cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Note on chaos and diffusion
Creators: name: Dettmann, C. P.
name: Cohen, E. G. D.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Using standard definitions of chaos (as positive Kolmogorov-Sinai entropy) and diffusion (that multiple time distribution functions are Gaussian), we show numerically that both chaotic and nonchaotic systems exhibit diffusion, and hence that there is no direct logical connection between the two properties. This extends a previous result for two time distribution functions.
description: 8 pages revtex, 4 figures incorporated with epsfig. See also chao-dyn/9904041 and nlin.CD/0001062
Numerical simulations of Gowdy spacetimes on S2XS1XR
Creators: name: Garfinkle, David
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Numerical simulations are performed of the approach to the singularity in Gowdy spacetimes on S2XS1XR. The behavior is similar to that of Gowdy spacetimes on T3XR. In particular, the singularity is asymptotically velocity term dominated, except at isolated points where spiky features develop.
description: 10 figures, Revtex
Calculated thermoelectric properties of La-filled skutterudites
Creators: name: Singh, D. J.
name: Mazin, I. I.
Publisher: name: arXiv
Year: 1997
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The thermoelectric properties of La-filled skutterudites are discussed from the point of view of their electronic structures. These are calculated from first principles within the local density approximation. The electronic structure is in turn used to determine transport related quantities. Virtual crystal calculations for La(Fe,Co)_4Sb_{12} show that the system obeys near rigid band behavior with varying Co concentration, and has a substantial band gap at a position corresponding to the composition LaFe_3% CoSb_{12}. The valence band maximum occurs at the $Γ$ point and is due to a singly degenerate dispersive band, which by itself would not be favorable for high thermopower. However, very flat transition metal derived bands occur in close proximity and become active as the doping level is increased, giving a non-trivial dependence of the properties on carrier concentration and explaining the favorable thermoelectric properties.
description: 4 RevTeX pages (10pt), 3 embedded figures
Campimoptilum simukondai Darge 2012
Creators: name: Mbata, Keith J.
name: Prins, Jurate De
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Saturniidae
Campimoptilum
Campimoptilum simukondai

description: Campimoptilum simukondai Darge, 2012
COMMON NAME(S): Saturniid.
SYNONYM(S): None.
IUCN STATUS: Not Evaluated (NE).
DISTRIBUTION: Known only from Zambia (endemic species).
LOCALITY IN ZAMBIA: Type locality is Mpandwa [Latitude, - 10°17’35” South; Longitude, 32°56’8” East; Altitude, 856 m], 25 km E of Isoka, in Muchinga Province.
LARVAL HOSTPLANT(S): Unknown.
SOURCES: Darge 2012; De Prins & De Prins 2022.
description: Published as part of Mbata, Keith J. & Prins, Jurate De, 2023, Annotated checklist of moths of Zambia (Insecta: Lepidoptera), pp. 1-503 in Zootaxa 5354 (1) on page 150, DOI: 10.11646/zootaxa.5354.1.1, http://zenodo.org/record/10130434
Centers of Mass and Rotational Kinematics for the Relativistic N-Body Problem in the Rest-Frame Instant Form
Creators: name: Alba, D.
name: Lusanna, L.
name: Pauri, M.
Publisher: name: arXiv
Year: 2001
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the Wigner-covariant rest-frame instant form of dynamics it is possible to develop a relativistic kinematics for the N-body problem. The Wigner hyperplanes define the intrinsic rest frame and realize the separation of the center-of-mass. Three notions of {\it external} relativistic center of mass can be defined only in terms of the {\it external} Poincaré group realization. Inside the Wigner hyperplane, an {\it internal} unfaithful realization of the Poincaré group is defined. The three concepts of {\it internal} center of mass weakly {\it coincide} and are eliminated by the rest-frame conditions. An adapted canonical basis of relative variables is found. The invariant mass is the Hamiltonian for the relative motions. In this framework we can introduce the same {\it dynamical body frames}, {\it orientation-shape} variables, {\it spin frame} and {\it canonical spin bases} for the rotational kinematics developed for the non-relativistic N-body problem.
description: 78 pages, revtex file
Spectrum of Anisotropic Exponents in Hydrodynamic Systems with Pressure
Creators: name: Arad, I.
