cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Revisit of Local X-ray Luminosity Function of Active Galactic Nuclei with the MAXI Extragalactic Survey
Creators: name: Ueda, Yoshihiro
name: Hiroi, Kazuo
name: Isobe, Naoki
name: Hayashida, Masaaki
name: Eguchi, Satoshi
name: Sugizaki, Mutsumi
name: Kawai, Nobuyuki
name: Tsunemi, Hiroshi
name: Mihara, Tatehiro
name: Matsuoka, Masaru
name: Ishikawa, Masaki
name: Kimura, Masashi
name: Kitayama, Hiroki
name: Kohama, Mitsuhiro
name: Matsumura, Takanori
name: Morii, Mikio
name: Nakagawa, Yujin E.
name: Nakahira, Satoshi
name: Nakajima, Motoki
name: Negoro, Hitoshi
name: Serino, Motoko
name: Shidatsu, Megumi
name: Sootome, Tetsuya
name: Sugimori, Kousuke
name: Suwa, Fumitoshi
name: Toizumi, Takahiro
name: Tomida, Hiroshi
name: Tsuboi, Yohko
name: Ueno, Shiro
name: Usui, Ryuichi
name: Yamamoto, Takayuki
name: Yamaoka, Kazutaka
name: Yamazaki, Kyohei
name: Yoshida, Atsumasa
name: collaboration, the MAXI
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We construct a new X-ray (2--10 keV) luminosity function of Compton-thin active galactic nuclei (AGNs) in the local universe, using the first MAXI/GSC source catalog surveyed in the 4--10 keV band. The sample consists of 37 non-blazar AGNs at $z=0.002-0.2$, whose identification is highly ($>97%$) complete. We confirm the trend that the fraction of absorbed AGNs with $N_{\rm H} > 10^{22}$ cm$^{-2}$ rapidly decreases against luminosity ($L_{\rm X}$), from 0.73$\pm$0.25 at $L_{\rm X} = 10^{42-43.5}$ erg s$^{-1}$ to 0.12$\pm0.09$ at $L_{\rm X} = 10^{43.5-45.5}$ erg s$^{-1}$. The obtained luminosity function is well fitted with a smoothly connected double power-law model whose indices are $γ_1 = 0.84$ (fixed) and $γ_2 = 2.0\pm0.2$ below and above the break luminosity, $L_{*} = 10^{43.3\pm0.4}$ ergs s$^{-1}$, respectively. While the result of the MAXI/GSC agrees well with that of HEAO-1 at $L_{\rm X} \gtsim 10^{43.5}$ erg s$^{-1}$, it gives a larger number density at the lower luminosity range. Comparison between our luminosity function in the 2--10 keV band and that in the 14--195 keV band obtained from the Swift/BAT survey indicates that the averaged broad band spectra in the 2--200 keV band should depend on luminosity, approximated by $Γ\sim1.7$ for $L_{\rm X} \ltsim 10^{44}$ erg s$^{-1}$ while $Γ\sim 2.0$ for $L_{\rm X} \gtsim 10^{44}$ erg s$^{-1}$. This trend is confirmed by the correlation between the luminosities in the 2--10 keV and 14--195 keV bands in our sample. We argue that there is no contradiction in the luminosity functions between above and below 10 keV once this effect is taken into account.
description: 9 pages including 6 figures and 2 tables, accepted for publication in PASJ; figure 4 and related numbers are updated to reflect the flux error in Sazonov & Revnivtsev (2004)
Finite Planes, Zigzag Sequences, Fibonacci Numbers, Artin's Conjecture and Trinomials
Creators: name: Campbell, H. E. A.
name: Wehlau, David L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: (Primary) 11B39 Secondary 11T06, 11A07, 11C08

description: We begin by considering faithful matrix representations of elementary abelian groups in prime characteristic. The representations considered are seen to be determined up to change of bases by a single number. Studying this number leads to a new family of polynomials which exhibit a number of special properties. These polynomials satisfy a three term recursion and are closely related to zigzag zero-one sequences. Interpreting the polynomials for the "prime" 1 yields the classical Morgan-Voyce polynomials, which form twoorthogonal families of polynomials and which have applications in the study of electrical resistance. Study of the general polynomials reveals deep connections with the Fibonacci series, the order of appearance of prime numbers in the Fibonacci sequence, the order of elements in cyclic groups, Artin's conjecture on primitive roots and the factorization of trinomials over finite fields.
