cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Ergodic Properties of Fractional Brownian-Langevin Motion
Creators: name: Deng, Weihua
name: Barkai, Eli
Publisher: name: arXiv
Year: 2008
Subjects: subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Astrophysics (astro-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We investigate the time average mean square displacement $\overline{δ^2}(x(t))=\int_0^{t-Δ}[x(t^\prime+Δ)-x(t^\prime)]^2 dt^\prime/(t-Δ)$ for fractional Brownian and Langevin motion. Unlike the previously investigated continuous time random walk model $\overline{δ^2}$ converges to the ensemble average $ \sim t^{2 H}$ in the long measurement time limit. The convergence to ergodic behavior is however slow, and surprisingly the Hurst exponent $H=3/4$ marks the critical point of the speed of convergence. When $H<3/4$, the ergodicity breaking parameter ${EB} = {Var} (\overline{δ^2}) / < \overline{δ^2} >^2\sim k(H) \cdotΔ\cdot t^{-1}$, when $H=3/4$, ${EB} \sim (9/16)(\ln t) \cdotΔ\cdot t^{-1}$, and when $3/4
description: 8 pages, 6 figures
Southern Pea
Creators: name: Traunfeld, Jon
name: Abend, Anne
name: Yen, Peggy
Publisher: name: University of Maryland Extension
Year: 2010

description: Vigna unguiculata is known by many names including “blackeyes”, “cowpeas”, “crowders” and “field peas”. This publication provides instruction for planting, cultivation, harvesting, storage, nutrition, and use.
An Experimental Urban Case Study with Various Data Sources and a Model for Traffic Estimation
Creators: name: Genser, Alexander
name: Hautle, Noel
name: Makridis, Michail
name: Kouvelas, Anastasios
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Accurate estimation of the traffic state over a network is essential since it is the starting point for designing and implementing any traffic management strategy. Hence, traffic operators and users of a transportation network can make reliable decisions such as influence/change route or mode choice. However, the problem of traffic state estimation from various sensors within an urban environment is very complex for several different reasons, such as availability of sensors, different noise levels, different output quantities, sensor accuracy, heterogeneous data fusion, and many more. To provide a better understanding of this problem, we organized an experimental campaign with video measurement in an area within the urban network of Zurich, Switzerland. We focus on capturing the traffic state in terms of traffic flow and travel times by ensuring measurements from established thermal cameras by the city's authorities, processed video data, and the Google Distance Matrix. We assess the different data sources, and we propose a simple yet efficient Multiple Linear Regression (MLR) model to estimate travel times with fusion of various data sources. Comparative results with ground-truth data (derived from video measurements) show the efficiency and robustness of the proposed methodology.
Hyperfine induced $1s2s ^1S_0 \to 1s^2 ^1S_0$ M1 transition of He-like ions
Creators: name: Li, Jiguang
name: Jönsson, Per
name: Gaigalas, Gediminas
name: Dong, Chenzhong
Publisher: name: arXiv
Year: 2008
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Hyperfine induced $1s2s ^1S_0 \to 1s^2 ^1S_0$ M1 transition probabilities of He-like ions have been calculated from relativistic configuration interaction wavefunctions including the frequency independent Breit interaction and QED effects. Present results for {$^{151}$}Eu and {$^{155}$}Gd are in good agreement with previous calculations [Phys. Rev. A {\bf 63}, 054105 (2001)]. Electronic data are given in terms of a general scaling law in $Z$ that, given isotopic nuclear spin and magnetic moment, allows hyperfine induced decay rates to be estimated for any isotope. The results should be helpful for future experimental investigations on QED and parity non-conservation effects.
description: 9 pages, 2 figures
Tomatoes
Creators: name: Traunfeld, Jon
name: Smetana, Jeanine
name: Yen, Peggy
Publisher: name: University of Maryland Extension
Year: 2019

description: Solanum lycopersicum is an herbaceous, usually sprawling plant in the nightshade family that is typically cultivated for its edible fruit. This publication briefly describes the types and varieties available from seed catalogs, and provides general instruction for planting, cultivation, harvesting, storage, nutrition, and cooking.
Military coup in Myanmar: ‘Garrison State’ back to dismantle democracy?
Creators: name: K.M. SEETHI
Publisher: name: figshare
Year: 2021
Subjects: subject: 160607 International Relations
subject: FOS: Political science

description: The Global South Colloquy paper deals with the military takeover in Myanmar on 1 February 2021 and its context and implications.