name: Procaccia, I.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We discuss the scaling exponents characterizing the power-law behavior of the anisotropic components of correlation functions in turbulent systems with pressure. The anisotropic components are conveniently labeled by the angular momentum index $\ell$ of the irreducible representation of the SO(3) symmetry group. Such exponents govern the rate of decay of anisotropy with decreasing scales. It is a fundamental question whether they ever increase as $\ell$ increases, or they are bounded from above. The equations of motion in systems with pressure contain nonlocal integrals over all space. One could argue that the requirement of convergence of these integrals bounds the exponents from above. It is shown here on the basis of a solvable model (the ``linear pressure model"), that this is not necessarily the case. The model introduced here is of a passive vector advection by a rapidly varying velocity field. The advected vector field is divergent free and the equation contains a pressure term that maintains this condition. The zero modes of the second-order correlation function are found in all the sectors of the symmetry group. We show that the spectrum of scaling exponents can increase with $\ell$ without bounds, while preserving finite integrals. The conclusion is that contributions from higher and higher anisotropic sectors can disappear faster and faster upon decreasing the scales also in systems with pressure.
description: 20 pages, 2 EPS figures, RevTeX Replaced with revised version
Thermalization of Poincaré Vacuum State and Fermion Emission from AdS_3 Black Holes in Bulk-Boundary Correspondence
Creators: name: Ohta, Nobuyoshi
name: Zhou, Jian-Ge
Publisher: name: arXiv
Year: 1998
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The greybody factors for spin 1/2 particles in the BTZ black holes are discussed from 2D CFT in bulk-boundary correspondence. It is found that the initial state of spin 1/2 particle in the BTZ black holes can be described by the Poincaré vacuum state in boundary 2D CFT, and the nonlinear coordinate transformation causes the thermalization of the Poincaré vacuum state. For special case, our results for the greybody factors agree with the semiclassical calculation.
description: 14 pages, Latex, discussions added
Divergence Measure Between Chaotic Attractors
Creators: name: Diambra, Luis
Publisher: name: arXiv
Year: 2000
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We propose a measure of divergence of probability distributions for quantifying the dissimilarity of two chaotic attractors. This measure is defined in terms of a generalized entropy. We illustrate our procedure by considering the effect of additive noise in the well known Hénon attractor. Comparison of two Hénon attractors for slighly different parameter values, has shown that the divergence has complex scaling structure. Finally, we show how our approach allows to detect non-stationary events in a time series.
description: 9 pages, 6 figures
Degeneracy of the b-boundary in General Relativity
Creators: name: Ståhl, Fredrik
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The b-boundary construction by B. Schmidt is a general way of providing a boundary to a manifold with connection. It has been shown to have undesirable topological properties however. C. J. S. Clarke gave a result showing that for space-times, non-Hausdorffness is to be expected in general, but the argument contains some errors. We show that under somewhat different conditions on the curvature, the b-boundary will be non-Hausdorff, and illustrate the degeneracy by applying the conditions to some well known exact solutions of general relativity.
description: 25 pages, AMS-LaTeX v1.2, AMSFonts, submitted to Commun. Math. Phys
Gravitational instantons, extra dimensions and form fields
Creators: name: Gray, J. A.
name: Copeland, E. J.
Publisher: name: arXiv
Year: 2001
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A broad class of higher dimensional instanton solutions are found for a theory which contains gravity, a scalar field and antisymmetric tensor fields of arbitrary rank. The metric used, a warp product of an arbitrary number of any compact Einstein manifolds, includes many of great interest in particle physics and cosmology. For example 4D FRW universes with additional dimensions compactified on a Calabi-Yau three fold, a torus, a compact hyperbolic manifold or a sphere are all included. It is shown that the solution of this form which dominates the Hartle Hawking path integral is always a higher dimensional generalisation of a Hawking Turok instanton when the potential of the scalar field is such that these instantons can exist. On continuation to Lorentzian signature such instantons give rise to a spacetime in which all of the spatial dimensions are of equal size and where the spatial topology is that of a sphere. The extra dimensions are thus not hidden. In the case where the potential for the scalar field is generated solely by a dilatonic coupling to the form fields we find no integrable instantons at all. In particular we find no integrable solutions of the type under consideration for the supergravity theories which are the low energy effective field theories of superstrings.
description: 11 pages, 4 figures
Variational method and duality in the 2D square Potts model
Creators: name: Angelini, L.
name: Pellicoro, M.
name: Sardella, I.
name: Villani, M.
