cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Distributed sampled-data control of nonholonomic multi-robot systems with proximity networks
Creators: name: Liu, Zhixin
name: Wang, Lin
name: Wang, Jinhuan
name: Dong, Daoyi
name: Hu, Xiaoming
Publisher: name: arXiv
Year: 2016
Subjects: subject: Systems and Control (eess.SY)
subject: Multiagent Systems (cs.MA)
subject: Robotics (cs.RO)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: This paper considers the distributed sampled-data control problem of a group of mobile robots connected via distance-induced proximity networks. A dwell time is assumed in order to avoid chattering in the neighbor relations that may be caused by abrupt changes of positions when updating information from neighbors. Distributed sampled-data control laws are designed based on nearest neighbour rules, which in conjunction with continuous-time dynamics results in hybrid closed-loop systems. For uniformly and independently initial states, a sufficient condition is provided to guarantee synchronization for the system without leaders. In order to steer all robots to move with the desired orientation and speed, we then introduce a number of leaders into the system, and quantitatively establish the proportion of leaders needed to track either constant or time-varying signals. All these conditions depend only on the neighborhood radius, the maximum initial moving speed and the dwell time, without assuming a prior properties of the neighbor graphs as are used in most of the existing literature.
description: 15 pages, 3 figures
On Deep Learning Classification of Digitally Modulated Signals Using Raw I/Q Data
Creators: name: Snoap, John A.
name: Popescu, Dimitrie C.
name: Spooner, Chad M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The paper considers the problem of deep-learning-based classification of digitally modulated signals using I/Q data and studies the generalization ability of a trained neural network (NN) to correctly classify digitally modulated signals it has been trained to recognize when the training and testing datasets are distinct. Specifically, we consider both a residual network (RN) and a convolutional neural network (CNN) and use them in conjunction with two different datasets that contain similar classes of digitally modulated signals but that have been generated independently using different means, with one dataset used for training and the other one for testing.
description: Published in IEEE CCNC 2022: 2022 IEEE 19th Annual Consumer Communications & Networking Conference
Enhancing thermal stability of solution-processed small molecule semiconductor thin films using a flexible linker approach
Creators: name: Gasperini, Andrea
name: Jeanbourquin, Xavier
name: Rahmanudin, Aiman
name: Yu, Xiaoyun
name: Sivula, Kevin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Solution-processed organic photovoltaics (OPV) have recently reached the target 10% power conversion efficiency expected to signal their viable commercialization as an inexpensive and scalable energy conversion technology. However, obtaining devices with suitable long-term stability remains an unsolved challenge. Here we present a new strategy to improve the thermal stability of small-molecule-based bulk-heterojunction OPVs by including a custom additive specifically designed to interact with the device active layer components. Our results indicate that active layer degradation under continuous thermal stress can be inhibited due to the formation of more robust thin film microstructure with the additive present. Since our additive employs the identical semiconductor core used in the active layer, but linked by aliphatic chains into a flexible polymer, this straightforward strategy can reasonably be applied to stabilize a wide variety of semiconducting small molecules in solution-processed molecular OPVs, transistors and light emitting diodes.
description: 17 pages, 4 figures
Plastic Leakage GIS Toolbox v.1
Creators: name: Nidia, Aprilia
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 370499
subject: Geoinformatics not elsewhere classified

description: The plastic leakage model in v.1 is developed using Model Builder which can be run in the ArcMap or ArcGIS Pro, limited to the manual data input.
Very accurate time propagation of coupled Schrödinger equations for femto- and attosecond physics and chemistry, with C++ source code
Creators: name: Kozicki, Janek
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this article, I present a very fast and high-precision (up to 33 decimal places) C++ implementation of the semi-global time propagation algorithm for a system of coupled Schrödinger equations with a time-dependent Hamiltonian. It can be used to describe time-dependent processes in molecular systems after excitation by femto- and attosecond laser pulses. It also works with an arbitrary user supplied Hamiltonian and can be used for nonlinear problems. The semi-global algorithm is briefly presented, the C++ implementation is described and five sample simulations are shown. The accompanying C++ source code package is included. The high precision benchmark (long double and float128) shows the estimated calculation costs. The presented method turns out to be faster and more accurate than the global Chebyshev propagator.
