cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
ELIXIR Europe on the Road to Sustainable Research Software
Creators: name: Mateusz, Kuzak
name: Harrow Jennifer
name: Jimenez Rafael
name: Psomopoulos Fotis
name: Via Allegra
name: Bampalikis Dimitrios
Publisher: name: Zenodo
Year: 2019
Subjects: Training, Open Source software guidelines, best practices, recommendations, Open Science, Reproducible Research, sustainability, FAIR

description: ELIXIR is an intergovernmental organization that brings together life science resources across Europe. These resources include databases, software tools, training materials, cloud storage, and supercomputers. One of the goals of ELIXIR is to coordinate these resources so that they form a single infrastructure. This infrastructure makes it easier for scientists to find and share data, exchange expertise, and agree on best practices. ELIXIR's activities are divided into the following five areas Data, Tools, Interoperability, Compute and Training known as “platforms”. The ELIXIR Tools Platform works to improve the discovery, quality and sustainability of software resources. Software Best Practices task of the Tools Platform aims to raise the quality and sustainability of research software by producing, adopting, promoting and measuring information standards and best practices applied to the software development life cycle. We have published four (4OSS) simple recommendations to encourage best practices in research software and the Top 10 metrics for life science software good practices. The next step is to adopt, promote, and recognise these information standards and best practices, by developing comprehensive guidelines for software curation, and through workshops for training researchers and developers towards the adoption of software best practices.
Cosmic acceleration from first principles
Creators: name: Garcia-Bellido, Juan
name: Espinosa-Portales, Llorenc
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: General relativistic entropic acceleration theory may explain the present cosmic acceleration from first principles without the need of introducing a cosmological constant. Following the covariant formulation of non-equilibrium phenomena in the context of a homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, we find that the growth of entropy associated with the causal horizon of our universe (inside a finite bubble in eternal inflation) induces an acceleration that is essentially indistinguishable from that of $Λ$CDM, except for a slightly larger present rate of expansion compared to what would be expected from the CMB in $Λ$CDM, possibly solving the so-called $H_0$ tension. The matter content of the universe is unchanged and the coincidence problem is resolved since it is the growth of the causal horizon of matter that introduces this new relativistic entropic force. The cosmological constant is made unnecessary and the future hypersurface is Minkowsky rather than de Sitter.
description: 6 pages, 5 figures. Comments added. Matches version accepted by PDU
Kinky Strings in AdS_5 x S^5
Creators: name: McLoughlin, Tristan
name: Wu, Xinkai
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct a family of closed string solutions with kinks in a subspace of AdS_5 x S^5 and study their properties. In certain limits these solutions become folded pulsating strings, although in general they are made of multiple pulsating rectangles. One unusual feature of these solutions is that their monodromy matrices are trivial, leading to vanishing quasi-momenta. Exact Backlund transformations of these solutions are found, again giving vanishing higher conserved charges. We also consider the fluctuation modes around these solutions as well as the semiclassical splitting of these strings.
description: 35 pages, 6 figures; Version 2 references added
Formation of long-lived, scarlike modes near avoided resonance crossings in optical microcavities
Creators: name: Wiersig, Jan
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We study the formation of long-lived states near avoided resonance crossings in open systems. For three different optical microcavities (rectangle, ellipse, and semi-stadium) we provide numerical evidence that these states are localized along periodic rays, resembling scarred states in closed systems. Our results shed light on the morphology of long-lived states in open mesoscopic systems.
description: 4 pages, 5 figures (in reduced quality), to appear in Phys. Rev. Lett
Establishment and evaluation of cover crops underseeded in sweet corn in Delta, British Columbia
Creators: name: Ismail, Aweis Aware Issa
Publisher: name: University of British Columbia
Year: 2009

description: A two year field experiment was carried out in Delta Municipality, British Columbia. The study was designed to investigate the effects of dates of underseeding different cover crops such as crimson, red clover and alsike clovers and annual ryegrass and fall rye with sweet com. The experiment was conducted as a split plot, randomized complete block design with 12 treatment combinations and four replicates. Main plots were the two dates of cover crop planting, one shortly after emergence and the second at side dressing time (~ 30 cm). Subplots were comprised of an unseeded control plus five different cover crops seeded under sweet com. In the 1992-1993 and 1993-1994 growing seasons, the effects of cover crops on fresh arid dry cob yield of sweet com were not significant. In the 1992-1993 experiment the type of underseeded cover crops had no effect on either fresh or dry stalk yield, while in the 1993-1994 growing season stalk yields were reduced by fall rye and annual ryegrass relative to red clover. Early planting of cover crops significantly reduced the fresh and dry stalk yield of sweet com. There were no differences due to cover crops in the com ear leaf nitrogen concentration in the 1992-1993 growing season. However, in the 1993-1994 growing season, sweet com/fall rye had significantly lower ear leaf nitrogen concentrations than sweet com/red clover. In the 1993-1994 growing season the ear leaf nitrogen concentrations of early underseeded sweet com were significantly lower than ear leaf nitrogen concentration of late underseeded sweet corn. In the 1992-1993 growing season, red clover produced the highest cover crop dry matter yield. Nitrogen concentrations in alsike and red clovers were higher than that of annual ryegrass. In 1993-1994 growing season, crimson clover produced the highest dry matter yield. The nitrogen content of crimson clover was higher than that of alsike clover, fall rye and annual ryegrass in that year. In both 1992-1993 and 1993-1994 growing seasons, annual ryegrass had the highest percent cover compared to the other treatments. Fresh and dry cob yields of sweet corn were not affected by date of seeding nor type of cover crop underseeded. Early underseeded cover crop appeared to compete with sweet corn for nitrogen as compared to late underseeding. Despite low dry matter production which may be attributed to different growth habits, annual ryegrass and alsike clover look promising soil cover crops because they gave higher percentage of soil cover.
