cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Macroscopic phase resetting-curves determine oscillatory coherence and signal transfer in inter-coupled neural circuits
Creators: name: Dumont, Gregory
name: Gutkin, Boris
Publisher: name: arXiv
Year: 2018
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Biological sciences

description: Macroscopic oscillations of different brain regions show multiple phase relationships that are persistent across time and have been implicated routing information. Various cellular level mechanisms influence the network dynamics and structure the macroscopic firing patterns. Key question is to identify the biophysical neuronal and synaptic properties that permit such motifs to arise and how the different coherence states determine the communication between the neural circuits. We analyse the emergence of phase locking within bidirectionally delayed-coupled spiking circuits showing global gamma band oscillations. We consider both the interneuronal (ING) and the pyramidal-interneuronal (PING) gamma rhythms and the inter coupling targeting the pyramidal or the inhibitory interneurons. Using a mean-field approach together with an exact reduction method, we break down each spiking network into a low dimensional nonlinear system and derive the macroscopic phase resetting-curves (mPRCs) that determine how the phase of the global oscillation responds to incoming perturbations. Depending on the type of gamma oscillation, we show that incoming excitatory inputs can either only speed up the oscillation (phase advance; type I PRC) or induce both an advance and a delay the macroscopic oscillation (phase delay; type II PRC). From there we determine the structure of macroscopic coherence states (phase locking) of two weakly synaptically-coupled networks. To do so we derive a phase equation for the coupled system which links the synaptic mechanisms to the coherence state of the system. We show that the transmission delay is a necessary condition for symmetry breaking, i.e. a non-symmetric phase lag between the macroscopic oscillations, potentially giving an explanation to the experimentally observed variety of gamma phase-locking modes.
description: 35 pages, 9 figures
Field theory models for variable cosmological constant
Creators: name: Dvali, Gia
name: Vilenkin, Alexander
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: Anthropic solutions to the cosmological constant problem require seemingly unnatural scalar field potentials with a very small slope or domain walls (branes) with a very small coupling to a four-form field. Here we introduce a class of models in which the smallness of the corresponding parameters can be attributed to a spontaneously broken discrete symmetry. We also demonstrate the equivalence of scalar field and four-form models. Finally, we show how our models can be naturally embedded into a left-right extension of the standard model.
description: A reference added
Quantum Monte Carlo Study of an Extended Hubbard Model on a Two-leg Ladder
Creators: name: Munehisa, Tomo
name: Munehisa, Yasuko
Publisher: name: arXiv
Year: 1997
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: An extended Hubbard model on a two-leg ladder is numerically studied by means of the quantum Monte Carlo techniques. The model we study has the nearest-neighbor interactions which are repulsive along chains and attractive for rungs. The plots of the doping parameter versus the chemical potential show two cliff-like regions and a large plateau region. Results on the charge susceptibility suggest it diverges in these cliff-like regions. These observations might imply a signal to the phase separation, which should be related to the effective attractive interactions along chains.
description: 12 pages, latex, 5 eps figures, to appear in J. Phys. Soc. Jpn. In order to make our discussions abundantly clear we added one figure and rewrote the section 4. A few references are also added
Inflation and Large Internal Dimensions
Creators: name: Kaloper, Nemanja
name: Linde, Andrei
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: We consider some aspects of inflation in models with large internal dimensions. If inflation occurs on a 3D wall after the stabilization of internal dimensions in the models with low unification scale (M ~ 1 TeV), the inflaton field must be extremely light. This problem may disappear In models with intermediate (M ~10^{11} GeV) to high (M ~ 10^{16} GeV) unification scale. However, in all of these cases the wall inflation does not provide a complete solution to the horizon and flatness problems. To solve them, there must be a stage of inflation in the bulk before the compactification of internal dimensions.
description: 4 pages, revtex, minor modifications
Generic spectral properties of right triangle billiards
Creators: name: Gorin, T.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: This article presents a new method to calculate eigenvalues of right triangle billiards. Its efficiency is comparable to the boundary integral method and more recently developed variants. Its simplicity and explicitness however allow new insight into the statistical properties of the spectra. We analyse numerically the correlations in level sequences at high level numbers (>10^5) for several examples of right triangle billiards. We find that the strength of the correlations is closely related to the genus of the invariant surface of the classical billiard flow. Surprisingly, the genus plays and important role on the quantum level also. Based on this observation a mechanism is discussed, which may explain the particular quantum-classical correspondence in right triangle billiards. Though this class of systems is rather small, it contains examples for integrable, pseudo integrable, and non integrable (ergodic, mixing) dynamics, so that the results might be relevant in a more general context.
description: 18 pages, 8 eps-figures, revised: stylistic changes, improved presentation
Chaos around the superposition of a black-hole and a thin disk
Creators: name: Saa, Alberto
name: Venegeroles, Roberto
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Motivated by the strong astronomical evidences supporting that huge black-holes might inhabit the center of many active galaxies, we have studied the integrability of oblique orbits of test particles around the exact superposition of a black-hole and a thin disk. We have considered the relativistic and the Newtonian limits. Exhaustive numerical analyses were performed, and bounded zones of chaotic behavior were found for both limits. An intrinsic relativistic gravitational effect is detected: the chaoticity of trajectories that do not cross the disk.
