cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Anomalous Surface Conductivity of Weyl Semimetals
Creators: name: Pal, Hridis K.
name: Obakpolor, Osakpolor Eki
name: Hosur, Pavan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We calculate the surface dc conductivity of Weyl semimetals and show that it contains an anomalous contribution in addition to a Drude contribution from the Fermi arc. The anomalous part is independent of the surface scattering time, and appears at nonzero temperature and doping (away from the Weyl nodes), increasing quadratically with both with a universal ratio of coefficients. Microscopically, it results from the contribution of the gapless bulk to the surface conductivity. We argue that this can be interpreted as the conductivity of an effective interacting surface fluid that coexists with the Fermi arc metal. In a certain regime of low temperatures, the temperature dependence of the surface conductivity is dominated by the anomalous response, which can be probed experimentally to unravel the unusual behavior.
Shear and interface modes in neutron stars with pasta structures
Creators: name: Sotani, Hajime
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We carefully examine the shear and interface modes, which are excited due to the presence of crust elasticity, in neutron stars with pasta structures, adopting the relativistic Cowling approximation. We find that the shear modes are independent of the presence of the cylindrical-hole and spherical-hole nuclei at least up to a few kilohertz, while the interface modes strongly depend on the presence of the cylindrical-hole and spherical-hole nuclei. In addition, we find empirical relations for the interface mode frequencies multiplied by the stellar mass and for the shear mode frequencies multiplied by the stellar radius. These relations are expressed as a function of the stellar compactness almost independently of the stiffness in a higher-density region inside the neutron star, once one selects the crust equation of state. Thus, if one would simultaneously observe the shear and interface modes from a neutron star, one might extract the neutron star mass and radius with the help of the constraint on the crust stiffness obtained from terrestrial experiments.
description: Accepted for publication in RPD
A comparative study of resistivity models for simulations of magnetic reconnection in the solar atmosphere
Creators: name: Færder, Øystein Håvard
name: Nóbrega-Siverio, Daniel
name: Carlsson, Mats
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Magnetic reconnection is a fundamental mechanism in astrophysics. A common challenge in mimicking this process numerically in particular for the Sun is that the solar electrical resistivity is small compared to the diffusive effects caused by the discrete nature of codes. We aim to study different anomalous resistivity models and their respective effects on simulations related to magnetic reconnection in the Sun. We used the Bifrost code to perform a 2D numerical reconnection experiment in the corona that is driven by converging opposite polarities at the solar surface. This experiment was run with three different commonly used resistivity models: 1) the hyper-diffusion model originally implemented in Bifrost, 2) a resistivity proportional to the current density, and 3) a resistivity proportional to the square of the electron drift velocity. The study was complemented with a 1D experiment of a Harris current sheet with the same resistivity models. The 2D experiment shows that the three resistivity models are capable of producing results in satisfactory agreement with each other in terms of the current sheet length, inflow velocity, and Poynting influx. Even though Petschek-like reconnection occurred with the current density-proportional resistivity while the other two cases mainly followed plasmoid-mediated reconnection, the large-scale evolution of thermodynamical quantities such as temperature and density are quite similar between the three cases. For the 1D experiment, some recalibration of the diffusion parameters is needed to obtain comparable results. Specifically the hyper-diffusion and the drift velocity-dependent resistivity model needed only minor adjustments, while the current density-proportional model needed a rescaling of several orders of magnitude.
description: 15 pages, 8 figures, 1 movie
Η αναδυόμενη ενηλικίωση στον κυβερνοχώρο: διερεύνηση του ρόλου του γονεϊκού δεσμού και των μηχανισμών άμυνας του Εγώ στην προβληματική χρήση του διαδικτύου
Creators: name: Τσινούλη, Άννα Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2025
Subjects: Αναδυόμενη ενηλικίωση
Διαδικτυακή εξάρτηση
Γονεϊκός δεσμός
Emerging adulthood
Internet addiction
Parental bonding

description: Κώνστα, Αναστασία, Αν. καθηγήτρια Ψυχιατρικής Α.Π.Θ. Τσαπάκη, Εύα-Μαρία, επικ. καθηγήτρια Ψυχιατρικής Α.Π.Θ.