Mapping of strongly correlated steady-state nonequilibrium to an effective equilibrium
Creators: name: Han, J. E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: By mapping steady-state nonequilibrium to an effective equilibrium, we formulate nonequilibrium problems within an equilibrium picture where we can apply existing equilibrium many-body techniques to steady-state electron transport problems. We study the analytic properties of many-body scattering states, reduce the boundary condition operator in a simple form and prove that this mapping is equivalent to the correct linear-response theory. In an example of infinite-U Anderson impurity model, we approximately solve for the scattering state creation operators, based on which we derive the bias operator Y to construct the nonequilibrium ensemble in the form of the Boltzmann factor exp(-beta(H-Y)). The resulting Hamiltonian is solved by the non-crossing approximation. We obtain the Kondo anomaly conductance at zero bias, inelastic transport via the charge excitation on the quantum dot and significant inelastic current background over a wide range of bias. Finally, we propose a self-consistent algorithm of mapping general steady-state nonequilibrium.
description: 15 pages, 9 figures
The light ring and the appearance of matter accreted by black holes
Creators: name: Cardoso, Vitor
name: Duque, Francisco
name: Foschi, Arianna
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: The geometry of black hole spacetimes can be probed with exquisite precision in the gravitational-wave window, and possibly also in the optical regime. We study the accretion of bright spots -- objects which emit strongly in the optical or in gravitational waves -- by non-spinning black holes. The emission as the object falls down the hole is dominated by photons or gravitons orbiting the light ring, causing the total luminosity to decrease exponentially as ${\cal L}_o\sim e^{-t/(3\sqrt{3}\,M)}$. Late-time radiation is blueshifted, due to its having been emitted during the infall, trapped at the light ring and subsequently re-emitted. These universal properties are a clear signature of the existence of light rings in the spacetime, and not particularly sensitive to near horizon details.
description: 11 pages, 10 figures, revtex4. v2: Several improvements, relation between geometric optics and quasinormal modes clarified. To appear in Physical Review D
Learning Stochastic Majority Votes by Minimizing a PAC-Bayes Generalization Bound
Creators: name: Zantedeschi, Valentina
name: Viallard, Paul
name: Morvant, Emilie
name: Emonet, Rémi
name: Habrard, Amaury
name: Germain, Pascal
name: Guedj, Benjamin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Methodology (stat.ME)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: We investigate a stochastic counterpart of majority votes over finite ensembles of classifiers, and study its generalization properties. While our approach holds for arbitrary distributions, we instantiate it with Dirichlet distributions: this allows for a closed-form and differentiable expression for the expected risk, which then turns the generalization bound into a tractable training objective. The resulting stochastic majority vote learning algorithm achieves state-of-the-art accuracy and benefits from (non-vacuous) tight generalization bounds, in a series of numerical experiments when compared to competing algorithms which also minimize PAC-Bayes objectives -- both with uninformed (data-independent) and informed (data-dependent) priors.
Effects of QCD phase transition on gravitational radiation from two-dimensional collapse and bounce of massive stars
Creators: name: Yasutake, Nobutoshi
name: Kotake, Kei
name: Hashimoto, Masa-aki
name: Yamada, Shoichi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We perform two-dimensional, magnetohydrodynamical core-collapse simulations of massive stars accompanying the QCD phase transition. We study how the phase transition affects the gravitational waveforms near the epoch of core-bounce. As for initial models, we change the strength of rotation and magnetic fields. Particularly, the degree of differential rotation in the iron core (Fe-core) is changed parametrically. As for the microphysics, we adopt a phenomenological equation of state above the nuclear density, including two parameters to change the hardness before the transition. We assume the first order phase transition, where the conversion of bulk nuclear matter to a chirally symmetric quark-gluon phase is described by the MIT bag model. Based on these computations, we find that the phase transition can make the maximum amplitudes larger up to $\sim$ 10 percents than the ones without the phase transition. On the other hand, the maximum amplitudes become smaller up to $\sim$ 10 percents owing to the phase transition, when the degree of the differential rotation becomes larger. We find that even extremely strong magnetic fields $\sim 10^{17}$ G in the protoneutron star do not affect these results.