description: Revtex, 13 pages, 3 figures
Highly efficient electromagnetic emission during 100 keV electron beam relaxation in a thin magnetized plasma
Creators: name: Annenkov, V. V.
name: Timofeev, I. V.
name: Volchok, E. P.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: In this paper, electromagnetic emissions produced by a beam-plasma system are investigated using particle-in-cell simulations for the particular case when the typical transverse size of both 100 keV electron beam and produced plasma channel is comparable to the radiation wavelength. The interest in this regime of beam-plasma interaction is associated with highly efficient generation of electromagnetic waves near the plasma frequency harmonics that has been recently observed in laboratory experiments on the GOL-3 mirror trap. It has been found that the radiation power only from the vicinity of the doubled plasma frequency in these experiments can reach 1% of the total beam power. Subsequent theoretical and simulation studies have shown that the most likely candidate for explaining such efficient generation of electromagnetic radiation is the mechanism of a beam-driven plasma antenna based on the conversion of the most unstable plasma oscillations on a longitudinal density modulation of plasma ions. In this paper, we investigate how effectively this mechanism can work in a real experiment at the GOL-3 facility, when a thin sub-relativistic electron beam gets a large angular spread due to compression by a magnetic field, and the gas into which it is injected has macroscopic density gradients.
Flavor Energy uncertainty relations for neutrino oscillations in quantum field theory
Creators: name: Blasone, Massimo
name: Jizba, Petr
name: Smaldone, Luca
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the context of quantum field theory, we derive flavor energy uncertainty relations for neutrino oscillations. By identifying the non conserved flavor charges with the clock observables, we arrive at the Mandelstam Tamm version of time energy uncertainty relations. In the ultrarelativistic limit these relations yield the well known condition for neutrino oscillations. Ensuing non relativistic corrections to the latter are explicitly evaluated. The analogy among flavor states and unstable particles and a novel interpretation of our uncertainty relations, based on the unitary inequivalence of Fock spaces for flavor and massive neutrinos, are also discussed.
description: 5 pages
Dolichopus migrans Zetterstedt 1843
Creators: name: Grichanov, I. Ya.
name: Selivanova, O. O.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Dolichopodidae
Dolichopus
Dolichopus migrans

description: Dolichopus migrans Zetterstedt, 1843
DISTRIBUTION. Europe, Russia (European part, Siberia, Kamchatka, Magadan, Primorsky Krai, Kuriles), Kazakhstan. This species was recorded from Kuriles without definite locality (Negrobov, 1991: 108).
description: Published as part of Grichanov, I. Ya. & Selivanova, O. O., 2022, The long-legged flies (Diptera: Dolichopodidae) from Kurile Islands, with description of a new species of the genus Sciapus Zeller, 1842, pp. 7-24 in Far Eastern Entomologist 445 on page 11, DOI: 10.25221/fee.445.2, http://zenodo.org/record/7166752
Supersymmetric Phase Transitions and Gravitational Waves at LISA
Creators: name: Apreda, R.
name: Maggiore, M.
name: Nicolis, A.
name: Riotto, A.
Publisher: name: arXiv
Year: 2001
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Gravitational waves generated during a first-order electroweak phase transition have a typical frequency which today falls just within the band of the planned space interferometer LISA. Contrary to what happens in the Standard Model, in its supersymmetric extensions the electroweak phase transition may be strongly first order, providing a mechanism for generating the observed baryon asymmetry in the Universe. We show that during the same transition the production of gravitational waves can be rather sizable. While the energy density in gravitational waves can reach at most $h_0^2 Ω_{\rm gw}\simeq 10^{-16}$ in the Minimal Supersymmetric Standard Model, in the Next-to-Minimal Supersymmetric Model, in some parameter range, $h_0^2 Ω_{\rm gw}$ can be as high as $4\times 10^{-11}$. A stochastic background of gravitational waves of this intensity is within the reach of the planned sensitivity of LISA. Since in the Standard Model the background of gravitational waves is totally neglegible, its detection would also provide a rather unexpected experimental signal of supersymmetry and a tool to descriminate among supersymmetric models with different Higgs content.
description: 4 pages, 5 figures
Dolichopus pennatus Meigen 1824
Creators: name: Grichanov, I. Ya.
name: Selivanova, O. O.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Dolichopodidae
Dolichopus
Dolichopus pennatus

description: Dolichopus pennatus Meigen, 1824
DISTRIBUTION. Europe, Russia (European part, Siberia, Far East), Turkey, Mongolia.
This species was recorded from Kuriles without definite locality (Negrobov, 1991: 111).
description: Published as part of Grichanov, I. Ya. & Selivanova, O. O., 2022, The long-legged flies (Diptera: Dolichopodidae) from Kurile Islands, with description of a new species of the genus Sciapus Zeller, 1842, pp. 7-24 in Far Eastern Entomologist 445 on page 12, DOI: 10.25221/fee.445.2, http://zenodo.org/record/7166752
Simple Exactly Solvable Models of non-Fermi Liquids
Creators: name: Lidsky, D.
name: Shiraishi, J.
name: Hatsugai, Y.
name: Kohmoto, M.
