cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Classification of finite dimensional nilpotent Lie superalgebras by their multiplier
Creators: name: Nayak, Saudamini
Publisher: name: arXiv
Year: 2018
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 17B30, 17B05

description: Let $L$ be a nilpotent Lie superalgebra of dimension $(m\mid n)$ and $s(L) = \frac{1}{2}[(m + n - 1)(m + n -2)]+ n+ 1 - \dim \mathcal{M}(L)$, where $\mathcal{M}(L)$ denotes the Schur multiplier of $L$. Here $s(L)\geq 0$ and the structure of all non-abelian nilpotent Lie superalgebras with $s(L)=0$ is known((\cite{Nayak2019}). This paper is devoted to obtain all nilpotent Lie superalgebras when $s(L) \leq 2$. Further, we apply those results to list all non-abelian nilpotent Lie superalgebras $L$ with $ t(L) \leq 4$.
description: 19 pages
Strong Equivalence and Program Structure in Arguing Essential Equivalence between Logic Programs
Creators: name: Lierler, Yuliya
Publisher: name: arXiv
Year: 2019
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: Answer set programming is a prominent declarative programming paradigm used in formulating combinatorial search problems and implementing different knowledge representation formalisms. Frequently, several related and yet substantially different answer set programs exist for a given problem. Sometimes these encodings may display significantly different performance. Uncovering precise formal links between these programs is often important and yet far from trivial. This paper presents formal results carefully relating a number of interesting program rewritings. It also provides the proof of correctness of system Projector concerned with automatic program rewritings for the sake of efficiency. Under consideration in Theory and Practice of Logic Programming (TPLP).
description: Under consideration in Theory and Practice of Logic Programming (TPLP)
On Mertens-Cesàro Theorem for Number Fields
Creators: name: Ferraguti, Andrea
name: Micheli, Giacomo
Publisher: name: arXiv
Year: 2014
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11R04, 11R45

description: Let $K$ be a number field with ring of integers $\mathcal O$. After introducing a suitable notion of density for subsets of $\mathcal O$, generalizing that of natural density for subsets of $\mathbb Z$, we show that the density of the set of coprime $m$-tuples of algebraic integers is ${1/ζ_K(m)}$, where $ζ_K$ is the Dedekind zeta function of $K$.
description: To appear in the Bulletin of the Australian Mathematical Society
Joint Audio/Text Training for Transformer Rescorer of Streaming Speech Recognition
Creators: name: Kim, Suyoun
name: Li, Ke
name: Kabela, Lucas
name: Huang, Rongqing
name: Zhu, Jiedan
name: Kalinli, Ozlem
name: Le, Duc
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: Sound (cs.SD)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Recently, there has been an increasing interest in two-pass streaming end-to-end speech recognition (ASR) that incorporates a 2nd-pass rescoring model on top of the conventional 1st-pass streaming ASR model to improve recognition accuracy while keeping latency low. One of the latest 2nd-pass rescoring model, Transformer Rescorer, takes the n-best initial outputs and audio embeddings from the 1st-pass model, and then choose the best output by re-scoring the n-best initial outputs. However, training this Transformer Rescorer requires expensive paired audio-text training data because the model uses audio embeddings as input. In this work, we present our Joint Audio/Text training method for Transformer Rescorer, to leverage unpaired text-only data which is relatively cheaper than paired audio-text data. We evaluate Transformer Rescorer with our Joint Audio/Text training on Librispeech dataset as well as our large-scale in-house dataset and show that our training method can improve word error rate (WER) significantly compared to standard Transformer Rescorer without requiring any extra model parameters or latency.
Pre-trained Speech Representations as Feature Extractors for Speech Quality Assessment in Online Conferencing Applications
Creators: name: Tamm, Bastiaan
name: Balabin, Helena
name: Vandenberghe, Rik
name: Van hamme, Hugo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: Sound (cs.SD)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Speech quality in online conferencing applications is typically assessed through human judgements in the form of the mean opinion score (MOS) metric. Since such a labor-intensive approach is not feasible for large-scale speech quality assessments in most settings, the focus has shifted towards automated MOS prediction through end-to-end training of deep neural networks (DNN). Instead of training a network from scratch, we propose to leverage the speech representations from the pre-trained wav2vec-based XLS-R model. However, the number of parameters of such a model exceeds task-specific DNNs by several orders of magnitude, which poses a challenge for resulting fine-tuning procedures on smaller datasets. Therefore, we opt to use pre-trained speech representations from XLS-R in a feature extraction rather than a fine-tuning setting, thereby significantly reducing the number of trainable model parameters. We compare our proposed XLS-R-based feature extractor to a Mel-frequency cepstral coefficient (MFCC)-based one, and experiment with various combinations of bidirectional long short term memory (Bi-LSTM) and attention pooling feedforward (AttPoolFF) networks trained on the output of the feature extractors. We demonstrate the increased performance of pre-trained XLS-R embeddings in terms a reduced root mean squared error (RMSE) on the ConferencingSpeech 2022 MOS prediction task.