Sentiment Analysis on Inflation after Covid-19
Creators: name: Li, Xinyu
name: Tang, Zihan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Econometrics (econ.EM)
subject: FOS: Economics and business

description: We implement traditional machine learning and deep learning methods for global tweets from 2017-2022 to build a high-frequency measure of the public's sentiment index on inflation and analyze its correlation with other online data sources such as google trend and market-oriented inflation index. We use manually labeled trigrams to test the prediction performance of several machine learning models(logistic regression,random forest etc.) and choose Bert model for final demonstration. Later, we sum daily tweets' sentiment scores gained from Bert model to obtain the predicted inflation sentiment index, and we further analyze the regional and pre/post covid patterns of these inflation indexes. Lastly, we take other empirical inflation-related data as references and prove that twitter-based inflation sentiment analysis method has an outstanding capability to predict inflation. The results suggest that Twitter combined with deep learning methods can be a novel and timely method to utilize existing abundant data sources on inflation expectations and provide daily indicators of consumers' perception on inflation.
description: 18 pages, 12 figures
Anisotropic magneto-resistance in a GaMnAs-based single impurity tunnel diode: a tight binding approach
Creators: name: Nestoklon, M. O.
name: Krebs, O.
name: Jaffrès, H.
name: Ruttala, S.
name: George, J. -M.
name: Jancu, J. -M.
name: Voisin, P.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Using an advanced tight-binding approach, we estimate the anisotropy of the tunnel transmission associated with the rotation of the 5/2 spin of a single Mn atom forming an acceptor state in GaAs and located near an AlGaAs tunnel barrier. Significant anisotropies in both in-plane and out-of-plane geometries are found, resulting from the combination of the large spin-orbit coupling associated with the p-d exchange interaction, cubic anisotropy of heavy-hole dispersion and the low C2v symmetry of the chemical bonds.
description: 4 pages, 3 figures
Character varieties of a transitioning Coxeter 4-orbifold
Creators: name: Riolo, Stefano
name: Seppi, Andrea
Publisher: name: arXiv
Year: 2020
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: In 2010, Kerckhoff and Storm discovered a path of hyperbolic 4-polytopes eventually collapsing to an ideal right-angled cuboctahedron. This is expressed by a deformation of the inclusion of a discrete reflection group (a right-angled Coxeter group) in the isometry group of hyperbolic 4-space. More recently, we have shown that the path of polytopes can be extended to Anti-de Sitter geometry so as to have geometric transition on a naturally associated 4-orbifold, via a transitional half-pipe structure. In this paper, we study the hyperbolic, Anti-de Sitter, and half-pipe character varieties of Kerckhoff and Storm's right-angled Coxeter group near each of the found holonomy representations, including a description of the singularity that appears at the collapse. An essential tool is the study of some rigidity properties of right-angled cusp groups in dimension four.
description: 52 pages, 7 figures, 4 tables. The content overlaps with Part 3 of arXiv:1908.05112v1, of which this paper constitutes a self-contained and enlarged version. To appear in GGD. (Main theorem restated, exposition and structure revised, no substantial changes in proofs)
Four-Month Rifapentine Based Regimen with Moxifloxacin for Drug- Susceptible Pulmonary Tuberculosis: A Path to Tread with Caution
Creators: name: Mishra, Gyanshankar
name: Mulani, Jasmin
Publisher: name: figshare
Year: 2021
Subjects: subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: Medicine

description: Recent evidence has shown that the efficacy of a four-month regimen composed of rifapentine, isoniazid, pyrazinamide and moxifloxacin is non-inferior to the standard six-month regimen in the treatment of drug-susceptible TB. The World Health Organisation has also issued interim recommendations for adopting this shorter regime by various countries. The current article discusses the various aspects of this regime that need to be considered before its wider use in the treatment of tuberculosis.
New Function Spaces Associated to Representations of Nilpotent Lie Groups and Generalized Time-Frequency Analysis
Creators: name: Gröchenig, Karlheinz
Publisher: name: arXiv
Year: 2020
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 42B35, 22E25, 46E35

description: We study function spaces that are related to square-integrable, irreducible, unitary representations of several low-dimensional nilpotent Lie groups. These are new examples of coorbit theory and yield new families of function spaces on $\mathbb{R}^d $. The concrete realization of the representation suggests that these function spaces are useful for generalized time-frequency analysis or phase-space analysis.
Lithium and Beryllium in One Solar Mass Stars
Creators: name: Boesgaard, Ann Merchant
name: Deliyannis, Constantine P.
name: Lum, Michael G.
name: Chontos, Ashley
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The surface content of lithium (Li) and beryllium (Be) in stars can reveal important information about the temperature structure and physical processes in their interior regions. This study focuses on solar-type stars with a sample that is more precisely defined than done previously. Our selection of stars studied for Be is constrained by five parameters: mass, temperature, surface gravity, metallicity, and age to be similar to the Sun and is focussed on stars within +-0.02 of 1 M_sun. We have used the Keck I telescope with HIRES to obtain spectra of the Be II spectral region of 52 such stars at high spectral resolution ($\sim$45,000) and high signal-to-noise ratios. While the spread in Li in these stars is greater than a factor of 400, the spread in Be is only 2.7 times. Two stars were without any Be, perhaps due to a merger or a mass transfer with a companion. We find a steep trend of Li with temperature but little for Be. While there is a downward trend in Li with [Fe/H] from -0.4 to +0.4 due to stellar depletion, there is a small increase in Be with Fe from Galactic Be enrichment. While there is a broad decline in Li with age, there may be a small increase in Be with age, though age is less well-determined. In the subset of stars closest to the Sun in temperature and other parameters we find that the ratio of the abundances of Be to Li is much lower than predicted by models; there may be other mixing mechanisms causing additional Li depletion.