description: 22 pages, 9 figures, 8 tables, 4 code listings
A Dataset of Inertial Measurement Units for Handwritten English Alphabets
Creators: name: Gupta, Hari Prabhat
name: Mishra, Rahul
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This paper presents an end-to-end methodology for collecting datasets to recognize handwritten English alphabets by utilizing Inertial Measurement Units (IMUs) and leveraging the diversity present in the Indian writing style. The IMUs are utilized to capture the dynamic movement patterns associated with handwriting, enabling more accurate recognition of alphabets. The Indian context introduces various challenges due to the heterogeneity in writing styles across different regions and languages. By leveraging this diversity, the collected dataset and the collection system aim to achieve higher recognition accuracy. Some preliminary experimental results demonstrate the effectiveness of the dataset in accurately recognizing handwritten English alphabet in the Indian context. This research can be extended and contributes to the field of pattern recognition and offers valuable insights for developing improved systems for handwriting recognition, particularly in diverse linguistic and cultural contexts.
description: 10 pages, 12 figures
A hot big bang theory: magnetic fields and the early evolution of the protolunar disk
Creators: name: Gammie, Charles F.
name: Liao, Wei-Ting
name: Ricker, Paul M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The leading theory for the formation of the Earth's moon invokes a collision between a Mars-sized body and the proto-Earth to produce a disk of orbiting material that later condenses to form the Moon. Here we study the early evolution of the protolunar disk. First, we show that the disk opacity is large and cooling is therefore inefficient (t_{cool} Ω>> 1). In this regime angular momentum transport in the disk leads to steady heating unless α< (t_{cool} Ω)^{-1} << 1. Following earlier work by Charnoz and Michaut, and Carballido et al., we show that once the disk is completely vaporized it is well coupled to the magnetic field. We consider a scenario in which turbulence driven by magnetic fields leads to a brief, hot phase where the disk is geometrically thick, wit h strong turbulent mixing. The disk cools by spreading until it decouples from the field. We point out that approximately half the accretion energy is dissipated in the boundary layer where the disk meets the Earth's surface. This creates high entropy material close to the Earth, driving convection and mixing. Finally, a hot, magnetized disk could drive bipolar outflows that remove mass and angular momentum from the Earth-Moon system.
description: 22 pages, 2 figures, accepted by ApJ
Motion magnification in coronal seismology
Creators: name: Anfinogentov, Sergey
name: Nakariakov, Valery M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We introduce a new method for the investigation of low-amplitude transverse oscillations of solar plasma non-uniformities, such as coronal loops, individual strands in coronal arcades, jets, prominence fibrils, polar plumes, and other contrast features, observed with imaging instruments. The method is based on the two-dimensional dual tree complex wavelet transform (DT$\mathbb{C}$WT). It allows us to magnify transverse, in the plane-of-the-sky, quasi-periodic motions of contrast features in image sequences. The tests performed on the artificial data cubes imitating exponentially decaying, multi-periodic and frequency-modulated kink oscillations of coronal loops showed the effectiveness, reliability and robustness of this technique. The algorithm was found to give linear scaling of the magnified amplitudes with the original amplitudes provided they are sufficiently small. Also, the magnification is independent of the oscillation period in a broad range of the periods. The application of this technique to SDO/AIA EUV data cubes of a non-flaring active region allowed for the improved detection of low-amplitude decay-less oscillations in the majority of loops.
description: Accepted for publication in Solar Physics
Irrationality proofs à la Hermite
Creators: name: Zhou, Li
Publisher: name: arXiv
Year: 2009
Subjects: subject: Number Theory (math.NT)
subject: History and Overview (math.HO)
subject: FOS: Mathematics
subject: 11J72

description: As rewards of reading two great papers of Hermite from 1873, we trace the historical origin of the integral Niven used in his well-known proof of the irrationality of $π$, uncover a rarely acknowledged simple proof by Hermite of the irrationality of $π^2$, give a new proof of the irrationality of $r\tan r$ for nonzero rational $r^2$, and generalize it to a proof of the irrationality of certain ratios of Bessel functions.
description: 8 pages
Small-volume effect enables the spine robust, sensitive and efficient information transfer
Creators: name: Fujii, Masashi
name: Ohashi, Kaoru
name: Karasawa, Yasuaki
name: Hikichi, Minori
name: Kuroda, Shinya
Publisher: name: arXiv
Year: 2016
Subjects: subject: Subcellular Processes (q-bio.SC)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Why is the spine of a neuron so small that only small numbers of molecules can exist and reactions inevitably become stochastic? Despite such noisy conditions, we previously showed that the spine exhibits robust, sensitive and efficient features of information transfer using probability of Ca$^{2+}$ increase; however, their mechanisms remains unknown. Here we show that the small-volume effect enables robust, sensitive and efficient information transfer in the spine volume, but not in the cell volume. In the spine volume, intrinsic noise in reactions becomes larger than extrinsic noise of input, making robust information transfer against input fluctuation. Stochastic facilitation of Ca$^{2+}$ increase occurs in the spine volume, making higher sensitivity to lower intensity of input. Volume-dependency of information transfer enables efficient information transfer per input in the spine volume. Thus, we propose that the small-volume effect is the functional reasons why the spine has to be so small.