description: 5 pages, submitted to INTERSPEECH 2022
ALMACAL VIII: A pilot survey for untargeted extragalactic CO emission lines in deep ALMA calibration data
Creators: name: Hamanowicz, Aleksandra
name: Zwaan, Martin A.
name: Péroux, Céline
name: Lagos, Claudia del P.
name: Klitsch, Anne
name: Ivison, Rob J.
name: Biggs, Andrew D.
name: Szakacs, Roland
name: Fresco, Alejandra
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a pilot, untargeted extragalactic carbon monoxide (CO) emission-line survey using ALMACAL, a project utilizing ALMA calibration data for scientific purposes. In 33 deep (Texp > 40 min) ALMACAL fields we report six CO emission-line detections above S/N > 4, one-third confirmed by MUSE observations. With this pilot survey, we probe a cosmologically significant volume of ~10^5 cMpc^3, widely distributed over many pointings in the southern sky, making the survey largely insusceptible to the effects of cosmic variance. We derive the redshift probability of the CO detections using probability functions from the Shark semi-analytical model of galaxy formation. By assuming typical CO excitations for the detections, we put constraints on the cosmic molecular gas mass density evolution over the redshift range 0 < z < 1.5. The results of our pilot survey are consistent with the findings of other untargeted emission-line surveys and the theoretical model predictions and currently cannot rule out a non-evolving molecular gas mass density. Our study demonstrates the potential of using ALMA calibrator fields as a multi-sightline untargeted CO emission line survey. Applying this approach to the full ALMACAL database will provide an accurate, free of cosmic variance, measurement of the molecular luminosity function as a function of redshift.
Body mapping of skin friction coefficient and tactile perception during the dynamic skin-textile interaction
Creators: name: Temel, Mevra
name: Johnson, Andrew A.
name: Lloyd, Alex B.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Physiology
subject: FOS: Biological sciences
subject: Environmental Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Science Policy
subject: Mental Health

description: The clothing fabric and skin interact continuously across the many regions of users′ bodies during wear, which can lead to both physical skin damage and discomfort. Therefore, this investigation aimed to explore the regional differences in skin friction, tactile perception, and sensitivity in both females and males during the skin-textile interaction. The static and dynamic friction coefficient and textile perception (texture, stickiness, pleasantness, and discomfort) were measured across the 36 selected testing body areas by using a friction measurement device. The results revealed there was a significant difference in skin friction, tactile perceptions, and sensitivity across the various body regions. The anterior neck had the highest skin friction in both females and males, and participants generally rated higher texture perception in their anterior aspects compared to posterior and lateral regions. There was no significant difference in skin friction, tactile perception ratings, and sensitivity between females and males. Practitioner summary: This study sought to examine regional variations in skin friction, tactile perception, and sensitivity during the skin-textile interaction. There was a significant difference in skin friction, tactile perceptions, and sensitivity across the various body regions and no significant sex effect on skin friction, tactile perception ratings, and sensitivity.
Symplectic Banach-Mazur distances between subsets of C^n
Creators: name: Usher, Michael
Publisher: name: arXiv
Year: 2018
Subjects: subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics

description: Following proposals of Ostrover and Polterovich, we introduce and study "coarse" and "fine" versions of a symplectic Banach-Mazur distance on certain open subsets of $\mathbb{C}^n$ and other open Liouville domains. The coarse version declares two such domains to be close to each other if each domain admits a Liouville embedding into a slight dilate of the other; the fine version, which is similar to the distance on subsets of cotangent bundles of surfaces recently studied by Stojisavljević and Zhang, imposes an additional requirement on the images of these embeddings that is motivated by the definition of the classical Banach-Mazur distance on convex bodies. Our first main result is that the coarse and fine distances are quite different from each other, in that there are sequences that converge coarsely to an ellipsoid but diverge to infinity with respect to the fine distance. Our other main result is that, with respect to the fine distance, the space of star-shaped domains in $\mathbb{C}^n$ admits quasi-isometric embeddings of $\mathbb{R}^D$ for every finite dimension $D$. Our constructions are obtained from a general method of constructing $(2n+2)$-dimensional Liouville domains whose boundaries have Reeb dynamics determined by certain autonomous Hamiltonian flows on a given $2n$-dimensional Liouville domain. The bounds underlying our main results are proven using filtered equivariant symplectic homology via methods from prior joint work with Gutt.
description: v2: 56 pages, several corrections and additional explanations based on referee's comments. To appear in J. Top. Anal
Bi_2C_sim.R
Creators: name: Jing, Han
Publisher: name: figshare
Year: 2020
Subjects: subject: 60102 Bioinformatics
subject: FOS: Computer and information sciences

description: A R-script to implement CellDMC and TCA on Bi-2C simuation model.A Rd data object containing the real cell type fraction matrix from Hannum et al.A rda data objuect containing the normalized DNA methylation data for 6 pure major immune cell subtypes from Reinius et al, which was used in the simulation model.