description: total 29 pages including 12 figures, 5 tables Accepted for Astrophysical Journal
Fast and Robust Iterative Closest Point
Creators: name: Zhang, Juyong
name: Yao, Yuxin
name: Deng, Bailin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Graphics (cs.GR)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: The Iterative Closest Point (ICP) algorithm and its variants are a fundamental technique for rigid registration between two point sets, with wide applications in different areas from robotics to 3D reconstruction. The main drawbacks for ICP are its slow convergence as well as its sensitivity to outliers, missing data, and partial overlaps. Recent work such as Sparse ICP achieves robustness via sparsity optimization at the cost of computational speed. In this paper, we propose a new method for robust registration with fast convergence. First, we show that the classical point-to-point ICP can be treated as a majorization-minimization (MM) algorithm, and propose an Anderson acceleration approach to speed up its convergence. In addition, we introduce a robust error metric based on the Welsch's function, which is minimized efficiently using the MM algorithm with Anderson acceleration. On challenging datasets with noises and partial overlaps, we achieve similar or better accuracy than Sparse ICP while being at least an order of magnitude faster. Finally, we extend the robust formulation to point-to-plane ICP, and solve the resulting problem using a similar Anderson-accelerated MM strategy. Our robust ICP methods improve the registration accuracy on benchmark datasets while being competitive in computational time.
The evolution of the surface brightness of a star cluster as a result of residual star-forming gas expulsion
Creators: name: Lueghausen, F.
name: Parmentier, G.
name: Pflamm-Altenburg, J.
name: Kroupa, P.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Direct N-body calculations are presented of the early evolution of exposed clusters to quantify the influence of gas expulsion on the time-varying surface brightness. By assuming that the embedded OB stars drive out most of the gas after a given time delay, the change of the surface brightness of expanding star clusters is studied. The influence of stellar dynamics and stellar evolution is discussed. The growth of the core radii of such models shows a remarkable core re-virialisation. The decrease of the surface mass density during gas expulsion is large and is only truncated by this re-virialisation process. However, the surface brightness within a certain radius does not increase noticeably. Thus, an embedded star cluster cannot reappear in observational surveys after re-virialisation. This finding has a bearing on the observed infant mortality fraction.
description: 7 pages, 4 figures, and 2 tables. Accepted 2011 November 29
Gluing and Hilbert functions of monomial curves
Creators: name: Arslan, Feza
name: Mete, Pınar
name: Şahin, Mesut
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: Commutative Algebra (math.AC)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 13H10, 14H20, 13P10

description: In this article, by using the technique of gluing semigroups, we give infinitely many families of 1-dimensional local rings with non-decreasing Hilbert functions. More significantly, these are local rings whose associated graded rings are not necessarily Cohen-Macaulay. In this sense, we give an effective technique to construct large families of 1-dimensional Gorenstein local rings associated to monomial curves, which support Rossi's conjecture saying that every Gorenstein local ring has non-decreasing Hilbert function.
Local indistinguishability and incompleteness of entangled orthogonal bases: Method to generate two-element locally indistinguishable ensembles
Creators: name: Halder, Saronath
name: Sen, Ujjwal
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We relate the phenomenon of local indistinguishability of orthogonal states with the properties of unextendibility and uncompletability of entangled bases for bipartite and multipartite quantum systems. We prove that all two-qubit unextendible entangled bases are of size three and they cannot be perfectly distinguished by separable measurements. We identify a method of constructing two-element orthogonal ensembles, based on the concept of unextendible entangled bases, that can potentially lead to information sharing applications. Two-element ensembles form the fundamental unit of ensembles, and yet does not offer locally indistinguishable ensembles for pure state elements. Going over to mixed states does open this possibility, but can be difficult to identify. The method provided using unextendible entangled bases can be used for their systematic generation. In multipartite systems, we find a class of unextendible entangled bases for which the unextendibility property remains conserved across all bipartitions. We also identify nonlocal operations, local implementation of which require entangled resource states from a higher-dimensional quantum system.
description: title changed; improved version
Characterization and Characteristics of mechanochemically synthesized amorphous fast ionic conductor 50 SISOMO (50AgI-25Ag2O-25MoO3)
Creators: name: Dayal, Saurabh
name: Shahi, K.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Mechanochemically synthesized amorphous 50SISOMO [50AgI-25Ag_2O-25MoO_3] fast ionic conductor shows high ionic conductivity of ~ 6x10^-3 Ω^-1 cm-1 at room temperature. The highest ionic conductivity is achieved for 36 h milled sample, which is more than three orders of magnitude higher than that of crystalline AgI at room temperature. The samples are thermally stable at least up to ~70 °C. Thermoelectric power studies on 50 SISOMO amorphous fast ionic conductors (a-SIC) have been carried out in the temperature range 300-330K. Thermoelectric power (S) is found to vary linearly with the inverse of the absolute temperature, and can be expressed by the equation -S = [(0.19 \times 10^3/T) + 0.25] mV/K. The heat of transport (q*) of Ag+ ion i.e. 0.19 eV is nearly equal to the activation energy (E) i.e. 0.20 eV of Ag+ ion migration calculated from the conductivity plots indicating that the material has an average structure. This is also in consonance with earlier theories on heats of transport of ions in ionic solids.