description: 12 pages, 12 figures. Resubmitted to Phys.Rev.D
Open Momentum Space Method for Hofstadter Butterfly and the Quantized Lorentz Susceptibility
Creators: name: Lian, Biao
name: Xie, Fang
name: Bernevig, B. Andrei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We develop a generic $\mathbf{k}\cdot \mathbf{p}$ open momentum space method for calculating the Hofstadter butterfly of both continuum (Moiré) models and tight-binding models, where the quasimomentum is directly substituted by the Landau level (LL) operators. By taking a LL cutoff (and a reciprocal lattice cutoff for continuum models), one obtains the Hofstadter butterfly with in-gap spectral flows. For continuum models such as the Moiré model for twisted bilayer graphene, our method gives a sparse Hamiltonian, making it much more efficient than existing methods. The spectral flows in the Hofstadter gaps can be understood as edge states on a momentum space boundary, from which one can determine the two integers ($t_ν,s_ν$) of a gap $ν$ satisfying the Diophantine equation. The spectral flows can also be removed to obtain a clear Hofstadter butterfly. While $t_ν$ is known as the Chern number, our theory identifies $s_ν$ as a dual Chern number for the momentum space, which corresponds to a quantized Lorentz susceptibility $γ_{xy}=eBs_ν$.
description: 5+30 pages, 3+4 figures
Thermodynamics second law and $ω=-1$ crossing(s) in interacting holographic dark energy model
Creators: name: Sadjadi, H. Mohseni
name: Honardoost, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: By the assumption that the thermodynamics second law is valid, we study the possibility of $ω=-1$ crossing in interacting holographic dark energy model. Depending on the choice of the horizon and the interaction, the transition from quintessence to phantom regime and subsequently from phantom to quintessence phase may be possible. The second transition avoids the big rip singularity. We compute the dark energy density at transition time and show that by choosing appropriate parameters we can alleviate the coincidence problem.
description: 13 pages, 1 figure, a shorter version to appear in Phys. Lett. B
Radiative corrections to the lepton current in unpolarized elastic $lp$-interaction for fixed $Q^2$ and scattering angle
Creators: name: Afanasev, A.
name: Ilyichev, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The kinematical difference between the description of radiative effects for fixed $Q^2$ vs a fixed scattering angle in the elastic lepton-proton ($lp$)-scattering is discussed. The technique of calculation as well as explicit expressions for radiative corrections to the lepton current in unpolarized elastic $lp$-scattering for these two cases are presented without using an ultrarelativistic approximation. A comparative numerical analysis within kinematic conditions of Jefferson Lab measurements and MUSE experiment in PSI is performed.
description: 12 pages, 5 figures, published in European Physical Journal A Topical Issue 'An Experimental Program with Positron Beams at Jefferson Lab'
Spectral Properties of Acoustic Gravity Wave Turbulence
Creators: name: Shaikh, Dastgeer
name: Shukla, Padma K
name: Stenflo, Lennart
Publisher: name: arXiv
Year: 2008
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The nonlinear turbulent interactions between acoustic gravity waves are investigated using two dimensional nonlinear fluid simulations. The acoustic gravity waves consist of velocity and density perturbations and propagate across the density gradients in the vertical direction in the Earth's atmosphere. We find that the coupled two component model exhibits generation of large scale velocity potential flows along the vertical direction, while the density perturbations relax towards an isotropic random distribution. The characteristic turbulent spectrum associated with the system has a Kolmogorov-like feature and tends to relax towards a $k^{-5/3}$ spectrum, where $k$ is a typical wavenumber. The cross field diffusion associated with the velocity potential grows linearly and saturates in the nonlinear phase.
Semiconductor quantum dots in high magnetic fields: The composite-fermion view
Creators: name: Jeon, Gun Sang
name: Chang, Chia-Chen
name: Jain, Jainendra K.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We review and extend the composite fermion theory for semiconductor quantum dots in high magnetic fields. The mean-field model of composite fermions is unsatisfactory for the qualitative physics at high angular momenta. Extensive numerical calculations demonstrate that the microscopic CF theory, which incorporates interactions between composite fermions, provides an excellent qualitative and quantitative account of the quantum dot ground state down to the largest angular momenta studied, and allows systematic improvements by inclusion of mixing between composite fermion Landau levels (called $Λ$ levels).
description: 13 pages, 8 figures
Excitations in a non-equilibrium Bose-Einstein condensate of exciton-polaritons
Creators: name: Wouters, M.
name: Carusotto, I.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We have developed a mean-field model to describe the dynamics of a non-equilibrium Bose-Einstein condensate of exciton-polaritons in a semiconductor microcavity. The spectrum of elementary excitations around the stationary state is analytically studied in different geometries. A diffusive behaviour of the Goldstone mode is found in the spatially homogeneous case and new features are predicted for the Josephson effect in a two-well geometry.
description: 5 pages, 2 figures
The drivers of avian haemosporidian prevalence in tropical lowland forest of New Guinea in three dimensions
Creators: name: Vinagre-Izquierdo, Celia
name: Kasun Bodawatta
name: Kryštof Chmel
name: Justinn Renelies-Hamilton
name: Paul, Luda
name: Munclinger, Pavel
name: Poulsen, Michael
name: Jønsson, Knud A.
