cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Atomistic spin textures on-demand in the van der Waals layered magnet CrSBr
Creators: name: Klein, Julian
name: Pham, Thang
name: Thomsen, Joachim Dahl
name: Curtis, Jonathan B.
name: Lorke, Michael
name: Florian, Matthias
name: Steinhoff, Alexander
name: Wiscons, Ren A.
name: Luxa, Jan
name: Sofer, Zdenek
name: Jahnke, Frank
name: Narang, Prineha
name: Ross, Frances M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Controlling magnetism in low dimensional materials is essential for designing devices that have feature sizes comparable to several critical length scales that exploit functional spin textures, allowing the realization of low-power spintronic and magneto-electric hardware. [1] Unlike conventional covalently-bonded bulk materials, van der Waals (vdW)-bonded layered magnets [2-4] offer exceptional degrees of freedom for engineering spin textures. [5] However, their structural instability has hindered microscopic studies and manipulations. Here, we demonstrate nanoscale structural control in the layered magnet CrSBr creating novel spin textures down to the atomic scale. We show that it is possible to drive a local structural phase transformation using an electron beam that locally exchanges the bondings in different directions, effectively creating regions that have vertical vdW layers embedded within the horizontally vdW bonded exfoliated flakes. We calculate that the newly formed 2D structure is ferromagnetically ordered in-plane with an energy gap in the visible spectrum, and weak antiferromagnetism between the planes. Our study lays the groundwork for designing and studying novel spin textures and related quantum magnetic phases down to single-atom sensitivity, potentially to create on-demand spin Hamiltonians probing fundamental concepts in physics, [6-10] and for realizing high-performance spintronic, magneto-electric and topological devices with nanometer feature sizes. [11,12]
description: Main manuscript: 11 pages, 4 figures ; Extended data: 22 pages, 19 figures
Full Counting Statistics of Yu-Shiba-Rusinov Bound States
Creators: name: Ohnmacht, David Christian
name: Belzig, Wolfgang
name: Cuevas, Juan Carlos
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: With the help of scanning tunneling microscopy (STM) it has become possible to address single magnetic impurities on superconducting surfaces and to investigate the peculiar properties of the in-gap states known as Yu-Shiba-Rusinov (YSR) states. However, until very recently YSR states were only investigated with conventional tunneling spectroscopy, missing the crucial information contained in other transport properties such as shot noise. Here, we adapt the concept of full counting statistics (FCS) to provide a very deep insight into the spin-dependent transport in these hybrid systems. We illustrate the power of FCS by analyzing different situations in which YSR states show up including single-impurity junctions, as well as double-impurity systems where one can probe the tunneling between individual YSR states. The FCS concept allows us to unambiguously identify every tunneling process that plays a role in these situations. Moreover, FCS provides all the relevant transport properties, including current, shot noise and all the cumulants of the current distribution. Our approach can reproduce the experimental results recently reported on the shot noise of a single-impurity junction with a normal STM tip. We also predict the signatures of resonant (and non-resonant) multiple Andreev reflections in the shot noise of single-impurity junctions with two superconducting electrodes. In the case of double-impurity junctions we show that the direct tunneling between YSR states is characterized by a strong reduction of the Fano factor that reaches a minimum value of 7/32, a new fundamental result in quantum transport. The FCS approach presented here can be naturally extended to investigate the spin-dependent superconducting transport in a variety of situations, and it is also suitable to analyze multi-terminal superconducting junctions, irradiated contacts, and many other basic situations.
description: 32 pages, 17 figures
MPLP: Massively Parallelized Lazy Planning
Creators: name: Mukherjee, Shohin
name: Aine, Sandip
name: Likhachev, Maxim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Lazy search algorithms have been developed to efficiently solve planning problems in domains where the computational effort is dominated by the cost of edge evaluation. The existing algorithms operate by intelligently balancing computational effort between searching the graph and evaluating edges. However, they are designed to run as a single process and do not leverage the multithreading capability of modern processors. In this work, we propose a massively parallelized, bounded suboptimal, lazy search algorithm (MPLP) that harnesses modern multi-core processors. In MPLP, searching of the graph and edge evaluations are performed completely asynchronously in parallel, leading to a drastic improvement in planning time. We validate the proposed algorithm in two different planning domains: 1) motion planning for 3D humanoid navigation and 2) task and motion planning for a robotic assembly task. We show that MPLP outperforms the state-of-the-art lazy search as well as parallel search algorithms. The open-source code for MPLP is available here: https://github.com/shohinm/parallel_search
description: IEEE Robotics and Automation Letters (RA-L) 2022
A QCD sum rule calculation of the $X^\pm(5568) \to B_{s}^0π^\pm$ decay width
Creators: name: Dias, J. M.
name: Khemchandani, K. P.
name: Torres, A. Martínez
name: Nielsen, M.