Publisher: name: arXiv
Year: 1997
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The ferromagnetic q-state Potts model on a square lattice is analyzed, for q>4, through an elaborate version of the operatorial variational method. In the variational approach proposed in the paper, the duality relations are exactly satisfied, involving at a more fundamental level, a duality relationship between variational parameters. Besides some exact predictions, the approach is very effective in the numerical estimates over the whole range of temperature and can be systematically improved.
description: 20 pages, 5 EPS figures
Geometrodynamical Formulation of Two-Dimensional Dilaton Gravity
Creators: name: Cavaglia, Marco
Publisher: name: arXiv
Year: 1998
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Two-dimensional matterless dilaton gravity with arbitrary dilatonic potential can be discussed in a unitary way, both in the Lagrangian and canonical frameworks, by introducing suitable field redefinitions. The new fields are directly related to the original spacetime geometry and in the canonical picture they generalize the well-known geometrodynamical variables used in the discussion of the Schwarzschild black hole. So the model can be quantized using the techniques developed for the latter case. The resulting quantum theory exhibits the Birkhoff theorem at the quantum level.
description: 15 pages, LATEX
Regularization of Synchronized Chaotic Bursts
Creators: name: Rulkov, Nikolai F.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Quantitative Biology (q-bio)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The onset of regular bursts in a group of irregularly bursting neurons with different individual properties is one of the most interesting dynamical properties found in neurobiological systems. In this paper we show how synchronization among chaotically bursting cells can lead to the onset of regular bursting. In order to clearly present the mechanism behind such regularization we model the individual dynamics of each cell with a simple two-dimensional map that produces chaotic bursting behavior similar to biological neurons.
description: 4 pages
Quantum discontinuity between zero and infinitesimal graviton mass with a Lambda term
Creators: name: Dilkes, F. A.
name: Duff, M. J.
name: Liu, James T.
name: Sati, H.
Publisher: name: arXiv
Year: 2001
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We show that the recently demonstrated absence of the usual discontinuity for massive spin 2 with a Lambda term is an artifact of the tree approximation, and that the discontinuity reappears at one loop.
description: 8 pages, revtex 3.1, title changed (version to appear in Phys. Rev. Lett.)
Inelastic Quantum Transport
Creators: name: Bonca, Janez
name: Trugman, S. A.
Publisher: name: arXiv
Year: 1997
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We solve a Schrodinger equation for inelastic quantum transport that retains full quantum coherence, in contrast to previous rate or Boltzmann equation approaches. The model Hamiltonian is the zero temperature 1d Holstein model for an electron coupled to optical phonons (polaron), in a strong electric field. The Hilbert space grows exponentially with electron position, forming a non-standard Bethe lattice. We calculate nonperturbatively the transport current, electron-phonon correlations, and quantum diffusion. This system is a toy model for the constantly branching ``wavefunction of the universe''.
description: revtex, 13 pages, 4 figures
Virtual dipoles and large fluctuations in quantum gravity
Creators: name: Modanese, G.
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The positive energy theorem precludes the possibility of Minkowski flat space decaying by any mechanism. In certain circumstances, however, large quantum fluctuations of the gravitational field could arise---not only at the Planck scale, but also at larger scales. This is because there exists a set of localised weak field configurations which satisfy the condition int d4x sqrt{g}R = 0 and thus give a null contribution to the Einstein action. Such configurations can be constructed by solving Einstein field equations with unphysical dipolar sources. We discuss this mechanism and its modification in the presence of a cosmological term and/or an external field.
description: LaTeX, 8 pages
Classical invariants and the quantum-classical link
Creators: name: Wisniacki, Diego. A.
name: Vergini, Eduardo
Publisher: name: arXiv
Year: 2000
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: The classical invariants of a Hamiltonian system are expected to be derivable from the respective quantum spectrum. In fact, semiclassical expressions relate periodic orbits with eigenfunctions and eigenenergies of classical chaotic systems. Based on trace formulae, we construct smooth functions highly localized in the neighborhood of periodic orbits using only quantum information. Those functions show how classical hyperbolic structures emerge from quantum mechanics in chaotic systems. Finally, we discuss the proper quantum-classical link.
description: 3 pages, 4 Postscript figures
Path integral derivation of the Brown-Henneaux central charge
Creators: name: Terashima, Hiroaki
Publisher: name: arXiv
Year: 2001
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We rederive the Brown-Henneaux commutation relation and central charge in the framework of the path integral. To obtain the Ward-Takahashi identity, we can use either the asymptotic symmetry or its leading part. If we use the asymptotic symmetry, the central charge arises from the transformation law of the charge itself. Thus, this central charge is clearly different from the quantum anomaly which can be understood as the Jacobian factor of the path integral measure. Alternatively, if we use the leading transformation, the central charge arises from the fact that the boundary condition of the path integral is not invariant under the transformation. This is in contrast to the usual quantum central charge which arises from the fact that the measure of the path integral is not invariant under the relevant transformation. Moreover, we discuss the implications of our analysis in relation to the black hole entropy.