Publisher: name: Zenodo
Year: 2021

description: Dataset for the publication, including sequences, climate data and networks.
Heating the intergalactic medium by radiative decay of neutrinos
Creators: name: Chan, M. H.
name: Chu, M. -C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Assuming that there exists a species of heavy sterile neutrinos($m_ν>1$ keV) and their decays can serve as a heating source of the hot gas in galaxy clusters, we study how the observational constraints on cooling flow limit the mass of these sterile neutrinos. We predict a relation among the luminosity, total mass and the redshift of a cluster, and we compare this relation with data from 12 clusters to obtain an estimate of the decay rate of the sterile neutrino.
description: 15 pages, 4 figures
Generation of polarization entangled photon pairs by a single crystal interferometric source pumped by femtosecond laser pulses
Creators: name: Barbieri, M.
name: Cinelli, C.
name: De Martini, F.
name: Mataloni, P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Photon pairs, highly entangled in polarization have been generated under femtosecond laser pulse excitation by a type I crystal source, operating in a single arm interferometric scheme. The relevant effects of temporal walk-off existing in these conditions between the ordinary and extraordinary photons were experimentally investigated. By introducing a suitable temporal compensation between the two orthogonal polarization components highly entangled pulsed states were obtained.
Theory and Simulations of Whistler Wave Propagation
Creators: name: Shaikh, Dastgeer
Publisher: name: arXiv
Year: 2008
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: A linear theory of whistler wave is developed wihtin the paradigm of a two dimensional incompressible electron magnetohydrodynamics model. Exact analytic wave solutions are obtained for a small amplitude whistler wave that exhibit magnetic field topological structures consistent with the observations and our simulations in linear regime. In agreement with experiment, we find that the parallel group velocity of the wave is large compared to its perpendicular counterpart. Numerical simulations of collisional interactions demonstrate that the wave magnetic field either coalesces or repels depending upon the polarity of the associated current. In the nonlinear regime, our simulations demonstrate that the evolution of wave magnetic field is governed essentially by the nonlinear Hall force.
Anisotropic properties of the layered superconductor Cu0.07TiSe2
Creators: name: Morosan, E.
name: Li, Lu
name: Ong, N. P.
name: Cava, R. J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The anisotropic superconducting properties of single crystals of Cu0.07TiSe2 were studied by measurements of magnetization and electrical resistivity. TC is around 3.9 K, and the measured upper critical field (Hc2) values are ~1.25 T and 0.8 T, for applied field parallel and perpendicular to the TiSe2 planes, respectively. The anisotropy ratio gamma_anis = H^ab_c2 / H^c_c2 is close to 1.6 and nearly temperature independent. The lower critical field (Hc1) values are much smaller (~ 32 Oe for H||ab and 17 Oe for H||c); demagnetizing corrections for field perpendicular to the thin plate crystals are required for the determination of H^c_c1. The anisotropy of the critical fields is described well by the anisotropic Ginzburg-Landau (GL) theory, and the characteristic GL parameters are determined and discussed.
description: Submitted to Physical Review B
Aharonov-Bohm effect on the Poincaré disk
Creators: name: Lisovyy, O.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider formal quantum hamiltonian of a charged particle on the Poincaré disk in the presence of an Aharonov-Bohm magnetic vortex and a uniform magnetic field. It is shown that this hamiltonian admits a four-parameter family of self-adjoint extensions. Its resolvent and the density of states are calculated for natural values of the extension parameters.
description: 21 pages, 1 figure, references added
Electronic width of the $ψ(3770)$ resonance interfering with the background
Creators: name: Achasov, N. N.
name: Shestakov, G. N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Methods for extracting the $ψ(3770)\to e^+e^-$ decay width from the data on the reaction cross section $e^+e^-\to D\bar D$ are discussed. Attention is drawn to the absence of the generally accepted method for determining $Γ_{ψ(3770)e^+e^-}$ in the presence of interference between the contributions of the $ψ(3770)$ resonance and background. It is shown that the model for the experimentally measured $D$ meson form factor, which satisfies the requirement of the Watson theorem and takes into account the contribution of the complex of the mixed $ψ(3770)$ and $ψ(2S)$ resonances, allows uniquely determine the value of $Γ_{ψ(3770)e^+e^-}$ by fitting. The $Γ_{ψ(3770)e^+ e^-}$ values found from the data processing are compared with the estimates in the potential models.