name: Zanetti, C. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: To understand the nature of the $X(5568)$, recently observed in the mass spectrum of the $B_{s}^0π^\pm$ system by the D0 Collaboration, we have investigated, in a previous work, a scalar tetraquark (diquak-antidiquark) structure for it, within the two-point QCD sum rules method. The result found for its mass agrees well with the experimental value. Encouraged by this finding we now extend our calculations to obtain the decay width of $X(5568)$ to $B_{s}^0π^\pm$ using the three-point QCD sum rule. We obtain a value of $(20.4\pm8.7)\MeV$, which, on comparing with the experimental value of $21.9\pm6.4 (\mbox{sta})^{+5.0}_{-2.5}(\mbox{syst}) \MeV/c^2$, reinforces the scalar four quark nature of $X(5568)$.
description: Minor modifications made. Some new discussions and references added
Satisfaction and Performance of Software Developers during Enforced Work from Home in the COVID-19 Pandemic
Creators: name: Russo, Daniel
name: Hanel, Paul H. P.
name: Altnickel, Seraphina
name: van Berkel, Niels
Publisher: name: arXiv
Year: 2021
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Following the onset of the COVID-19 pandemic and subsequent lockdowns, the daily lives of software engineers were heavily disrupted as they were abruptly forced to work remotely from home. To better understand and contrast typical working days in this new reality with work in pre-pandemic times, we conducted one exploratory (N = 192) and one confirmatory study (N = 290) with software engineers recruited remotely. Specifically, we build on self-determination theory to evaluate whether and how specific activities are associated with software engineers' satisfaction and productivity. To explore the subject domain, we first ran a two-wave longitudinal study. We found that the time software engineers spent on specific activities (e.g., coding, bugfixing, helping others) while working from home was similar to pre-pandemic times. Also, the amount of time developers spent on each activity was unrelated to their general well-being, perceived productivity, and other variables such as basic needs. Our confirmatory study found that activity-specific variables (e.g., how much autonomy software engineers had during coding) do predict activity satisfaction and productivity but not by activity-independent variables such as general resilience or a good work-life balance. Interestingly, we found that satisfaction and autonomy were significantly higher when software engineers were helping others and lower when they were bugfixing. Finally, we discuss implications for software engineers, management, and researchers. In particular, active company policies to support developers' need for autonomy, relatedness, and competence appear particularly effective in a WFH context.
description: arXiv admin note: substantial text overlap with arXiv:2101.04363
Uncertainty Prediction for Machine Learning Models of Material Properties
Creators: name: Tavazza, Francesca
name: De Cost, Brian
name: Choudhary, Kamal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Uncertainty quantification in Artificial Intelligence (AI)-based predictions of material properties is of immense importance for the success and reliability of AI applications in material science. While confidence intervals are commonly reported for machine learning (ML) models, prediction intervals, i.e., the evaluation of the uncertainty on each prediction, are seldomly available. In this work we compare 3 different approaches to obtain such individual uncertainty, testing them on 12 ML-physical properties. Specifically, we investigated using the Quantile loss function, machine learning the prediction intervals directly and using Gaussian Processes. We identify each approachs advantages and disadvantages and end up slightly favoring the modeling of the individual uncertainties directly, as it is the easiest to fit and, in most cases, minimizes over-and under-estimation of the predicted errors. All data for training and testing were taken from the publicly available JARVIS-DFT database, and the codes developed for computing the prediction intervals are available through JARVIS-Tools.
title: Modelling Low-Carbon Energy System Designs with the ETI ESME Model
Creators: name: Heaton, C.
Publisher: name: ETI
Year: 2014
Subjects: subject: Cross Cutting Programme (Strategy)
subject: OTHER CROSS-CUTTING TECHNOLOGIES or RESEARCH (Energy Models)

description: This paper provides an overview of ETI’s Energy System Modelling Environment (ESME).The first objective of this paper is to describe, in general terms, what the tool does and what it isused for. This is intended to act as background reference material for anyone who has seen ESME cited in a presentation or report and wishes to find out more about the modelling work behind the headline results.The second objective of this paper is to give a more detailed guide to the modelling approach, describing how key features of the problem are represented in the model and noting someof the key assumptions and limitations of the approach. This material is more technical, and willbe particularly useful for people with knowledge of other energy models.

This publication has been produced as part of the work on the ETI’s internationally peer reviewed energy system modelling environment (ESME) - a national energy system design and planning capability that helps to identify key areas for ETI investments. ESME is also used by UK Government to underpin and inform energy policy.