description: The rapid digitization that occurs nowadays establishes the topic of Internet addiction in young adulthood as a major subject of study in literature. Emerging adulthood (18-29 years) is a transitional stage where addictive behaviors often begin to develop. The current research examines the relationship of intra-individual factors, such as Ego defense mechanisms, and factors connected to the family environment, such as remembered parental bonding, with internet addiction during emerging adulthood. A questionnaire was developed online and completed by 116 participants aged 18-29 in Greece, of which 80 were women and 36 were men. Participants answered questions regarding sociodemographic data and filled out the Parental Bonding Instrument (PBI-25), the Defense Style Questionnaire (DSQ-88), and the Internet Addiction Test (IAT-20)]. Analysis was completed with the use of the statistical package IBM SPSS Statistics 29. The Internet Addiction Test showed that 63.8% of the sample scored mild or moderate internet addiction. Non-parametric Kruskal-Wallis analysis showed that participants who reported “affectionless control” parental bonding, characterized by overprotection and low levels of care, scored higher on the Maladaptive Action and the Image Distorting defense style subscales of the DSQ-88. They also scored higher on the Internet Addiction Test than the rest of the participants. Simple linear regression showed that combining the Maladaptive Action and Image Distorting defense style has a significant effect on the development of internet addiction. Findings confirmed the hypotheses about the relationship of the variables examined. The enhancement of adaptive defense mechanisms, with the contribution of factors such as parental care, is suggested in order to deal with the internet addiction as way out of a stressful reality
Improved (Related-key) Differential-based Neural Distinguishers for SIMON and SIMECK Block Ciphers
Creators: name: Lu, Jinyu
name: Liu, Guoqiang
name: Sun, Bing
name: Li, Chao
name: Liu, Li
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: In CRYPTO 2019, Gohr made a pioneering attempt and successfully applied deep learning to the differential cryptanalysis against NSA block cipher SPECK32/64, achieving higher accuracy than the pure differential distinguishers. By its very nature, mining effective features in data plays a crucial role in data-driven deep learning. In this paper, in addition to considering the integrity of the information from the training data of the ciphertext pair, domain knowledge about the structure of differential cryptanalysis is also considered into the training process of deep learning to improve the performance. Meanwhile, taking the performance of the differential-neural distinguisher of SIMON32/64 as an entry point, we investigate the impact of input difference on the performance of the hybrid distinguishers to choose the proper input difference. Eventually, we improve the accuracy of the neural distinguishers of SIMON32/64, SIMON64/128, SIMECK32/64, and SIMECK64/128. We also obtain related-key differential-based neural distinguishers on round-reduced versions of SIMON32/64, SIMON64/128, SIMECK32/64, and SIMECK64/128 for the first time.
The Binary Demographics of Omega Centauri
Creators: name: Wragg, Florence
Publisher: name: Zenodo
Year: 2023

description: Omega Centauri (ω Cen) is the closest candidate for a Nuclear Star Cluster that has been stripped of its host galaxy in the Milky Way. Despite extensive studies through the last decades, many open questions about the cluster remain, including the origin of its complex stellar populations or whether an intermediate-mass black hole is residing in the cluster centre. Owing to their fragility in dense cluster environments, binary stars are excellent tracers to help answering these questions. However, the properties of the binary population of ω Cen is largely unknown to date. In this first of its kind study, we identified a sample of 300 likely binary systems and map them across the CMD and present the likely parameter distribution across the cluster. We are also in the process of fitting Keplerian orbits to the velocity curves of likely binaries in order to constrain the masses of their companions, to determine if there are any black holes (BHs) within the cluster. Thanks to the Multi Unit Spectroscopic Explorer (MUSE), we now have a sample of approximately 30000 stars that have been monitored for radial velocity variations over the past 9 years. Using radial velocity measurements from spectroscopic analysis is one of the most successful ways to detect binary systems and BHs in clusters, as radial velocity measurements are particularly sensitive when searching for unseen companions of luminous stars and can allow us to estimate companion mass.
Pure classical correlation dominant quantum thermal diode via three triangular-coupled qubits
Creators: name: Yang, Yi-jia
name: Liu, Yu-qiang
name: Yu, Chang-shui
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A quantum thermal diode is designed based on three pairwise coupled qubits, two connected to a common reservoir and the other to an independent reservoir. It is found that the internal couplings between qubits can enhance heat currents. If the two identical qubits uniformly couple with the common reservoir, the crossing dissipation will occur, leading to the initial-state-dependent steady state, which can be decomposed into the mixture of two particular steady states: the heat-conducting state generating maximum heat current and the heat-resisting state not transporting heat. However, the rectification factor does not depend on the initial state. In particular, we find that neither quantum entanglement nor quantum discord is present in the steady state, but the pure classical correlation shows a remarkably consistent behavior as the heat rectification factor, which reveals the vital role of classical correlation in the system.
Pure spin current and perfect valley filter by designed separation of the chiral states in two-dimensional honeycomb lattices
Creators: name: Liu, Da-Ping
name: Yu, Zhi-Ming
name: Liu, Yu-Liang
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a realization of pure spin currents and perfect valley filter based on a quantum anomalous Hall insulator, around which edge states with up-spin and down-spin circulate. By applying staggered sublattice potential on the strips along the edges of sample, the edge states with down spin can be pushed into the inner boundaries of the strips while the other edge states with up spin remain on the outer boundaries, resulting in spatially separated chiral states with perfect spin polarization. Moreover, a valley filter, which is immune to short-range and smooth long-range scatterers, can be engineered by additionally applying boundary potentials on the outmost lattices of the sample. We also find that the boundary potential can be used to control the size effect induced oscillation of the inner chiral states. The connection of the boundary potential to size effect is revealed.
