and the approximate degeneracy of the Landau levels are known to also survive on crystalline lattices with discrete translation symmetry when the magnetic flux through a primitive cell is small compared to the flux quantum. Here we show that the notion of Landau levels and the quantum Hall effect can be generalized to 2d non-crystalline lattices without spatial long-range order. Remarkably, even when the spatial correlations decay over microscopic distances, 2d systems can exhibit a number of well-resolved Landau-like bands. The existence of these bands imply that non-crystalline systems in magnetic fields can support the hallmark quantum effects which have been typically associated with crystalline solids.
description: 5 pages + 2.5-page appendix, 4+1 figures
Towards Robust Metrics for Concept Representation Evaluation
Creators: name: Zarlenga, Mateo Espinosa
name: Barbiero, Pietro
name: Shams, Zohreh
name: Kazhdan, Dmitry
name: Bhatt, Umang
name: Weller, Adrian
name: Jamnik, Mateja
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: I.2.6
subject: 68T07

description: Recent work on interpretability has focused on concept-based explanations, where deep learning models are explained in terms of high-level units of information, referred to as concepts. Concept learning models, however, have been shown to be prone to encoding impurities in their representations, failing to fully capture meaningful features of their inputs. While concept learning lacks metrics to measure such phenomena, the field of disentanglement learning has explored the related notion of underlying factors of variation in the data, with plenty of metrics to measure the purity of such factors. In this paper, we show that such metrics are not appropriate for concept learning and propose novel metrics for evaluating the purity of concept representations in both approaches. We show the advantage of these metrics over existing ones and demonstrate their utility in evaluating the robustness of concept representations and interventions performed on them. In addition, we show their utility for benchmarking state-of-the-art methods from both families and find that, contrary to common assumptions, supervision alone may not be sufficient for pure concept representations.
description: To appear at AAAI 2023
Constructing electrically charged Riemannian manifolds with minimal boundary, prescribed asymptotics, and controlled mass
Creators: name: Pacheco, Armando J. Cabrera
name: Cederbaum, Carla
name: Gehring, Penelope
name: Diaz, Alejandro Peñuela
Publisher: name: arXiv
Year: 2021
Subjects: subject: Differential Geometry (math.DG)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In 2015, Mantoulidis and Schoen constructed $3$-dimensional asymptotically Euclidean manifolds with non-negative scalar curvature whose ADM mass can be made arbitrarily close to the optimal value of the Riemannian Penrose Inequality, while the intrinsic geometry of the outermost minimal surface can be ``far away'' from being round. The resulting manifolds, called extensions, are geometrically not ``close'' to a spatial Schwarzschild manifold. This suggests instability of the Riemannian Penrose Inequality. Their construction was later adapted to $n+1$ dimensions by Cabrera Pacheco and Miao. In recent papers by Alaee, Cabrera Pacheco, and Cederbaum and by Cabrera Pacheco, Cederbaum, and McCormick, a similar construction was performed for asymptotically Euclidean electrically charged Riemannian manifolds and for asymptotically hyperbolic Riemannian manifolds, respectively, obtaining $3$-dimensional extensions. This paper combines and generalizes all the aforementioned results by constructing suitable asymptotically hyperbolic or asymptotically Euclidean extensions with electric charge in $n+1$ dimensions for $n\geq2$. We study in detail the sub-extremality of these manifolds, consider the so far unstudied case of extremality in extensions with electric charge and allow more general conditions for the metric of our extensions. Besides suggesting instability of a naturally conjecturally generalized Riemannian Penrose Inequality, the constructed extensions give insights into an ad hoc generalized notion of Bartnik mass, similar to the Bartnik mass estimate for minimal surfaces proven by Mantoulidis and Schoen via their extensions, and unifying the Bartnik mass estimates in the various scenarios mentioned above.
Time-of-flight spectroscopy of ultracold neutrons at the PSI UCN source
Creators: name: Bison, G.
name: Chen, W.
name: Chiu, P. -J.
name: Daum, M.
name: Doorenbos, C. B.
name: Kirch, K.
name: Kletzl, V.
name: Lauss, B.
name: Pais, D.
name: Rienäcker, I.
name: Schmidt-Wellenburg, P.
name: Zsigmond, G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The ultracold neutron (UCN) source at the Paul Scherrer Institute (PSI) provides high intensities of storable neutrons for fundamental physics experiments. The neutron velocity spectrum parallel to the beamline axis was determined by time-of-flight spectroscopy using a neutron chopper. In particular, the temporal evolution of the spectrum during neutron production and UCN storage in the source storage volume was investigated and compared to Monte Carlo simulation results. A softening of the measured spectrum from a mean velocity of 7.7(1) m s$^{-1}$ to 5.1(1) m s$^{-1}$ occurred within the first 30 s after the proton beam pulse had impinged on the spallation target. A spectral hardening was observed over longer time scales of one measurement day, consistent with the effect of surface degradation of the solid deuterium moderator.