Formation and stability of icosahedral phase in Al65Ga5Pd17Mn13 alloy
Creators: name: Yadav, T. P.
name: Shaz, M. A.
name: Tiwari, R. S.
name: Srivastava, O. N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: In this work, we present the formation and characterization of a quaternary (pseudo ternary) icosahedral quasicrystal in Al65Ga5Pd17Mn13 alloy. The X ray diffraction and transmission electron microscopy confirmed the formation of icosahedral B2 type and O crystalline (orthorhombic structure) phases in as cast alloy. The icosahedral phase gets formed after annealing at 800 C for 60 hours. The formation of icosahedral phase in AlGaPdMn quaternary alloy by present technique has been studied for the first time. The Energy dispersive X-ray analysis investigations suggest the presence of Ga (5 at) in the alloy. It is interesting to note that pseudo twelve fold pattern in the as cast alloy has been observed. Icosahedral AlGaPdMn provides a new opportunity to investigate the various characteristics including surface characteristics. Attempts will be made to discuss the micromechanisms for the formation of quasicrystalline phase in Al-Ga-Pd-Mn alloys.
description: 14 pages 5 figures
Inverse Compton gamma-ray models for remnants of Galactic type Ia supernovae?
Creators: name: Voelk, H. J.
name: Ksenofontov, L. T.
name: Berezhko, E. G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We theoretically and phenomenologically investigate the question whether the gamma-ray emission from the remnants of the type Ia supernovae SN 1006, Tycho's SN and Kepler's SN can be the result of electron acceleration alone. The observed synchrotron spectra of the three remnants are used to determine the average momentum distribution of nonthermal electrons as a function of the assumed magnetic field strength. Then the inverse Compton emission spectrum in the Cosmic Microwave Background photon field is calculated and compared with the existing upper limits for the very high energy gamma-ray flux from these sources. It is shown that the expected interstellar magnetic fields substantially overpredict even these gamma-ray upper limits. Only rather strongly amplified magnetic fields could be compatible with such low gamma-ray fluxes. However this would require a strong component of accelerated nuclear particles whose energy density substantially exceeds that of the synchrotron electrons, compatible with existing theoretical acceleration models for nuclear particles and electrons. Even though the quantitative arguments are simplistic, they appear to eliminate simplistic phenomenological claims in favor of a inverse Compton gamma-ray scenario for these sources.
description: 6 pages, 1 figure, accepted for publication in Astronomy and Astrophysics
The minimum rotation period of millisecond pulsars
Creators: name: Ertan, Unal
name: Alpar, M. Ali
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: A simple and natural explanation for the minimum period of millisecond pulsars follows from a correlation between the accretion rate and the frozen surface dipole magnetic field resulting from Ohmic diffusion through the neutron star crust in initial stages of accretion in low mass X-ray binaries.
description: 3 pages, 1 figure, accepted for publication in MNRAS Letters
D7.5 Second set of recommendations for development of future rural policies
Creators: name: Chartier, Olivier
name: Irvine, Kate
name: Martino, Giulia
name: Miller, David
name: Pagnon, Juliette
name: Salle, Elodie
name: Gerald, Schwarz
name: Muro, Melanie
Publisher: name: Zenodo
Year: 2023
Subjects: Rural areas
Rural Interfaces
European Union
Resilience
Recommendations
Policy

description: This deliverable reports the second set of policy recommendations of the SHERPA project, developed from its Multi-Actor Platforms (MAPs). It builds on the first set of recommendations for policy and actions which contributed to planning of the Long Vision for Rural Areas (LTVRA; European Commission, 2021a) and its Rural Action Plan. 
The second set of recommendations for future rural policies developed from the SHERPA process have been aligned to the four pillars and component building blocks of the Rural Action Plan.
The process of formulating and synthesising recommendations for future rural policies was based on a continuous dialogue between MAPs, the SHERPA partners in charge of drafting Position Papers, and the SHERPA Think Tank. The draft recommendations were reviewed and debated by panels drawn from European level interests and SHERPA MAPs at the SHERPA Final Conference (1st, 2nd June 2023), Their relative importance was then ranked by participants, and a follow-up poll of members of all SHERPA MAPs.
Towards Relativistic Atomic Physics. I. The Rest-Frame Instant Form of Dynamics and a Canonical Transformation for a System of Charged Particles plus the Electro-Magnetic Field
Creators: name: Alba, David
name: Crater, Horace
name: Lusanna, Luca
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mathematical Physics (math-ph)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A complete exposition of the rest-frame instant form of dynamics for arbitrary isolated systems (particles, fields, strings, fluids)admitting a Lagrangian description is given. The starting point is the parametrized Minkowski theory describing the system in arbitrary admissible non-inertial frames in Minkowski space-time, which allows one to define the energy-momentum tensor of the system and to show the independence of the description from the clock synchronization convention and from the choice of the 3-coordinates. In the inertial rest frame the isolated system is seen as a decoupled non-covariant canonical external center of mass carrying a pole-dipole structure (the invariant mass $M$ and the rest spin ${\vec {\bar S}}$ of the system) and an external realization of the Poincare' group. Then an isolated system of positive-energy charged scalar articles plus an arbitrary electro-magnetic field in the radiation gauge is investigated as a classical background for defining relativistic atomic physics. The electric charges of the particles are Grassmann-valued to regularize the self-energies. The rest-frame conditions and their gauge-fixings (needed for the elimination of the internal 3-center of mass) are explicitly given. It is shown that there is a canonical transformation which allows one to describe the isolated system as a set of Coulomb-dressed charged particles interacting through a Coulomb plus Darwin potential plus a free transverse radiation field: these two subsystems are not mutually interacting and are interconnected only by the rest-frame conditions and the elimination of the internal 3-center of mass. Therefore in this framework with a fixed number of particles there is a way out from the Haag theorem,at least at the classical level.