description: Presented in the "National Symposium on Advances in Material Science" held at Gorakhpur, India during 17-19 March 2005
Symmetries, conservation laws, invariant solutions and difference schemes of the one-dimensional Green-Naghdi equations
Creators: name: Dorodnitsyn, V. A.
name: Kaptsov, E. I.
name: Meleshko, S. V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences
subject: 76B07, 65N06

description: The paper is devoted to the Lie group properties of the one-dimensional Green-Naghdi equations describing the behavior of fluid flow over uneven bottom topography. The bottom topography is incorporated into the Green-Naghdi equations in two ways: in the classical Green-Naghdi form and in the approximated form of the same order. The study is performed in Lagrangian coordinates which allows one to find Lagrangians for the analyzed equations. Complete group classification of both cases of the Green-Naghdi equations with respect to the bottom topography is presented. Applying Noether's theorem, the obtained Lagrangians and the group classification, conservation laws of the one-dimensional Green-Naghdi equations with uneven bottom topography are obtained. Difference schemes which preserve the symmetries of the original equations and the conservation laws are constructed. Analysis of the developed schemes is given. The schemes are tested numerically on the example of an exact traveling-wave solution.
description: 22 pages, 8 figures
Invariant conservative difference schemes for shallow water equations in Eulerian and Lagrangian coordinates
Creators: name: Dorodnitsyn, V. A.
name: Kaptsov, E. I.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: Mathematical Physics (math-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The one-dimensional shallow water equations in Eulerian coordinates are considered. Relations between symmetries and conservation laws for the potential form of the equations, and symmetries and conservation laws in Eulerian coordinates are shown. An invariant difference scheme for equations in Eulerian coordinates with arbitrary bottom topography is constructed. It possesses all the finite-difference analogues of the conservation laws. Some bottom topographies require moving meshes in Eulerian coordinates, which are stationary meshes in mass Lagrangian coordinates. The developed invariant conservative difference schemes are verified numerically using examples of flow with various bottom topographies.
description: 40 pages, 16 figures, 2 tables
Retrieving C and O Abundance of HR 8799 c by Combining High- and Low-Resolution Data
Creators: name: Wang, Ji
name: Wang, Jason J.
name: Ruffio, Jean-Baptiste
name: Blake, Geoffrey A.
name: Mawet, Dimitri
name: Baker, Ashley
name: Bartos, Randall
name: Bond, Charlotte Z.
name: Calvin, Benjamin
name: Cetre, Sylvain
name: Delorme, Jacques-Robert
name: Doppmann, Greg
name: Echeverri, Daniel
name: Finnerty, Luke
name: Fitzgerald, Michael P.
name: Jovanovic, Nemanja
name: Lopez, Ronald
name: Martin, Emily C.
name: Morris, Evan
name: Pezzato, Jacklyn
name: Ragland, Sam
name: Ruane, Garreth
name: Sappey, Ben
name: Schofield, Tobias
name: Skemer, Andrew
name: Venenciano, Taylor
name: Wallace, J. Kent
name: Wizinowich, Peter
name: Xuan, Jerry W.
name: Bryan, Marta L.
name: Roy, Arpita
name: Wallack, Nicole L.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The formation and evolution pathway for the directly-imaged multi-planetary system HR 8799 remains mysterious. Accurate constraints on the chemical composition of the planetary atmosphere(s) are key to solving the mystery. We perform a detailed atmospheric retrieval on HR 8799~c to infer the chemical abundances and abundance ratios using a combination of photometric data along with low- and high-resolution spectroscopic data (R$\sim$20-35,000). We specifically retrieve [C/H], [O/H], and C/O and find them to be 0.55$^{+0.36}_{-0.39}$, 0.47$^{+0.31}_{-0.32}$, and 0.67$^{+0.12}_{-0.15}$ at 68\% confidence. The super-stellar C and O abundances, yet a stellar C/O ratio, reveal a potential formation pathway for HR 8799~c. Planet c, and likely the other gas giant planets in the system, formed early on (likely within $\sim$1 Myr), followed by further atmospheric enrichment in C and O through the accretion of solids beyond the CO iceline. The enrichment either preceded or took place during the early phase of the inward migration to the planet current locations.