description: 32 pages, 7 figures in main text; 12 pages, 9 figures, 2 tables in Supplementary Information (combined)
Transverse Thermoelectric Response as a Probe for Existence of Quasiparticles
Creators: name: Schattner, Yoni
name: Oganesyan, Vadim
name: Orgad, Dror
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The electrical Hall conductivities of any anisotropic interacting system with reflection symmetry obey sigma_{xy} = - sigma_{yx}. In contrast, we show that the analogous relation between the transverse thermoelectric Peltier coefficients, alpha_{xy}= - alpha_{yx}, does not generally hold in the same system. This fact may be traced to interaction contributions to the heat current operator and the mixed nature of the thermoelectric response functions. Remarkably, however, it appears that emergence of quasiparticles at low temperatures forces alpha_{xy} = - alpha_{yx}. This suggests that quasiparticle-free groundstates (so-called non-Fermi liquids) may be detected by examining the relationship between alpha_{xy} and alpha_{yx} in the presence of reflection symmetry and microscopic anisotropy. These conclusions are based on the following results: (i) The relation between the Peltier coefficients is exact for elastically scattered noninteracting particles; (ii) It holds approximately within Boltzmann theory for interacting particles when elastic scattering dominates over inelastic processes. In a disordered Fermi liquid the latter lead to deviations that vanish as T^3. (iii) We calculate the thermoelectric response in a model of weakly-coupled spin-gapped Luttinger liquids and obtain strong breakdown of antisymmetry between the off-diagonal components of alpha. We also find that the Nernst signal in this model is enhanced by interactions and can change sign as function of magnetic field and temperature.
description: 15 pages, 4 figures
Parametric symmetries in exactly solvable real and P T symmetric complex potentials
Creators: name: Yadav, Rajesh Kumar
name: Khare, Avinash
name: Bagchi, Bijan
name: Kumari, Nisha
name: Mandal, Bhabani Prasad
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In this paper, we discuss the parametric symmetries in different exactly solvable systems characterized by real or complex P T symmetric potentials. We focus our at- tention on the conventional potentials such as the generalized Poschl Teller (GPT), o Scarf-I and P T symmetric Scarf-II which are invariant under certain parametric transformations. The resulting set of potentials are shown to yield a completely dif- ferent behavior of the bound state solutions. Further the supersymmetric (SUSY) partner potentials acquire different forms under such parametric transformations leading to new sets of exactly solvable real and P T symmetric complex potentials. These potentials are also observed to be shape invariant (SI) in nature. We subse- quently take up a study of the newly discovered rationally extended SI Potentials, corresponding to the above mentioned conventional potentials, whose bound state solutions are associated with the exceptional orthogonal polynomials (EOPs). We discuss the transformations of the corresponding Casimir operator employing the properties of the so(2,1) algebra.
description: 22 pages, Latex, No figs
Bounding the Complexity of Replica Symmetry Breaking for Spherical Spin Glasses
Creators: name: Jagannath, Aukosh
name: Tobasco, Ian
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper, we study the Crisanti-Sommers variational problem, which is a variational formula for the free energy of spherical mixed $p$-spin glasses. We begin by computing the dual of this problem using a min-max argument. We find that the dual is a 1-D problem of obstacle type, where the obstacle is related to the covariance structure of the underlying process. This approach yields an alternative way to understand Replica Symmetry Breaking at the level of the variational problem through topological properties of the coincidence set of the optimal dual variable. Using this duality, we give an algorithm to reduce this a priori infinite dimensional variational problem to a finite dimensional one, thereby confining all possible forms of Replica Symmetry Breaking in these models to a finite parameter family. These results complement the authors' related results for the low temperature $Γ$-limit of this variational problem. We briefly discuss the analysis of the Replica Symmetric phase using this approach.
Solar Flare Prediction Model with Three Machine-Learning Algorithms Using Ultraviolet Brightening and Vector Magnetogram
Creators: name: Nishizuka, N.
name: Sugiura, K.
name: Kubo, Y.
name: Den, M.
name: Watari, S.
