cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Crucial Factors for Lyα Transmission in the Reionizing Intergalactic Medium: Infall Motion, HII Bubble Size, and Self-shielded Systems
Creators: name: Park, Hyunbae
name: Jung, Intae
name: Song, Hyunmi
name: Ocvirk, Pierre
name: Shapiro, Paul R.
name: Dawoodbhoy, Taha
name: Iliev, Ilian T.
name: Ahn, Kyungjin
name: Bianco, Michele
name: Kim, Hyo Jeong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Using the CoDa II simulation, we study the Ly$α$ transmissivity of the intergalactic medium (IGM) during reionization. At $z>6$, a typical galaxy without an active galactic nucleus fails to form a proximity zone around itself due to the overdensity of the surrounding IGM. The gravitational infall motion in the IGM makes the resonance absorption extend to the red side of Ly$α$, suppressing the transmission up to roughly the circular velocity of the galaxy. In some sight lines, an optically thin blob generated by a supernova in a neighboring galaxy results in a peak feature, which can be mistaken for a blue peak. Redward of the resonance absorption, the damping-wing opacity correlates with the global IGM neutral fraction and the UV magnitude of the source galaxy. Brighter galaxies tend to suffer lower opacity because they tend to reside in larger HII regions, and the surrounding IGM transmits redder photons, which are less susceptible to attenuation, owing to stronger infall velocity. The HII regions are highly nonspherical, causing both sight-line-to-sight-line and galaxy-to-galaxy variation in opacity. Also, self-shielded systems within HII regions strongly attenuate the emission for certain sight lines. All these factors add to the transmissivity variation, requiring a large sample size to constrain the average transmission. The variation is largest for fainter galaxies at higher redshift. The 68\% range of the transmissivity is similar to or greater than the median for galaxies with $M_{\rm UV}\ge-21$ at $z\ge7$, implying that more than a hundred galaxies would be needed to measure the transmission to 10\% accuracy.
description: 18 pages, 16 figures, 4 tables, Published in ApJ
CP Violation in the General Two-Higgs-Doublet Model: a Geometric View
Creators: name: Maniatis, M.
name: von Manteuffel, A.
name: Nachtmann, O.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss the CP properties of the potential in the general Two-Higgs-Doublet Model (THDM). This is done in a concise way using real gauge invariant functions built from the scalar products of the doublet fields. The space of these invariant functions, parametrising the gauge orbits of the Higgs fields, is isomorphic to the forward light cone and its interior. CP transformations are shown to correspond to reflections in the space of the gauge invariant functions. We consider CP transformations where no mixing of the Higgs doublets is taken into account as well as the general case where the Higgs basis is not fixed. We present basis independent conditions for explicit CP violation which may be checked easily for any THDM potential. Conditions for spontaneous CP violation, that is CP violation through the vacuum expectation values of the Higgs fields, are also derived in a basis independent way.
description: 19 pages, minor additions, minor typos corrected, results unchanged
Delay estimation in a two-node acyclic network
Creators: name: Nagarajan, Radhakrishnan
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Molecular Networks (q-bio.MN)
subject: FOS: Biological sciences

description: Linear measures such as cross-correlation have been used successfully to determine time delays from the given processes. Such an analysis often precedes identifying possible causal relationships between the observed processes. The present study investigates the impact of a positively correlated driver whose correlation function decreases monotonically with lag on the delay estimation in a two-node acyclic network with one and two-delays. It is shown that cross-correlation analysis of the given processes can result in spurious identification of multiple delays between the driver and the dependent processes. Subsequently, delay estimation of increment process as opposed to the original process under certain implicit constraints is explored. Short-range and long-range correlated driver processes along with those of their coarse-grained counterparts are considered.
description: 33 Pages, 6 Figures
Noise-Aware Video Saliency Prediction
Creators: name: Prashnani, Ekta
name: Gallo, Orazio
name: Kim, Joohwan
name: Spjut, Josef
name: Sen, Pradeep
name: Frosio, Iuri
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: We tackle the problem of predicting saliency maps for videos of dynamic scenes. We note that the accuracy of the maps reconstructed from the gaze data of a fixed number of observers varies with the frame, as it depends on the content of the scene. This issue is particularly pressing when a limited number of observers are available. In such cases, directly minimizing the discrepancy between the predicted and measured saliency maps, as traditional deep-learning methods do, results in overfitting to the noisy data. We propose a noise-aware training (NAT) paradigm that quantifies and accounts for the uncertainty arising from frame-specific gaze data inaccuracy. We show that NAT is especially advantageous when limited training data is available, with experiments across different models, loss functions, and datasets. We also introduce a video game-based saliency dataset, with rich temporal semantics, and multiple gaze attractors per frame. The dataset and source code are available at https://github.com/NVlabs/NAT-saliency.