description: 18 pages, some clarifying comments are added
D-branes and Cosmology
Creators: name: Maggiore, Michele
name: Riotto, Antonio
Publisher: name: arXiv
Year: 1998
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: D-branes, topological defects in string theory on which string endpoints can live, may give new insight into the understanding of the cosmological evolution of the Universe at early epochs. We analyze the dynamics of D-branes in curved backgrounds and discuss the parameter space of M-theory as a function of the coupling constant and of the curvature of the Universe. We show that D-branes may be efficiently produced by gravitational effects. Furthermore, in curved spacetimes the transverse fluctuations of the D-branes develop a tachyonic mode and when the fluctuations grow larger than the horizon the branes become tensionless and break up. This signals a transition to a new regime. We discuss the implications of our findings for the singularity problem present in string cosmology, suggesting the existence of a limiting value for the curvature which is in agreement with the value suggested by the cosmological version of the holography principle. We also comment on possible implications for the so-called brane world scenario, where the Standard Model gauge and matter fields live inside some branes while gravitons live in the bulk.
description: LaTeX file, 30 pages, 2 eps figures, 1 reference added
Critical geometry of two-dimensional passive scalar turbulence
Creators: name: Kondev, J.
name: Huber, G.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: Passive scalars advected by a magnetically driven two-dimensional turbulent flow are analyzed using methods of statistical topography. The passive tracer concentration is interpreted as the height of a random surface and the scaling properties of its contour loops are analyzed. Various exponents that describe the loop ensemble are measured and compared to a scaling theory. This leads to a geometrical criterion of intermittency of scalar fluctuations.
description: 4 pages, 1 figure; comments to kondev@brandeis.edu
X-ray photoemission spectroscopy of La(0.67)Ca(0.33)MnO(3) films
Creators: name: Broussard, P. R.
name: Qadri, S. B.
name: Cestone, V. C.
Publisher: name: arXiv
Year: 1997
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We have performed x-ray photoemission spectroscopy (XPS) on thin films of (001) and (200) oriented La(0.67)Ca(0.33)MnO(3) grown on (100) and (110) SrTiO(3) substrates by off-axis sputtering. The films were examined by XPS without exposing them to air. We have compared the core levels and the valence spectra between the two different orientations, as well as after the effects of air exposure and annealing in UHV. We find that the surfaces are very stable against exposure to air. Comparing the measured intensity ratios to a model for the uniform termination of the film shows the terminating layer to be MnO(2) for both the (001) and (200) oriented La(0.67)Ca(0.33)MnO(3) films.
description: 7 pages, 6 jpg figures, to appear in Applied Surface Science
Dynamical system analysis for the Einstein-Yang-Mills equations
Creators: name: Zotov, M. Yu.
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Local solutions of the static, spherically symmetric Einstein-Yang-Mills (EYM) equations with SU(2) gauge group are studied on the basis of dynamical systems methods. This approach enables us to classify EYM solutions in the origin neighborhood, to prove the existence of solutions with the oscillating metric as well as the existence of local solutions for all known formal power series expansions, to study the extendibility of solutions, and to find two new local singular solutions.
description: 25 pages with 2 figures; v.2: subsec. V.B partially revised, minor style and grammar changes in the rest of the text; the main result unchanged
Observer-independent quanta of mass and length
Creators: name: Kowalski-Glikman, Jerzy
Publisher: name: arXiv
Year: 2001
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It has been observed recently by Giovanni Amelino-Camelia \cite{gac1, gac2} that the hypothesis of existence of a minimal observer-independent (Planck) length scale is hard to reconcile with special relativity. As a remedy he postulated to modify special relativity by introducing an observer-independent length scale. In this letter we set forward a proposal how one should modify the principles of special relativity, so as to assure that the values of mass and length scales are the same for any inertial observer. It turns out that one can achieve this by taking dispersion relations such that the speed of light goes to infinity for finite momentum (but infinite energy), proposed e.g., in the framework of the quantum $κ$-Poincaré symmetry. It follows that at the Planck scale the world may be non-relativistic.
description: 8 pages, LaTeX; some speculative comments concerning the structure of space-time removed; one reference added
Exclusion process subject to conformational size changes
Creators: name: Rousset, Yvan
name: Ciandrini, Luca
name: Kern, Norbert
Publisher: name: arXiv
Year: 2019
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We introduce a model for stochastic transport on a one-dimensional substrate with particles assuming different conformations during their stepping cycles. These conformations correspond to different footprints on the substrate: in order to advance, particles are subject to successive contraction and expansion steps with different characteristic rates. We thus extend the paradigmatic exclusion process, provide predictions for all regimes of these rates that are in excellent agreement with simulations, and show that the current-density relation may be affected considerably. Symmetries are discussed, and exploited. We discuss our results in the context of molecular motors, confronting a hand-over-hand and an inchworm stepping mechanism, as well as for ribosomes.