name: Ishii, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We developed a flare prediction model using machine learning, which is optimized to predict the maximum class of flares occurring in the following 24 h. Machine learning is used to devise algorithms that can learn from and make decisions on a huge amount of data. We used solar observation data during the period 2010-2015, such as vector magnetogram, ultraviolet (UV) emission, and soft X-ray emission taken by the Solar Dynamics Observatory and the Geostationary Operational Environmental Satellite. We detected active regions from the full-disk magnetogram, from which 60 features were extracted with their time differentials, including magnetic neutral lines, the current helicity, the UV brightening, and the flare history. After standardizing the feature database, we fully shuffled and randomly separated it into two for training and testing. To investigate which algorithm is best for flare prediction, we compared three machine learning algorithms: the support vector machine (SVM), k-nearest neighbors (k-NN), and extremely randomized trees (ERT). The prediction score, the true skill statistic (TSS), was higher than 0.9 with a fully shuffled dataset, which is higher than that for human forecasts. It was found that k-NN has the highest performance among the three algorithms. The ranking of the feature importance showed that the previous flare activity is most effective, followed by the length of magnetic neutral lines, the unsigned magnetic flux, the area of UV brightening, and the time differentials of features over 24 h, all of which are strongly correlated with the flux emergence dynamics in an active region.
description: 27 pages, 3 figures
Application of the Non-extensive Statistical Approach to High Energy Particle Collisions
Creators: name: Bíró, Gábor
name: Barnaföldi, Gergely Gábor
name: Biró, Tamás Sándor
name: Ürmössy, Károly
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In high-energy collisions the number of the created particles is far less than the thermodynamic limit, especially in small colliding systems (e.g. proton-proton). Therefore final-state effects and fluctuations in the one-particle energy distribution are appreciable. As a consequence the characterization of identified hadron spectra with the Boltzmann\,--\,Gibbs thermodynamical approach is insufficient. Instead particle spectra measured in high-energy collisions can be described very well with Tsallis\,--\,Pareto distributions, derived from non-extensive thermodynamics. Using the Tsallis q-entropy formula, a generalization of the Boltzmann\,--\,Gibbs entropy, we interpret the microscopical physics by analysing the Tsallis $q$ and $T$ parameters. In this paper we give a quick overview on these parameters, analyzing identified hadron spectra from recent years in a wide center of mass energy range. We demonstrate that the fitted Tsallis-parameters show dependency on this energy and on the particle species. Our findings are described well by a QCD inspired evolution ansatz.
The Stefan outflow in a multicomponent vapor-gas atmosphere around a droplet and its role for cloud expansion
Creators: name: Kuchma, A. E.
name: Shchekin, A. K.
name: Martyukova, D. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: A new comprehensive analysis of Stefan's flow caused by a free growing droplet in vapor-gas atmosphere with several condensing components is presented. This analysis, based on the nonstationary heat and material balance and diffusion transport equations, shows the appearance of the Stefan inflow in the vicinity of the growing droplet and the outflow at large distances from the droplet as a consequence of nonisothermal condensation. For an ensemble of droplets in the atmospheric cloud, this flow provides an increase of the total volume of the cloud, which can be treated as cloud thermal expansion and leads to floating the cloud as a whole due to buoyancy. We have formulated the self-similar solutions of the nonstationary diffusion and heat conduction equations for a growing multicomponent droplet and have derived analytical expressions for the nonstationary velocity profile of Stefan's flow and the expansion volume of the vapor-gas mixture around the growing droplet. To illustrate the approach, we computed these quantities in the case of droplet of stationary composition in air with several specific vapors (${\mathrm{C_2H_5OH/H_2O}}$; ${\mathrm{H_2SO_4/H_2O}}$; ${\mathrm{H_2O}}$).
description: 10 pages, 1 figure, 1 table
The environment of radio sources in the VLA-COSMOS Survey field
Creators: name: Malavasi, Nicola
name: Bardelli, Sandro
name: Ciliegi, Paolo
name: Ilbert, Olivier
name: Pozzetti, Lucia
name: Zucca, Elena
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: This work studies the correlation among environmental density and radio AGN presence up to $z = 2$. Using data from the photometric COSMOS survey and its radio 1.4 GHz follow-up (VLA-COSMOS), a sample of radio AGNs has been defined. The environment was studied using the richness distributions inside a parallelepiped with base side of 1 Mpc and height proportional to the photometric redshift precision. Radio AGNs are found to be always located in environments significantly richer than those around galaxies with no radio emission. Moreover, a distinction based on radio AGN power shows that the significance of the environmental effect is only maintained for low-power radio sources. The results of this work show that denser environments play a significant role in enhancing the probability that a galaxy hosts a radio AGN and, in particular, low-power ones.