Hidden flavor symmetries of SO(10) GUT
Creators: name: Bajc, Borut
name: Smirnov, Alexei Yu.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Yukawa interactions of the SO(10) GUT with fermions in 16-plets (as well as with singlets) have certain intrinsic ("built-in") symmetries which do not depend on the model parameters. Thus, the symmetric Yukawa interactions of the 10 and 126 dimensional Higgses have intrinsic discrete $Z_2\times Z_2$ symmetries, while the antisymmetric Yukawa interactions of the 120 dimensional Higgs have a continuous SU(2) symmetry. The couplings of SO(10) singlet fermions with fermionic 16-plets have $U(1)^3$ symmetry. We consider a possibility that some elements of these intrinsic symmetries are the residual symmetries, which originate from the (spontaneous) breaking of a larger symmetry group $G_f$. Such an embedding leads to the determination of certain elements of the relative mixing matrix $U$ between the matrices of Yukawa couplings $Y_{10}$, $Y_{126}$, $Y_{120}$, and consequently, to restrictions of masses and mixings of quarks and leptons. We explore the consequences of such embedding using the symmetry group conditions. We show how unitarity emerges from group properties and obtain the conditions it imposes on the parameters of embedding. We find that in some cases the predicted values of elements of $U$ are compatible with the existing data fits. In the supersymmetric version of SO(10) such results are renormalization group invariant.
description: 28 pages, a reference added, typos corrected, to be published in NPB
Universal cutoff for Dyson Ornstein Uhlenbeck process
Creators: name: Boursier, Jeanne
name: Chafaï, Djalil
name: Labbé, Cyril
Publisher: name: arXiv
Year: 2021
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60J60 (Diffusion processes), 82C22 (Interacting particle systems)

description: We study the Dyson-Ornstein-Uhlenbeck diffusion process, an evolving gas of interacting particles. Its invariant law is the beta Hermite ensemble of random matrix theory, a non-product log-concave distribution. We explore the convergence to equilibrium of this process for various distances or divergences, including total variation, relative entropy, and transportation cost. When the number of particles is sent to infinity, we show that a cutoff phenomenon occurs: the distance to equilibrium vanishes abruptly at a critical time. A remarkable feature is that this critical time is independent of the parameter beta that controls the strength of the interaction, in particular the result is identical in the non-interacting case, which is nothing but the Ornstein-Uhlenbeck process. We also provide a complete analysis of the non-interacting case that reveals some new phenomena. Our work relies among other ingredients on convexity and functional inequalities, exact solvability, exact Gaussian formulas, coupling arguments, stochastic calculus, variational formulas and contraction properties. This work leads, beyond the specific process that we study, to questions on the high-dimensional analysis of heat kernels of curved diffusions.
description: Corrections and additions, 40 pages
Simulation and modeling of the vaporization of a freely moving and deforming drop at low to moderate Weber numbers
Creators: name: Boyd, Bradley
name: Becker, Sid
name: Ling, Yue
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The vaporization of a freely moving drop in a uniform, high-temperature gas stream is investigated through direct numerical simulation. The incompressible Navier-Stokes equations with surface tension and phase change are solved in conjunction with the energy equations of each phase. The sharp liquid-gas interface is tracked using the geometric Volume-of-Fluid (VOF) method and an immersed Dirichlet boundary condition for temperature is imposed at the interface. The simulation approach is validated by simulating water and acetone drops at nearly zero Weber numbers, and the simulation results agree very well with the empirical relation for spherical drops. Parametric simulations were conducted to investigate the aerodynamic breakup of vaporizing drops at low to moderate Weber and Reynolds numbers. The range of Weber numbers considered has covered the vibrational and bag breakup regimes. Through the simulation results, we have characterized the impact of drop deformation and breakup on the drop vaporization rate. When the drop Weber number increases, the windward surface area increases more rapidly over time. As a result, the rate of drop volume reduction also increases. The correlation between the vaporization rate and the windward surface area is examined for different Weber and Reynolds numbers. Using the approximate correlation between the drop vaporization rate and the windward surface area and the TAB model for drop deformation, a new time-dependent drop vaporization model is proposed. The present model agrees well with the simulation results and shows a significant improvement over the conventional model for spherical drops.
Existence, Stability and Scalability of Orthogonal Convolutional Neural Networks
Creators: name: Achour, El Mehdi
name: Malgouyres, François
name: Mamalet, Franck
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistics Theory (math.ST)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: Imposing orthogonality on the layers of neural networks is known to facilitate the learning by limiting the exploding/vanishing of the gradient; decorrelate the features; improve the robustness. This paper studies the theoretical properties of orthogonal convolutional layers.We establish necessary and sufficient conditions on the layer architecture guaranteeing the existence of an orthogonal convolutional transform. The conditions prove that orthogonal convolutional transforms exist for almost all architectures used in practice for 'circular' padding.We also exhibit limitations with 'valid' boundary conditions and 'same' boundary conditions with zero-padding.Recently, a regularization term imposing the orthogonality of convolutional layers has been proposed, and impressive empirical results have been obtained in different applications (Wang et al. 2020).The second motivation of the present paper is to specify the theory behind this.We make the link between this regularization term and orthogonality measures. In doing so, we show that this regularization strategy is stable with respect to numerical and optimization errors and that, in the presence of small errors and when the size of the signal/image is large, the convolutional layers remain close to isometric.The theoretical results are confirmed with experiments and the landscape of the regularization term is studied. Experiments on real data sets show that when orthogonality is used to enforce robustness, the parameter multiplying the regularization termcan be used to tune a tradeoff between accuracy and orthogonality, for the benefit of both accuracy and robustness.Altogether, the study guarantees that the regularization proposed in Wang et al. (2020) is an efficient, flexible and stable numerical strategy to learn orthogonal convolutional layers.