description: Submission to SciPost
Niamh Tumelty on the Crisis in HE and the future of diamond open access
Creators: name: Tumelty, Niamh
Publisher: name: Zenodo
Year: 2024

description: In this presentation, Niamh Tumelty (Director, LSE Library / Managing Director, LSE Press) outlines some of the unsustainable financial pressures on academic libraries, as well as the challenges faced by academics and new Gold & Diamond OA publishers. Nevertheless, Tumelty argues that there are reasons to remain optimistic: increasing uptake amongst scholars, growing recognition for OA publishers, and new policy developments all suggest that a brighter and more equitable future for OA book publishing is possible.

This presentation was delivered as part of the event: “Crisis in Higher Education and the Future of Diamond Open Access” on 19 September 2024, at the London School of Economics and online. The event was supported by LSE Library, LSE Press and Copim's Open Book Futures project. To find out more about the event, please visit: https://copim.pubpub.org/pub/futureofdiamond

View a recording of this presentation on Internet Archive  or on YouTube. 

 
description: The Open Book Futures project is co-funded by Arcadia and Research England Development (RED) Fund (UKRI). Arcadia is a charitable foundation that works to protect nature, preserve cultural heritage and promote open access to knowledge. Since 2002 Arcadia has awarded more than $1 billion to organizations around the world. Research England Development (RED) Fund (UKRI) is a fund supporting institutional-level innovative projects in research and knowledge exchange including collaborations between education providers and between education providers and business.
Linear Stability of Scroll Waves
Creators: name: Henry, H.
name: Hakim, V.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Condensed Matter (cond-mat)
subject: FOS: Physical sciences

description: A full linear stability of a straight scroll wave in an excitable medium is presented. The five eigenmode branches which correspond to deformation in the third dimension of the five main modes of two-dimensional (2D) spiral dynamics are found to play a dominant role. Modulations in the third dimension have stabilizing or destabilizing effects on the different modes depending on the parameter regimes. For untwisted scroll waves, our numerical results confirm the relation between the long-wavelength behavior of the translation branches and 2D spiral drift in an external field but show no similar direct relation for the meander branches. The influence of twist on the different branches is investigated. In particular, the sproing instability is seen to arise from the twist induced deformation of the translation branches above a threshold twist.
description: 5 pages 4 figures, to appear in Physical Review Letters
Three-dimensional Magnetic Reconnection Triggering an X-class Confined Flare in Active Region 12192
Creators: name: Li, Ting
name: Hou, Yijun
name: Yang, Shuhong
name: Zhang, Jun
Publisher: name: arXiv
Year: 2018
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present an extensive analysis of the X2.0-class confined flare on 2014 October 27 in the great active region AR 12192, observed by the \emph{Interface Region Imaging Spectrograph} and the \emph{Solar Dynamics Observatory}. The slipping motion of the substructures within the negative-polarity flare ribbon (R1) and continual reconnection-induced flows during the confined flare are first presented. The substructures within ribbon R1 were observed to slip in opposite directions at apparent speeds of 10-70 km s$^{-1}$. The slipping motion exhibited the quasi-periodic pattern with a period of 80-110 s, which can be observed since the flare start and throughout the impulsive phase of the flare. Simultaneously quasi-periodic flows moved along a reverse-S shaped filament, with an average period of about 90 s. The period of reconnection-induced flows is similar to that of the slippage of ribbon substructures, implying the occurrence of quasi-periodic slipping magnetic reconnection. The spectral observations showed that the Si {\sc iv} line was blueshifted by 50-240 km s$^{-1}$ at the location of the flows. During the process of the flare, the filament did not show the rise phase and was not associated with any failed eruption. The flare mainly consisted of two sets of magnetic systems, with both of their east ends anchoring in ribbon R1. We suggest that the slipping magnetic reconnection between two magnetic systems triggers the confined flare.
description: 21 pages, 7 figures; accepted for publication in ApJ
Single-Particle Properties of a Two-Dimensional Fermi Liquid at finite Frequencies and Temperatures
Creators: name: Kim, Jungsoo
name: Coffey, D.