description: 4 pages, 2 figures. Contribution to the proceedings of the conference "The Universe of Digital Sky Surveys", Napoli, November 25th-28th, 2014
Unsupervised Image Segmentation using the Deffuant-Weisbuch Model from Social Dynamics
Creators: name: Kayal, Subhradeep
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Unsupervised image segmentation algorithms aim at identifying disjoint homogeneous regions in an image, and have been subject to considerable attention in the machine vision community. In this paper, a popular theoretical model with it's origins in statistical physics and social dynamics, known as the Deffuant-Weisbuch model, is applied to the image segmentation problem. The Deffuant-Weisbuch model has been found to be useful in modelling the evolution of a closed system of interacting agents characterised by their opinions or beliefs, leading to the formation of clusters of agents who share a similar opinion or belief at steady state. In the context of image segmentation, this paper considers a pixel as an agent and it's colour property as it's opinion, with opinion updates as per the Deffuant-Weisbuch model. Apart from applying the basic model to image segmentation, this paper incorporates adjacency and neighbourhood information in the model, which factors in the local similarity and smoothness properties of images. Convergence is reached when the number of unique pixel opinions, i.e., the number of colour centres, matches the pre-specified number of clusters. Experiments are performed on a set of images from the Berkeley Image Segmentation Dataset and the results are analysed both qualitatively and quantitatively, which indicate that this simple and intuitive method is promising for image segmentation. To the best of the knowledge of the author, this is the first work where a theoretical model from statistical physics and social dynamics has been successfully applied to image processing.
description: This paper is under consideration at Signal Image and Video Processing journal
Distinct magnetic spectra in the hidden order and antiferromagnetic phases in URu2-xFexSi2
Creators: name: Butch, Nicholas P.
name: Ran, Sheng
name: Jeon, Inho
name: Kanchanavatee, Noravee
name: Huang, Kevin
name: Breindel, Alexander
name: Maple, M. Brian
name: Stillwell, Ryan L.
name: Zhao, Yang
name: Harriger, Leland
name: Lynn, Jeffrey W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We use neutron scattering to compare the magnetic excitations in the hidden order (HO) and antiferromagnetic (AFM) phases in URu2-xFexSi2 as a function of Fe concentration. The magnetic excitation spectra change significantly between x = 0.05 and x = 0.10, following the enhancement of the AFM ordered moment, in good analogy to the behavior of the parent compound under applied pressure. Prominent lattice-commensurate low-energy excitations characteristic of the HO phase vanish in the AFM phase. The magnetic scattering is dominated by strong excitations along the Brillouin zone edges, underscoring the important role of electron hybridization to both HO and AFM phases, and the similarity of the underlying electronic structure. The stability of the AFM phase is correlated with enhanced local-itinerant electron hybridization.
description: 4 figures
Ultra-wide frequency response measurement of an optical system with a DC photo-detector
Creators: name: Kuntz, Katanya B.
name: Wheatley, Trevor A.
name: Song, Hongbin
name: Webb, James G.
name: Mabrok, Mohamed A.
name: Huntington, Elanor H.
name: Yonezawa, Hidehiro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Precise knowledge of an optical device's frequency response is crucial for it to be useful in most applications. Traditional methods for determining the frequency response of an optical system (e.g. optical cavity or waveguide modulator) usually rely on calibrated broadband photo-detectors or complicated RF mixdown operations. As the bandwidths of these devices continue to increase, there is a growing need for a characterization method that does not have bandwidth limitations, or require a previously calibrated device. We demonstrate a new calibration technique on an optical system (consisting of an optical cavity and a high-speed waveguide modulator) that is free from limitations imposed by detector bandwidth, and does not require a calibrated photo-detector or modulator. We use a low-frequency (DC) photo-detector to monitor the cavity's optical response as a function of modulation frequency, which is also used to determine the modulator's frequency response. Knowledge of the frequency-dependent modulation depth allows us to more precisely determine the cavity's characteristics (free spectral range and linewidth). The precision and repeatability of our technique is demonstrated by measuring the different resonant frequencies of orthogonal polarization cavity modes caused by the presence of a non-linear crystal. Once the modulator has been characterized using this simple method, the frequency response of any passive optical element can be determined.
description: 10 pages, 7 figures
The Dirichlet problem for second order parabolic operators in divergence form
Creators: name: Auscher, Pascal
name: Egert, Moritz
name: Nyström, Kaj
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We study parabolic operators H = $\partial$t -- div $λ$,x A(x, t)$\nabla$ $λ$,x in the parabolic upper half space R n+2 + = {($λ$, x, t) : $λ$ > 0}. We assume that the coefficients are real, bounded, measurable, uniformly elliptic, but not necessarily symmetric. We prove that the associated parabolic measure is absolutely continuous with respect to the surface measure on R n+1 in the sense defined by A$\infty$(dx dt). Our argument also gives a simplified proof of the corresponding result for elliptic measure.