Sparse Stream Semantic Registers: A Lightweight ISA Extension Accelerating General Sparse Linear Algebra
Creators: name: Scheffler, Paul
name: Zaruba, Florian
name: Schuiki, Fabian
name: Hoefler, Torsten
name: Benini, Luca
Publisher: name: arXiv
Year: 2023
Subjects: subject: Hardware Architecture (cs.AR)
subject: FOS: Computer and information sciences

description: Sparse linear algebra is crucial in many application domains, but challenging to handle efficiently in both software and hardware, with one- and two-sided operand sparsity handled with distinct approaches. In this work, we enhance an existing memory-streaming RISC-V ISA extension to accelerate both one- and two-sided operand sparsity on widespread sparse tensor formats like compressed sparse row (CSR) and compressed sparse fiber (CSF) by accelerating the underlying operations of streaming indirection, intersection, and union. Our extensions enable single-core speedups over an optimized RISC-V baseline of up to 7.0x, 7.7x, and 9.8x on sparse-dense multiply, sparse-sparse multiply, and sparse-sparse addition, respectively, and peak FPU utilizations of up to 80% on sparse-dense problems. On an eight-core cluster, sparse-dense and sparse-sparse matrix-vector multiply using real-world matrices are up to 4.9x and 5.9x faster and up to 2.9x and 3.0x more energy efficient. We explore further applications for our extensions, such as stencil codes and graph pattern matching. Compared to recent CPU, GPU, and accelerator approaches, our extensions enable higher flexibility on data representation, degree of sparsity, and dataflow at a minimal hardware footprint, adding only 1.8% in area to a compute cluster. A cluster with our extensions running CSR matrix-vector multiplication achieves 9.9x and 1.7x higher peak floating-point utilizations than recent highly optimized sparse data structures and libraries for CPU and GPU, respectively, even when accounting for off-chip main memory (HBM) and on-chip interconnect latency and bandwidth effects.
description: 15 pages, 8 figures. Accepted for publication in IEEE TPDS
Trions in MoS$_2$ are quantum superpositions of intra- and intervalley spin states
Creators: name: Klein, Julian
name: Florian, Matthias
name: Hötger, Alexander
name: Steinhoff, Alexander
name: Delhomme, Alex
name: Taniguchi, Takashi
name: Watanabe, Kenji
name: Jahnke, Frank
name: Holleitner, Alexander W.
name: Potemski, Marek
name: Faugeras, Clément
name: Stier, Andreas V.
name: Finley, Jonathan J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report magneto-photoluminescence spectroscopy of gated MoS$_2$ monolayers in high magnetic fields to 28 T. At B = 0T and electron density $n_s\sim 10^{12}cm^-2$, we observe three trion resonances that cannot be explained within a single-particle picture. Employing ab initio calculations that take into account three-particle correlation effects as well as local and non-local electron-hole exchange interaction, we identify those features as quantum superpositions of inter- and intravalley spin states. We experimentally investigate the mixed character of the trion wave function via the filling factor dependent valley Zeeman shift in positive and negative magnetic fields. Our results highlight the importance of exchange interactions for exciton physics in monolayer MoS$_2$ and provide new insights into the microscopic understanding of trion physics in 2D multi-valley semiconductors for low excess carrier densities.
description: Main manuscript: 7 pages, 3 figures ; Supplemental material: 16 pages, 4 figures
Enhanced Organic Solar Cells Efficiency through Additive Electronic and Electro-optic Effects Resulting from Doping a Polymer Hole Transport Layer
Creators: name: Howells, C. T.
name: Marbou, K.
name: Kim, H.
name: Lee, K. J.
name: Heinrich, B.
name: Kim, S. J.
name: Nakao, A.
name: Aoyama, T.
name: Furukawa, S.
name: Kim, J. -H.
name: Kim, E. S.
name: Mathevet, F.
name: Mery, S.
name: Samuel, I. D. W.
name: Ghaferi, A. Al
name: Dahlem, M. S.
name: Uchiyama, M.
name: Kim, S. Y.
name: Wu, J. W.
name: Ribierre, J. -C.
name: Adachi, C.
name: Kim, D. -W.