Keck Spectroscopy of NGC 1052-DF9: Stellar Populations in the Context of the NGC 1052 Group
Creators: name: Gannon, Jonah S.
name: Buzzo, Maria Luisa
name: Ferré-Mateu, Anna
name: Forbes, Duncan A.
name: Brodie, Jean P.
name: Romanowsky, Aaron J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this study, we use Keck/KCWI spectroscopy to measure the age, metallicity and recessional velocity of NGC~1052-DF9 (DF9), a dwarf galaxy in the NGC~1052 group. We compare these properties to those of two other galaxies in the group, NGC~1052-DF2 and NGC~1052-DF4, which have low dark matter content. The three galaxies are proposed constituents of a trail of galaxies recently hypothesised to have formed as part of a ``bullet dwarf'' collision. We show that the ages and total metallicities of the three galaxies are within uncertainties of one another which may be expected if they share a related formation pathway. However, the recessional velocity we recover for DF9 (1680 $\pm$ 10 km s$^{-1}$) is higher than predicted for a linearly projected interpretation of the ``bullet dwarf'' trail. DF9 is then either not part of the trail or the correlation of galaxy velocities along the trail is not linear in 2D projection due to their 3D geometry. After examining other proposed formation pathways for the galaxies, none provide a wholly satisfactory explanation for all of their known properties. We conclude further work is required to understand the formation of this interesting group of galaxies.
description: 6 pages, 3 figures, 2 tables. Submitted to arxiv after including minor changes requested by the MNRAS referee in the second round of comments
Expectile-based hydrological modelling for uncertainty estimation: Life after mean
Creators: name: Tyralis, Hristos
name: Papacharalampous, Georgia
name: Khatami, Sina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Predictions of hydrological models should be probabilistic in nature. Our aim is to introduce a method that estimates directly the uncertainty of hydrological simulations using expectiles, thus complementing previous quantile-based direct approaches as well as generalizing mean-based approaches. Expectiles are new risk measures in hydrology. Compared to quantiles that use information of the frequency of process realizations over a specified value, expectiles use additional information of the magnitude of the exceedances over the specified value. Expectiles are least square analogues of quantiles and can characterize the probability distribution in much the same way as quantiles do. Moreover, the mean of the probability distribution is the special case of the expectile at level 0.5. To this end, we propose calibrating hydrological models using the expectile loss function, which is strictly consistent for expectiles. We apply our method to 511 basins in contiguous US and deliver predictive expectiles of hydrological simulations with the GR4J, GR5J and GR6J hydrological models at expectile levels 0.5, 0.9, 0.95 and 0.975. An honest assessment empirically proves that the GR6J model outperforms the other two models at all expectile levels. Great opportunities are offered for moving beyond the mean in hydrological modelling by simply adjusting the objective function.
description: 23 pages, 7 figures
Consensus in Complex Networks with Noisy Agents and Peer Pressure
Creators: name: Griffin, Christopher
name: Squicciarini, Anna
name: Jia, Feiran
Publisher: name: arXiv
Year: 2023
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: In this paper we study a discrete time consensus model on a connected graph with monotonically increasing peer-pressure and noise perturbed outputs masking a hidden state. We assume that each agent maintains a constant hidden state and a presents a dynamic output that is perturbed by random noise drawn from a mean-zero distribution. We show consensus is ensured in the limit as time goes to infinity under certain assumptions on the increasing peer-pressure term and also show that the hidden state cannot be exactly recovered even when model dynamics and outputs are known. The exact nature of the distribution is computed for a simple two vertex graph and results found are shown to generalize (empirically) to more complex graph structures.
description: 11 pages, 10 figures
Scaling of collision strengths for highly-excited states of ions of the H- and He-like sequences
Creators: name: Fernandez-Menchero, L.
name: Del Zanna, G.
name: Badnell, N. R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Emission lines from highly-excited states (n >= 5) of H- and He-like ions have been detected in astrophysical sources and fusion plasmas. For such excited states, R-matrix or distorted wave calculations for electron-impact excitation are very limited, due to the large size of the atomic basis set needed to describe them. Calculations for n >= 6 are also not generally available. We study the behaviour of the electron-impact excitation collision strengths and effective collision strengths for the most important transitions used to model electron collision dominated astrophysical plasmas, solar, for example. We investigate the dependence on the relevant parameters: the principal quantum number n or the nuclear charge Z. We also estimate the importance of coupling to highly-excited states and the continuum by comparing the results of different sized calculations. We provide analytic formulae to calculate the electron-impact excitation collision strengths and effective collision strengths to highly-excited states (n >= 8) of H- and He-like ions. These extrapolated effective collision strengths can be used to interpret astrophysical and fusion plasma via collisional-radiative modelling.
description: 9 pages, 11 figures, 5 tables, online material
A Transiting Super-Earth in the Radius Valley and An Outer Planet Candidate Around HD 307842
Creators: name: Hua, Xinyan
name: Wang, Sharon Xuesong
name: Teske, Johanna K.