description: Upload of the published version
On Rational Sets in Euclidean Spaces and Spheres
Creators: name: Kumar, C P Anil
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: Primary 11J17, 11J83 Secondary 14G05

description: IFor a positive rational $l$, we define the concept of an $l$-elliptic and an $l$-hyperbolic rational set in a metric space. In this article we examine the existence of (i) dense and (ii) infinite $l$-hyperbolic and $l$-ellitpic rationals subsets of the real line and unit circle. For the case of a circle, we prove that the existence of such sets depends on the positivity of ranks of certain associated elliptic curves. We also determine the closures of such sets which are maximal in case they are not dense. In higher dimensions, we show the existence of $l$-ellitpic and $l$-hyperbolic rational infinite sets in unit spheres and Euclidean spaces for certain values of $l$ which satisfy a weaker condition regarding the existence of elements of order more than two, than the positivity of the ranks of the same associated elliptic curves. We also determine their closures. A subset $T$ of the $k$-dimensional unit sphere $S^k$ has an antipodal pair if both $x,-x\in T$ for some $x\in S^k$. In this article, we prove that there does not exist a dense rational set $T\subset S^2$ which has an antipodal pair by assuming Bombieri-Lang Conjecture for surfaces of general type. We actually show that the existence of such a dense rational set in $S^k$ is equivalent to the existence of a dense $2$-hyperbolic rational set in $S^k$ which is further equivalent to the existence of a dense 1-elliptic rational set in the Euclidean space $\mathbb{R}^k$.
description: 20 pages
Electron Bubbles in Superfluid $^3$He-A: Exploring the Quasiparticle-Ion Interaction
Creators: name: Shevtsov, Oleksii
name: Sauls, J. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: When an electron is forced into liquid $^3$He it forms an "electron bubble", a heavy ion with radius, $R\simeq 1.5$ nm, and mass, $M\simeq 100\,m_3$, where $m_3$ is the mass of a $^3$He atom. These negative ions have proven to be powerful local probes of the physical properties of the host quantum fluid, especially the excitation spectra of the superfluid phases. We recently developed a theory for Bogoliubov quasiparticles scattering off electron bubbles embedded in a chiral superfluid that provides a detailed understanding of the spectrum of Weyl Fermions bound to the negative ion, as well as a theory for the forces on moving electron bubbles in superfluid $^3$He-A (Shevtsov et al. in arXiv:1606.06240). This theory is shown to provide quantitative agreement with measurements reported by the RIKEN group [Ikegami et al., Science 341:59, 2013] for the drag force and anomalous Hall effect of moving electron bubbles in superfluid $^3$He-A. In this report, we discuss the sensitivity of the forces on the moving ion to the effective interaction between normal-state quasiparticles and the ion. We consider models for the quasiparticle-ion (QP-ion) interaction, including the hard-sphere potential, constrained random-phase-shifts, and interactions with short-range repulsion and intermediate range attraction. Our results show that the transverse force responsible for the anomalous Hall effect is particularly sensitive to the structure of the QP-ion potential, and that strong short-range repulsion, captured by the hard-sphere potential, provides an accurate model for computing the forces acting on the moving electron bubble in superfluid $^3$He-A.
description: 13 pages, 2 figures, presentation at the International Conference on Quantum Fluids and Solids, Prague, Czech Republic, 2016
Norm of the Bergman projection onto the Bloch space with $\mathcal{M}-$invariant gradient
Creators: name: Melentijević, Petar
Publisher: name: arXiv
Year: 2017
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics

description: The value of the operator norm of Bergman projections from $L^{\infty}(\mathbb{B}^n)$ to Bloch space is found in \cite{KalajMarkovic2014}. The authors of mentioned paper proposed the problem of calculating the norm of the same class of operators with different norm on the Bloch space - $\mathcal{M}$-invariant gradient. Here we prove that it has the conjectured value.
description: 8 pages
Fundamental Parameters of Main-Sequence Stars in an Instant with Machine Learning
Creators: name: Bellinger, Earl P.
name: Angelou, George C.