name: André, P.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We demonstrate that blending fluorinated molecules in PEDOT:PSS hole transport layers (HTL) induces charge transfers which impact on both charge extraction and photogeneration within organic photovoltaic (OPV) devices. OPVs fabricated with modified HTL and two photoactive polymer blends led systematically to power conversion efficiencies (PCE) increases, with PTB7:PC70BM blend exhibiting PCE of ~ 8.3 %, i.e. ~ 15 % increase compared to pristine HTL devices. A reduced device-to-device characteristics variations was also noticed when fluorinated additives were used to modify the PEDOT:PSS. Shading lights onto the effect of HTL fluorination, we show that the morphology of the polymer:PCBM blends remains surprisingly unaffected by the fluorinated HTL surface energy but that, instead, the OPVs are impacted not only by the HTL electronic properties (work function, dipole layer, open circuit voltage, charge transfer dynamic) but also by alteration of the complex refractive indices (photogeneration, short circuit current density, external quantum efficiencies, electro-optic modelling). Both mechanisms find their origin in fluorination induced charge transfers. This work points towards fluorination as a promising strategy toward combining both external quantum efficiency modulation and power conversion efficiency enhancement in OPVs. Charge transfers could also be used more broadly to tune the optical constants and electric field distribution, as well as to reduce interfacial charge recombinations within OPVs.
description: 11 pages, 8 figures in J. Mater. Chem. A, 2016
title: Trimalchio’s Superstitions: Traditional Customs or their Distortion? I
Creators: name: Keyer, Denis
Publisher: name: Hyperboreus 29: 2 (2023) 241–264
Year: 2023

description: The author objects to H. Petersmann’s view that Trimalchio’s superstitious practice distorts common Roman customs and betrays his ignorance. The first half of the paper discusses two passages (Petr. 32. 3–4; 30. 5–6). (1) Petersmann erroneously states that Romans did not wear rings on their ring fingers and, relying on Plin. NH 28. 24, claims that Romans took off their rings during a meal. Yet, there is direct evidence for the opposite (Ov. Am. 1. 4. 26; Macr. Sat. 7. 13. 6), and for several reasons Pliny’s words nam si mensa adsit are likely to have been corrupt or misinterpreted. (2) Relying on Vitruv. 3. 4. 4 (on entering temples), Petersmann presumes that entering with the right foot forward was confined to sacred places, so that the prescript to enter Trimalchio’s triclinium “dextro pede” renders divine honors to his house. Yet, passages like Ov. Ibis 101 with schol.; Apul. Met. 6. 26; Amm. Marc. 26. 6. 18 make it likely that not only temples, but also private houses were to be entered with the right foot forward.
Quark exchange effects in single flavored dibaryons
Creators: name: Deng, Cheng-Rong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We reveal the quark exchange effects related to both the kinetic energy and various interactions in the single flavored dibaryon bound states with $^1S_0$ in the quark models. The hadron covalent bond can be established by the shared identical quarks due to the quark exchange effect between two colorless baryons. Such hadron covalent bond plays a decisive role in the deuteronlike di-$Ω_{ccc}$ and di-$Ω_{bbb}$ covalent molecule states. The $σ$-meson exchange is indispensable in the deuteronlike di-$Δ^{++}$ and compact di-$Ω$ states. The hadron covalent bond clearly appears in the di-$Δ^{++}$ state but is hidden in the di-$Ω$ state. The chromomagnetic interaction is always repulsive in the di-$Δ^{++}$, di-$Ω$, di-$Ω_{ccc}$, and di-$Ω_{bbb}$ states. The color-electric interaction is strongly attractive in the di-$Ω$ state but weakly attractive or repulsive in the di-$Δ^{++}$, di-$Ω_{ccc}$, and di-$Ω_{bbb}$ states.
description: 7 pages, 4 tables
ALL-Ready Flyer - The European Agroecology Living Lab and Research Infrastructure Network: Preparation phase
Creators: name: McKhann, Heather
Publisher: name: Zenodo
Year: 2023
Subjects: agroeclogy
research infrastructure
agroecology transition
living labs
horizon2020

description: Flyer for ALL-Ready the European Agroecology Living Lab and Research Infrastructure Network: Preparation phase, a Horizon 2020 project.
VarStar Detect, a Python library dedicated to the semi-automatic detection of stellar variability
Creators: name: Gonzalez, Jorge Perez
name: Arias, Nicolas Carrizosa
name: Blanco, Andres Cadenas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: VarStar Detect is a Python package available on PyPI optimized for the detection of variability inside photometric measurements. Based off of the Least Squares method of regression, VarStar Detect calculates the amplitude of a Fourier Polynomial fit of the data as a measure of variability to assess if the star is indeed variable. This work shows the mathematical background of the package and an analysis of the code's functionality on TESS Sector 1 Data.