A Measure of Non-Markovianity for Unital Quantum Dynamical Maps
Creators: name: Haseli, S.
name: Salimi, S.
name: Khorashad, A. S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: One of the most important topics in the study of the dynamics of open quantum system is information exchange between system and environment. Based on the features of a back-flow information from an environment to a system, an approach is provided to detect non-Markovianity for unital dynamical maps. The method takes advantage of non-contractive property of the von Neumann entropy under completely positive and trace preserving unital maps. Accordingly, for the dynamics of a single qubit as an open quantum system, the sign of the time-derivative of the density matrix eigenvalues of the system determines the non-Markovianity of unital quantum dynamical maps. The main characteristics of the measure is to make the corresponding calculations and optimization procedure simpler.
description: 7 pages, 4 figures. Add new comments and new co-author
Gravitational Waves Induced by Scalar Perturbations during a Gradual Transition from an Early Matter Era to the Radiation Era
Creators: name: Inomata, Keisuke
name: Kohri, Kazunori
name: Nakama, Tomohiro
name: Terada, Takahiro
Publisher: name: arXiv
Year: 2019
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We revisit the effects of an early matter-dominated era on gravitational waves induced by scalar perturbations. We carefully take into account the evolution of the gravitational potential, the source of these induced gravitational waves, during a gradual transition from an early matter-dominated era to the radiation-dominated era, where the transition timescale is comparable to the Hubble time at that time. Realizations of such a gradual transition include the standard perturbative reheating with a constant decay rate. Contrary to previous works, we find that the presence of an early matter-dominated era does not necessarily enhance the induced gravitational waves due to the decay of the gravitational potential around the transition from an early matter-dominated era to the radiation-dominated era.
description: 14 pages, 5 figures, v3: error in numerical calculation for Figures 4 and 5 corrected, revised Figure 4 showing small-scale induced GWs suppressed more, typo in Eq.(4.3) corrected, conclusion unchanged
Solar Power Time Series Forecasting Utilising Wavelet Coefficients
Creators: name: Almaghrabi, Sarah
name: Rana, Mashud
name: Hamilton, Margaret
name: Rahaman, Mohammad Saiedur
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Accurate and reliable prediction of Photovoltaic (PV) power output is critical to electricity grid stability and power dispatching capabilities. However, Photovoltaic (PV) power generation is highly volatile and unstable due to different reasons. The Wavelet Transform (WT) has been utilised in time series applications, such as Photovoltaic (PV) power prediction, to model the stochastic volatility and reduce prediction errors. Yet the existing Wavelet Transform (WT) approach has a limitation in terms of time complexity. It requires reconstructing the decomposed components and modelling them separately and thus needs more time for reconstruction, model configuration and training. The aim of this study is to improve the efficiency of applying Wavelet Transform (WT) by proposing a new method that uses a single simplified model. Given a time series and its Wavelet Transform (WT) coefficients, it trains one model with the coefficients as features and the original time series as labels. This eliminates the need for component reconstruction and training numerous models. This work contributes to the day-ahead aggregated solar Photovoltaic (PV) power time series prediction problem by proposing and comprehensively evaluating a new approach of employing WT. The proposed approach is evaluated using 17 months of aggregated solar Photovoltaic (PV) power data from two real-world datasets. The evaluation includes the use of a variety of prediction models, including Linear Regression, Random Forest, Support Vector Regression, and Convolutional Neural Networks. The results indicate that using a coefficients-based strategy can give predictions that are comparable to those obtained using the components-based approach while requiring fewer models and less computational time.
A Lyapunov Approach to Robust Regulation of Distributed Port-Hamiltonian Systems
Creators: name: Paunonen, Lassi
name: Gorrec, Yann Le
name: Ramírez, Héctor
Publisher: name: arXiv
Year: 2019
Subjects: subject: Optimization and Control (math.OC)
subject: Analysis of PDEs (math.AP)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 93C05, 93B52 35K90, (93B28)

description: This paper studies robust output tracking and disturbance rejection for boundary controlled infinite-dimensional port--Hamiltonian systems including second order models such as the Euler--Bernoulli beam. The control design is achieved using the internal model principle and the stability analysis using a Lyapunov approach. Contrary to existing works on the same topic no assumption is made on the external well-posedness of the considered class of PDEs. The results are applied to robust tracking of a piezo actuated tube used in atomic force imaging.