name: Hekker, Saskia
name: Basu, Sarbani
name: Ball, Warrick
name: Guggenberger, Elisabeth
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Owing to the remarkable photometric precision of space observatories like Kepler, stellar and planetary systems beyond our own are now being characterized en masse for the first time. These characterizations are pivotal for endeavors such as searching for Earth-like planets and solar twins, understanding the mechanisms that govern stellar evolution, and tracing the dynamics of our Galaxy. The volume of data that is becoming available, however, brings with it the need to process this information accurately and rapidly. While existing methods can constrain fundamental stellar parameters such as ages, masses, and radii from these observations, they require substantial computational efforts to do so. We develop a method based on machine learning for rapidly estimating fundamental parameters of main-sequence solar-like stars from classical and asteroseismic observations. We first demonstrate this method on a hare-and-hound exercise and then apply it to the Sun, 16 Cyg A & B, and 34 planet-hosting candidates that have been observed by the Kepler spacecraft. We find that our estimates and their associated uncertainties are comparable to the results of other methods, but with the additional benefit of being able to explore many more stellar parameters while using much less computation time. We furthermore use this method to present evidence for an empirical diffusion-mass relation. Our method is open source and freely available for the community to use. The source code for all analyses and for all figures appearing in this manuscript can be found electronically at https://github.com/earlbellinger/asteroseismology
description: 26 pages, 18 figures, accepted for publication in ApJ
Homology groups of cubical sets
Creators: name: Husainov, Ahmet A.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Algebraic Topology (math.AT)
subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 18G10 18G40 55U15 55T99

description: The paper is devoted to homology groups of cubical sets with coefficients in contravariant systems of Abelian groups. The study is based on the proof of the assertion that the homology groups of the category of cubes with coefficients in the diagram of Abelian groups are isomorphic to the homology groups of normalized complex of the cubical Abelian group corresponding to this diagram. The main result shows that the homology groups of a cubical set with coefficients in a contravariant system of Abelian groups are isomorphic to the values of left derived functors of the colimit functor on this contravariant system. This is used to obtain the isomorphism criterion for homology groups of cubical sets with coefficients in contravariant systems, and also to construct spectral sequences for the covering of a cubical set and for a morphism between cubical sets. This version of the preprint contains a refinement of the proof of Lemma 3.2 corresponding to Lemma 4 from the paper of the same name published in the journal Appl. Category. Struct. 27, 199-216 (2019).
description: 25 pages
Mathematical and Numerical Models of Lava Dome Dynamics
Creators: name: Zeinalova, Natalya
name: Ismail-Zadeh, Alik
name: Melnik, Oleg
name: Tsepelev, Igor
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2022

description: Dome-building eruptions may vary from unthreatening effusion to highly unpredictable and hazardous activity including collapse of domes and associated pyroclastic flow hazards. We analyse the influence of the thermal cooling and the crystal content growth on the lava dome morphology at Volcán de Colima in Mexico during a long dome-building episode lasting from early 2007 to fall 2009 without explosive dome destruction. For this, we develop several mathematical models of lava dome dynamics including the kinetics of crystal content growth, temperature-dependence of melt viscosity, latent heat, and nonlinear heat exchange between the lava and the air. Camera images of the lava dome growth together with recorded volumes of the erupted lava have been used to constrain our numerical models and hence to fit the observation data of the dome growth at Volcán de Colima by nudging model forecasts to observations. We shall present the mathematical models and results of the ongoing modelling.
Photo-modulation of the spin Hall conductivity of mono-layer transition metal dichalcogenides
Creators: name: Sengupta, Parijat
name: Bellotti, Enrico
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report on a possible optical tuning of the spin Hall conductivity in mono-layer transition metal dichalcogenides. Light beams of frequencies much higher than the energy scale of the system (the \textit{off-resonant} condition) does not excite electrons but rearranges the band structure. The rearrangement is quantitatively established using the Floquet formalism. For such a system of mono-layer transition metal dichalcogenides, the spin Hall conductivity (calculated with the Kubo expression in presence of disorder) exhibits a drop at higher frequencies and lower intensities. Finally, we compare the spin Hall conductivity of the higher spin-orbit coupled WSe$_{2} $ to MoS$_{2} $; the spin Hall conductivity of WSe$_{2}$ was found to be larger.
description: 4 pages, 3 figures
Methods for the inclusion of real world evidence in network meta-analysis
Creators: name: Jenkins, David
name: Hussein, Humaira
name: Martina, Reynaldo
name: Dequen-O'Byrne, Pascale
name: Abrams, Keith R
name: Bujkiewicz, Sylwia
Publisher: name: arXiv
Year: 2018
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Background: Network Meta-Analysis (NMA) is a key component of submissions to reimbursement agencies world-wide, especially when there is limited direct head-to-head evidence for multiple technologies from randomised controlled trials (RCTs). Many NMAs include only data from RCTs. However, real-world evidence (RWE) is also becoming widely recognised as a valuable source of clinical data. We investigate methods for the inclusion of RWE in NMA and its impact on the uncertainty around the effectiveness estimates. Methods: A range of methods for inclusion of RWE in evidence synthesis, including Bayesian hierarchical and power prior models, were investigated by applying them to an example in relapsing remitting multiple sclerosis. The effect of the inclusion of RWE was investigated by varying the degree of down weighting of this part of evidence by the use of a power prior. Results: Whilst the inclusion of the RWE led to an increase in the level of uncertainty surrounding effect estimates in this example, this depended on the method of inclusion adopted for the RWE. Power prior NMA model resulted in stable effect estimates for fingolimod yet increasing the width of the credible intervals with increasing weight given to RWE data. The hierarchical NMA models were effective in allowing for heterogeneity between study designs; however, this also increased the level of uncertainty. Conclusion: The power prior approach for the inclusion of RWE in NMAs indicates that the degree to which RWE is taken into account can have a significant impact on the overall level of uncertainty. The hierarchical modelling approach further allowed for accommodating differences between study types. Consequently, further work investigating both empirical evidence for biases associated with individual RWE studies and methods of elicitation from experts on the extent of such biases is warranted.
description: 24 pages, 3 figures
MPEC 2024-Q81 : DAILY ORBIT UPDATE (2024 August 30)
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469

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.