Publisher: name: arXiv
Year: 1997
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We review the leading momentum, frequency and temperature dependences of the single particle self-energy and the corresponding term in the entropy of a two dimensional Fermi liquid (FL) with a free particle spectrum. We calculate the corrections to these leading dependences for the paramagnon model and the electron gas and find that the leading dependences are limited to regions of energy and temperature which decrease with decreasing number density of fermions. This can make it difficult to identify the frequency and temperature dependent characteristics of a FL ground state in experimental quantities in low density systems even when complications of band structure and other degrees of freedom are absent. This is an important consideration when the normal state properties of the undoped cuprate superconductors are analyzed.
description: Revtex, 15 pages with 13 figures. minor corrections. Accepted for publication in Phy. Rev. B
Scale Symmetry Spontaneously Broken by Asymptotic Behavior
Creators: name: Guendelman, E. I.
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Conserved quantities are obtained and analyzed in the new models with global scale invariance recently proposed. Such models allow for non tivial scalar field potentials and masses for particles, so that the scale symmetry must be broken somehow. We get to this conclusion by showing that the infrared behavior of the conserved currents is singular so that there are no conserved charges associated with the global scale symmetry. The scale symmetry plays nevertheless a crucial role in determining the structure of the theory and it implies that in some high field regions the potentials become flat.
Rotating Black Branes wrapped on Einstein Spaces
Creators: name: Klemm, Dietmar
Publisher: name: arXiv
Year: 1998
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present new rotating black brane solutions which solve Einstein's equations with cosmological constant $Λ$ in arbitrary dimension $d$. For negative $Λ$, the branes naturally appear in AdS supergravity compactifications, and should therefore play some role in the AdS/CFT correspondence. The spacetimes are warped products of a four-dimensional part and an Einstein space of dimension $d-4$, which is not necessarily of constant curvature. As a special subcase, the solutions contain the higher dimensional generalization of the Kerr-AdS metric recently found by Hawking et al.
description: 11 pages, RevTeX, no figures, thermodynamical discussion and 2 references added
Symplectic Structures for the Cubic Schrodinger equation in the periodic and scattering case
Creators: name: Vaninsky, K. L.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: We develop a unified approach for construction of symplectic forms for 1D integrable equations with the periodic and rapidly decaying initial data. As an example we consider the cubic nonlinear Schrödinger equation.
description: This is expanded and corrected version
Gravitational waves and massless particle fields
Creators: name: van Holten, J. W.
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: These notes address the planar gravitational wave solutions of general relativity in empty space-time, and analyze the motion of test particles in the gravitational wave field. Next we consider related solutions of the Einstein equations for the gravitational field accompanied by long-range wave fields of scalar, spinor and vector type, corresponding to particles of spin s=(0,1/2,1). The motion of test masses in the combined gravitational and scalar, spinor or vector wave fields is discussed.
description: 10 pages, no figures, Contr. to Proceedings XXXVth Karpacz Winterschool of Theoretical Physics; update: typos corrected
Black Holes and Instabilities of Negative Tension Branes
Creators: name: Marolf, Donald
name: Trodden, Mark
Publisher: name: arXiv
Year: 2001
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider the collision in 2+1 dimensions of a black hole and a negative tension brane on an orbifold. Because there is no gravitational radiation in 2+1 dimensions, the horizon area shrinks when part of the brane falls through. This provides a potential violation of the generalized second law of thermodynamics. However, tracing the details of the dynamical evolution one finds that it does not proceed from equilibrium configuration to equilibrium configuration. Instead, a catastrophic space-time singularity develops similar to the `big crunch' of $Ω>1$ FRW space-times. In the context of classical general relativity, our result demonstrates a new instability of constructions with negative tension branes.
description: 18 pages, 3 figures, uses RevTeX. Minor typos fixed. References and one footnote added
Signs of outflow feedback from a nearby young stellar object on the protostellar envelope around HL Tau
Creators: name: Yen, Hsi-Wei
name: Takakuwa, Shigehisa
name: Gu, Pin-Gao
name: Hirano, Naomi
name: Lee, Chin-Fei
name: Liu, Hauyu Baobab
name: Liu, Sheng-Yuan
name: Wu, Chun-Ju
Publisher: name: arXiv
Year: 2019
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: HL Tau is a Class I-II protostar embedded in an infalling and rotating envelope and possibly associated with a planet forming disk, and it is co-located in a 0.1 pc molecular cloud with two nearby young stellar objects. Our ALMA observations revealed two arc-like structures on a 1000 au scale connected to the disk, and their kinematics could not be explained with any conventional model of infalling and rotational motions. In this work, we investigate the nature of these arc-like structures connected to the HL Tau disk. We conducted new observations in the 13CO and C18O (3-2; 2-1) lines with JCMT and IRAM 30m, and obtained the ACA data with the 7-m array. With the single-dish, ACA, and ALMA data, we analyzed the gas motions on both 0.1 pc and 1000 au scales in the HL Tau region. We constructed new kinematical models of an infalling and rotating envelope with the consideration of relative motion between HL Tau and the envelope. By including the relative motion between HL Tau and its protostellar envelope, our kinematical model can explain the observed velocity features in the arc-like structures. The morphologies of the arc-like structures can also be explained with an asymmetric initial density distribution in our model envelope. In addition, our single-dish results support that HL Tau is located at the edge of a large-scale (0.1 pc) expanding shell driven by the wind or outflow from XZ Tau, as suggested in the literature. The estimated expanding velocity of the shell is comparable to the relative velocity between HL Tau and its envelope in our kinematical model. These results hints that the large-scale expanding motion likely impacts the protostellar envelope around HL Tau and affects its gas kinematics. We found that the mass infalling rate from the envelope onto the HL Tau disk can be decreased by a factor of two due to this impact by the large-scale expanding shell.