description: 10 pages, 3 figures, 7 tables
A remark on the quasilocal calculation of tidal heating: energy transfer through the quasilocal surface
Creators: name: Huber, Albert
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this note, using the quasilocal formalism of Brown and York, the flow of energy through a closed surface containing a gravitating physical system is calculated in a way that augments earlier results on the subject by Booth and Creighton. To this end, by performing a variation of the total gravitational Hamiltonian (bulk plus boundary part), it is shown that associated tidal heating and deformation effects generally are larger than expected. This is because this variation leads to previously unrecognized correction terms, including a bulk-to-boundary inflow term that does not appear in the original calculation of the time derivative of the Brown-York energy and leads to corrective extensions of Einstein's quadrupole formula in the large sphere limit.
description: extended version; accepted for publication in PRD
Smectic elastomer membranes
Creators: name: Stenull, Olaf
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We present a model for smectic elastomer membranes which includes elastic and liquid crystalline degrees of freedom. Based on our model, we determined the qualitative phase diagram of a smectic elastomer membrane using mean-field theory. This phase diagram is found to comprise five phases, viz. smectic-A--flat, smectic-A--crumpled, smectic-C--flat, smectic-C--crumpled and smectic-C--tubule, where in the latter phase, the membrane is flat in the direction of mesogenic tilt and crumpled in the perpendicular direction. The transitions between adjacent phases are second order phase transitions. We study in some detail the elasticity of the smectic-C--flat and the smectic-C--tubule phases which are associated with a spontaneous breaking of in-plane rotational symmetry. As a consequence of the Goldstone theorem, these phases exhibit soft elasticity characterized by the vanishing of in-plane shear moduli.
description: 10 pages, 2 figures
Circular Pearson correlation using cosine series expansion
Creators: name: Shih-Gu Huang
name: Gritsenko, Andrey
name: Lindquist, Martin A.
name: Chung, Moo K.
Publisher: name: F1000 Research Limited
Year: 2019

description: In resting-state fMRI, there is no starting time point to correlate two signals across different voxels. There are often time lags between fMRI time series in different voxels. The functional connectivity based on the usual zero-lag correlation is heavily influenced by a complex time lag structure. The goal of this study is to directly find the correlation measure that remains invariant to such time lag. For this purpose, circular shift and circular Pearson correlation are proposed. The circular shift is an action of the Abelian group built by rotations on a circle. By projecting signals onto the unit circle, the translation of the signals can be defined as the circular shift. The circular Pearson correlation between signals f and g is the integral version of the Pearson correlation between f and the circular shift of g. By maximizing the circular Pearson correlation, we obtain the maximum correlation, which is invariant to the time lag, and the time lag at the maximum.

To filter out noise, fMRI signals are represented by the cosine series expansion. We propose to compute the circular Pearson correlation directly from the cosine series coefficients. The method is applied to the resting-state fMRI of genetically confirmed 131 monozygotic (MZ) and 77 same-sex dizygotic (DZ) twin pairs. The subject level connectivity between two different brain regions is measured by the maximum correlations and time lags. The group-level twin correlation is computed by the Pearson correlation of the paired maximum correlations or time lags. Heritability index (HI), which determines the amount of variation due to genetic influence in a population, is then estimated from the twin correlations.  From twin correlations and HI, we showed that the maximum correlation and time lag are genetically heritable features, and further identified the most heritable brain network connections based on these two features.
Spin-locking effect in the nanoscale ordered perovskite cobaltite LaBaCo2O6
Creators: name: Kundu, Asish K.
name: Rautama, E. -L.
name: Boullay, Ph.
name: Caignaert, V.
name: Pralong, V.
name: Raveau, B.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: A new nanoscale ordered perovskite cobaltite, which consists of 90 degree ordered domains of the layered-112 LaBaCo2O6 has been evidenced by high resolution- transmission electron microscopy. This new form, like the disordered La0.5Ba0.5CoO3 and ordered LaBaCo2O6, exhibits a ferromagnetic transition at TC around 179 K. However, it differs from the two previous forms by its strong magnetic anisotropy, and correlatively by its high value of coercivity (0.42 Tesla) at low temperature. We suggest that this behaviour originates from the locking of magnetic spins in the 90 degree oriented nano-domain. Moreover, one observes a semi-metal/semi-metal transition at TC with a maximum magnetoresistance of 6.5 % at this temperature.