description: Submitted to AASP
Regularizing properties of n-Laplace systems with antisymmetric potentials in Lorentz spaces
Creators: name: Martino, Dorian
name: Schikorra, Armin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We show continuity of solutions $u \in W^{1,n}(B^n,\mathbb{R}^N)$ to the system \[ -{\rm div} (|\nabla u|^{n-2} \nabla u) = Ω\cdot |\nabla u|^{n-2} \nabla u \] when $Ω$ is an $L^n$-antisymmetric potential -- and additionally satisfies a Lorentz-space assumption. To obtain our result we study a rotated n-Laplace system \[ -{\rm div} (Q|\nabla u|^{n-2} \nabla u) = \tildeΩ \cdot |\nabla u|^{n-2} \nabla u, \] where $Q \in W^{1,n}(B^n,SO(N))$ is the Coulomb gauge which ensures improved Lorentz-space integrability of $\tildeΩ$. Because of the matrix-term $Q$, this system does not fall directly into Kuusi-Mingione's vectorial potential theory. However, we adapt ideas of their theory together with Iwaniec' stability result to obtain $L^{(n,\infty)}$-estimates of the gradient of a solution which, by an iteration argument leads to the regularity of solutions. As a corollary of our argument we see that $n$-harmonic maps into manifolds are continuous if their gradient belongs to the Lorentz-space $L^{(n,2)}$ -- which is a trivial and optimal assumption if $n=2$, and the weakest assumption to date for the regularity of critical $n$-harmonic maps, without any added differentiability assumption. We also discuss an application to H systems.
description: Added application to H-systems
Dependability Analysis of Deep Reinforcement Learning based Robotics and Autonomous Systems through Probabilistic Model Checking
Creators: name: Dong, Yi
name: Zhao, Xingyu
name: Huang, Xiaowei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: Artificial Intelligence (cs.AI)
subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: While Deep Reinforcement Learning (DRL) provides transformational capabilities to the control of Robotics and Autonomous Systems (RAS), the black-box nature of DRL and uncertain deployment environments of RAS pose new challenges on its dependability. Although existing works impose constraints on the DRL policy to ensure successful completion of the mission, it is far from adequate to assess the DRL-driven RAS in a holistic way considering all dependability properties. In this paper, we formally define a set of dependability properties in temporal logic and construct a Discrete-Time Markov Chain (DTMC) to model the dynamics of risk/failures of a DRL-driven RAS interacting with the stochastic environment. We then conduct Probabilistic Model Checking (PMC) on the designed DTMC to verify those properties. Our experimental results show that the proposed method is effective as a holistic assessment framework while uncovering conflicts between the properties that may need trade-offs in training. Moreover, we find that the standard DRL training cannot improve dependability properties, thus requiring bespoke optimisation objectives. Finally, our method offers sensitivity analysis of dependability properties to disturbance levels from environments, providing insights for the assurance of real RAS.
description: Accepted by IROS2022
Collisionless dynamics of superconducting gap excited by spin-splitting field
Creators: name: Plastovets, V.
name: Mel'nikov, A. S.
name: Buzdin, A. I.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study the coherent dynamic interaction of a time-dependent spin-splitting field with the homogeneous superconducting order parameter $Δ(t)$ mediated by spin-orbit coupling using the time-dependent Bogoliubov-de Gennes theory. In the first part of the work we show that linear response of the superconductor is strongly affected by the Zeeman field and spin-flip processes, giving rise to multiple resonant frequencies of the superconducting Higgs modes. These modes can be excited either by a quench, or by an additional non-stationary component of the spin-splitting field, which couples linearly to the Higgs modes. In the second part, we analyze the nonadiabatic dynamics of quasiparticle states arising from the intersection of spectral branches from different spin subbands, which can be provoked by a linearly growing Zeeman field. We provide insights into the dependence of the order parameter $Δ(t)$ on this field and interference effects caused by tunneling of states at the avoided crossing points. We also show that since the nonadiabatic tunneling is related to spin-flip processes, the quasiparticle gas experiences a dynamic magnetization that contributes to its spin susceptibility.
Second Data Release of the COSMOS Lyman-alpha Mapping and Tomographic Observation: The First 3D Maps of the Detailed Cosmic Web at 2.05
Creators: name: Horowitz, Benjamin
name: Lee, Khee-Gan
name: Ata, Metin
name: Müller, Thomas
name: Krolewski, Alex
name: Prochaska, J. Xavier
name: Hennawi, Joseph F.
name: White, Martin
name: Schlegel, David
name: Rich, R. Michael
name: Nugent, Peter E.
name: Suzuki, Nao
name: Kashino, Daichi
name: Koekemoer, Anton M.