description: 10 pages, 3 figures, v2: clarifications and two references added, version published in Phys. Rev. D
Quantum field-theoretic machine learning
Creators: name: Bachtis, Dimitrios
name: Aarts, Gert
name: Lucini, Biagio
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Machine Learning (cs.LG)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We derive machine learning algorithms from discretized Euclidean field theories, making inference and learning possible within dynamics described by quantum field theory. Specifically, we demonstrate that the $ϕ^{4}$ scalar field theory satisfies the Hammersley-Clifford theorem, therefore recasting it as a machine learning algorithm within the mathematically rigorous framework of Markov random fields. We illustrate the concepts by minimizing an asymmetric distance between the probability distribution of the $ϕ^{4}$ theory and that of target distributions, by quantifying the overlap of statistical ensembles between probability distributions and through reweighting to complex-valued actions with longer-range interactions. Neural network architectures are additionally derived from the $ϕ^{4}$ theory which can be viewed as generalizations of conventional neural networks and applications are presented. We conclude by discussing how the proposal opens up a new research avenue, that of developing a mathematical and computational framework of machine learning within quantum field theory.
A Lopsided Outer Solar System
Creators: name: Zderic, Alexander
name: Tiongco, Maria
name: Collier, Angela
name: Wernke, Heather
name: Generozov, Aleksey
name: Madigan, Ann-Marie
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Axisymmetric disks of eccentric orbits in near-Keplerian potentials are unstable to an out-of-plane buckling. Recently, Zderic et al. (2020) showed that an idealized disk saturates to a lopsided mode. Here we show that this apsidal clustering also occurs in a primordial scattered disk in the outer solar system which includes the orbit-averaged gravitational influence of the giant planets. We explain the dynamics using Lynden-Bell (1979)'s mechanism for bar formation in galaxies. We also show surface density and line of sight velocity plots at different times during the instability, highlighting the formation of concentric circles and spiral arms in velocity space.
description: 17 pages, 13 figures
Independent particle descriptions of tunneling from a many-body perspective
Creators: name: Fagas, Giorgos
name: Delaney, Paul
name: Greer, James C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Currents across thin insulators are commonly taken as single electrons moving across classically forbidden regions; this independent particle picture is well-known to describe most tunneling phenomena. Examining quantum transport from a different perspective, i.e., by explicit treatment of electron-electron interactions, we evaluate different single particle approximations with specific application to tunneling in metal-molecule-metal junctions. We find maximizing the overlap of a Slater determinant composed of single particle states to the many-body current-carrying state is more important than energy minimization for defining single particle approximations in a system with open boundary conditions. Thus the most suitable single particle effective potential is not one commonly in use by electronic structure methods, such as the Hartree-Fock or Kohn-Sham approximations.
description: 4+ pages, 4 figures; accepted to Phys. Rev. B Rapid Communications
D7.1: Project communication plan
Creators: name: Gourcuff, Claire
name: Evrard, Estérine
name: Maze, Guillaume
name: Velez-Belchi, Pedro
name: D'Ortenzio, Fabrizio
name: Tuomi, Laura
name: Notarstefano, Giulio
name: O' Conchubhair, Diarmuid
Publisher: name: Zenodo
Year: 2019

description: Project’s communication plan document
Horizon Acoustics of the GHS Black Hole and the Spectrum of ${\rm AdS}_2$
Creators: name: Porfyriadis, Achilleas P.
name: Remmen, Grant N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We uncover a novel structure in Einstein-Maxwell-dilaton gravity: an ${\rm AdS}_2 \times S^2$ solution in string frame, which can be obtained by a near-horizon limit of the extreme GHS black hole with dilaton coupling $λ\neq 1$. Unlike the Bertotti-Robinson spacetime, our solution has independent length scales for the ${\rm AdS}_2$ and $S^2$, with ratio controlled by $λ$. We solve the perturbation problem for this solution, finding the independently propagating towers of states in terms of superpositions of gravitons, photons, and dilatons and their associated effective potentials. These potentials describe modes obeying conformal quantum mechanics, with couplings that we compute, and can be recast as giving the spectrum of the effective masses of the modes. By dictating the conformal weights of boundary operators, this spectrum provides crucial data for any future construction of a holographic dual to these ${\rm AdS}_2\times S^2$ configurations.