description: 16 pages including figures
Existence of exponentially spatially localised breather solutions for lattices of nonlinearly coupled particles: Schauder's fixed point theorem approach
Creators: name: Hennig, Dirk
name: Karachalios, Nikos I.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 37K60, 37K40, 47H10

description: The problem of showing the existence of localised modes in nonlinear lattices has attracted considerable efforts from the physical but also from the mathematical viewpoint where a rich variety of methods has been employed. In this paper we prove that a fixed point theory approach based on the celebrated Schauder's Fixed Point Theorem may provide a general method to establish concisely not only the existence of localised structures but also a required rate of spatial localisation. As a case study we consider lattices of coupled particles with nonlinear nearest neighbour interaction and prove the existence of exponentially spatially localised breathers exhibiting either even-parity or odd-parity symmetry under necessary non-resonant conditions accompanied with the proof of energy bounds of the solutions.
description: 12 pages. To appear in Journal of Mathematical Physics
Toward a Consistent Taxonomy for Scenario-Based Development and Test Approaches for Automated Vehicles: A Proposal for a Structuring Framework, a Basic Vocabulary, and its Application
Creators: name: Steimle, Markus
name: Menzel, Till
name: Maurer, Markus
Publisher: name: arXiv
Year: 2021
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Ensuring and validating the safe operation of automated vehicles are key challenges for their market launch. Scenario-based development and test approaches are currently being pursued as possible solutions. An essential prerequisite for researching, applying, and standardizing these approaches is a consistent and agreed-upon taxonomy. This taxonomy must include relevant terms, their description, and the relationships between the respective terms. To the best of our knowledge, such a taxonomy does not yet exist, which often leads to misunderstandings, for example, in coordination processes and discussions. This publication contributes to this taxonomy. For this purpose, we propose a framework for structuring the taxonomy. Within this framework, we propose a basic vocabulary by identifying and describing terms that we consider particularly relevant for an overview of such scenario-based development and test approaches. Additionally, we visualize the proposed terms and the relationships between these terms with UML diagrams and explain the application of the proposed basic vocabulary with an example.
description: Published in IEEE Access, vol. 9, pp. 147828- 147854, 2021, doi: 10.1109/ACCESS.2021.3123504
Power-grid stability predictions using transferable machine learning
Creators: name: Yang, Seong-Gyu
name: Kim, Beom Jun
name: Son, Seung-Woo
name: Kim, Heetae
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Machine Learning (cs.LG)
subject: Systems and Control (eess.SY)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Complex network analyses have provided clues to improve power-grid stability with the help of numerical models. The high computational cost of numerical simulations, however, has inhibited the approach, especially when it deals with the dynamic properties of power grids such as frequency synchronization. In this study, we investigate machine learning techniques to estimate the stability of power-grid synchronization. We test three different machine learning algorithms -- random forest, support vector machine, and artificial neural network -- training them with two different types of synthetic power grids consisting of homogeneous and heterogeneous input-power distribution, respectively. We find that the three machine learning models better predict the synchronization stability of power-grid nodes when they are trained with the heterogeneous input-power distribution than the homogeneous one. With the real-world power grids of Great Britain, Spain, France, and Germany, we also demonstrate that the machine learning algorithms trained on synthetic power grids are transferable to the stability prediction of the real-world power grids, which implies the prospective applicability of machine learning techniques on power-grid studies.
description: 10 pages, 6 figures, 4 tables
3D spectral synthesis and rotational line broadening
Creators: name: Ludwig, Hans-G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Spectral synthesis calculations based on three-dimensional stellar atmosphere models are limited by the affordable angular resolution of the radiation field. This hampers an accurate treatment of rotational line broadening. We aim to find a treatment of rotational broadening of a spherical star when the radiation field is only available at a modest number of limb-angles. We apply a combination of analytical considerations of the line-broadening process and numerical tests. We obtain a method which is closely related to classical flux convolution and which performs noticeably better than a previously suggested procedure. It can be applied to rigid as well as differential rotation.
description: 3 pages, 4 figures, accepted for publication by A&A
The Long Period, Massive Binaries HD 37366 and HD 54662: Potential Targets for Long Baseline Optical Interferometry
Creators: name: Boyajian, T. S.
name: Gies, D. R.
name: Dunn, J. P.
name: Farrington, C. D.
name: Grundstrom, E. D.
name: Huang, W.
name: McSwain, M. V.
name: Williams, S. J.
name: Wingert, D. W.
name: Fullerton, A. W.
name: Bolton, C. T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results from an optical spectroscopic analysis of the massive stars HD 37366 and HD 54662. We find that HD 37366 is a double-lined spectroscopic binary with a period of 31.8187 +/- 0.0004 days, and HD 54662 is also a double lined binary with a much longer period of 557.8 +/- 0.3 days. The primary of HD 37366 is classified as O9.5 V, and it contributes approximately two-thirds of the optical flux. The less luminous secondary is a broad-lined, early B-type main-sequence star. Tomographic reconstruction of the individual spectra of HD 37366 reveals absorption lines present in each component, enabling us to constrain the nature of the secondary and physical characteristics of both stars. Tomographic reconstruction was not possible for HD 54662; however, we do present mean spectra from our observations that show that the secondary component is approximately half as bright as the primary. The observed spectral energy distributions (SEDs) were fit with model SEDs and galactic reddening curves to determine the angular sizes of the stars. By assuming radii appropriate for their classifications, we determine distance ranges of 1.4 - 1.9 and 1.2 - 1.5 kpc for HD 37366 and HD 54662, respectively.