description: 19 pages, 6 figures, 3 tables, accepted to AAS journals
Topological convexity in complex surfaces
Creators: name: Gompf, Robert E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Geometric Topology (math.GT)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 32T15, 57K40

description: We study a notion of strict pseudoconvexity in the context of topologically (often unsmoothably) embedded 3-manifolds in complex surfaces. Topologically pseudoconvex (TPC) 3-manifolds behave similarly to their smooth analogues, cutting out open domains of holomorphy (Stein surfaces), but they are much more common. We provide tools for constructing TPC embeddings, and show that every closed, oriented 3-manifold M has a TPC embedding in a compact, complex surface (without boundary) realizing any homotopy class of almost-complex structures (the analogue of the homotopy class of the contact plane field in the smooth case). We prove our tool theorems with invariants that classify almost-complex structures on any 4-manifold homotopy equivalent to M. These invariants are amenable to computation and respected by homeomorphisms (not necessarily smooth). We study the two equivalence classes of smoothings on the product of a 3-manifold with a line, and on collared ends. Both classes of smoothings are realized by holomorphic embeddings exhibiting any preassigned homotopy class of almost-complex structures. One class arises from TPC embedded 3-manifolds, while the other likely does not.
description: 22 pages. Slightly improved exposition. V3 is to appear in Asian J. Math
On the choice of diameters in a polydisperse model glassformer: deterministic or stochastic?
Creators: name: Küchler, Niklas
name: Horbach, Jürgen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: In particle-based computer simulations of polydisperse glassforming systems, the particle diameters $σ= σ_1, \dots, σ_N$ of a system with $N$ particles are chosen with the intention to approximate a desired distribution density $f$ with the corresponding histogram. One method to accomplish this is to draw each diameter randomly from the density $f$. We refer to this stochastic scheme as model $\mathcal{S}$. Alternatively, one can apply a deterministic method, assigning an appropriate set of $N$ values to the diameters. We refer to this method as model $\mathcal{D}$. We show that especially for the glassy dynamics at low temperatures it matters whether one chooses model $\mathcal{S}$ or model $\mathcal{D}$. Using molecular dynamics computer simulation, we investigate a three-dimensional polydisperse non-additive soft-sphere system with $f(s) \sim s^{-3}$. The Swap Monte Carlo method is employed to obtain equilibrated samples at very low temperatures. We show that for model $\mathcal{S}$ the sample-to-sample fluctuations due to the quenched disorder imposed by the diameters $σ$ can be explained by an effective packing fraction. Dynamic susceptibilities in model $\mathcal{S}$ can be split into two terms: One that is of thermal nature and can be identified with the susceptibility of model $\mathcal{D}$, and another one originating from the disorder in $σ$. At low temperatures the latter contribution is the dominating term in the dynamic susceptibility.
description: 15 pages, 11 figures
A comparative study on different background estimation methods for extensive air shower arrays
Creators: name: Wang, Yan-Jin
name: Zha, Min
name: Hu, Shi-Cong
name: Gao, Chuan-Dong
name: Zhang, Jian-Li
name: Zhang, Xin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Background estimation is essential when studying TeV gamma-ray astronomy for extensive air shower arrays. In this work, by applying four applying four different methods including equi-zenith angle method, surrounding window method, direct integration method, and time-swapping method, the number of the background events is calculated. Based on simulation samples, the statistical significance of the excess signal from different background estimation methods is determined. Following this, we discuss the limits and the applicability of the four methods under different conditions. Under the detector stability assumption with signal, the results from the above four methods are consistent at the 1 sigma level. In the no signal condition, when the acceptance of the detector changes with both space and time, the surrounding window method is most stable and hardly affected. In this acceptance assumption, we find that the background estimation in the direct integration and time-swapping methods are sensitive to the selection of time window, and the shorter time window can reduce the impact on the background estimation to some extent.
description: 19 pages
A Self-Organization Framework for Wireless Ad Hoc Networks as Small Worlds
Creators: name: Banerjee, Abhik
name: Agarwal, Rachit
name: Gauthier, Vincent
name: Yeo, Chai Kiat
name: Afifi, Hossam
name: Lee, Bu Sung
Publisher: name: arXiv
Year: 2012
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Motivated by the benefits of small world networks, we propose a self-organization framework for wireless ad hoc networks. We investigate the use of directional beamforming for creating long-range short cuts between nodes. Using simulation results for randomized beamforming as a guideline, we identify crucial design issues for algorithm design. Our results show that, while significant path length reduction is achievable, this is accompanied by the problem of asymmetric paths between nodes. Subsequently, we propose a distributed algorithm for small world creation that achieves path length reduction while maintaining connectivity. We define a new centrality measure that estimates the structural importance of nodes based on traffic flow in the network, which is used to identify the optimum nodes for beamforming. We show, using simulations, that this leads to significant reduction in path length while maintaining connectivity.
description: Submitted to IEEE Transactions on Vehicular Technology
Design and Analysis of a Novel Digital Image Encryption Scheme
Creators: name: Pareek, Narendra K
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: In this paper, a new image encryption scheme using a secret key of 144-bits is proposed. In the substitution process of the scheme, image is divided into blocks and subsequently into color components. Each color component is modified by performing bitwise operation which depends on secret key as well as a few most significant bits of its previous and next color component. Three rounds are taken to complete substitution process. To make cipher more robust, a feedback mechanism is also applied by modifying used secret key after encrypting each block. Further, resultant image is partitioned into several key based dynamic sub-images. Each sub-image passes through the scrambling process where pixels of sub-image are reshuffled within itself by using a generated magic square matrix. Five rounds are taken for scrambling process. The propose scheme is simple, fast and sensitive to the secret key. Due to high order of substitution and permutation, common attacks like linear and differential cryptanalysis are infeasible. The experimental results show that the proposed encryption technique is efficient and has high security features.