name: Gan, Tianjun
name: Shporer, Avi
name: Zhou, George
name: Stassun, Keivan G.
name: Rabus, Markus
name: Howell, Steve B.
name: Ziegler, Carl
name: Lissauer, Jack J.
name: Winn, Joshua N.
name: Jenkins, Jon M.
name: Ting, Eric B.
name: Collins, Karen A.
name: Mann, Andrew W.
name: Zhu, Wei
name: Wang, Su
name: Butler, R. Paul
name: Crane, Jeffrey D.
name: Shectman, Stephen A.
name: Bouma, Luke G.
name: Briceno, Cesar
name: Dragomir, Diana
name: Fong, William
name: Law, Nicholas
name: Medina, Jennifer V.
name: Quinn, Samuel N.
name: Ricker, George R.
name: Schwarz, Richard P.
name: Seager, Sara
name: Sefako, Ramotholo
name: Stockdale, Chris
name: Vanderspek, Roland
name: Villasenor, Joel
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We report the confirmation of a TESS-discovered transiting super-Earth planet orbiting a mid-G star, HD 307842 (TOI-784). The planet has a period of 2.8 days, and the radial velocity (RV) measurements constrain the mass to be 9.67+0.83/-0.82 [Earth Masses]. We also report the discovery of an additional planet candidate on an outer orbit that is most likely non-transiting. The possible periods of the planet candidate are approximately 20 to 63 days, with the corresponding RV semi-amplitudes expected to range from 3.2 to 5.4 m/s and minimum masses from 12.6 to 31.1 [Earth Masses]. The radius of the transiting planet (planet b) is 1.93+0.11/-0.09 [Earth Radii], which results in a mean density of 7.4+1.4/-1.2 g/cm^3 suggesting that TOI-784b is likely to be a rocky planet though it has a comparable radius to a sub-Neptune. We found TOI-784b is located at the lower edge of the so-called ``radius valley'' in the radius vs. insolation plane, which is consistent with the photoevaporation or core-powered mass loss prediction. The TESS data did not reveal any significant transit signal of the planet candidate, and our analysis shows that the orbital inclinations of planet b and the planet candidate are 88.60+0.84/-0.86 degrees and <= 88.3-89.2 degrees, respectively. More RV observations are needed to determine the period and mass of the second object, and search for additional planets in this system.
description: 30 pages, 21 figures, accepted for publication in AJ
A new framework for feedback from massive binaries in simulations of cluster formation
Creators: name: Cournoyer-Cloutier, Claude
Publisher: name: Zenodo
Year: 2023
Subjects: Interacting binaries (801)
Massive stars (732)
Stellar feedback (1602)
Star forming regions (1565)

description: Massive stars are born in clusters embedded within giant molecular clouds, which they in turn influence via radiative and momentum feedback. Most massive stars are also born in binaries or higher-order systems, with companions close enough to trigger mass loss in excess of what is expected for single stars. Those interactions shape the feedback coming from massive stars, by increasing the amount of ionizing radiation and delaying some of the first core-collapse supernovae. It is therefore crucial to model concurrently those massive interacting binaries and the giant molecular cloud in which they form to reach a more comprehensive understanding of cluster formation. I will present a new model for the implementation of feedback from massive binaries in simulations of cluster formation. This model couples hydrodynamics, stellar dynamics, stellar evolution, and star and binary formation, and innovates by modelling the feedback from both massive single stars and massive binaries. I will discuss our first results and highlight future outlooks for this novel framework.
description: This work was started during a research visit at the Max Planck Institute for Astrophysics, supported by a Michael Smith Foreign Studies Supplement from the Natural Sciences and Engineering Research Council of Canada (NSERC). This work is further supported by a Canada Graduate Scholarship – Doctoral from NSERC.
Black-box Error Diagnosis in Deep Neural Networks for Computer Vision: a Survey of Tools
Creators: name: Fraternali, Piero
name: Milani, Federico
name: Torres, Rocio Nahime
name: Zangrando, Niccolò
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: The application of Deep Neural Networks (DNNs) to a broad variety of tasks demands methods for coping with the complex and opaque nature of these architectures. When a gold standard is available, performance assessment treats the DNN as a black box and computes standard metrics based on the comparison of the predictions with the ground truth. A deeper understanding of performances requires going beyond such evaluation metrics to diagnose the model behavior and the prediction errors. This goal can be pursued in two complementary ways. On one side, model interpretation techniques "open the box" and assess the relationship between the input, the inner layers and the output, so as to identify the architecture modules most likely to cause the performance loss. On the other hand, black-box error diagnosis techniques study the correlation between the model response and some properties of the input not used for training, so as to identify the features of the inputs that make the model fail. Both approaches give hints on how to improve the architecture and/or the training process. This paper focuses on the application of DNNs to Computer Vision (CV) tasks and presents a survey of the tools that support the black-box performance diagnosis paradigm. It illustrates the features and gaps of the current proposals, discusses the relevant research directions and provides a brief overview of the diagnosis tools in sectors other than CV.