description: 27 pages, 8 figures, Accepted for publication in ApJ
Verasight: Variety Survey June 2021
Creators: name: Reality Check Insights
Publisher: name: Roper Center for Public Opinion Research
Year: 2021

description: Volunteering in past 12 months (1); coronavirus (COVID-19) vaccination (1); President Joe Biden job approval (1); Child Tax Credit (2); unemployment benefits (2); agreement with organizations being able to require coronavirus vaccination (5); voted for in 2020 presidential election (1).
Ligand-Constraint-Induced Peroxide Activation for Electrophilic Reactivity
Creators: name: Chandra, Anirban
name: Ansari, Mursaleem
name: Monte-Pérez, Inés
name: Kundu, Subrata
name: Rajaraman, Gopalan
name: Ray, Kallol
Publisher: name: Humboldt-Universität zu Berlin
Year: 2021
Subjects: subject: C−H bond oxidations
subject: electrophilic reactions
subject: phenol oxidations
subject: reaction mechanism
subject: μ-1,2-peroxo dicobalt(III)
subject: 540 Chemie und zugeordnete Wissenschaften

description: An end-on μ-1,2-peroxodicobalt(III) complex 1 involving a non-heme ligand system, L1, supported on a Sn6O6 stannoxane core has been found to be a reactive electrophile that is capable of initiating hydrogen atom and oxygen atom transfer reactions. The electrophilicity of 1 is attributed to the constraints provided by the Sn6O6 core and represents a new domain for metal−peroxo reactivity. μ-1,2-peroxo-bridged diiron(III) intermediates P are proposed as reactive intermediates in various biological oxidation reactions. In sMMO, P acts as an electrophile, and performs hydrogen atom and oxygen atom transfers to electron-rich substrates. In cyanobacterial ADO, however, P is postulated to react by nucleophilic attack on electrophilic carbon atoms. In biomimetic studies, the ability of μ-1,2-peroxo-bridged dimetal complexes of Fe, Co, Ni and Cu to act as nucleophiles that effect deformylation of aldehydes is documented. By performing reactivity and theoretical studies on an end-on μ-1,2-peroxodicobalt(III) complex 1 involving a non-heme ligand system, L1, supported on a Sn6O6 stannoxane core, we now show that a peroxo-bridged dimetal complex can also be a reactive electrophile. The observed electrophilic chemistry, which is induced by the constraints provided by the Sn6O6 core, represents a new domain for metal−peroxide reactivity.
Spin gap and Luttinger liquid description of the NMR relaxation in carbon nanotubes
Creators: name: Dóra, Balázs
name: Gulácsi, Miklós
name: Simon, Ferenc
name: Kuzmany, Hans
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Recent NMR experiments by Singer et al. [Singer et al. Phys. Rev. Lett. 95, 236403 (2005).] showed a deviation from Fermi-liquid behavior in carbon nanotubes with an energy gap evident at low temperatures. Here, a comprehensive theory for the magnetic field and temperature dependent NMR 13C spin-lattice relaxation is given in the framework of the Tomonaga-Luttinger liquid. The low temperature properties are governed by a gapped relaxation due to a spin gap (~ 30K), which crosses over smoothly to the Luttinger liquid behaviour with increasing temperature.
description: 5 pages, 1 figure, 1 table
Time scale of entropic segregation of flexible polymers in confinement: Implications for chromosome segregation in filamentous bacteria
Creators: name: Arnold, Axel
name: Jun, Suckjoon
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We report molecular dynamics simulations of the segregation of two overlapping chains in cylindrical confinement. We find that the entropic repulsion between the chains can be sufficiently strong to cause segregation on a time scale that is short compared to the one for diffusion. This result implies that entropic driving forces are sufficiently strong to cause rapid bacterial chromosome segregation.
description: Minor changes. Added some references, corrected the labels in figure 6 and reformatted in two columns. Also added reference to published version in PRE
Super-resolved imaging of a single cold atom on a nanosecond timescale
Creators: name: Qian, Zhong-Hua
name: Cui, Jin-Ming
name: Luo, Xi-Wang
name: Zheng, Yong-Xiang
name: Huang, Yun-Feng
name: Ai, Ming-Zhong
name: He, Ran
name: Li, Chuan-Feng
name: Guo, Guang-Can
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In cold atomic systems, fast and high-resolution microscopy of individual atoms is crucial, since it can provide direct information on the dynamics and correlations of the system. Here, we demonstrate nanosecond-scale two-dimensional stroboscopic pictures of a single trapped ion beyond the optical diffraction limit, by combining the main idea of ground-state depletion microscopy with quantum state transition control in cold atoms. We achieve a spatial resolution up to 175~nm using an NA = 0.1 objective in the experiment, which represents a more than tenfold improvement compared with direct fluorescence imaging. To show the potential of this method, we apply it to observe the secular motion of the trapped ion, we demonstrate a temporal resolution up to 50~ns with a displacement detection sensitivity of 10~nm. Our method provides a powerful tool for probing particle positions, momenta, and correlations, as well as their dynamics in cold atomic systems.