description: Accepted by A&A
The nitrogen carrier in protoplanetary disks
Creators: name: Pontoppidan, Klaus M.
name: Salyk, Colette
name: Banzatti, Andrea
name: Blake, Geoffrey A.
name: Walsh, Catherine
name: Lacy, John H.
name: Richter, Matthew J.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The dominant reservoirs of elemental nitrogen in protoplanetary disks have not yet been observationally identified. Likely candidates are HCN, NH$_3$ and N$_2$. The relative abundances of these carriers determine the composition of planetesimals as a function of disk radius due to strong differences in their volatility. A significant sequestration of nitrogen in carriers less volatile than N$_2$ is likely required to deliver even small amounts of nitrogen to the Earth and potentially habitable exo-planets. While HCN has been detected in small amounts in inner disks ($<10$ au), so far only relatively insensitive upper limits on inner disk NH$_3$ have been obtained. We present new Gemini-TEXES high resolution spectroscopy of the 10.75 $μ$m band of warm NH$_3$, and use 2-dimensional radiative transfer modeling to improve previous upper limits by an order of magnitude to $\rm [NH_3/H_{nuc}]<10^{-7}$ at 1 au. These NH$_3$ abundances are significantly lower than those typical for ices in circumstellar envelopes ($[{\rm NH_3/H_{nuc}}]\sim 3\times 10^{-6}$). We also consistently retrieve the inner disk HCN gas abundances using archival Spitzer spectra, and derive upper limits on the HCN ice abundance in protostellar envelopes using archival ground-based 4.7 $μ$m spectroscopy ([HCN$_{\rm ice}$]/[H$_2$O$_{\rm ice}$]$<1.5-9$\%). We identify the NH$_3$/HCN ratio as an indicator of chemical evolution in the disk, and use this ratio to suggest that inner disk nitrogen is efficiently converted from NH$_3$ to N$_2$, significantly increasing the volatility of nitrogen in planet-forming regions.
description: Accepted for publication in the Astrophysical Journal
Self-Avoiding Walks with Writhe
Creators: name: Moroz, J. David
name: Kamien, Randall D.
Publisher: name: arXiv
Year: 1997
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We map self-avoiding random walks with a chemical potential for writhe to the three-dimensional complex O(N) Chern-Simons theory as N -> 0. We argue that at the Wilson-Fisher fixed point which characterizes normal self-avoiding walks (with radius of gyration exponent nu = 0.588) a small chemical potential for writhe is irrelevant and the Chern-Simons field does not modify the monomer- monomer correlation function. For a large chemical potential the polymer collapses.
description: 20 pages, LaTex. Requires epsf and psfig. One included eps file. Revision adds a reference
Spatial evolution of Hindmarsh-Rose neural network with time delays
Creators: name: Łepek, Michał
name: Fronczak, Piotr
Publisher: name: arXiv
Year: 2018
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: Spatial relations between neurons in the network with time delays play a crucial role in determining dynamics of the system. During the development of the nervous system different types of neurons group together to enable specific functions of the network. Right spatial distances, thus right time delays between cells are crucial for an appropriate functioning of the system. To model the process of neural migration we proposed simple but effective model of network spatial evolution based on Hindmarsh-Rose neurons and Metropoli-Hastings Monte Carlo algorithm. Under the specific assumptions and using appropriate parameters of the neural evolution the network can converge to the desirable state giving the opportunity of achieving large variety of spectra. We show that there is a specific range of network size in space which allows it to generate assumed output. A network or generally speaking a system with time delays (corresponding to the arrangement in the physical space) of specific output properties has a specific spatial dimension that allows it to function properly.
description: 14 pages, 13 figures. Original work
Multi-Leg One-Loop Gravity Amplitudes from Gauge Theory
Creators: name: Bern, Z.
name: Dixon, L.
name: Perelstein, M.
name: Rozowsky, J. S.