description: A minor revision with a correction to the simulation example in Section 6. 18 pages, 2 figures. Accepted for publication as a Technical Note in the IEEE Transactions on Automatic Control. The preprint is the final author submitted version. The reproducible simulation code is available in CodeOcean at https://doi.org/10.24433/CO.8086839.v1
Analysis of sagittal spinal alignment at the adolescent age: for furniture design
Creators: name: Fang, Jiao-Jiao
name: Shen, Li-Ming
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Medicine
subject: Physiology
subject: FOS: Biological sciences
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Science Policy

description: Knowledge of the parameters of the human spine is essential in designing ergonomic furniture. The purpose of this study was to evaluate spinal alignment in adolescents of various ages. The lengths, curvatures, and concave-convex spacings of the spine were investigated in 268 participants aged 9–18 years. Ten ages were classified, and the rate of increase of parameters was calculated for each age and age group. The results showed that spinal parameters, except for cervical lordosis, increased with age. Adolescents were classified as 9–10, 11–12, 13–15, and 16–18 years old. A rapid increment of lengths and concave-convex spacings occurred at ages 13–15, while that of curvatures occurred at ages 16–18. Spinal parameters differed significantly among the age groups (p < 0.05). Concave-convex spacings reflected differences in the spine more clearly than the other parameters. This study suggests the necessity of designing spine-related furniture based on spinal parameters, thus providing adaptive support for the adolescent spine, particularly the lumbar spine. This study examined spinal lengths, curvatures, and concave-convex spacings in adolescents aged 9–8 years and then divided them into four age groups. Concave-convex spacings effectively reflected spinal differences between age groups, particularly the lumbar spine. These results can inform the ergonomic design of spine-related furniture.
Precise near-infrared photometry, accounting for precipitable water vapour at SPECULOOS Southern Observatory
Creators: name: Pedersen, Peter P.
name: Murray, C. A.
name: Queloz, D.
name: Gillon, M.
name: Demory, B. O.
name: Triaud, A. H. M. J.
name: de Wit, J.
name: Delrez, L.
name: Dransfield, G.
name: Ducrot, E.
name: Garcia, L. J.
name: Chew, Y. Gómez Maqueo
name: Günther, M. N.
name: Jehin, E.
name: McCormac, J.
name: Niraula, P.
name: Pozuelos, F. J.
name: Rackham, B. V.
name: Schanche, N.
name: Sebastian, D.
name: Thompson, S. J.
name: Timmermans, M.
name: Wells, R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The variability induced by precipitable water vapour (PWV) can heavily affect the accuracy of time-series photometric measurements gathered from the ground, especially in the near-infrared. We present here a novel method of modelling and mitigating this variability, as well as open-sourcing the developed tool -- Umbrella. In this study, we evaluate the extent to which the photometry in three common bandpasses (r', i', z'), and SPECULOOS' primary bandpass (I+z'), are photometrically affected by PWV variability. In this selection of bandpasses, the I+z' bandpass was found to be most sensitive to PWV variability, followed by z', i', and r'. The correction was evaluated on global light curves of nearby late M- and L-type stars observed by SPECULOOS' Southern Observatory (SSO) with the I+z' bandpass, using PWV measurements from the LHATPRO and local temperature/humidity sensors. A median reduction in RMS of 1.1% was observed for variability shorter than the expected transit duration for SSO's targets. On timescales longer than the expected transit duration, where long-term variability may be induced, a median reduction in RMS of 53.8% was observed for the same method of correction.
description: Accepted for publication in MNRAS, 10 pages, 7 figures, 3 tables
The Effects of Total Sleep Deprivation on Time Estimation
Creators: name: Moslener, Emily Morgan
Publisher: name: Washington State University
Year: 2024
Subjects: Interval production
Prediction motion
Time estimation

description: The aim of the present study was to investigate the effects of total sleep deprivation on time estimation. N = 86 healthy adults (47 females, age 21 – 38) completed a 4-day/3-night in-laboratory study with 10-hour sleep opportunities on the first and third nights, and a 38-hour total sleep deprivation (TSD) period (TSD condition) or a 10-hour sleep opportunity (control condition) on the second night. A computerized time estimation assessment was administered twice during the study – once after 7h of wakefulness and once after 31h or 7h of wakefulness (TSD and control group, respectively). Two separate tasks were used in the time estimation assessment: interval production and prediction motion. For the interval production task, participants were to produce an interval of either 5, 10, or 15 seconds. For the prediction motion task, a ball moved down the screen at a constant speed, then became occluded partway down, and participants indicated when they believed the ball had reached the bottom of the screen. The duration for which the ball was occluded was randomized to either 5, 10, or 15 seconds. Performance was quantified in terms of bias, which provided a metric of individuals’ tendency to over- or underestimate the target duration, and variability, which was a measure of how variable individuals were in their estimates of the target duration. The results showed that on both tasks, sleep deprivation was associated with a tendency to underestimate the target duration, implying an accelerated perception of time. Additionally, there was a significant effect of sleep deprivation on variability for the prediction motion task, but not for the interval production task. This indicates that sleep-deprived individuals were more variable in their ability to track the movement of an occluded object and estimate when it will reach a target, but not in their ability to estimate a target number of seconds. Finally, correlations between the interval production and prediction motion tasks during session 1 (when all participants were well-rested) revealed that performance on the two tasks was not related, indicating that there may be different processes or techniques involved in completion of the tasks.