description: 5 pages, 3 figures
Equality of ultradifferentiable classes by means of indices of mixed O-regular variation
Creators: name: Jiménez-Garrido, Javier
name: Sanz, Javier
name: Schindl, Gerhard
Publisher: name: arXiv
Year: 2021
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: primary 46E10, secondary 26A12, 26A48, 46A13

description: We characterize the equality between ultradifferentiable function classes defined in terms of abstractly given weight matrices and in terms of the corresponding matrix of associated weight functions by using new growth indices. These indices, defined by means of weight sequences and (associated) weight functions, are extending the notion of O-regular variation to a mixed setting. Hence we are extending the known comparison results concerning classes defined in terms of a single weight sequence and of a single weight function and give also these statements an interpretation expressed in O-regular variation.
description: 26 pages; some typos are corrected; this version has been accepted for publication in Res. Math
Peculiarities of Rabi oscillations and free induction decay in two-component nuclear spin systems with Ising nuclei interactions
Creators: name: Rusetsky, G. A.
name: Kolesenko, V. M.
name: Shymanovich, U.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Nuclear spin systems in manganites, having separation of ferromagnetic and antiferromagnetic phases, which are manifested as two lines in the NMR spectrum, are studied. Taking into account the Ising nuclear interaction, we obtain an analytical description of Rabi oscillations and free induction decay in two-component nuclear spin systems when a radio-frequency pulse non-resonantly excites the nuclei of one magnetic phase and resonantly the nuclei of the other phase. It is revealed that the nonlinearity of interaction between the nuclei of these phases results in additional harmonics in the Rabi oscillations of the non-resonantly excited subsystem. We also show that the Ising interaction inside this subsystem forms multiple echoes in the free induction decay, whereas their non-monotonic damping and amplitude modulation is caused by the spin coupling between the subsystems.
description: 8 pages, 5 figures
Relativistic runaway electron avalanches within complex thunderstorm electric field structures
Creators: name: Stadnichuk, E.
name: Svechnikova, E.
name: Nozik, A.
name: Zemlianskaya, D.
name: Khamitov, T.
name: Zelenyy, M.
name: Dolgonosov, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: Relativistic runaway electron avalanches (RREAs) are generally accepted as a source of thunderstorms gamma-ray radiation. Avalanches can multiply in the electric field via the relativistic feedback mechanism based on processes with gamma-rays and positrons. This paper shows that a non-uniform electric field geometry can lead to the new RREAs multiplication mechanism - "reactor feedback", due to the exchange of high-energy particles between different accelerating regions within a thundercloud. A new method for the numerical simulation of RREA dynamics within heterogeneous electric field structures is proposed. The developed analytical description and the numerical simulation enables us to derive necessary conditions for TGF occurrence in the system with the reactor feedback Observable properties of TGFs influenced by the proposed mechanism are discussed.
Slowly rotating pulsars
Creators: name: Alloy, M. D.
name: Menezes, D. P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the present work we investigate one possible variation on the usual static pulsars: the inclusion of rotation. We use a formalism proposed by Hartle and Thorne to calculate the properties of rotating pulsars with all possible compositions. All calculations were performed for zero temperature and also for fixed entropy equations of state.
Robust Self-Testing of Multiparticle Entanglement
Creators: name: Wu, Dian
name: Zhao, Qi
name: Gu, Xue-Mei
name: Zhong, Han-Sen
name: Zhou, You
name: Peng, Li-Chao
name: Qin, Jian
name: Luo, Yi-Han
name: Chen, Kai
name: Li, Li
name: Liu, Nai-Le
name: Lu, Chao-Yang
name: Pan, Jian-Wei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum self-testing is a device-independent way to certify quantum states and measurements using only the input-output statistics, with minimal assumptions about the quantum devices. Because of the high demand on tolerable noise, however, experimental self-testing was limited to two-photon systems. Here, we demonstrate the first robust self-testing for multi-photon genuinely entangled quantum states. We prepare two examples of four-photon graph states, the Greenberger-Horne-Zeilinger (GHZ) states with a fidelity of 0.957(2) and the linear cluster states with a fidelity of 0.945(2). Based on the observed input-output statistics, we certify the genuine four-photon entanglement and further estimate their qualities with respect to realistic noise in a device-independent manner.