description: 35 pages, 3 figures
Οι κοινωνικές διαστάσεις και οι πρακτικές του πολέμου στην Κεντρική και Νότια Ελλάδα κατά την Μυκηναϊκή περίοδο
Creators: name: Κομίτσας, Ιωάννης Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Πολεμική εικονογραφία
Ηπειρωτική Ελλάδα
Ύστερη Εποχή Χαλκού
Warfare iconography
Mainland Greece
Late Bronze Age

description: Στόχος της παρούσας διατριβής είναι η διερεύνηση των πολεμικών ηθών κατά τις τελευταίες φάσεις της Ύστερης Εποχής Χαλκού (ανακτορικής και μετανακτορικής περιόδου) στην Κεντρική και Νότια Ελλάδα, όπως αυτά εκφράζονται μέσω της εικονογραφίας. Τα δυο κύρια ερευνητικά ζητούμενα περιλαμβάνουν την καταγραφή και ανάλυση θεματικών (αφηγηματικών και αφηρημένων) με πολεμικά χαρακτηριστικά και του πολεμικού εξοπλισμού. Διερευνήθηκε το πρωτογενές υλικό ποικίλων εικονογραφικών κατηγοριών και οι αποκαταστάσεις αξιοποιήθηκαν υποστηρικτικά. Επιχειρήθηκε η αποκωδικοποίηση του νοήματος των συνθέσεων μέσα από την ανάλυση των εικόνων και σε συνάρτηση με το κοινωνικό τους πλαίσιο. Από την μελέτη προκύπτει πως η πολεμική εικονογραφία της κάθε εποχής διαμορφώνεται μέσα από διαφορετικά εικονιστικά μέσα, θεματολογίες, καθώς και στοιχεία πολεμικού εξοπλισμού. Ακόμη, η έρευνα αναδεικνύει σημαντικές μεταβολές στο νόημα και την χρήση της εικονογραφίας της κάθε περιόδου. Τέλος, είναι αξιοσημείωτη η συσχέτιση της πολεμικής εικονογραφίας με τις κυρίαρχες κοινωνικές ομάδες εντός διαφορετικών κοινωνικών και ιστορικών συγκειμένων.
description: The aim of the current dissertation is the study of the ethos of warfare during the last phases of the Late Bronze age (palatial and post-palatial period) in Central and Southern Greece, as expressed through imagery. The two main research questions include the recording and analysis of themes (narrative and abstract) with martial features and military equipment. The primary material of various iconographic categories was studied and the restorations were used supportively. The decoding of meaning of the compositions was attempted through the analysis of the images and in relation to their social context. From the study occurs that the iconography of each era is shaped through different pictorial media, themes, and elements of weaponry. Furthermore, the research highlights important changes in the meaning and use of the iconography of each period. Finally, the relation of martial iconography with the dominant social groups within different social and historical contexts is remarkable.
Preserving records bearing on the experience of women in North America : The women’s archives movement and its significance for appraisal for acquisition
Creators: name: Earnshaw, Gabrielle Lili
Publisher: name: University of British Columbia
Year: 2009

description: This thesis is an historical study of efforts which have taken place in English speaking North America to preserve records bearing on women's experience. It has been found that efforts have centered on two positions: separation from traditional archives and reform of traditional archives. Approaches have varied and changed according to the political ideology of the women's movement at different historical moments. In the 1930s, efforts were made to develop separate "Women's Archives" to complement the records held by traditional archives. In the 1960s and 1970s, some feminists, primarily radical and lesbian feminists aimed at the establishment of independent women-centered archives that were separate from traditional archives and were operated according to feminist principles. Other efforts by liberal feminists have concentrated on the reform of traditional archives through the development of preferential acquisition policies for records bearing on women's experience. In the 1980s and 1990s, while earlier efforts continued, challenges of racism and classism have been made to traditional archives and the women's archives movement by women of color and other minorities. Most recently, feminist scholars have argued for the integration of women's history with that of men. This has influenced a growing trend towards integration of women's records with those of traditional archives. The women's archives movement suggests that appraisal for acquisition in traditional archives has discriminated against the records created by women. Although archival theory and methodology of appraisal for acquisition are not inherently biased, in practice acquisition of private records takes place in a haphazard manner according to the value system of the ruling political ideology. Because of structural and societal discrimination women have not been part of this ruling elite and interest in the preservation of their records has been minimal. To ensure the preservation of women's records archivists must develop national, systematic and comprehensive acquisition strategies which acquire records from all spheres of human activity, improve intellectual access to women's records, and recognize and respect efforts which have taken place outside of traditional archives. The role of the archivist must be expanded to provide consultation and outreach for creators of records bearing on women's experience and the women-centered archives which preserve them.