A classical SEIR model of transmission dynamics and clinical dynamics in controlling of coronavirus disease 2019 (COVID-19) with reproduction number
Creators: name: Iqra Liaqat
Publisher: name: figshare
Year: 2020
Subjects: subject: 10202 Biological Mathematics
subject: FOS: Mathematics

description: This paper obtains a classical SEIR model of transmission dynamics and clinical dynamics in controlling of coronavirus disease 2019 (COVID-19) with Reproduction number. We discussed the parameter estimation of the transmission and clinical dynamics. The control of the COVID-19 was calculated by basic reproduction number. Therefore, the process was defined only epidemic calculator. The reproduction number value of above one or less than one are defined the recovery percentage of the whole mathematical modeling. The estimations of the basic reproduction number level may be as high as 10 (99.97% recuperated). Finally we illustrate the cure rate of the COVID-19 from the controlling of transmission dynamics parameters and also show the graphical representations from the numerical experiment.
Numerical study of a confined vesicle in shear flow at finite temperature
Creators: name: Lamura, A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The dynamics and rheology of a vesicle confined in a channel under shear flow are studied at finite temperature. The effect of finite temperature on vesicle motion and system viscosity is investigated. A two-dimensional numerical model, which includes thermal fluctuations and is based on a combination of molecular dynamics and mesoscopic hydrodynamics, is used to perform a detailed analysis in a wide range of the Peclet numbers (the ratio of the shear rate to the rotational diffusion coefficient). The suspension viscosity is found to be a monotonous increasing function of the viscosity contrast (the ratio of the viscosity of the encapsulated fluid to that of the surrounding fluid) both in the tank-treading and the tumbling regime due to the interplay of different temperature-depending mechanisms. Thermal effects induce shape and inclination fluctuations of the vesicle which experiences also Brownian diffusion across the channel increasing the viscosity. These effects reduces when increasing the Peclet number.
Using Shell Models to Investigate Clumping in the WN4 Star HD 50896
Creators: name: Flores, Brian L.
name: Hillier, D. John
name: Dessart, Luc
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The spectra of Wolf-Rayet (WR) stars exhibit strong, broad emission lines that originate in the wind. These winds are radiatively driven and are susceptible to hydrodynamic instabilities that result in the formation of clumps. When modelling spectra of WR stars the volume-filling factor (VFF) approach is usually employed to treat clumpy winds. However, it is based on the assumption that the entire wind mass resides in optically thin clumps, which is not necessarily justifiable in dense winds. To test the validity of the VFF approach we use a previously described method of treating clumping, the ``Shell'' approach, to study line and continuum formation in the dense wind of the WN4 star, HD 50896. Our models indicate that fully intact spherical shells are in tension with observed spectra; a persistent ``dip'' in emission lines occurs at line centre. Removing this dip requires our models to use ``broken'' shells -- shells that are highly decoherent laterally. This insinuates that the wind of HD 50896, and by extension the winds of other WR stars, are comprised of small laterally confined and radially compressed clumps -- clumps smaller than the Sobolev length. We discuss some of the conditions necessary for the VFF approach to be valid.
description: 18 pages, 17 figures. Accepted for publication in MNRAS
On the phase diagram of the anisotropic XY chain in transverse magnetic field
Creators: name: Maciążek, Tomasz
name: Wojtkiewicz, Jacek
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate an explicite formula for ground state energy of the anisotropic XY chain in transverse magnetic field. In particular, we examine the smoothness properties of the expression, given in terms of elliptic integrals. We confirm known 2d-Ising type behaviour in the neighbourhood of certain lines of phase diagram and give more detailed information there, calculating a few next-to-leading exponents as well as corresponding amplitudes. We also explicitly demonstrate that the ground-state energy is infinitely differentiable on the boundary between ferromagnetic and oscillatory phases.
description: 15 pages, 8 figures
Globular cluster formation with multiple stellar populations: A single-binary composite scenario
Creators: name: Bekki, Kenji
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We discuss a GC formation scenario in which the first generation (1G) of single asymptotic giant branch (AGB) stars and intermediate-mass close binaries (IMCBs) eject gas, from which the second generation (2G) of stars can be formed. The two key parameters in the scenario are the fractions of binary stars (f_b) and the slopes (alpha) of the stellar initial mass functions (IMFs) for 1G stars. Principle results derived by analytic and one-zone models of GC formation are as follows. The mass fraction of 2G stars (f_2g) can be higher than ~0.4 for alpha < 1.8 and is not so dependent on f_b. The ratio of the initial mass of a GC to the present-day mass (M_gc) ranges from 2 to 7 depending on alpha for 0.5 < f_b <0.9. The differences in [Na/Fe] between 1G and 2G stars can be as large as 0.7 for a wide range of model parameters. The Li abundances of 2G stars can be as high as those of 1G even if the pristine gas from IMCBs is assumed to be Li-free. Formation histories of 2G stars show at least two peaks owing to two peaks in the total ejection rate of gas from IMCB populations. The observed correlation between f_2g and M_gc can be due to alpha depending on M_gc. The hypothetical long duration of 2G formation (~ 10^8 yr) is possible, because massive star formation can be suppressed through frequent dynamical interaction between 1G stars and gas clouds.