The Phase Structure of the Polyakov--Quark-Meson Model
Creators: name: Schaefer, Bernd-Jochen
name: Pawlowski, Jan M.
name: Wambach, Jochen
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The relation between the deconfinement and chiral phase transition is explored in the framework of an Polyakov-loop-extended two-flavor quark-meson (PQM) model. In this model the Polyakov loop dynamics is represented by a background temporal gauge field which also couples to the quarks. As a novelty an explicit quark chemical potential and N_f-dependence in the Polyakov loop potential is proposed by using renormalization group arguments. The behavior of the Polyakov loop as well as the chiral condensate as function of temperature and quark chemical potential is obtained by minimizing the grand canonical thermodynamic potential of the system. The effect of the Polyakov loop dynamics on the chiral phase diagram and on several thermodynamic bulk quantities is presented.
description: 13 pages, 12 figures, RevTex4; discussion of mu-dependence extended, references added, version to be published in PRD
Balance of power theory reconsidered : the distribution of capabilities and alliances 1816-1939
Creators: name: Fergusson, James Gordon
Publisher: name: University of British Columbia
Year: 2010

description: This study examines the European International system from 1816 to 1939, focusing on the relationship between the distribution of capabilities and alliances. Two distinct versions of Balance of Power theory are employed to test this relationship. The manual version posits a direct or positive relationship between an unequal distribution and the number of alliances in the system. The semi-automatic or balancer version posits the same relationship but limits its applicability to a single Great Power, Great Britain. The findings support the semi-automatic version and also indicate an inverse relationship between equality and alliances. Finally, an examination of the relationship between polarization, defined as the pattern of alliances in the system, and the distribution of capabilities is undertaken. No clear relationship is found between polarization and an unequal distribution, although some evidence points towards a relationship between po1arization and war. The analysis concludes by positing conflicting, if not contradictory, security demands and thus conflicting behavior for continental and insular Powers. This finding sheds some light on conflicting evidence in the quantitative literature on the relationship between the distribution of capabi1ities and war, and may provide an additional explanation for the level of hostility between the Soviet Union and the United States since World War II.
XMM-Newton X-ray Observations of the Wolf-Rayet Binary System WR 147
Creators: name: Skinner, S. L.
name: Zhekov, S. A.
name: Guedel, M.
name: Schmutz, W.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present results of a 20 ksec X-ray observation of the Wolf-Rayet (WR) binary system WR 147 obtained with XMM-Newton. Previous studies have shown that this system consists of a nitrogen-type WN8 star plus an OB companion whose winds are interacting to produce a colliding wind shock. X-ray spectra from the pn and MOS detectors confirm the high extinction reported from IR studies and reveal hot plasma including the first detection of the Fe K-alpha line complex at 6.67 keV. Spectral fits with a constant-temperature plane-parallel shock model give a shock temperature kT(shock) = 2.7 keV [T(shock) ~ 31 MK], close to but slightly hotter than the maximum temperature predicted for a colliding wind shock. Optically thin plasma models suggest even higher temperatures, which are not yet ruled out. The X-ray spectra are harder than can be accounted for using 2D numerical colliding wind shock models based on nominal mass-loss parameters. Possible explanations include: (i) underestimates of the terminal wind speeds or wind abundances, (ii) overly simplistic colliding wind models, or (iii) the presence of other X-ray emission mechanisms besides colliding wind shocks. Further improvement of the numerical models to include potentially important physics such as non-equilibrium ionization will be needed to rigorously test the colliding wind interpretation.
description: 8 pages, 7 figures
The multiple effects of gradient coupling on network synchronization
Creators: name: Wang, Xingang
name: Lai, Ying-Cheng
name: Zhou, Cangtao
name: Lai, Choy Heng
Publisher: name: arXiv
Year: 2007
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Recent studies have shown that synchronizability of complex networks can be significantly improved by asymmetric couplings, and increase of coupling gradient is always in favor of network synchronization. Here we argue and demonstrate that, for typical complex networks, there usually exists an optimal coupling gradient under which the maximum network synchronizability is achieved. After this optimal value, increase of coupling gradient could deteriorate synchronization. We attribute the suppression of network synchronization at large gradient to the phenomenon of network breaking, and find that, in comparing with sparsely connected homogeneous networks, densely connected heterogeneous networks have the superiority of adopting large gradient. The findings are supported by indirect simulations of eigenvalue analysis and direct simulations of coupled nonidentical oscillator networks.