description: Minor changes
Hopfing and Puffing Warped Anti-de Sitter Space
Creators: name: Anninos, Dionysios
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Three dimensional spacelike warped anti-de Sitter space is studied in the context of Einstein theories of gravity and string theory, where there is no gravitational Chern-Simons term in the action. We propose that it is holographically dual to a two-dimensional conformal field theory with equal left and right moving central charges. Various checks of the central charges are offered, based on the Bekenstein-Hawking entropy of the stretched warped black holes and warped self-dual solutions. The proposed central charges are applied to compute the Bekenstein-Hawking entropy of the Hopf T-dual of six-dimensional dyonic black strings which have a near horizon consisting of three dimensional warped anti-de Sitter space times a three-sphere. We find that the Hopf T-duality is a map between thermal states with equal entropy of the CFTs dual to the dyonic black string and the Hopf T-dualized black string.
description: 24 pages; v3. Minor modifications in the text
ICDAR 2021 Competition on On-Line Signature Verification
Creators: name: Tolosana, Ruben
name: Vera-Rodriguez, Ruben
name: Gonzalez-Garcia, Carlos
name: Fierrez, Julian
name: Rengifo, Santiago
name: Morales, Aythami
name: Ortega-Garcia, Javier
name: Ruiz-Garcia, Juan Carlos
name: Romero-Tapiador, Sergio
name: Jiang, Jiajia
name: Lai, Songxuan
name: Jin, Lianwen
name: Zhu, Yecheng
name: Galbally, Javier
name: Diaz, Moises
name: Ferrer, Miguel Angel
name: Gomez-Barrero, Marta
name: Hodashinsky, Ilya
name: Sarin, Konstantin
name: Slezkin, Artem
name: Bardamova, Marina
name: Svetlakov, Mikhail
name: Saleem, Mohammad
name: Szücs, Cintia Lia
name: Kovari, Bence
name: Pulsmeyer, Falk
name: Wehbi, Mohamad
name: Zanca, Dario
name: Ahmad, Sumaiya
name: Mishra, Sarthak
name: Jabin, Suraiya
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: This paper describes the experimental framework and results of the ICDAR 2021 Competition on On-Line Signature Verification (SVC 2021). The goal of SVC 2021 is to evaluate the limits of on-line signature verification systems on popular scenarios (office/mobile) and writing inputs (stylus/finger) through large-scale public databases. Three different tasks are considered in the competition, simulating realistic scenarios as both random and skilled forgeries are simultaneously considered on each task. The results obtained in SVC 2021 prove the high potential of deep learning methods. In particular, the best on-line signature verification system of SVC 2021 obtained Equal Error Rate (EER) values of 3.33% (Task 1), 7.41% (Task 2), and 6.04% (Task 3). SVC 2021 will be established as an on-going competition, where researchers can easily benchmark their systems against the state of the art in an open common platform using large-scale public databases such as DeepSignDB and SVC2021_EvalDB, and standard experimental protocols.
Synthetic studies towards the tetracyclic diterpenoids aphidicolin and stemodin
Creators: name: Herbert, David John
Publisher: name: University of British Columbia
Year: 2010

description: The work described in this thesis is concerned with the development of a general synthetic approach to the tetracyclic diterpenoids aphidicolin 8 and stemodin 9. This novel class of diterpenoids has to date been represented by aphidicolin 8 and stemodin 9. Although these materials contain different substituents, they do possess remarkably similar carbon skeletons. This work began with the transformation of the Wieland-Miescher ketone 46, using a six-step sequence, into the bicyclic ketal ketone 45. The conversion of this material into the next key intermediate, the tricyclic ketal enone 44 was accomplished in two manners. The first approach made use of, as the key reaction, the internal Wittig-Horner cyclization of the β,Є-diketo phosphonate 108 to the desired enone 44 while the second proposal involved the aldol condensation of the bicyclic diketone 131 to the desired enone 44. This second pathway was initially explored by means of a model system. The β,Є -diketo phosphonate 108 was prepared in the following manner. Alkylation of the enolate of 45 with methyl iodoacetate gave the keto ester 105. Saponification of the ester 105 gave the acid 123 which was converted into the corresponding acyl chloride and treatment of this material with the anion of dimethyl methylphosphonate gave the desired β,Є -diketo phosphonate 108. The bicyclic diketone 131 was prepared as follows. Alkylation of the enolate of the bicyclic ketone 45 with methallyl iodide gave the keto olefin 130 and oxidative cleavage of the olefinic double bond in 130 using osmium tetraoxide and sodium meta-periodate gave the bicyclic diketone 131. The next phase of this work dealt with the construction of the tetracyclic ketones 55 and 60, possessing the basic tetracyclic carbon skeletons of aphidicolin 8 and stemodin 9 respectively. The proposed synthetic pathway to these materials is discussed but only partially realized during the scope of this work. The photochemically induced addition of allene to the enone 44 gave the photoadducts 56 and 57. The keto olefins 56 and 57 were transformed into the keto esters 59 and 133, obvious precursors to the tetracyclic ketones 55 and 60.