description: 14 page, 7 figures, accepted by MNRAS
On the module categories of generalized preprojective algebras of Dynkin type
Creators: name: Murakami, Kota
Publisher: name: arXiv
Year: 2019
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 16G10 (Primary), 16G20 (Secondary)

description: For a symmetrizable GCM $C$ and its symmetrizer $D$, Geiss-Leclerc-Schröer [Invent. Math. 209 (2017)] has introduced a generalized preprojective algebra $Π$ associated to $C$ and $D$, that contains a class of modules, called locally free modules. We show that any basic support $τ$-tilting $Π$-module is locally free and gives a classification theorem of torsion-free classes in $\operatorname{\mathbf{rep}}Π$ as the generalization of the work of Mizuno [Math. Z. 277 (2014)].
description: 17 pages; v3: final version, slightly changed the title
Residual estimates for post-processors in elliptic problems
Creators: name: Dedner, Andreas
name: Giesselmann, Jan
name: Pryer, Tristan
name: Ryan, Jennifer K
Publisher: name: arXiv
Year: 2019
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: In this work we examine a posteriori error control for post-processed approximations to elliptic boundary value problems. We introduce a class of post-processing operator that `tweaks' a wide variety of existing post-processing techniques to enable efficient and reliable a posteriori bounds to be proven. This ultimately results in optimal error control for all manner of reconstruction operators, including those that superconverge. We showcase our results by applying them to two classes of very popular reconstruction operators, the Smoothness-Increasing Accuracy-Enhancing filter and Superconvergent Patch Recovery. Extensive numerical tests are conducted that confirm our analytic findings.
description: 25 pages, 17 figures
Weak Lensing with Sizes, Magnitudes and Shapes
Creators: name: Alsing, Justin
name: Kirk, Donnacha
name: Heavens, Alan
name: Jaffe, Andrew
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Weak lensing can be observed through a number of effects on the images of distant galaxies; their shapes are sheared, their sizes and fluxes (magnitudes) are magnified and their positions on the sky are modified by the lensing field. Galaxy shapes probe the shear field whilst size, magnitude and number density probe the convergence field. Both contain cosmological information. In this paper we are concerned with the magnification of the size and magnitude of individual galaxies as a probe of cosmic convergence. We develop a Bayesian approach for inferring the convergence field from a measured size, magnitude and redshift and demonstrate that the inference on convergence requires detailed knowledge of the joint distribution of intrinsic sizes and magnitudes. We build a simple parameterised model for the size-magnitude distribution and estimate this distribution for CFHTLenS galaxies. In light of the measured distribution, we show that the typical dispersion on convergence estimation is ~0.8, compared to ~0.38 for shear. We discuss the possibility of physical systematics for magnification (similar to intrinsic alignments for shear) and compute the expected gains in the Dark Energy Figure-of-Merit (FoM) from combining magnification with shear for different scenarios regarding systematics: when accounting for intrinsic alignments but no systematics on the magnification signal, including magnification could improve the FoM by upto a factor of ~2.5, whilst when accounting for physical systematics in both shear and magnification we anticipate a gain between ~25% and ~65%. In addition to the statistical gains, the fact that cosmic shear and magnification are subject to different systematics makes magnification an attractive complement to any cosmic shear analysis.
description: 15 pages, 5 figures, accepted by MNRAS
Tunneling transport in NSN junctions made of Majorana nanowires across the topological quantum phase transition
Creators: name: Lobos, Alejandro M.
name: Sarma, S. Das
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We theoretically consider transport properties of a normal metal (N)- superconducting semiconductor nanowire (S)-normal metal (N) structure (NSN) in the context of the possible existence of Majorana bound states in disordered semiconductor-superconductor hybrid systems in the presence of spin-orbit coupling and Zeeman splitting induced by an external magnetic field. We study in details the transport signatures of the topological quantum phase transition as well as the existence of the Majorana bound states in the electrical transport properties of the NSN structure. Our theory includes the realistic nonperturbative effects of disorder, which is detrimental to the topological phase (eventually suppressing the superconducting gap completely), and the effects of the tunneling barriers (or the transparency at the tunneling NS contacts), which affect (and suppress) the zero bias conductance peak associated with the zero energy Majorana bound states. We show that in the presence of generic disorder and barrier transparency the interpretation of the zero bias peak as being associated with the Majorana bound state is problematic since the nonlocal correlations between the two NS contacts at two ends may not manifest themselves in the tunneling conductance through the whole NSN structure. We establish that a simple modification of the standard transport measurements using conductance differences (rather than the conductance itself as in a single NS junction) as the measured quantity can allow direct observation of the nonlocal correlations inherent in the Majorana bound states and enables the mapping out of the topological phase diagram (even in the presence of considerable disorder) by precisely detecting the topological quantum phase transition point.