description: 15 pages, 5 figures
Entanglement Renyi entropy of two disjoint intervals for large $c$ Liouville field theory
Creators: name: Tsujimura, Jun
name: Nambu, Yasusada
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Entanglement entropy (EE) is a quantitative measure of the effective degrees of freedom and the correlation between the sub-systems of a physical system. Using the replica trick, we can obtain the EE by evaluating the entanglement Renyi entropy (ERE). The ERE is a $q$-analogue of the EE and expressed by the $q$ replicated partition function. In the semi-classical approximation, it is apparently easy to calculate the EE because the classical action represents the partition function by the saddle point approximation and we do not need to perform the path integral for the evaluation of the partition function. In previous studies, it has been assumed that only the minimal-valued saddle point contributes to the EE. In this paper, we propose that all the saddle points contribute equally to the EE by dealing carefully with the semi-classical limit and then the $q \to 1$ limit. For example, we numerically evaluate the ERE of two disjoint intervals for the large $c$ Liouville field theory with $q \sim 1$. We exploit the BPZ equation with the four twist operators, whose solution is given by the Heun function. We determine the ERE by tuning the behavior of the Heun function such that it becomes consistent with the geometry of the replica manifold. We find the same two saddle points as previous studies for $q \sim 1$ in the above system. Then, we provide the ERE for the large but finite $c$ and the $q \sim 1$ in case that all the saddle points contribute equally to the ERE. Based on this work, it shall be of interest to reconsider EE in other semi-classical physical systems with multiple saddle points.
description: 14 pages, 3 figures
Stochastic gravitational wave background: methods and Implications
Creators: name: van Remortel, Nick
name: Janssens, Kamiel
name: Turbang, Kevin
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Beyond individually resolvable gravitational wave events such as binary black hole and binary neutron star mergers, the superposition of many more weak signals coming from a multitude of sources is expected to contribute to an overall background, the so-called stochastic gravitational wave background. In this review, we give an overview of possible detection methods in the search for this background and provide a detailed review of the data-analysis techniques, focusing primarily on current Earth-based interferometric gravitational-wave detectors. In addition, various validation techniques aimed at reinforcing the claim of a detection of such a background are discussed as well. We conclude this review by listing some of the astrophysical and cosmological implications resulting from current upper limits on the stochastic background of gravitational waves.
description: 71 pages, 17 figures, review article
Analysis on trees with nondoubling flow measures
Creators: name: Levi, Matteo
name: Santagati, Federico
name: Tabacco, Anita
name: Vallarino, Maria
Publisher: name: arXiv
Year: 2020
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: We consider trees with root at infinity endowed with flow measures, which are nondoubling measures of at least exponential growth and which do not satisfy the isoperimetric inequality. In this setting, we develop a Calderon-Zygmund theory and we define BMO and Hardy spaces, proving a number of desired results extending the corresponding theory as known in more classical settings.
description: With respect to the previous version, we rephrased Proposition 2.2, which is now more precise. Corollary 2.3 does not need a proof anymore, since it is included in that of the proposition. These changes have no effects on the rest of the paper. 31 pages, no figures. You can retrieve the open access paper at https://link.springer.com/article/10.1007/s11118-021-09957-6
Inverse problems associated with integrable equations of Camassa-Holm type; explicit formulas on the real axis, I
Creators: name: Mohajer, Keivan
name: Szmigielski, Jacek
Publisher: name: arXiv
Year: 2011
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: The inverse problem which arises in the Camassa--Holm equation is revisited for the class of discrete densities. The method of solution relies on the use of orthogonal polynomials. The explicit formulas are obtained directly from the analysis on the real axis without any additional transformation to a "string" type boundary value problem known from prior works.
Appendix IV: Terra Petraea Chronological Inconsistencies R-script
Creators: name: Kennedy, Will M.
Publisher: name: Zenodo
Year: 2021
Subjects: Terra Petraea

description: This fourth appendix to "Terra Petraea. The Archaeological Landscape of the Petraean Hinterland from the Hellenistic to the Byzantine Period" (ISBN 978-3-8325-5171-1) is a PDF version of an exemplary R-script written by the author for evaluating the chronological inconsistencies inherent to the original survey data (cf. chapter 2).