Demystifying the nonlocality problem in Aharonov-Bohm effect
Creators: name: Bhattacharya, Kolahal
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: In this paper, we present a novel semi-classical theory of the electrostatic and magnetostatic fields and explain the nonlocality problem in the context of the Aharonov-Bohm effect [1]. Specifically, we show that the electrostatic and the magnetostatic fields possess a quantum nature that manifests if certain conditions are met. In particular, the wave amplitudes of the fields are seen to exist even in the regions where the classical fields vanish and they operate on the electron wave functions locally as unitary phases. This formulation also sheds light on the quantisation of electric charges and magnetic flux.
description: 15 pages, 1 figure
title: RTA 2012 Proceedings Frontmatter
Creators: name: Tiwari, Ashish
Publisher: name: Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Year: 2012
Subjects: subject: Frontmatter
subject: Table of Contents
subject: Conference Organization
subject: External Reviewers
subject: Author Index
subject: RTA 2012
subject: proceedings

description: Frontmatter, Table of Contents, Conference Organization, External Reviewers, Author Index.
description: LIPIcs, Vol. 15, 23rd International Conference on Rewriting Techniques and Applications (RTA'12), pages i-xiii
Calculation of the total gamma-spectra of the fast neutrons capture in the isotopes 117,119Sn for the different parameters of cascade gamma-decay
Creators: name: Sukhovoj, A. M.
name: Khitrov, V. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The gamma-spectra were calculated for the set of different level densities and radiative strength functions. The sufficiently precise reproduction of the experiment is impossible without taking into account the influence of the process of the nucleons Cooper pairs breaking on any nuclei cascade gamma-decay parameters.
description: 8 pages, 4 figures, 1 table
The chemistry of chlorine-bearing species in the diffuse interstellar medium, and new SOFIA/GREAT observations of HCl$^+$
Creators: name: Neufeld, David A.
name: Wiesemeyer, Helmut
name: Wolfire, Mark J.
name: Jacob, Arshia
name: Buchbender, Christof
name: Gerin, Maryvonne
name: Gupta, Harshal
name: Güsten, Rolf
name: Schilke, Peter
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We have revisited the chemistry of chlorine-bearing species in the diffuse interstellar medium with new observations of the HCl$^+$ molecular ion and new astrochemical models. Using the GREAT instrument on board SOFIA, we observed the $^2Π_{3/2}\, J = 5/2 - 3/2$ transition of HCl$^+$ near 1444 GHz toward the bright THz continuum source W49N. We detected absorption by diffuse foreground gas unassociated with the background source, and were able to thereby measure the distribution of HCl$^+$ along the sight-line. We interpreted the observational data using an updated version of an astrochemical model used previously in a theoretical study of Cl-bearing interstellar molecules. The abundance of HCl$^+$ was found to be almost constant relative to the related H$_2$Cl$^+$ ion, but the observed $n({\rm H_2Cl^+})/n({\rm HCl^+})$ abundance ratio exceeds the predictions of our astrochemical model by an order-of-magnitude. This discrepancy suggests that the rate of the primary destruction process for ${\rm H_2Cl^+}$, dissociative recombination, has been significantly overestimated. For HCl$^+$, the model predictions can provide a satisfactory fit to the observed column densities along the W49N sight-line while simultaneously accounting for the ${\rm OH^+}$ and ${\rm H_2O^+}$ column densities.
description: 34 pages. 8 figures. Accepted for publication in the Astrophysical Journal
The Highly Self-Absorbed Blazar, PKS\,1351$-$018
Creators: name: Punsly, Brian
name: Frey, Sandor
name: Reynolds, Cormac
name: Marziani, Paola
name: Pushkarev, Alexander
name: Chen, Sina
name: Li, Shang
name: Kharb, Preeti
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: PKS\,1351$-$018 at a redshift of $z=3.71$ is one of the most luminous, steady synchrotron sources with a luminosity $> 10^{47}$\,erg~s$^{-1}$. The synchrotron luminosity does not seem to vary by more than $\sim 25\%$ over 35 years. In order to appreciate this remarkable behavior, if it were at $z=0.5$, it would have a flux density at 15 GHz in a range of $110 - 137$\,Jy over 11 yrs. In spite of this steady behavior, two strong $γ$-ray flares $\lesssim 10^{49}$\,erg~s$^{-1}$ were detected in 2011 and 2016. There is blazar-like behavior coexisting with the steady behavior. This study is aimed at elucidating the dual nature of this source. We find that the radio source is extremely compact with a bright core and a steep spectrum secondary component, 12\,mas away, that appears to be constant in position and flux density in six epochs from 1995 to 2018. We estimate that a jet with a time averaged power of $(5.2 \pm 3.2) \times 10^{45}$\,erg~s$^{-1}$ terminates in this lobe that is advancing $\gtrsim 0.9 c$ at a deprojected distance of $1-3$\,kpc from the central engine. This is the rare case of a young ($\sim 6000$\,yr), very powerful radio source that is viewed a few degrees from the jet axis. We find evidence of a high velocity (4000\,km~s$^{-1}$), high ionization wind emanating form a luminous quasar. The young radio jet appears to experience modest bending as it navigates through the intense quasar environment.