Publisher: name: arXiv
Year: 1998
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: By exploiting relations between gravity and gauge theories, we present two infinite sequences of one-loop n-graviton scattering amplitudes: the `maximally helicity-violating' amplitudes in N=8 supergravity, and the `all-plus' helicity amplitudes in gravity with any minimally coupled massless matter content. The all-plus amplitudes correspond to self-dual field configurations and vanish in supersymmetric theories. We make use of the tree-level Kawai-Lewellen-Tye (KLT) relations between open and closed string theory amplitudes, which in the low-energy limit imply relations between gravity and gauge theory tree amplitudes. For n < 7, we determine the all-plus amplitudes explicitly from their unitarity cuts. The KLT relations, applied to the cuts, allow us to extend to gravity a previously found `dimension-shifting' relation between (the cuts of) the all-plus amplitudes in gauge theory and the maximally helicity-violating amplitudes in N=4 super-Yang-Mills theory. The gravitational version of the relation lets us determine the n < 7 N=8 supergravity amplitudes from the all-plus gravity amplitudes. We infer the two series of amplitudes for all n from their soft and collinear properties, which can also be derived from gauge theory using the KLT relations.
description: Minor errors corrected, Latex, 53 pages
BRITE photometry of the massive post-RLOF system HD149404
Creators: name: Rauw, G.
name: Pigulski, A.
name: Nazé, Y.
name: David-Uraz, A.
name: Handler, G.
name: Raucq, F.
name: Gosset, E.
name: Moffat, A. F. J.
name: Neiner, C.
name: Pablo, H.
name: Popowicz, A.
name: Rucinski, S. M.
name: Wade, G. A.
name: Weiss, W.
name: Zwintz, K.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: HD149404 is an evolved non-eclipsing O-star binary that has previously undergone a Roche lobe overflow interaction. Understanding some key properties of the system requires a determination of the orbital inclination and of the dimensions of the components. The BRITE-Heweliusz satellite was used to collect photometric data of HD149404. Additional photometry was retrieved from the SMEI archive. These data were analysed using a suite of period search tools. The orbital part of the lightcurve was modelled with the nightfall binary star code. The Gaia-DR2 parallax of HD149404 was used to provide additional constraints. The periodograms reveal a clear orbital modulation of the lightcurve with a peak-to-peak amplitude near 0.04 mag. The remaining non-orbital part of the variability is consistent with red noise. The lightcurve folded with the orbital period reveals ellipsoidal variations, but no eclipses. The minimum when the secondary star is in inferior conjunction is deeper than the other minimum due to mutual reflection effects between the stars. Combined with the Gaia-DR2 parallaxes, the photometric data indicate an orbital inclination in the range of 23° to 31° and a Roche lobe filling factor of the secondary larger than or equal to 0.96. The luminosity of the primary star is consistent with its present-day mass, whereas the more evolved secondary appears overluminous for its mass. We confirm that the primary's rotation period is about half the orbital period. Both features most probably stem from the past Roche lobe overflow episode.
description: Accepted for publication in Astronomy & Astrophysics
Self-organized stable pacemakers near the onset of birhythmicity
Creators: name: Stich, Michael
name: Ipsen, Mads
name: Mikhailov, Alexander S.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: General amplitude equations for reaction-diffusion systems near to the soft onset of birhythmicity described by a supercritical pitchfork-Hopf bifurcation are derived. Using these equations and applying singular perturbation theory, we show that stable autonomous pacemakers represent a generic kind of spatiotemporal patterns in such systems. This is verified by numerical simulations, which also show the existence of breathing and swinging pacemaker solutions. The drift of self-organized pacemakers in media with spatial parameter gradients is analytically and numerically investigated.
description: 4 pages, 4 figures
Parity Violating Gravitational Coupling Of Electromagnetic Fields
Creators: name: Majumdar, Parthasarathi
name: SenGupta, Soumitra
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: A manifestly gauge invariant formulation of the coupling of the Maxwell theory with an Einstein Cartan geometry is given, where the space time torsion originates from a massless Kalb-Ramond field augmented by suitable U(1) Chern Simons terms.We focus on the situation where the torsion violates parity, and relate it to earlier proposals for gravitational parity violation.
description: 7 Pages, Latex . no figures, Replaced with Revtex version, many references added and typos corrected