Mass and spin for classical strings in $dS_3$
Creators: name: Parmentier, Klaas
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We demonstrate that all rigidly rotating strings with center of mass at the origin of the $dS_3$ static patch satisfy the Higuchi bound. This extends the observation of Noumi et al. for the open GKP-like string to all solutions of the Larsen-Sanchez class. We argue that strings violating the bound end up expanding towards the horizon and provide a numerical example. Adding point masses to the open string only increases the mass/spin ratio. For segmented strings, we write the conserved quantities, invariant under Gubser's algebraic evolution equation, in terms of discrete lightcone coordinates describing kink collisions. Randomly generated strings are found to have a tendency to escape through the horizon that is mostly determined by their energy. For rapidly rotating segmented strings with mass/spin $
description: v2 -- 38 pages, 9 figures -- references added
Effects of Multi-scale Plasma Waves on Electron Preacceleration at Weak Quasi-perpendicular Intracluster Shocks
Creators: name: Ha, Ji-Hoon
name: Kim, Sunjung
name: Ryu, Dongsu
name: Kang, Hyesung
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Radio relics associated with merging galaxy clusters indicate the acceleration of relativistic electrons in merger-driven shocks with low sonic Mach numbers ($M_{\rm s}\lesssim 3$) in the intracluster medium (ICM). Recent studies have suggested that electron injection to diffusive shock acceleration (DSA) could take place through the so-called Fermi-like acceleration in the shock foot of $β=P_{\rm gas}/P_{\rm B}\approx 20-100$ shocks and the stochastic shock drift acceleration (SSDA) in the shock transition of $β\approx 1-5$ shocks. Here we explore how the SSDA can facilitate electron preacceleration in weak quasi-perpendicular ($Q_{\perp}$) shocks in $β\approx 20-100$ plasmas by performing particle-in-cell simulations in the two-dimensional domain large enough to encompass ion-scale waves. We find that in supercritical shocks with $M_{\rm s}\gtrsim M_{\rm AIC}^*\sim 2.3$, multi-scale waves are excited by the ion and electron temperature anisotropies in the downstream of the shock ramp, and that through stochastic pitch-angle scattering off the induced waves, electrons are confined in the shock transition for an extended period. Gaining energy through the gradient-drift along the motional electric field, electrons could be preaccelerated all the way to injection to DSA at such ICM shocks. Our findings imply that the electron DSA process at weak ICM shocks could explain the origin of radio relics. However, a further investigation of electron acceleration at subcritical shocks with $M_{\rm s}< 2.3$ is called for, since the Mach numbers of some observed radio relic shocks derived from radio or X-ray observations are as low as $M_{\rm s}\sim 1.5$.
description: 17 pages, 9 figures, to appear in ApJ
The relationship between irradiance (quantity, quality and photoperiod), sinking rate and carbohydrate content in two marine diatoms
Creators: name: Fisher, Anne Elizabeth
Publisher: name: University of British Columbia
Year: 2009

description: Diatoms are physiologically able to control their sinking rates through the selective accumulation of lighter ions in the vacuole (an energy-requiring process). The extent to which a diatom needs to physiologically control its sinking rate will depend on its excess density (i.e. the degree to which the cell is denser than seawater). The excess density of a diatom, and thus the amount of energy required to maintain a low sinking rate, might change with the carbohydrate content of the cells. The purpose of this work was to simultaneously measure sinking rate and carbohydrate content in 2 marine diatoms (Thalassiosira weissflogii and Ditylum brightwellii) to see if sinking rate is affected by irradiance driven changes in carbohydrate content. In the first set of experiments, carbohydrate content was varied by growing cells on light/dark cycles under high and low light. Sinking rate measurements (SETCOL method) were made at the end of the light period and the end of the dark period. Sinking rates were measured on live and heat-killed cells in order to compare the inherent sinking rate of the cell (determined by ballast) to the physiologically-determined sinking rate. In the second set of experiments, carbohydrate content was varied by growing cells under continuous red, white or blue light. Sinking rate was not positively correlated to carbohydrate content in T. weissflogii or D. brightwellii grown on light/dark cycles under low or high white light. Sinking rate in D. brightwellii was under physiological control in all experiments, but in T. weissflogii physiological sinking rate control was intermittent. D. brightwellii showed diel changes in buoyancy, with higher sinking rates at the end of the dark period than at the end of the light period, when cells were positively buoyant. T. weissflogii had higher sinking rates when grown under red light than under white or blue light, but there were no differences in carbohydrate content. D. brightwellii contained twice as much carbohydrate when grown under red light than under white or blue light, but there were no differences in sinking rate.
Lorentz violation and the speed of gravitational waves in brane-worlds
Creators: name: Ahmadi, F.
name: Jalalzadeh, S.
name: Sepangi, H. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Lorentz violation in a brane-world scenario is presented and used to obtain a relationship between the speed of gravitational waves in the bulk and that on the brane. Lorentz violating effects would manifest themselves in gravitational waves travelling with a greater speed in the bulk than on the brane and this effect is independent of the signature of the extra dimension.