name: Lemaux, Brian C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present the second data release of the COSMOS Lyman-Alpha Mapping And Tomography Observations (CLAMATO) Survey conducted with the LRIS spectrograph on the Keck-I telescope. This project used Lyman-alpha forest absorption in the spectra of faint star forming galaxies and quasars at z ~ 2-3 to trace neutral hydrogen in the intergalactic medium. In particular, we use 320 objects over a footprint of ~0.2 deg^2 to reconstruct the absorption field at 2.05 < z < 2.55 at ~2 h^{-1}Mpc resolution. We apply a Wiener filtering technique to the observed data to reconstruct three dimensional maps of the field over a volume of 4.1 x 10^5 comoving cubic Mpc. In addition to the filtered flux maps, for the first time we infer the underlying dark matter field through a forward modeling framework from a joint likelihood of galaxy and Lyman-alpha forest data, finding clear examples of the detailed cosmic web consisting of cosmic voids, sheets, filaments, and nodes. In addition to traditional figures, we present a number of interactive three dimensional models to allow exploration of the data and qualitative comparisons to known galaxy surveys. We find that our inferred over-densities are consistent with those found from galaxy fields. Our reduced spectra, extracted Lyman-alpha forest pixel data, and reconstructed tomographic maps are available publicly at https://doi.org/10.5281/zenodo.7524313
description: 20 pages, 15 figures. Data is available at https://doi.org/10.5281/zenodo.7524313 arXiv admin note: text overlap with arXiv:1710.02894
A Survey on Deep Learning-Based Monocular Spacecraft Pose Estimation: Current State, Limitations and Prospects
Creators: name: Pauly, Leo
name: Rharbaoui, Wassim
name: Shneider, Carl
name: Rathinam, Arunkumar
name: Gaudilliere, Vincent
name: Aouada, Djamila
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Estimating the pose of an uncooperative spacecraft is an important computer vision problem for enabling the deployment of automatic vision-based systems in orbit, with applications ranging from on-orbit servicing to space debris removal. Following the general trend in computer vision, more and more works have been focusing on leveraging Deep Learning (DL) methods to address this problem. However and despite promising research-stage results, major challenges preventing the use of such methods in real-life missions still stand in the way. In particular, the deployment of such computation-intensive algorithms is still under-investigated, while the performance drop when training on synthetic and testing on real images remains to mitigate. The primary goal of this survey is to describe the current DL-based methods for spacecraft pose estimation in a comprehensive manner. The secondary goal is to help define the limitations towards the effective deployment of DL-based spacecraft pose estimation solutions for reliable autonomous vision-based applications. To this end, the survey first summarises the existing algorithms according to two approaches: hybrid modular pipelines and direct end-to-end regression methods. A comparison of algorithms is presented not only in terms of pose accuracy but also with a focus on network architectures and models' sizes keeping potential deployment in mind. Then, current monocular spacecraft pose estimation datasets used to train and test these methods are discussed. The data generation methods: simulators and testbeds, the domain gap and the performance drop between synthetically generated and lab/space collected images and the potential solutions are also discussed. Finally, the paper presents open research questions and future directions in the field, drawing parallels with other computer vision applications.
A Tweezer for Chimeras in Small Networks
Creators: name: Omelchenko, Iryna
name: Omel'chenko, Oleh E.
name: Zakharova, Anna
name: Wolfrum, Matthias
name: Schoell, Eckehard
Publisher: name: arXiv
Year: 2015
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We propose a control scheme which can stabilize and fix the position of chimera states in small networks. Chimeras consist of coexisting domains of spatially coherent and incoherent dynamics in systems of nonlocally coupled identical oscillators. Chimera states are generally difficult to observe in small networks due to their short lifetime and erratic drifting of the spatial position of the incoherent domain. The control scheme, like a tweezer, might be useful in experiments, where usually only small networks can be realized.
title: Energy From Waste : WP3.3 - Technology System Improvement Opportunity Report
Creators: name: Hillier, G.
name: Donegan, S.
Publisher: name: ETI
Year: 2011
Subjects: subject: Bioenergy
subject: OTHER POWER and STORAGE TECHNOLOGIES (Electric power conversion)

description: This deliverable is number 3 of 3 in Work Package 3 and describes the findings and outputs from the technology system modelling work carried out by the consortium. It draws on the outputs from WP1 ? Waste Assessment and WP2 ? Assessment of EfW technologies. It combines the arising data from each work package into an economic, mass and energy model which takes into account the changing availability of wastes in the UK and aligns technology choices with the likely waste arisings.
Control of wave scattering for robust coherent transmission in a disordered medium
Creators: name: Ong, Zhun-Yong
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The spatial structure of the inhomogeneity in a disordered medium determines how waves scatter and propagate in it. We present a theoretical model of how the Fourier components of the disorder control wave scattering in a two-dimensional disordered medium, by analyzing the disordered Green's function for scalar waves. By selecting a set of Fourier components with the appropriate wave vectors, we can enhance or suppress wave scattering to filter out unwanted waves and allow the robust coherent transmission of waves at specific angles and wavelengths through the disordered medium. Based on this principle, we propose an approach for creating selective transparency, band gaps and anisotropy in disordered media. This approach is validated by direct numerical simulations of coherent wave transmission over a wide range of incident angles and frequencies and can be experimentally realized in disordered photonic crystals. Our approach, which requires neither nontrivial topological wave properties nor a non-Hermitian medium, creates opportunities for exploring a broad range of wave phenomena in disordered systems.
description: 11 pages with 7 figures
Converse effect of pressure on quadrupolar and magnetic transition in Ce$_{3}$Pd$_{20}$Si$_{6}$
Creators: name: Larrea, J.
name: Strydom, A. M.
name: Martelli, V.
name: Prokofiev, A.
name: Lorenzer, K. - A.
name: Rønnow, H. M.