description: Published in Springer Neural Computing and Applications, https://link.springer.com/article/10.1007/s00521-022-08100-9
Characterizing octagonal and rectangular fibers for MAROON-X
Creators: name: Sutherland, Adam P.
name: Stürmer, Julian
name: Miller, Katrina R.
name: Seifahrt, Andreas
name: Bean, Jacob L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We report on the scrambling performance and focal-ratio-degradation (FRD) of various octagonal and rectangular fibers considered for MAROON-X. Our measurements demonstrate the detrimental effect of thin claddings on the FRD of octagonal and rectangular fibers and that stress induced at the connectors can further increase the FRD. We find that fibers with a thick, round cladding show low FRD. We further demonstrate that the scrambling behavior of non-circular fibers is often complex and introduce a new metric to fully capture non-linear scrambling performance, leading to much lower scrambling gain values than are typically reported in the literature (<1000 compared to 10,000 or more). We find that scrambling gain measurements for small-core, non-circular fibers are often speckle dominated if the fiber is not agitated.
description: 10 pages, 8 figures, submitted to SPIE Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation 2016 (9912-185)
Astrophysical Fluids of Novae: High Resolution Pre-decay X-ray spectrum of V4743 Sagittarii
Creators: name: Ramírez-Velasquez, J. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Eight X-ray observations of V4743 Sgr (2002), observed with Chandra and XMM-Newton are presented. The nova turned off some time between days 301.9 and 371, and the X-ray flux subsequently decreased from day 301.9 to 526 following an exponential decline time scale of $(96 \pm 3)$ days. We use the absorption lines present in the SSS spectrum for diagnostic purposes, and characterize the physics and the dynamics of the expanding atmosphere during the explosion of the nova. The information extracted from this first stage is then used as input for computing full photoionization models of the ejecta in V4743 Sgr. The SSS spectrum is modeled with a simple black-body and multiplicative Gaussian lines, which provides us of a general kinematical picture of the system, before it decays to its faint phase (Ness et al. 2003). In the grating spectra taken between days 180.4 and 370, we can resolve the line profiles of absorption lines arising from H-like and He-like C, N, and O, including transitions involving higher principal quantum numbers. Except for a few interstellar lines, all lines are significantly blue-shifted, yielding velocities between 1000 and 6000 km/s which implies an ongoing mass loss. It is shown that significant expansion and mass loss occur during this phase of the explosion, at a rate $\dot{M} \approx (3-5) \times 10^{-4} ~ (\frac{L}{L_{38}}) ~ M_{\odot}/yr$. Our measurements show that the efficiency of the amount of energy used for the motion of the ejecta, defined as the ratio between the kinetic luminosity $L_{\rm kin}$ and the radiated luminosity $L_{\rm rad}$, is of the order of one.
description: 25 pages, 9 figures. Accepted in book: Recent Advances in Fluid Dynamics with Environmental Applications, pp.365-390
Using CO line ratios to trace the physical properties of molecular clouds
Creators: name: Peñaloza, Camilo H.
name: Clark, Paul C.
name: Glover, Simon C. O.
name: Shetty, Rahul
name: Klessen, Ralf S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The carbon monoxide (CO) rotational transition lines are the most common tracers of molecular gas within giant molecular clouds (MCs). We study the ratio ($R_{2-1/1-0}$) between CO's first two emission lines and examine what information it provides about the physical properties of the cloud. To study $R_{2-1/1-0}$ we perform smooth particle hydrodynamic simulations with time dependent chemistry (using GADGET-2), along with post-process radiative transfer calculations on an adaptive grid (using RADMC-3D) to create synthetic emission maps of a MC. $R_{2-1/1-0}$ has a bimodal distribution that is a consequence of the excitation properties of each line, given that $J=1$ reaches local thermal equilibrium (LTE) while $J=2$ is still sub-thermally excited in the considered clouds. The bimodality of $R_{2-1/1-0}$ serves as a tracer of the physical properties of different regions of the cloud and it helps constrain local temperatures, densities and opacities. Additionally this bimodal structure shows an important portion of the CO emission comes from diffuse regions of the cloud, suggesting that the commonly used conversion factor of $R_{2-1/1-0}\sim 0.7$ between both lines may need to be studied further.
description: 10 pages, 8 figures, accepted to MNRAS
DuoSearch: A Novel Search Engine for Bulgarian Historical Documents
Creators: name: Beshirov, Angel
name: Hadzhieva, Suzan
name: Koychev, Ivan
name: Dobreva, Milena
Publisher: name: arXiv
Year: 2023
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Search in collections of digitised historical documents is hindered by a two-prong problem, orthographic variety and optical character recognition (OCR) mistakes. We present a new search engine for historical documents, DuoSearch, which uses ElasticSearch and machine learning methods based on deep neural networks to offer a solution to this problem. It was tested on a collection of historical newspapers in Bulgarian from the mid-19th to the mid-20th century. The system provides an interactive and intuitive interface for the end-users allowing them to enter search terms in modern Bulgarian and search across historical spellings. This is the first solution facilitating the use of digitised historical documents in Bulgarian.