description: 8 pages, to appear in PLB
Δυναμικό μοντέλο προσρόφησης ρυπαντών σε ιζήματα για τον υπολογισμό περιβαλλοντικής έκθεσης
Creators: name: Τσιακαλάς, Αναστάσιος Ευάγγελου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Δυναμικό μοντέλο
Προσρόφηση
Περιβαλλοντική έκθεση
Dynamic model
Adsorption
Environmental Exposure assessment

description: Η σημασία της ύπαρξης δυναμικών μοντέλων για τον υπολογισμό της περιβαλλοντικής έκθεσης στη περίπτωση των υδάτινων συστημάτων είναι αδιαμφισβήτητη κυρίως εξαιτίας της ανάγκης διαχείρισης και εκτίμησης του κινδύνου από χημικές ουσίες. Η παρούσα διπλωματική εργασία είχε ως στόχο την προσέγγιση ενός θεωρητικού δυναμικού μοντέλου το οποίο θα υπολογίζει τη συγκέντρωση ενός προσροφούμενου ρυπαντή σε αιωρούμενα σωματίδια ιζήματος εντός υδάτινου όγκου, χρησιμοποιώντας γραμμικές συσχετίσεις ανάμεσα στις παραμέτρους ισορροπίας και την αρχική συγκέντρωση του ρυπαντή. Επιπλέον παρουσιάζεται μια αναφορά στα διάφορα μοντέλα που χρησιμοποιούνται για την Εκτίμηση Κινδύνου από χημικούς παράγοντες και αναλύεται η σημασία και τα οφέλη τους όπως επίσης και οι περιορισμοί τους.
description: The scopus of this thesis was the approach of a dynamic model that predicts the concentration of an adsorbed pollutant on sediment particles versus time using linear correlations amongst equilibrium parameters and the initial pollutant concentration. Through the dynamic concentrations an estimation of the environmental exposure of various receivers to the pollutant will then be plausible. Furthermore, a brief review related to the existing models that are used on Risk Assessment of chemicals is presented as well as their benefits and limitations.
Direct images of bundles under Frobenius morphisms
Creators: name: Sun, Xiaotao
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14H60, 14D20, 13A35

description: Let $X$ be a smooth projective variety of dimension $n$ over an algebraically closed field $k$ with ${\rm char}(k)=p>0$ and $F:X\to X_1$ be the relative Frobenius morphism. For any vector bundle $W$ on $X$, we prove that instability of $F_*W$ is bounded by instability of $W\otimes{\rm T}^{\ell}(Ω^1_X)$ ($0\le \ell\le n(p-1)$)(Corollary \ref{cor3.8}). When $X$ is a smooth projective curve of genus $g\ge 2$, it implies $F_*W$ being stable whenever $W$ is stable.
description: the final version to appear in Invent. math. (2008)
Avoiding the Seventy Year Itch: 'Transformative' Open Access via Diamond Funding Models
Creators: name: Hopkins, Kira
name: Harris-Birtill, Rose
Publisher: name: Zenodo
Year: 2025
Subjects: subject: Publishing
subject: Journals
subject: Books
subject: Higher education
subject: Open Access Publishing

description: This presentation was delivered at the Researcher to Reader (R2R) Conference, 25-26 February 2025. 

Speakers:Dr Kira HOPKINS, Scholarly Publishing Outreach Officer at Copim Open Book FuturesDr Rose HARRIS-BIRTILL, Editorial Director at Open Library of Humanities (online)

Abstract: The Jisc review of transitional agreements, and its 70-year transformation estimate, necessitates rethinking current approaches to OA journal funding. OA book publishers have had to grapple with the funding question later than journals due to slower policy changes, taking different approaches (outside of BPCs), including various collective/subscription models that support Diamond OA. We outline some of these approaches, and how they can be used to help publishers work collaboratively with libraries to fund journals equitably. We present the Open Library of Humanities as an established, sustainable case study for how this can – and does – work for journals. 
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.
The Slow X-Ray Expansion of the Northwestern Rim of the Supernova Remnant RX J0852.0-4622
Creators: name: Katsuda, S.
name: Tsunemi, H.
name: Mori, K.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The detection of radioactive decay line of 44Ti provides a unique evidence that the gamma-ray source is a young (< 1,000 yr) supernova remnant because of its short lifetime of about 90 yr. Only two Galactic remnants, Cassiopeia A and RX J0852.0-4622, are hitherto reported to be the 44Ti line emitter, although the detection from the latter has been debated. Here we report on an expansion measurement of the northwestern rim of RX J0852.0-4622 obtained with X-ray observations separated by 6.5 yr. The expansion rate is derived to be 0.023+/-0.006% that is about five times lower than those of young historical remnants. Such a slow expansion suggests that RX J0852.0-4622 is not a young remnant as has been expected. We estimate the age of 1,700-4,300 yr of this remnant depending on its evolutionary stage. Assuming a high shock speed of about 3000 km/sec, which is suggested by the detection of non-thermal X-ray radiation, the distance of about 750 pc to this remnant is also derived.
description: 12 pages, 3 figures, Accepted for publication in the Astrophysical Journal Letters