description: To appear in ApJ
Elena KORKA – Joseph L. RIFE (Hgg.), On the Edge of a Roman Port. Excavations at Koutsongila, Kenchreai, 2007-2014
Creators: name: Adlung, Sebastian
Publisher: name: Göttinger Forum für Altertumswissenschaft
Year: 2024

description: Rezension zu: Elena Korka – Joseph L. Rife (Hgg.), On the Edge of a Roman Port. Excava­tions at Koutsongila, Kenchreai, 2007-2014. Hesperia Supplement, Bd. 52. Princeton, NJ: American School of Classical Studies at Athens 2022, 1376 S., 672 s/w-Abb., 61 farb. Abb., 49 Taf., USD 150,00. ISBN: 978-0-87661-554-6
description: Göttinger Forum für Altertumswissenschaft, Bd. 26 (2023): Göttinger Forum für Altertumswissenschaft
DIGITAL SOCIETY: A QUEST FOR A NEW REALITY
Creators: name: Elkhova, Oxana
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 500312
subject: Philosophy of cognition
classificationCode: 460708
subject: Virtual and mixed reality
classificationCode: 500311
subject: Philosophical psychology (incl. moral psychology and philosophy of action)

description: At the same time, the creation of digital twins remains an important area of modern science. The meaning of digital twins is revealed through the concept of «artificial society». To simulate real society, computer programs use agent-based models, which are computational or computer models designed to study the behavior of agents in various environments and situations. In such models there is a division into agents and environment. Agents, in turn, can be abstract representatives of individuals, groups, organizations, and their goal is to interact with each other and with the environment. To study social processes using computer simulation, scientists interested in social simulation are provided with platforms where they can publish their research and results. For example, the interdisciplinary journal JASSS (Journal of Artificial Societies and Social Simulation), the online nature of the journal guarantees a large audience, and the inclusion of multimedia content such as animation, color diagrams and a toolkit improves the readability and usability of articles. This approach to the study of society has a number of advantages: agent-based models allow us to identify main trends in the behavior of groups, see changes in the environment, determine interactions between individuals, conduct experiments and test hypotheses in a virtual environment, which is often impossible or impractical in the real world.
Penetration depth, multiband superconductivity, and absence of muon-induced perturbation in superconducting PrOs$_{4}$Sb$_{12}$
Creators: name: Shu, Lei
name: MacLaughlin, D. E.
name: Beyermann, W. P.
name: Heffner, R. H.
name: Morris, G. D.
name: Bernal, O. O.
name: Callaghan, F. D.
name: Sonier, J. E.
name: Yuhasz, W. M.
name: Frederick, N. A.
name: Maple, M. B.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Transverse-field muon spin rotation ($μ$SR) experiments in the heavy-fermion superconductor PrOs$_{4}$Sb$_{12}$ ($T_{c}=1.85$ K) suggest that the superconducting penetration depth $λ(T)$ is temperature-independent at low temperatures, consistent with a gapped quasiparticle excitation spectrum. In contrast, radiofrequency (rf) inductive measurements yield a stronger temperature dependence of $λ(T)$, indicative of point nodes in the gap. This discrepancy appears to be related to the multiband structure of PrOs$_{4}$Sb$_{12}$. Muon Knight shift measurements in PrOs$_{4}$Sb$_{12}$ suggest that the perturbing effect of the muon charge on the neighboring Pr$^{3+}$ crystalline electric field is negligibly small, and therefore is unlikely to cause the difference between the $μ$SR and rf results.
description: 10 pages, 7 figures
Dynamics of Negativity of a Wannier-Stark Many-Body Localized System Coupled to a Bath
Creators: name: Wybo, Elisabeth
name: Knap, Michael
name: Pollmann, Frank
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: An interacting system subjected to a strong linear potential can host a many-body localized (MBL) phase when being slightly perturbed. This so-called Wannier-Stark or `tilted-field' MBL phase inherits many properties from the well-investigated disordered MBL phase, and provides an alternative route to experimentally engineer interacting localized systems without quenched disorder. In this work, we investigate the dynamics of entanglement in a Wannier-Stark MBL system coupled to a dephasing environment. As an accessible entanglement proxy, we use the third Rényi negativity $R_3$, which reduces to the third Rényi entropy in case the system is isolated from the environment. This measure captures the characteristic logarithmic growth of interacting localized phases in the intermediate-time regime, where the effects of the coupling to the environment are not yet dominating the dynamics. Thus it forms a tool to distinguish Wannier-Stark MBL from non-interacting Wannier-Stark localization up to intermediate time-scales, and to quantify quantum correlations in mixed-state dynamics.