description: Accepted to ECIR 2022 (Demo paper)
Perpendicularly magnetized CoFeB multilayers with tunable interlayer exchange for synthetic ferrimagnets
Creators: name: Pirro, Philipp
name: Hamadeh, Abbass
name: Lavanant-Jambert, Marion
name: Meyer, Thomas
name: Tao, Bingshan
name: Rosario, Enzo
name: Lu, Yuan
name: Hehn, Michel
name: Mangin, Stephane
name: Petit-Watelot, Sebastien
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: A study of the multilayer system MgO/CoFeB(1.1nm)/Ta($t$)/CoFeB(0.8nm)/MgO is presented, where the two CoFeB layers are separated by a Ta interlayer of varying thickness $t$. The magnetization properties deduced from complementary techniques such as superconducting quantum interference magnetometry, ferromagnetic resonance frequency measurements and Brillouin light scattering spectroscopy can be tuned by changing the Ta thickness between $t$=0.25 nm, 0.5 nm and 0.75 nm. For $t$=0.5 nm, a ferromagnetic coupling is observed, whereas for t=0.75 nm, the antiferromagnetic coupling needed to construct a synthetic ferrimagnet is realized. In the later case, the shape of magnetic domain walls between two ferrimagnetic alignments or between a ferro- and a ferrimagnetic alignment is very different. This behavior can be interpreted as a result of the change in dipolar as well as interlayer exchange energy and domain wall pinning, which is an important conclusion for the realization of data storage devices based on synthetic ferri- and antiferromagnets.
description: 5 pages, 3 figures
Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances
Creators: name: Kahil, F.
name: Gandorfer, A.
name: Hirzberger, J.
name: Calchetti, D.
name: Sinjan, J.
name: Valori, G.
name: Solanki, S. K.
name: Van Noort, M.
name: Albert, K.
name: Jorge, N. Albelo
name: Alvarez-Herrero, A.
name: Appourchaux, T.
name: Rubio, L. R. Bellot
name: guez, J. Blanco Rodrí
name: Feller, A.
name: Fiethe, B.
name: Germerott, D.
name: Gizon, L.
name: Guerrero, L.
name: Gutierrez-Marques, P.
name: Kolleck, M.
name: Korpi-Lagg, A.
name: Michalik, H.
name: Vacas, A. Moreno
name: arez, D. Orozco Su\'
name: erez-Grande, I. P\'
name: Kilders, E. Sanchis
name: Schou, J.
name: uhle, U. Sch\"
name: Staub, J.
name: Strecker, H.
name: iniesta, J. C. del Toro
name: Volkmer, R.
name: Woch, J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We use wavefront sensing to characterise the image quality of the the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) data products during the second remote sensing window of the Solar Orbiter (SO) nominal mission phase. Our ultimate aims are to reconstruct the HRT data by deconvolving with the HRT point spread function (PSF) and to correct for the effects of optical aberrations on the data. We use a pair of focused--defocused images to compute the wavefront error and derive the PSF of HRT by means of a phase diversity (PD) analysis. The wavefront error of HRT depends on the orbital distance of SO to the Sun. At distances $>0.5$\,au, the wavefront error is small, and stems dominantly from the inherent optical properties of HRT. At distances $<0.5$\,au, the thermo-optical effect of the Heat Rejection Entrance Window (HREW) becomes noticeable. We develop an interpolation scheme for the wavefront error that depends on the thermal variation of the HREW with the distance of SO to the Sun. We also introduce a new level of image reconstruction, termed `aberration correction', which is designed to reduce the noise caused by image deconvolution while removing the aberrations caused by the HREW. The computed PSF via phase diversity significantly reduces the degradation caused by the HREW in the near-perihelion HRT data. In addition, the aberration correction increases the noise by a factor of only $1.45$ compared to the factor of $3$ increase that results from the usual PD reconstructions.
Adversarial Jamming for a More Effective Constellation Attack
Creators: name: Xie, Haidong
name: Xu, Yizhou
name: Chen, Yuanqing
name: Ji, Nan
name: Yuan, Shuai
name: Liu, Naijin
name: Xiang, Xueshuang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The common jamming mode in wireless communication is band barrage jamming, which is controllable and difficult to resist. Although this method is simple to implement, it is obviously not the best jamming waveform. Therefore, based on the idea of adversarial examples, we propose the adversarial jamming waveform, which can independently optimize and find the best jamming waveform. We attack QAM with adversarial jamming and find that the optimal jamming waveform is equivalent to the amplitude and phase between the nearest constellation points. Furthermore, by verifying the jamming performance on a hardware platform, it is shown that our method significantly improves the bit error rate compared to other methods.