description: 4 pages, 4 figures
Topological Flexural Modes in Polarized Bilayer Lattices
Creators: name: Charara, Mohammad
name: Sun, Kai
name: Mao, Xiaoming
name: Gonella, Stefano
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Topological lattices have recently generated a great deal of interest based on the unique mechanical properties rooted in their topological polarization, including the ability to support localized modes at certain floppy edges. The study of these systems has been predominantly restricted to the realm of in-plane mechanics, to which many topological effects are germane. In this study, we stretch this paradigm by exploring the possibility to export certain topological attributes to the flexural wave behavior of thin lattice sheets. To couple the topological modes to the out-of-plane response, we assemble a bilayer lattice by stacking a thick topological kagome layer onto a thin twisted kagome lattice. The band diagram reveals the existence of modes whose out-of-plane character is controlled by the edge modes of the topological layer, a behavior elucidated via simulations and confirmed via laser vibrometer experiments on a bilayer prototype specimen. These results open an alternative direction for topological mechanics whereby flexural waves are controlled by the in-plane topology, leading to potential applications for flexural wave devices with engineered polarized response.
Quel rôle pour les bibliothèques universitaires dans la formation des maîtres de conférences stagiaires ? L'exemple de l'université Paris Nanterre
Creators: name: Laillier, Benjamin
name: SCD Université Paris Nanterre
Publisher: name: Zenodo
Year: 2022
Subjects: maîtres de conférences stagiaires
trainees lecturers

description: A partir de l’exemple de l’université Paris Nanterre, cette note entend donner quelques éléments de réflexions sur le rôle que peuvent jouer les bibliothèques universitaires dans la formation des maîtres de conférences stagiaires. Using the example of university Paris Nanterre, this text aims to provide some elements on the role that university libraries can play in the formation of trainees lecturers.
A "diamond-ring" star: the unusual morphologic structure of a young (multiple?) object
Creators: name: Yun, Joao L.
name: Torrelles, Jose M.
name: Santos, Nuno C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have observed IRAS06468-0325 obtaining optical and infrared images through IJHKs and L' filters, K-band low-resolution spectroscopy, together with millimetre line observations of CO and CS. IRAS06468-0325 has a very unusual and enigmatic morphology with two components: a bright, close to point-like source (the diamond) and a sharp-edge ring-like structure (the ring). The source is not detected in the optical, at wavelengths shorter than the I-band. The diamond is seen in all the imaging bands observed. The ring-like structure in IRAS06468-0325 is clearly seen in the I, J, H, and Ks. It is not detected in the L'-band image. Infrared colours of the diamond are compatible with excess circumstellar emission and a young stellar nature. A strongly non-gaussian and moderately bright CO(1-0) and {13}CO(2-1) lines are seen towards IRAS06468-0325, at v_{LSR} of 30.5 km s{-1} (corresponding to a kinematic distance of 3 kpc). Very weak C{18}O(2-1) and CS(2-1) lines were detected. K-band spectra of the diamond and of the ring are similar both in the slope of the continuum and in the presence of lines supporting the idea that the ring is reflected light from the diamond. With the current data, a few different scenarios are possible to explain the morphology of this object. However, the available data seem to favour that the morphology of IRAS06468-0325 correspond to a young stellar multiple system in a transient stage where a binary co-exists with a circumbinary disc, similar to the case of GG Tau. In this case, the sharpness of the well-defined ring may be due to tidal truncation from dynamic interactions between components in a binary or multiple stellar system. IRAS06468-0325 may be an important rare case that illustrates a short-lived stage of the process of binary or multiple star formation.
description: 7 pages, 6 figures
Generalized-Hydrodynamic approach to Inhomogeneous Quenches: Correlations, Entanglement and Quantum Effects
Creators: name: Alba, Vincenzo
name: Bertini, Bruno
name: Fagotti, Maurizio
name: Piroli, Lorenzo
name: Ruggiero, Paola
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Gases (cond-mat.quant-gas)
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 give a pedagogical introduction to the Generalized Hydrodynamic approach to inhomogeneous quenches in integrable many-body quantum systems. We review recent applications of the theory, focusing in particular on two classes of problems: bipartitioning protocols and trap quenches, which represent two prototypical examples of broken translational symmetry in either the system initial state or post-quench Hamiltonian. We report on exact results that have been obtained for generic time-dependent correlation functions and entanglement evolution, and discuss in detail the range of applicability of the theory. Finally, we present some open questions and suggest perspectives on possible future directions.
description: 46 pages, 13 figures. To appear in JSTAT special issue "Emergent Hydrodynamics in Integrable Many-body Systems"; v2 minor revision. As appears in JSTAT special issue "Emergent Hydrodynamics in Integrable Many-body Systems"
Indications of a Four-Quark Structure for the X(3872) and X(3876) Particles from Recent Belle and BABAR Data
Creators: name: Maiani, L.
name: Polosa, A. D.