Leading Edge Vortex Dynamics of Airfoils, Pitching Continuously at High Amplitudes
Creators: name: Aravind, Akhil
name: Seshadri, Pradeep Kumar
name: De, Ashoke
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Airfoils pitching in the stalled regime have been of keen interest in recent years due to their desirable aerodynamic force characteristics. In this study, we are numerically investigating the unsteady flow past a NACA 0012 airfoil under sinusoidally pitching motion, using a finite volume based sharp interface immersed boundary solver. The flow is investigated in the low Reynolds number regime (Re=3000) for reduced frequencies of 0.1 and 0.5, at three different pivot locations (c/3, c/2 and 2c/3 from the leading edge). The airfoil is subjected to sinusoidal oscillations with its incidence angle varying from 15o to 45o. Leading edge vortices (LEVs) that are formed during the pitching motion dictate the transient aerodynamic characteristics. The flow field data is used to identify individual LEVs in the flow field. The spatio-temporal evolution of LEVs in terms of their strengths are traced throughout the pitching cycle to obtain a quantitative estimate of its evolution. The effect of pivot location and pitching frequency on the vortex evolution and aerodynamic forces is investigated. Change in pitching frequency is found to have a drastic effect on the vortex dynamics. LEV formation is delayed to higher fractional times and LEVs are found to interact and merge into each other at higher frequencies. The maximum lift and drag are also found to increase with pitching frequency. Pivot location is found to have a higher influence on the magnitude and phase of aerodynamic coefficients at higher frequencies. However, at both frequencies, moving the pivot axis aftward is found to delay LEV evolution and cause a phase lag on the aerodynamic forces.
Understanding the Loss in Community Resilience due to Hurricanes using Facebook Data
Creators: name: Jamal, Tasnuba Binte
name: Hasan, Samiul
Publisher: name: arXiv
Year: 2023
Subjects: subject: Social and Information Networks (cs.SI)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Significant negative impacts are observed in productivity, economy, and social wellbeing because of the reduced human activity due to extreme events. Community resilience is an important and widely used concept to understand the impacts of an extreme event to population activity. Resilience is generally defined as the ability of a system to manage shocks and return to a steady state in response to an extreme event. In this study, aggregate location data from Facebook in response to Hurricane Ida are analyzed. Using changes in the number of Facebook users before, during, and after the disaster, community resilience is quantified as a function of the magnitude of impact and the time to recover from the extreme situation. Based on the resilience function, the transient loss of resilience in population activity is measured for the affected communities in Louisiana. The loss in resilience of the affected communities are explained by three types of factors, including disruption in physical infrastructures, disaster conditions due to hurricanes, and socio-economic characteristics. A greater loss in community resilience is associated with factors such as disruptions in power and transportation services and disaster conditions. Socioeconomic disparities in loss of resilience are found with respect to median income of a community. Understanding community resilience using decreased population activity levels due to a disaster and the factors associated with losses in resilience will enable us improve hazard preparedness, enhance disaster management practices, and create better recovery policies towards strengthening infrastructure and community resilience.
Impact of vorticity and viscosity on the hydrodynamic evolution of hot QCD medium
Creators: name: Sahoo, Bhagyarathi
name: Singh, Captain R.
name: Sahu, Dushmanta
name: Sahoo, Raghunath
name: Alam, Jan-e
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The strongly interacting transient state of quark-gluon plasma (QGP) medium created in ultra-relativistic collisions survives for a duration of a few fm/c. The spacetime evolution of QGP crucially depends on the equation of state (EoS), vorticity, viscosity, and external magnetic field. In the present study, we obtain the lifetime of a vortical QGP fluid within the ambit of relativistic second-order viscous hydrodynamics. We observe that the coupling of vorticity and viscosity significantly increases the lifetime of vortical QGP. The inclusion of a static magnetic field, vorticity, and viscosity makes the evolution slower. However, the static magnetic field slightly decreases the QGP lifetime by accelerating the evolution process for a non-rotating medium. We also report the rate of change of vorticity in the QGP, which will be helpful in studying the behavior of the medium in detail.
description: Same as the EPJC published version
Additional file 1 of Cost-effectiveness of prehabilitation prior to elective surgery: a systematic review of economic evaluations
Creators: name: Rombey, Tanja
name: Eckhardt, Helene
name: Kiselev, Jörn
name: Silzle, Julia
name: Mathes, Tim
name: Quentin, Wilm
Publisher: name: figshare
Year: 2023
Subjects: subject: Medicine
subject: Pharmacology
subject: Sociology
subject: FOS: Sociology
classificationCode: 69999
subject: Biological Sciences not elsewhere classified
subject: Science Policy

description: Additional file 1: App1. Important changes made to the protocol. App2. Search strategies. App3. Data items. App4. List of excluded studies. App5. Characteristics of ongoing economic evaluations. App6. Funding and competing interest of included economic evaluations. App7. Methods of completed economic evaluations. App8. Methods of ongoing economic evaluations with a published protocol. App9. Description of prehabilitation programmes in ongoing studies. App10. Risk of bias and methodological quality of included economic evaluations. App11. Detailed costs results of included economic evaluations. App12. Results of adherence and safety outcomes. App13. Results of descriptive post-hoc subgroup analyses to explore heterogeneity in cost-effectiveness results.