description: 3 pages, 2 figures, published in The 13th International Symposium on Antennas, Propagation and EM Theory (ISAPE 2021)
Using epigenetics to identify transcription factors implicated in coordinating the critical period for song learning in juvenile male zebra finches
Creators: name: Johnson, David
Publisher: name: University of Chicago
Year: 2020
Subjects: subject: epigenetics
subject: critical period
subject: learning

description: While it has long been observed that zebra finches (Taeniopygia guttata) have a critical period for song learning between post-hatch day 30 and post-hatch day 65, it remains an open question as to the underlying neural machinery that coordinates the onset as well as the offset of this learning period. Epigenetic mechanisms of regulation are now thought to play a key role in the transcriptional plasticity of key song-learning structures in the brain and can begin to account for the learning potential of a zebra finch during this period of its development. For example, the addition of an acetyl group to the lysine residue at position 27 on histone H3 as a result of exposure to song was postulated to affect the relationship between the histones and the genomic DNA and alter the probability that one or more transcription factors could bind to their corresponding binding sites. The total sum of these altered probabilities is what then could be a key driver of establishing the critical period for song learning in juvenile male zebra finches. ChIPseq analysis performed here confirmed this hypothesis, identifying a number of transcription factor binding sites differentially expressed in the finches that were exposed to song versus those that were not. Specifically, we identified the binding sites for transcription factors Zic1, Zic2, and MEIS3 which all have known functions in nervous system organization and proliferation, as well as HES6 and Hic1 which modulate neurogenesis and cell growth. Taken together, these results help to confirm the robust role that the acetylation of H3K27 has in mediating the accessibility of transcription factor binding sites and warrants further investigation into its putative role in the onset and offset of the critical period for song learning in zebra finches.
Covariant Differential Calculi on $SP_q^{1|2}$
Creators: name: Celik, Salih
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: 17B37, 81R60

description: A unitary orthosymplectic quantum supergroup is introduced. Two covariant differential calculi on the quantum superspace $SP_q^{1|2}$ are presented. The $h$-deformed symplectic superspaces via a contraction of the $q$-deformed symplectic superspaces are obtained. A new $h$-deformation of the Heisenberg superalgebra is given.
description: 18 pages
MPEC 2023-R222 : 2023 RZ9
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 RZ9

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Nondeterminism and an abstract formulation of Nečiporuk's lower bound method
Creators: name: Beame, Paul
name: Grosshans, Nathan
name: McKenzie, Pierre
name: Segoufin, Luc
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computational Complexity (cs.CC)
subject: FOS: Computer and information sciences

description: A formulation of "Nečiporuk's lower bound method" slightly more inclusive than the usual complexity-measure-specific formulation is presented. Using this general formulation, limitations to lower bounds achievable by the method are obtained for several computation models, such as branching programs and Boolean formulas having access to a sublinear number of nondeterministic bits. In particular, it is shown that any lower bound achievable by the method of Nečiporuk for the size of nondeterministic and parity branching programs is at most $O(n^{3/2}/\log n)$.
Convergence of Invariant Graph Networks
Creators: name: Cai, Chen
name: Wang, Yusu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Although theoretical properties such as expressive power and over-smoothing of graph neural networks (GNN) have been extensively studied recently, its convergence property is a relatively new direction. In this paper, we investigate the convergence of one powerful GNN, Invariant Graph Network (IGN) over graphs sampled from graphons. We first prove the stability of linear layers for general $k$-IGN (of order $k$) based on a novel interpretation of linear equivariant layers. Building upon this result, we prove the convergence of $k$-IGN under the model of \citet{ruiz2020graphon}, where we access the edge weight but the convergence error is measured for graphon inputs. Under the more natural (and more challenging) setting of \citet{keriven2020convergence} where one can only access 0-1 adjacency matrix sampled according to edge probability, we first show a negative result that the convergence of any IGN is not possible. We then obtain the convergence of a subset of IGNs, denoted as IGN-small, after the edge probability estimation. We show that IGN-small still contains function class rich enough that can approximate spectral GNNs arbitrarily well. Lastly, we perform experiments on various graphon models to verify our statements.
description: 29 pages, 11 figures
Relational coupling of multiple streams: The case of COVID‐19 infections in German abattoirs
Creators: name: Möck, Malte
name: Vogeler, Colette S.
name: Bandelow, Nils C.
name: Hornung, Johanna
Publisher: name: Humboldt-Universität zu Berlin
Year: 2022
Subjects: subject: COVID‐19
subject: labor policy
subject: multiple streams framework
subject: relational coupling
subject: 2019冠状病毒病
subject: 多源流框架
subject: 320 Politikwissenschaft (Politik und Regierung)

description: After a series of COVID-19 outbreaks among employees in the German meat-processing industry, the Work Safety Control Act protecting these workers made it on the government's agenda in July 2020. From a Multiple Streams perspective, local corona hotspots may be understood as policy windows for introducing respective measures. However, this alone is not sufficient to explain agenda setting. This study investigates the coupling of streams within policy windows. Introducing the notion of relational coupling to the MSF research agenda, discourse network analysis provides a new methodology to reveal entrepreneurial activities. Studying the German mass media discourse on the issue identifies two stages: (1) An initial problem brokerage without coupling of core policies, followed by (2) a coupling across all streams based on a focusing event. We argue that relational coupling allows for an enhanced understanding of agenda setting.