description: 34 pages, 7 figures, 1 table. New version with minor modifications and more physical discussions
On isomorphisms between Siegel modular threefolds
Creators: name: Perna, Sara
Publisher: name: arXiv
Year: 2014
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14J15

description: The Satake compactification of the moduli space of principally polarized abelian surfaces with a level two structure has a degree 8 endomorphism. The aim of this paper is to show that this result can be extended to other modular threefolds. The main tools are Siegel modular forms and Satake compactifications of arithmetic quotients of the Siegel upper-half space. Indeed, the construction of the degree 8 endomorphism on suitable modular threefolds is done via an isomorphism of graded rings of modular forms. By studying the action of the Fricke involution one gets a further extension of the previous result to other modular threefolds. The possibility of a similar situation in higher dimensions is also discussed.
description: 13 pages, revised version
Chemical Evolution of Fluorine in the Milky Way
Creators: name: Womack, Kate A.
name: Vincenzo, Fiorenzo
name: Gibson, Brad K.
name: Côté, Benoit
name: Pignatari, Marco
name: Brinkman, Hannah E.
name: Ventura, Paolo
name: Karakas, Amanda
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Fluorine has many different potential sites and channels of production, making narrowing down a dominant site of fluorine production particularly challenging. In this work, we investigate which sources are the dominant contributors to the galactic fluorine by comparing chemical evolution models to observations of fluorine abundances in Milky Way stars covering a metallicity range -2$<$[Fe/H]$<$0.4 and upper limits in the range -3.4$<$[Fe/H]$<$-2.3. In our models, we use a variety of stellar yield sets in order to explore the impact of varying both AGB and massive star yields on the chemical evolution of fluorine. In particular, we investigate different prescriptions for initial rotational velocity in massive stars as well as a metallicity dependent mix of rotational velocities. We find that the observed [F/O] and [F/Fe] abundance ratios at low metallicity and the increasing trend of [F/Ba] at [Fe/H]$\gtrsim$-1 can only be reproduced by chemical evolution models assuming, at all metallicities, a contribution from rapidly rotating massive stars with initial rotational velocities as high as 300km s$^{-1}$. A mix of rotational velocities may provide a more physical solution than the sole use of massive stars with $v_{\text{rot}}$=300$\text{km s}^{-1}$, which are predicted to overestimate the fluorine and average s-process elemental abundances at [Fe/H]$\gtrsim$-1. The contribution from AGB stars is predicted to start at [Fe/H]$\approx$-1 and becomes increasingly important at high metallicity, being strictly coupled to the evolution of the nitrogen abundance. Finally, by using modern yield sets, we investigate the fluorine abundances of Wolf-Rayet winds, ruling them out as dominant contributors to the galactic fluorine.
description: 14 pages, 10 figures, Accepted for publication in MNRAS
Spin and quadrupolar effects in the secular evolution of precessing compact binaries with black hole, neutron star, gravastar, or boson star components
Creators: name: Keresztes, Zoltán
name: Tápai, Márton
name: Gergely, László Árpád
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We discuss precessing compact binaries on eccentric orbit with gravastar, black hole, neutron star, or boson star components. We derive secular evolution equations to second post-Newtonian--order accuracy, with leading-order spin-orbit, spin-spin, and mass quadrupole-monopole contributions. The emerging closed system of first-order differential equations evolves the pairs of polar and azimuthal angles of the spin and orbital angular momentum vectors together with the periastron angle. The secular dynamics is autonomous. We confirm numerically, that secular evolutions look like smoothed-out instantaneous evolutions over timescales where radiation reaction is negligible. The secular evolution of the spin polar angles and the difference of their azimuthal angles generates a closed subsystem. We study analytically this system for the particular cases of one spin dominating over the other and for black hole - boson star binaries of equal masses. In the first case known large flip-flops of the smaller spin are reproduced, when the larger spin is almost coplanar with the orbit. We also find new, quadrupole-induced flip-flops occurring when the neutron star with dominant spin has a quadrupolar parameter $w_1\approx 3$. Finally we analyze the evolutions of the spin angles numerically by comparing the cases when the black hole companion is either a gravastar, another black hole or a boson star with identical mass. We find that both the amplitude and period of the flip-flop are the largest, when the companion is a black hole. In the case of a boson star companion the frequency of the flip-flop increases significantly. Further, while in the case of gravastars and black holes a swinging-type azimuthal evolution occurs, with the spins of the components periodically overpassing each other, their sequence is conserved when the companion is a boson star.