name: Paschen, S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The heavy fermion compound Ce$_{3}$Pd$_{20}$Si$_{6}$ displays unconventional quantum criticality as the lower of two consecutive phase transitions is fully suppressed by magnetic field. Here we report on the effects of pressure as additional tuning parameter. Specific heat and electrical resistivity measurements reveal a converse effect of pressure on the two transitions, leading to the merging of both transitions at 6.2 kbar. The field-induced quantum criticality is robust under pressure tuning. We rationalize our findings within an extended version of the global phase diagram for antiferromagnetic heavy fermion quantum criticality.
description: accepted for publication in Phys. Rev. B
Global Well-Posedness For Half-Wave Maps With $S^2$ and $\mathbb{H}^2$ Targets For Small Smooth Initial Data
Creators: name: Liu, Yang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35L05, 35A01, 35B40

description: We prove global well-posedness for the half-wave map with $S^2$ target for small $\dot{H}^{\frac{n}{2}} \times \dot{H}^{\frac{n}{2}-1}$ initial data. We also prove the global well-posedness for the equation with $\mathbb{H}^2$ target for small smooth $\dot{B}^{\frac{n}{2}}_{2,1} \times \dot{B}^{\frac{n}{2}-1}_{2,1}$ initial data.
description: 48 pages
Satellite radio detection via dual-microwave Rydberg spectroscopy
Creators: name: Elgee, Peter K
name: Hill, Joshua C
name: Leblanc, Kermit-James E
name: Ko, Gabriel D
name: Kunz, Paul D
name: Meyer, David H
name: Cox, Kevin C
Publisher: name: arXiv
Year: 2023
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Applied Physics (physics.app-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Rydberg electric field sensors exploit the large number of Rydberg resonances to provide sensitivity over a broad range of the electromagnetic spectrum. However, due to the difficulty of accessing resonant Rydberg states at ultra-high frequency (UHF) and below, ubiquitous bands in the world's current wireless communications infrastructure, they currently fall short in sensitivity in this range. We present a resonant Rydberg electric field sensor operating in the UHF band using a dual-optical dual-microwave spectroscopy scheme. Adding an additional microwave photon allows us to access transitions between Rydberg states with higher angular momentum ($L = 3 \rightarrow 4$), which have lower resonant frequencies than transitions typically used in Rydberg sensors. We discuss the applicability of this type of sensor across the UHF band and below, and measure the resonant sensitivity of our system at 2.3 GHz to be 70(5) $μ$Vm$^{-1}\text{Hz}^{-1/2}$, 50 times better than the measured sensitivity with a far off-resonant probing scheme at this frequency. We also show the effectiveness of this sensing scheme by measuring Sirius XM satellite radio (2.320 - 2.345 GHz) received outside the laboratory and rebroadcast onto the atoms.
description: 6 pages, 3 figures
Configuration mixing and intertwined quantum phase transitions in odd-mass niobium isotopes
Creators: name: Gavrielov, N.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Nuclei in the $Z\!\approx\!40,N\!\approx\!60$ region have one of the most complicated structural evolution across the nuclear chart, with coexisting shapes arising from different mixed configurations. In such a region, it is difficult to investigate odd-mass nuclei. In this paper a new algebraic framework is introduced, the interacting boson-fermion model with configuration mixing. Using this framework, with a boson core and a proton in the $1f_{5/2},2p_{3/2},2p_{1/2},1g_{9/2}$ orbits, a calculation is carried out to understand the structural evolution of the odd-mass niobium isotopes $(Z=41)$ with neutron number 52-62. The calculated results are compared to energy levels, two neutron separation energies, $E2$ and $M1$ transition rates, and to quadrupole and magnetic moments. The detailed analysis discloses the effects of an abrupt crossing of states between normal and intruder configurations (Type II QPT), which is accompanied by a gradual evolution from spherical- to deformed-core shapes within the intruder configuration (Type I QPT), where both types of QPTs occur around the critical point of neutron number 60. The identification of both types of QPTs in the same chain of isotopes provides an empirical manifestation of intertwined quantum phase transitions (IQPTs) in odd-mass nuclei and the relevance of IQPTs to the niobium chain.
description: 20 pages, 24 figures, 2 tables. arXiv admin note: text overlap with arXiv:2210.00441
Composite operators of stochastic model A
Creators: name: Davletbaeva, D.
name: Hnatič, M.
name: Komarova, M. V.
name: Lučivjanský, T.
name: Mižišin, L.
name: Nalimov, M. Yu.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: By means of the field-theoretic renormalization group, we study the damping of the viscosity coefficient near the superfluid phase transition. We utilize the fact that in the infrared region, the complex model used to describe the phase transition belongs to the same universality class as the well-known stochastic model A. This allows us a determination of the critical behavior of viscosity using composite operators for model A. Our analysis is based on the $\varepsilon$-expansion near the upper critical dimension $d_c = 4$ of model A. The critical exponent of viscosity is then calculated from the critical dimensions of composite operators of massless two-component model A. In particular, we present results for critical dimensions of a selected class of composite operators with the canonical dimension $8$ to the leading order.
description: Accepted for publication in Theor. Math. Phys