description: 10 pages, 11 figures
Spectral energy density in an axisymmetric galaxy as predicted by an analytical model for the Maxwell field
Creators: name: Arminjon, Mayeul
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: An analytical model for the Maxwell radiation field in an axisymmetric galaxy, proposed previously, is first checked for its predictions of the spatial variation of the spectral energy distributions (SEDs) in our Galaxy. First, the model is summarized. It is now shown how to compute the SED with this model. Then the model is adjusted by asking that the SED predicted at our local position in the Galaxy coincide with the available observations. Finally the first predictions of the model for the spatial variation of the SED in the Galaxy are compared with those of a radiation transfer model. We find that the two predictions do not differ too much. This indicates that, in a future work, it should be possible with the present model to check if the "interaction energy" predicted by an alternative, scalar theory of gravitation, contributes to the dark matter. Keywords: Disk galaxy; interstellar radiation field; axial symmetry; electromagnetic field; Milky Way.
description: 25 pages, including 11 figures, matches published version. The latter is Open Access at the Publisher, see DOI
Problems of experimental determination of parameters of nucleus and applicability of the Bohr-Mottelson hypothesis
Creators: name: Sukhovoj, A. M.
name: Khitrov, V. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Population of a number of excited levels of 51V and 57Fe has been determined from the data of the ENDSF file up to the excitation energy of about 7 and 5.2 MeV, respectively. It cannot be reproduced in the region of their maximal energies in the framework of assumption on the independence of partial radiative widths on the structure of decaying level and excited one, at least, lower than 0.5Bn. Therefore, it is impossible to estimate the actual degree of reliability of data on the level density and radiative widths of cascade gamma-transitions in light spherical nuclei obtained from the spectrum analysis of nuclear reactions, which do not take into account this circumstance.
description: 5 pages, 2 figures
Radio observations of NGC 2808 and other globular clusters: constraints on intermediate mass black holes
Creators: name: Maccarone, Thomas J.
name: Servillat, Mathieu
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of a deep radio observation of the globular cluster NGC 2808. We show that there are no sources detected within the core of the cluster, placing constraints on both the pulsar population of the cluster and the mass of a possible intermediate mass black hole in NGC 2808. We compare the results for this cluster with other constraints on intermediate mass black holes derived from accretion measures. With the exception of G1 in M~31 which has previously shown radio emission, even with considerably more conservative assumptions, only the clusters with the poorest of observational constraints are consistent with falling on the $M_{BH}-σ$ relation. This result is interpreted in terms of the fundamental differences between galaxies and globular clusters.
description: 6 pages, 1 table, no figures, accepted to MNRAS
Profile and polarization characteristics of energetic pulsars
Creators: name: Weltevrede, Patrick
name: Johnston, Simon
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In this paper we compare the characteristics of pulsars with a high spin-down energy loss rate (Edot) against those with a low Edot. We show that the differences in the total intensity pulse morphology between the two classes are in general rather subtle. A much more significant difference is the fractional polarization which is very high for high Edot pulsars and low for low Edot pulsars. The Edot at the transition is very similar to the death line predicted for curvature radiation. This suggests a possible link between high energy and radio emission in pulsars and could imply that gamma-ray efficiency is correlated with the degree of linear polarization in the radio band. The degree of circular polarization is in general higher in the second component of doubles, which is possibly caused by the effect of co-rotation on the curvature of the field lines in the inertial observer frame. The most direct link between the high energy emission and the radio emission could be the sub-group of pulsars which we call the energetic wide beam pulsars. These young pulsars have very wide profiles with steep edges and are likely to be emitted from a single magnetic pole. The similarities with the high energy profiles suggest that both types of emission are produced at the same extended height range in the magnetosphere. Alternatively, the beams of the energetic wide beam pulsars could be magnified by propagation effects in the magnetosphere. This would naturally lead to decoupling of the wave modes, which could explain the high degree of linear polarization. As part of this study, we have discovered three previous unknown interpulse pulsars (and we detected one for the first time at 20 cm). We also obtained rotation measures for 18 pulsars whose values had not previously been measured.