Dust grains cannot grow to millimeter sizes in protostellar envelopes
Creators: name: Silsbee, Kedron
name: Akimkin, Vitaly
name: Ivlev, Alexei V.
name: Testi, Leonardo
name: Gong, Munan
name: Caselli, Paola
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: A big question in the field of star and planet formation is the time at which substantial dust grain growth occurs. The observed properties of dust emission across different wavelength ranges have been used as an indication that millimeter-sized grains are already present in the envelopes of young protostars. However, this interpretation is in tension with results from coagulation simulations, which are not able to produce such large grains in these conditions. In this work, we show analytically that the production of millimeter-sized grains in protostellar envelopes is impossible under the standard assumptions about the coagulation process. We discuss several possibilities that may serve to explain the observed dust emission in the absence of in-situ grain growth to millimeter sizes.
description: Accepted to ApJ
Universal crossovers between entanglement entropy and thermal entropy
Creators: name: Swingle, Brian
name: Senthil, T.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We postulate the existence of universal crossover functions connecting the universal parts of the entanglement entropy to the low temperature thermal entropy in gapless quantum many-body systems. These scaling functions encode the intuition that the same low energy degrees of freedom which control low temperature thermal physics are also responsible for the long range entanglement in the quantum ground state. We demonstrate the correctness of the proposed scaling form and determine the scaling function for certain classes of gapless systems whose low energy physics is described by a conformal field theory. We also use our crossover formalism to argue that local systems which are "natural" can violate the boundary law at most logarithmically. In particular, we show that several non-Fermi liquid phases of matter have entanglement entropy that is at most of order $L^{d-1}\log{(L)} $ for a region of linear size $L$ thereby confirming various earlier suggestions in the literature. We also briefly apply our crossover formalism to the study of fluctuations in conserved quantities and discuss some subtleties that occur in systems that spontaneously break a continuous symmetry.
description: 12 pages
Keep the bursts and ditch the interleavers
Creators: name: An, Wei
name: Médard, Muriel
name: Duffy, Ken R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: To facilitate applications in IoT, 5G, and beyond, there is an engineering need to enable high-rate, low-latency communications. Errors in physical channels typically arrive in clumps, but most decoders are designed assuming that channels are memoryless. As a result, communication networks rely on interleaving over tens of thousands of bits so that channel conditions match decoder assumptions. Even for short high rate codes, awaiting sufficient data to interleave at the sender and de-interleave at the receiver is a significant source of unwanted latency. Using existing decoders with non-interleaved channels causes a degradation in block error rate performance owing to mismatch between the decoder's channel model and true channel behaviour. Through further development of the recently proposed Guessing Random Additive Noise Decoding (GRAND) algorithm, which we call GRAND-MO for GRAND Markov Order, here we establish that by abandoning interleaving and embracing bursty noise, low-latency, short-code, high-rate communication is possible with block error rates that outperform their interleaved counterparts by a substantial margin. Moreover, while most decoders are twinned to a specific code-book structure, GRAND-MO can decode any code. Using this property, we establish that certain well-known structured codes are ill-suited for use in bursty channels, but Random Linear Codes (RLCs) are robust to correlated noise. This work suggests that the use of RLCs with GRAND-MO is a good candidate for applications requiring high throughput with low latency.
description: 6 pages
SHARP - I. A high-resolution multi-band view of the infra-red Einstein ring of JVAS B1938+666
Creators: name: Lagattuta, D. J.
name: Vegetti, S.
name: Fassnacht, C. D.
name: Auger, M. W.
name: Koopmans, L. V. E.
name: McKean, J. P.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present new mass models for the gravitational lens system B1938+666, using multi-wavelength data acquired from Keck adaptive optics (AO) and Hubble Space Telescope (HST) observations. These models are the first results from the Strong-lensing at High Angular Resolution Program (SHARP), a project designed to study known quadruple-image and Einstein ring lenses using high-resolution imaging, in order to probe their mass distributions in unprecedented detail. Here, we specifically highlight differences between AO- and HST-derived lens models, finding that -- at least when the lens and source galaxies are both bright and red, and the system has a high degree of circular symmetry -- AO-derived models place significantly tighter constraints on model parameters. Using this improved precision, we infer important physical properties about the B1938+666 system, including the mass density slope of the lensing galaxy (gamma = 2.045), the projected dark matter mass fraction within the Einstein radius (M_dark/M_lens = 0.55), and the total magnification factor of the source galaxy (~ 13). Additionally, we measure an upper-limit constraint on luminous substructure (M_V > 16.2), based on the non-detection of bright satellite galaxies in all data sets. Finally, we utilize the improved image resolution of the AO data to reveal the presence of faint arcs outside of the primary Einstein ring. The positions and orientations of these arcs raise the intriguing possibility that B1938+666 has a second source galaxy, located at a more distant redshift. However, future work is needed to verify this hypothesis.
description: 12 pages, 7 figures; Accepted for publication in MNRAS
Appendix III: Terra Petraea Viewshed R-script
Creators: name: Kennedy, Will M.
Publisher: name: Zenodo
Year: 2021
Subjects: Terra Petraea

description: This third appendix to "Terra Petraea. The Archaeological Landscape of the Petraean Hinterland from the Hellenistic to the Byzantine Period" (ISBN 978-3-8325-5171-1) is a PDF version of an exemplary R-script written by the author for conducting the visibility analyses (cf. chapter 2).