On Relaxed Averaged Alternating Reflections (RAAR) Algorithm for Phase Retrieval from Structured Illuminations
Creators: name: Li, Ji
name: Zhou, Tie
Publisher: name: arXiv
Year: 2016
Subjects: subject: Numerical Analysis (math.NA)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: In this paper, as opposed to the random phase masks, the structured illuminations with a pixel-dependent deterministic phase shift are considered to derandomize the model setup. The RAAR algorithm is modified to adapt to two or more diffraction patterns, and the modified RAAR algorithm operates in Fourier domain rather than space domain. The local convergence of the RAAR algorithm is proved by some eigenvalue analysis. Numerical simulations is presented to demonstrate the effectiveness and stability of the algorithm compared to the HIO (Hybrid Input-Output) method. The numerical performances show the global convergence of the RAAR in our tests.
description: 17 pages, 26 figures, submitting to Inverse Problems
Unfolded Seiberg-Witten Floer spectra, II: Relative invariants and the gluing theorem
Creators: name: Khandhawit, Tirasan
name: Lin, Jianfeng
name: Sasahira, Hirofumi
Publisher: name: arXiv
Year: 2018
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: We use the construction of unfolded Seiberg-Witten Floer spectra of general 3-manifolds defined in our previous paper to extend the notion of relative Bauer-Furuta invariants to general 4-manifolds with boundary. One of the main purposes of this paper is to give a detailed proof of the gluing theorem for the relative invariants.
description: 83 pages. Typos fixed. Small changes
Bond disproportionation and dynamical charge fluctuations in the perovskite rare earth nickelates
Creators: name: Green, Robert J.
name: Haverkort, Maurits W.
name: Sawatzky, George A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a theory describing the local electronic properties of the perovskite rare earth nickelates--materials which have negative charge transfer energies, strong O $2p$ -- Ni $3d$ covalence, and breathing mode lattice distortions at the origin of highly studied metal-insulator and antiferromagnetic ordering transitions. Utilizing a full orbital, full correlation double cluster approach, we find strong charge fluctuations in agreement with a bond disproportionation interpretation. The unique double cluster formulation permits the inclusion of necessary orbital degeneracies and Coulomb interactions to calculate resonant x-ray spectral responses, with which we find excellent agreement with well-established experimental results. This previously absent, crucial link between theory and experiment provides validation of the recently proposed bond disproportionation theory, and provides an analysis methodology for spectroscopic studies of engineered phases of nickelates and other high valence transition metal compounds.
Analysis of a space--time hybridizable discontinuous Galerkin method for the advection--diffusion problem on time-dependent domains
Creators: name: Kirk, Keegan L. A.
name: Horvath, Tamas L.
name: Cesmelioglu, Aycil
name: Rhebergen, Sander
Publisher: name: arXiv
Year: 2018
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65N12, 65M15, 65N30, 35R37, 35Q35

description: This paper presents the first analysis of a space--time hybridizable discontinuous Galerkin method for the advection--diffusion problem on time-dependent domains. The analysis is based on non-standard local trace and inverse inequalities that are anisotropic in the spatial and time steps. We prove well-posedness of the discrete problem and provide a priori error estimates in a mesh-dependent norm. Convergence theory is validated by a numerical example solving the advection--diffusion problem on a time-dependent domain for approximations of various polynomial degree.
A locally conservative and energy-stable finite element for the Navier--Stokes problem on time-dependent domains
Creators: name: Horvath, Tamas L.
name: Rhebergen, Sander
Publisher: name: arXiv
Year: 2018
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We present a finite element method for the incompressible Navier--Stokes problem that is locally conservative, energy-stable and pressure-robust on time-dependent domains. To achieve this, the space--time formulation of the Navier--Stokes problem is considered. The space--time domain is partitioned into space--time slabs which in turn are partitioned into space--time simplices. A combined discontinuous Galerkin method across space--time slabs, and space--time hybridized discontinuous Galerkin method within a space--time slab, results in an approximate velocity field that is $H({\rm div})$-conforming and exactly divergence-free, even on time-dependent domains. Numerical examples demonstrate the convergence properties and performance of the method.