name: Riquer, V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Recent results by BELLE and BaBar point to the existence of a second X particle decaying in D^0 D^0bar pi^0, a few MeV above the X(3872). We identify the two X states with the neutral particles predicted by the 4-quark model and show that production and decays are consistent with this assignement. We consider the yet-to-be-observed charged partners and give new hints on how to look for them.
description: 5 pages, some revision of the text, results unchanged. To appear in Phys. Rev. Lett
Three-Family Models from a Heterotic Orbifold on the E_6 Root Lattice
Creators: name: Takahashi, Kei-Jiro
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We classify N=1 orbifolds on the E_6 root lattice and investigate explicit model constructions on the Z_3xZ_3 orbifold in heterotic string theory. Interestingly some of the twisted sectors from the Z_3xZ_3 orbifold on the E_6 root lattice have just three fixed tori respectively, and generate three degenerate massless states. We also found three point functions with flavor mixing terms. We assume only non-standard gauge embeddings and find that they lead to three-family SU(5) and SO(10) GUT-like models. These models also include strongly coupled sectors in the low energy and messenger states charged with both hidden and visible sectors.
description: 20 pages, 1 figures; v3: Classification for orbifolds on the E_6 lattice is added, typos corrected, published version
Alternative axiomatics and complexity of deliberative STIT theories
Creators: name: Balbiani, Philippe
name: Herzig, Andreas
name: Troquard, Nicolas
Publisher: name: arXiv
Year: 2007
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We propose two alternatives to Xu's axiomatization of the Chellas STIT. The first one also provides an alternative axiomatization of the deliberative STIT. The second one starts from the idea that the historic necessity operator can be defined as an abbreviation of operators of agency, and can thus be eliminated from the logic of the Chellas STIT. The second axiomatization also allows us to establish that the problem of deciding the satisfiability of a STIT formula without temporal operators is NP-complete in the single-agent case, and is NEXPTIME-complete in the multiagent case, both for the deliberative and the Chellas' STIT.
description: Submitted to the Journal of Philosophical Logic; 13 pages excluding annex
Measuring the kinetic power of AGN in the radio mode
Creators: name: Merloni, Andrea
name: Heinz, Sebastian
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: (Abridged) We have studied the relationship among nuclear radio and X-ray power, Bondi rate and the kinetic luminosity of sub-Eddington active galactic nuclear (AGN) jets. Besides the recently discovered correlation between jet kinetic and Bondi power, we show that a clear correlation exists also between Eddington-scaled kinetic power and bolometric luminosity, given by: Log(L_kin/L_Edd)=0.49*Log(L_bol/L_Edd)-0.78. The measured slope suggests that these objects are in a radiatively inefficient accretion mode, and has been used to put stringent constraints on the properties of the accretion flow. We found no statistically significant correlations between Bondi power and bolometric AGN luminosity, apart from that induced by their common dependence on L_kin. Analyzing the relation between kinetic power and radio core luminosity, we are then able to determine, statistically, both the probability distribution of the mean jets Lorentz factor, peaking at Γ~7, and the intrinsic relation between kinetic and radio core luminosity, that we estimate as: Log(L_kin)=0.81*Log(L_R)+11.9, in good agreement with theoretical predictions of synchrotron jet models. With the aid of these findings, quantitative assessments of kinetic feedback from supermassive black holes in the radio mode will be possible based on accurate determinations of the central engine properties alone. As an example, Sgr A* may follow the correlations of radio mode AGN, based on its observed radiative output and on estimates of the accretion rate both at the Bondi radius and in the inner flow. If this is the case, the SMBH in the Galactic center is the source of ~ 5 times 10^38 ergs/s of mechanical power, equivalent to about 1.5 supernovae every 10^5 years.
description: 13 pages, 6 figures. Accepted for publication in MNRAS
A general approach to few-cycle intense laser interactions with complex atoms
Creators: name: Guan, X.
name: Zatsarinny, O.
name: Bartschat, K.
name: Schneider, B. I.
name: Feist, J.
name: Noble, C. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: A general {\it ab-initio} and non-perturbative method to solve the time-dependent Schrödinger equation (TDSE) for the interaction of a strong attosecond laser pulse with a general atom, i.e., beyond the models of quasi-one-electron or quasi-two-electron targets, is described. The field-free Hamiltonian and the dipole matrices are generated using a flexible $B$-spline $R$-matrix method. This numerical implementation enables us to construct term-dependent, non-orthogonal sets of one-electron orbitals for the bound and continuum electrons. The solution of the TDSE is propagated in time using the Arnoldi-Lanczos method, which does not require the diagonalization of any large matrices. The method is illustrated by an application to the multi-photon excitation and ionization of Ne atoms. Good agreement with $R$-matrix Floquet calculations for the generalized cross sections for two-photon ionization is achieved.
description: 7 pages (in the Phys. Rev. double column format) with 5 figures; processed with REVTEX