description: Corrected typo in pulsar name. 26 pages, 11 figures, accepted for publication in MNRAS. Astro-ph version is missing 528 figures due to file size restrictions. Please download complete paper from http://www.atnf.csiro.au/people/pulsar/wj08b.pdf
Network representation learning systematic review: ancestors and current development state
Creators: name: Amara, Amina
name: Taieb, Mohamed Ali Hadj
name: Aouicha, Mohamed Ben
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Real-world information networks are increasingly occurring across various disciplines including online social networks and citation networks. These network data are generally characterized by sparseness, nonlinearity and heterogeneity bringing different challenges to the network analytics task to capture inherent properties from network data. Artificial intelligence and machine learning have been recently leveraged as powerful systems to learn insights from network data and deal with presented challenges. As part of machine learning techniques, graph embedding approaches are originally conceived for graphs constructed from feature represented datasets, like image dataset, in which links between nodes are explicitly defined. These traditional approaches cannot cope with network data challenges. As a new learning paradigm, network representation learning has been proposed to map a real-world information network into a low-dimensional space while preserving inherent properties of the network. In this paper, we present a systematic comprehensive survey of network representation learning, known also as network embedding, from birth to the current development state. Through the undertaken survey, we provide a comprehensive view of reasons behind the emergence of network embedding and, types of settings and models used in the network embedding pipeline. Thus, we introduce a brief history of representation learning and word representation learning ancestor of network embedding. We provide also formal definitions of basic concepts required to understand network representation learning followed by a description of network embedding pipeline. Most commonly used downstream tasks to evaluate embeddings, their evaluation metrics and popular datasets are highlighted. Finally, we present the open-source libraries for network embedding.
description: 65 pages 11 Figures 6 Tables
Expansion Formula For the Magnetic Field of a Periodically Deformed Circular Current Loop
Creators: name: Salazar, Robert
name: Téllez, Gabriel
name: Bayona-Roa, Camilo
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: A method is derived to obtain an expansion formula for the magnetic field $\boldsymbol{B}(\boldsymbol{r})$ generated by a closed planar wire carrying a steady electric current. The parametric equation of the loop is $\mathcal{R}(ϕ)=R+Hf(ϕ)$, with $R$ the radius of the circle, $H \in [0,R)$ the radial deformation amplitude, and $f(ϕ)\in[-1,1]$ a periodic function. The method is based on the replacement of the $1/|\boldsymbol{r} - \boldsymbol{r}'|^3$ factor by an infinite series in terms of Gegenbauer polynomials, as well as the use of the Taylor series. This approach makes it feasible to write $\boldsymbol{B}(\boldsymbol{r})$ as the circular loop magnetic field contribution plus a sum of powers of $H/R$. Analytic formulas for the magnetic field are obtained from truncated finite expansions outside the neighborhood of the wire. These showed to be computationally less expensive than numerical integration in regions where the dipole approximation is not enough to describe the field properly. Illustrative examples of the magnetic field due to circular wires deformed harmonically are developed in the article, obtaining exact expansion coefficients and accurate descriptions. Error estimates are calculated to identify the regions in $\mathbb{R}^3$ where the analytical expansions perform well. Finally, first-order deformation formulas for the magnetic field are studied for generic even deformation functions $f(ϕ)$. Keywords: Magnetic Field, Gegenbauer Polynomials, Arbitrary current loop, Biot-Savart law.
description: Phys. Scr 2021
Twist-bend nematics and heliconical cholesterics: a physico-chemical analysis of phase transitions and related specific properties
Creators: name: Kasian, Natalia
name: Lisetski, Longin
name: Gvozdovskyy, Igor
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Certain nematic liquid crystals, e.g., those formed by banana-shaped molecules, can exhibit a low-temperature twist-bend nematic (Ntb) phase. Upon addition of chiral dopants, a chiral version of the twist-bend phase (N*tb) can be observed below the conventional chiral nematic (N*) phase, while under electric field the N* phase is transformed into a specific state known as "heliconical cholesteric". In this work, we have studied the well-known Ntb-forming system CB7CB:CB6OCB with addition of 5CB and chiral dopants (ChD) using optical microscopy, differential scanning calorimetry (DSC), and measurements of temperature-dependent optical transmission using optical microscopy. Effects of 5CB and different chiral dopants (of steroid or non-steroid nature) upon thermal stability of Ntb phase were analyzed, and selective reflection in the visible range could be observed in the N* phase with a sufficiently high ChD content. As a peculiar feature, sharp unwinding of the cholesteric helix was observed at lower temperatures when approaching the N*tb phase, which appears to be similar to the helix unwinding close to the smectic-A transition.
description: 32 pages, 10 figures
Kinematic singularities of Feynman integrals and principal A-determinants
Creators: name: Klausen, René Pascal
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the analytic properties of Feynman integrals from the perspective of general A-discriminants and A-hypergeometric functions introduced by Gelfand,Kapranov and Zelevinsky (GKZ). This enables us, to give a clear and mathematically rigour description of the singular locus, also known as Landau variety, via principal A-determinants. We also comprise a description of the various second type singularities. Moreover, by the Horn-Kapranov-parametrization we give a very efficient way to calculate a parametrization of Landau varieties. We furthermore present a new approach to study the sheet structure of multivalued Feynman integrals by use of coamoebas.