description: 24 pages, 6 figures
Stability analysis of the spin evolution fix points in inspiraling compact binaries with black hole, neutron star, gravastar, or boson star components
Creators: name: Keresztes, Zoltán
name: Gergely, László Árpád
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Based on the secular spin evolution of black holes, neutron stars, gravastars, or boson stars in precessing compact binaries on eccentric orbit, we identify the aligned and more generic coplanar configurations of the spins and orbital angular momentum as fix points. Through a dynamical system analysis, we investigate their linear stability as function of the mass quadrupole parameter. Marginal stability holds for the binary configurations with both spins antialigned to the orbital angular momentum, for both spins aligned to the orbital angular momentum (with the exception of certain quadrupolar parameter ranges of neutron stars and boson stars), and for the extremal mass ratio. For equal masses, the configurations of one of the spins aligned and the other antialigned is stable for gravastar binaries, for neutron star binaries in the high quadrupolar parameter range, and for boson star binaries. For some unequal mass gravastar binaries, black hole binaries or neutron star binaries, a transition from stability to instability can occur during the inspiral, when one of the spins is aligned, while the other is antialigned to the orbital angular momentum. We discover a transitional instability regime during the inspiral of certain gravastar, neutron star, or boson star binaries with opposing spins. For coplanar configurations we find instabilities only for the gravastar - gravastar, boson star - boson star and black hole - boson star binaries. For a given spin configuration, marginal stability strongly depends on the value of the quadrupolar parameters. The stability region is larger for neutron star binaries than for black hole binaries, while the mixed systems have a restricted stability parameter region.
description: 14 pages, 7 figures
An observational study of ballooning in large spiders: Nanoscale multifibers enable large spiders’ soaring flight
Creators: name: Cho, Moonsung
name: Neubauer, Peter
name: Fahrenson, Christoph
name: Rechenberg, Ingo
Publisher: name: Technische Universität Berlin
Year: 2018
Subjects: subject: 570 Biowissenschaften; Biologie
subject: ballooning behavior
subject: spiders
subject: nanoscale multifibers

description: The physical mechanism of aerial dispersal of spiders, “ballooning behavior,” is still unclear because of the lack of serious scientific observations and experiments. Therefore, as a first step in clarifying the phenomenon, we studied the ballooning behavior of relatively large spiders (heavier than 5 mg) in nature. Additional wind tunnel tests to identify ballooning silks were implemented in the laboratory. From our observation, it seems obvious that spiders actively evaluate the condition of the wind with their front leg (leg I) and wait for the preferable wind condition for their ballooning takeoff. In the wind tunnel tests, as-yet-unknown physical properties of ballooning fibers (length, thickness, and number of fibers) were identified. Large spiders, 16–20 mg Xysticus spp., spun 50–60 nanoscale fibers, with a diameter of 121–323 nm. The length of these threads was 3.22 ± 1.31 m (N = 22). These physical properties of ballooning fibers can explain the ballooning of large spiders with relatively light updrafts, 0.1–0.5 m s−1, which exist in a light breeze of 1.5–3.3 m s−1. Additionally, in line with previous research on turbulence in atmospheric boundary layers and from our wind measurements, it is hypothesized that spiders use the ascending air current for their aerial dispersal, the “ejection” regime, which is induced by hairpin vortices in the atmospheric boundary layer turbulence. This regime is highly correlated with lower wind speeds. This coincides well with the fact that spiders usually balloon when the wind speed is lower than 3 m s−1.
A silicon-based surface code quantum computer
Creators: name: O'Gorman, Joe
name: Nickerson, Naomi H.
name: Ross, Philipp
name: Morton, John J. L.
name: Benjamin, Simon C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Individual impurity atoms in silicon can make superb individual qubits, but it remains an immense challenge to build a multi-qubit processor: There is a basic conflict between nanometre separation desired for qubit-qubit interactions, and the much larger scales that would enable control and addressing in a manufacturable and fault tolerant architecture. Here we resolve this conflict by establishing the feasibility of surface code quantum computing using solid state spins, or `data qubits', that are widely separated from one another. We employ a second set of `probe' spins which are mechanically separate from the data qubits and move in-and-out of their proximity. The spin dipole-dipole interactions give rise to phase shifts; measuring a probe's total phase reveals the collective parity of the data qubits along the probe's path. We introduce a protocol to balance the systematic errors due to the spins being imperfectly located during device fabrication. Detailed simulations show that the surface code's threshold then corresponds to misalignments that are substantial on the scale of the array, indicating that it is very robust. We conclude that this simple `orbital probe' architecture overcomes many of the difficulties facing solid state quantum computing, while minimising the complexity and offering qubit densities that are several orders of magnitude greater than other systems.
description: Improved discussion of generalisation to universal computation. Two figures added. Appendices extended