Betriebswirtschaftliche Stellungnahme zu FISG und Risikomanagement
Creators: name: Berger, Thomas
name: Erben, Roland F.
name: Ernst, Dietmar
name: Gleißner, Werner
name: Holst, Hans-Ulrich
name: Meyer, Matthias
name: Scherer, Josef
name: Schneck, Ottmar
name: Ulrich, Patrick
name: Vanini, Ute
Publisher: name: TUHH Universitätsbibliothek
Year: 2021
Subjects: classificationCode: 330
subject: Wirtschaft

description: Aufgrund des "Falls Wirecard" hat der Gesetzgeber mit dem FISG (Finanzmarkintegritätsstärkungsgesetz) neue gesetzliche Regelungen geschaffen, die insbesondere das Risikomanagement der Unternehmen stärken sollen. Sie sind eine wesentliche Ergänzung zu den neuen Anforderungen aus § 1 StaRUG [vgl. Braun 2021; Gleißner/Lienhard/Kühne 2021; Nickert/Nickert 2021 und Weitzmann 2021], demzufolge Unternehmen "bestandsgefährdende Entwicklungen" früh erkennen sollen, und erstmalig alle haftungsbeschränkten Unternehmen auch verpflichtet werden, bei Bedarf "geeignete Gegenmaßnahmen" zu initiieren. Das Anliegen dieser Stellungnahme war es, aus betriebswirtschaftlicher Perspektive auf besonders wesentliche Aspekte hinzuweisen; eine Kommentierung einzelner Formulierungen des FISG oder eine Umsetzung unserer Empfehlungen in Formulierungen für einen Gesetzestext ist nicht unsere Absicht. Als Ökonomen sehen die Autoren an einigen Stellen Präzisierungsbedarf [siehe grundlegend auch Velte 2020]. Die Stellungnahme ist insbesondere das Resultat des Sachverhalts, dass - trotz Abschlussprüfung - eine Vielzahl auch der börsennotierten Unternehmen die gesetzlichen Anforderungen aus §§ 91 und 93 AktG bisher nicht erfüllen [was man meist sehr leicht beweisen kann, siehe vertiefend Gleißner 2020].
Hausdorff dimension of escaping sets of meromorphic functions II
Creators: name: Aspenberg, Magnus
name: Cui, Weiwei
Publisher: name: arXiv
Year: 2020
Subjects: subject: Dynamical Systems (math.DS)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 37F10, 30D05, 37F31, 30D30

description: A function which is transcendental and meromorphic in the plane has at least two singular values. On one hand, if a meromorphic function has exactly two singular values, it is known that the Hausdorff dimension of the escaping set can only be either $2$ or $1/2$. On the other hand, the Hausdorff dimension of escaping sets of Speiser functions can attain every number in $[0,2]$ (cf. \cite{ac1}). In this paper, we show that number of singular values which is needed to attain every Hausdorff dimension of escaping sets is not more than $4$.
description: 22 pages, 5 figures; minor revisions and corrections; to appear in Ergodic Theory and Dynamical Systems
Electroweak lights from Dark Matter annihilations
Creators: name: De Simone, Andrea
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The energy spectra of Standard Model particles originated from Dark Matter annihilations can be significantly altered by the inclusion of electroweak gauge boson radiation from the final state. A situation where this effect is particularly important is when a Majorana Dark Matter particle annihilates into two light fermions. This process is in p-wave and hence suppressed by the small value of the relative velocity of the annihilating particles. The inclusion of electroweak radiation eludes this suppression and opens up a potentially sizeable s-wave contribution to the annihilation cross section. I will discuss the impact of this effect on the fluxes of stable particles resulting from the Dark Matter annihilations, which are relevant for Dark Matter indirect searches.
description: 4 pages, 2 figures. Contribution to the conference proceedings of TAUP 2011, Munich - Germany (5-9 September 2011)
Symmetries, conservation laws and difference schemes of the (1+2)-dimensional shallow water equations in Lagrangian coordinates
Creators: name: Dorodnitsyn, V. A.
name: Kaptsov, E. I.
name: Meleshko, S. V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences
subject: 76B07, 65N06

description: The two-dimensional shallow water equations in Eulerian and Lagrangain coordinates are considered. Lagrangian and Hamiltonian formalism of the equations is given. The transformations mapping the two-dimensional shallow water equations with a circular or plane bottom into the gas dynamics equations of a polytropic gas with polytropic exponent $γ=2$ is represented. Group properties of the equations are considered, and the group classification for the case of the elliptic paraboloid bottom topography is performed. The properties of the two-dimensional shallow water equations in Lagrangian coordinates are discussed from the discretization point of view. New invariant conservative finite-difference schemes for the equations and their one-dimensional reductions are constructed. The schemes are derived either by extending the known one-dimensional schemes or by direct algebraic construction based on some assumptions on the form of the energy conservation law. Among the proposed schemes there are schemes possessing conservation laws of mass and energy.
description: 24 pages, 2 figures, 1 table