Wreath Product Symmetric Functions
Creators: name: Ingram, Frank
name: Jing, Naihuan
name: Stitzinger, Ernie
Publisher: name: arXiv
Year: 2008
Subjects: subject: Combinatorics (math.CO)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 05E10, 20E22, 20C30

description: We systematically study wreath product Schur functions and give a combinatorial construction using colored partitions and tableaux. The Pieri rule and the Littlewood-Richardson rule are studied. We also discuss the connection with representations of generalized symmetric groups.
description: 20 pages
Inflation in the nonminimal theory with `K(phi)R' term
Creators: name: Park, Seong Chan
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A class of inflationary models with the nonminimal coupling term `K(phi)R' is considered. We show that the successful inflation can take place if the ratio between the square of the nonminimal coupling term and the potential for the scalar goes asymptotically constant.
description: 3 pages, 1 figure, Talk given at 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY08), Seoul, Korea, 16-21 Jun 2008
Constraining the Spin-Independent WIMP-Nucleon Coupling from Direct Dark Matter Detection Data
Creators: name: Drees, Manuel
name: Shan, Chung-Lin
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Weakly Interacting Massive Particles (WIMPs) are one of the leading candidates for Dark Matter. For understanding the properties of WIMPs and identifying them among new particles produced at colliders (hopefully in the near future), determinations of their mass and their couplings on nucleons from direct Dark Matter detection experiments are essential. Based on our method for determining the WIMP mass model-independently from experimental data, we present a way to also estimate the spin-independent (SI) WIMP-nucleon coupling by using measured recoil energies directly. This method isindependent of the as yet unknown velocity distribution of halo WIMPs. In spite of the uncertainty of the local WIMP density (of a factor of ~ 2), at least an upper limit on the SI WIMP-nucleon coupling could be given, once two (or more) experiments with different target nuclei obtain positive signals. In a background-free environment, for a WIMP mass of 100 GeV its SI coupling on nucleons could in principle be estimated with a statistical error of only ~ 15% with just 50 events from each experiment.
description: 5 pages, 4 figures, plots updated, to appear in the proceedings of Identification of Dark Matter (IDM 2008), Stockholm, Sweden, 18-22 August, 2008
Ultra-High Energy Cosmic Rays, Spiral galaxies and Magnetars
Creators: name: Ghisellini, G.
name: Ghirlanda, G.
name: Tavecchio, F.
name: Fraternali, F.
name: Pareschi, G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We measure the correlation between the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory with the position of the galaxies in the HI Parkes All Sky Survey (HIPASS) catalogue, weighted for their HI flux and Auger exposure. The use of this absorption-free catalogue, complete also along the galactic plane, allows us to use all the Auger events. The correlation is significant, being 86.2% for the entire sample of HI galaxies, and becoming 99% when considering the richest galaxies in HI content, or 98% with those lying between 40-55. We interpret this result as the evidence that spiral galaxies are the hosts of the producers of UHECR and we briefly discuss classical (i.e energetic and distant) long Gamma Ray Burst (GRBs), short GRBs, as well as newly born or late flaring magnetars as possible sources of the Auger events. With the caveat that these events are still very few, and that the theoretical uncertainties are conspicuous, we found that newly born magnetars are the best candidates. If so, they could also be associated with sub-energetic, spectrally soft, nearby, long GRBs. We finally discuss why there is a clustering of Auger events in the direction on the radio-galaxy Cen A and an absence of events in the direction of the radio-galaxy M87.
description: 5 pages, 3 figures, minor changes, accepted for publication in MNRAS Letters
Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
Creators: name: Doeleman, Sheperd
name: Weintroub, Jonathan
name: Rogers, Alan E. E.
name: Plambeck, Richard
name: Freund, Robert
name: Tilanus, Remo P. J.
name: Friberg, Per
name: Ziurys, Lucy M.
name: Moran, James M.
name: Corey, Brian
name: Young, Ken H.
name: Smythe, Daniel L.
name: Titus, Michael
name: Marrone, Daniel P.
name: Cappallo, Roger J.
name: Bock, Douglas C. J.
name: Bower, Geoffrey C.
name: Chamberlin, Richard
name: Davis, Gary R.
name: Krichbaum, Thomas P.
name: Lamb, James
name: Maness, Holly
name: Niell, Arthur E.
name: Roy, Alan
name: Strittmatter, Peter
name: Werthimer, Daniel
name: Whitney, Alan R.
name: Woody, David
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The cores of most galaxies are thought to harbour supermassive black holes, which power galactic nuclei by converting the gravitational energy of accreting matter into radiation (ref 1). Sagittarius A*, the compact source of radio, infrared and X-ray emission at the centre of the Milky Way, is the closest example of this phenomenon, with an estimated black hole mass that is 4 million times that of the Sun (refs. 2,3). A long-standing astronomical goal is to resolve structures in the innermost accretion flow surrounding Sgr A* where strong gravitational fields will distort the appearance of radiation emitted near the black hole. Radio observations at wavelengths of 3.5 mm and 7 mm have detected intrinsic structure in Sgr A*, but the spatial resolution of observations at these wavelengths is limited by interstellar scattering (refs. 4-7). Here we report observations at a wavelength of 1.3 mm that set a size of 37 (+16, -10; 3-sigma) microarcseconds on the intrinsic diameter of Sgr A*. This is less than the expected apparent size of the event horizon of the presumed black hole, suggesting that the bulk of SgrA* emission may not be not centred on the black hole, but arises in the surrounding accretion flow.
description: 12 pages including 2 figures