description: 德国肉制品加工业出现一系列2019冠状病毒病(COVID-19)员工感染事件后,用于保护这类员工的《工作安全防控法》(Work Safety Control Act)于2020年7月被纳入政府议程。从多源流视角来看,地方COVID-19事件可被理解为用于引入相应措施的政策之窗。不过,仅这一方面并不足以解释议程设置。本研究分析了政策之窗中各源流的耦合。通过将关系耦合(relational coupling)的概念引入多源流框架(MSF)的研究议程,话语网络分析为揭示企业活动一事提供新方法。通过研究有关该议题的德国大众媒体话语,识别了两个阶段:(1)核心政策未发生耦合的情况下出现的最初问题；(2)基于焦点事件出现的各源流耦合。我们论证认为,关系耦合促进了对议程设置的理解。
Using binaries in globular clusters to catch sight of intermediate-mass black holes
Creators: name: Aros, Francisco I.
name: Sippel, Anna C.
name: Mastrobuono-Battisti, Alessandra
name: Bianchini, Paolo
name: Askar, Abbas
name: van de Ven, Glenn
Publisher: name: Zenodo
Year: 2023

description: The dynamical evolution of globular clusters (GCs) is tied to their binary population, as binaries segregate to the cluster centre, leading to an increased binary fraction in the core. This central overabundance of mainly hard binaries can serve as a source of energy for the cluster and might significantly affect the observed kinematics of the GC. We analyse the binary fractions and distributions of 95 simulated GCs, with and without an intermediate-mass black hole (IMBH) in their centre. We show that an IMBH will not only halt the segregation of binaries towards the cluster centre but also, directly and indirectly, disrupt the binaries that segregate, thus depleting binaries in the cluster core. We illustrate this by showing that clusters with an IMBH have fewer binaries and flatter radial binary distributions than their counterparts without one. These binary fraction and distribution differences provide an additional indicator of a central IMBH in GCs.
description: Full article: Aros et al. 2021, MNRAS, 508, 4385 (https://doi.org/10.1093/mnras/stab2872)
The TESS-Keck Survey. XV. Precise Properties of 108 TESS Planets and Their Host Stars
Creators: name: MacDougall, Mason G.
name: Petigura, Erik A.
name: Gilbert, Gregory J.
name: Angelo, Isabel
name: Batalha, Natalie M.
name: Beard, Corey
name: Behmard, Aida
name: Blunt, Sarah
name: Brinkman, Casey
name: Chontos, Ashley
name: Crossfield, Ian J. M.
name: Dai, Fei
name: Dalba, Paul A.
name: Dressing, Courtney
name: Fetherolf, Tara
name: Fulton, Benjamin
name: Giacalone, Steven
name: Hill, Michelle L.
name: Holcomb, Rae
name: Howard, Andrew W.
name: Huber, Daniel
name: Isaacson, Howard
name: Kane, Stephen R.
name: Kosiarek, Molly
name: Lubin, Jack
name: Mayo, Andrew
name: Močnik, Teo
name: Murphy, Joseph M. Akana
name: Pidhorodetska, Daria
name: Polanski, Alex S.
name: Rice, Malena
name: Robertson, Paul
name: Rosenthal, Lee J.
name: Roy, Arpita
name: Rubenzahl, Ryan A.
name: Scarsdale, Nicholas
name: Turtelboom, Emma V.
name: Tyler, Dakotah
name: Van Zandt, Judah
name: Weiss, Lauren M.
name: Yee, Samuel W.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the stellar and planetary properties for 85 TESS Objects of Interest (TOIs) hosting 108 planet candidates which comprise the TESS-Keck Survey (TKS) sample. We combine photometry, high-resolution spectroscopy, and Gaia parallaxes to measure precise and accurate stellar properties. We then use these parameters as inputs to a lightcurve processing pipeline to recover planetary signals and homogeneously fit their transit properties. Among these transit fits, we detect significant transit-timing variations among at least three multi-planet systems (TOI-1136, TOI-1246, TOI-1339) and at least one single-planet system (TOI-1279). We also reduce the uncertainties on planet-to-star radius ratios $R_p/R_\star$ across our sample, from a median fractional uncertainty of 8.8$\%$ among the original TOI Catalog values to 3.0$\%$ among our updated results. With this improvement, we are able to recover the Radius Gap among small TKS planets and find that the topology of the Radius Gap among our sample is broadly consistent with that measured among Kepler planets. The stellar and planetary properties presented here will facilitate follow-up investigations of both individual TOIs and broader trends in planet properties, system dynamics, and the evolution of planetary systems.
description: Accepted at The Astronomical Journal; 21 pages, 9 figures