Publisher: name: arXiv
Year: 1997
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We generalize the model of Hatsugai and Kohmoto [J. Phys. Soc. Jpn, 61, 2056 (1992)] and find ground states which do not show the properties of Fermi liquids. We work in two space dimensions, but it is straightforward to generalize to higher dimensions. The ground state is highly degenerate and there is no discontinuity in the momentum distribution; i.e., there is no Fermi surface. The Green's function generically has a branch cut.
description: Revtex
Domain wall interacting with a black hole: A new example of critical phenomena
Creators: name: Frolov, V. P.
name: Larsen, A. L.
name: Christensen, M.
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 study a simple system that comprises all main features of critical gravitational collapse, originally discovered by Choptuik and discussed in many subsequent publications. These features include universality of phenomena, mass-scaling relations, self-similarity, symmetry between super-critical and sub-critical solutions, etc. The system we consider is a stationary membrane (representing a domain wall) in a static gravitational field of a black hole. For a membrane that spreads to infinity, the induced 2+1 geometry is asymptotically flat. Besides solutions with Minkowski topology there exists also solutions with the induced metric and topology of a 2+1 dimensional black hole. By changing boundary conditions at infinity, one finds that there is a transition between these two families. This transition is critical and it possesses all the above-mentioned properties of critical gravitational collapse. It is remarkable that characteristics of this transition can be obtained analytically. In particular, we find exact analytical expressions for scaling exponents and wiggle-periods. Our results imply that black hole formation as a critical phenomenon is far more general than one might expect.
description: 23 pages, 5 postscript figures included
Two Open Universes Connected by a Wormhole: Exact Solutions
Creators: name: Li, Li-Xin
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: FOS: Physical sciences

description: In this paper I present a spacetime of two open universes connected by a Lorentzian wormhole. The spacetime has the following features: (1) It can exactly solve the Einstein equations; (2) The weak energy condition is satisfied everywhere; (3) It has a topology of R^2\times T_g (g\ge 2); (4) It has no event horizons.
description: 10 pages, latex
A Microscopic Recoil Model for Light-Cone Fluctuations in Quantum Gravity
Creators: name: Ellis, John
name: Mavromatos, N. E.
name: Nanopoulos, D. V.
Publisher: name: arXiv
Year: 1999
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: We present a microscopic model for light-cone fluctuations ``in vacuo'', which incorporates a treatment of quantum-gravitational recoil effects induced by energetic particles. Treating defects in space-time as solitons in string theory, we derive an energy-dependent refractive index and a stochastic spread in the arrival times of mono-energetic photons due to quantum diffusion through space-time foam, as found previously using an effective Born-Infeld action. Distant astrophysical sources provide sensitive tests of these possible quantum-gravitational phenomena.
description: 4 pages revtex no figures
Estimating the Milky Way's Mass via Hierarchical Bayes: A Blind Test on MUGS2 Simulated Galaxies
Creators: name: Eadie, Gwendolyn M.
name: Keller, Benjamin W.
name: Harris, William E.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: In a series of three papers, Eadie et al. developed a hierarchical Bayesian method to estimate the Milky Way Galaxy's mass given a physical model for the potential, a measurement model, and kinematic data of test particles such as globular clusters (GCs) or halo stars in the Galaxy's halo. The Galaxy's virial mass was found to have a 95\% Bayesian credible region (c.r.) of $(0.67, 1.09) \times 10^{12} M_{\odot}$. In the present study, we test the hierarchical Bayesian method against simulated galaxies created in the McMaster Unbiased Galaxy Simulations 2 (MUGS2), for which the true mass is known. We estimate the masses of MUGS2 galaxies using GC analogs from the simulations as tracers. The analysis, completed as a blind test, recovers the true $M_{200}$ of the MUGS2 galaxies within 95\% Bayesian c.r. in 8 out of 18 cases. Of the 10 galaxy masses that were not recovered within the 95\% c.r., a large subset have posterior distributions that occupy extreme ends of the parameter space allowed by the priors. A few incorrect mass estimates are explained by the exceptional evolution history of the galaxies. We also find evidence that the model cannot describe both the galaxies' inner and outer structure simultaneously in some cases. After removing the GC analogs associated with the galactic disks, the true masses were found more reliably (13 out of 18 were predicted within the c.r.). Finally, we discuss how representative the GC analogs are of the real GC population in the Milky Way.
description: Published in ApJ. 17 pages, 12 figures, 4 tables
A Quantum Monte Carlo Method and Its Applications to Multi-Orbital Hubbard Models
Creators: name: Motome, Yukitoshi
name: Imada, Masatoshi
Publisher: name: arXiv
Year: 1997
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a framework of an auxiliary field quantum Monte Carlo (QMC) method for multi-orbital Hubbard models. Our formulation can be applied to a Hamiltonian which includes terms for on-site Coulomb interaction for both intra- and inter-orbitals, intra-site exchange interaction and energy differences between orbitals. Based on our framework, we point out possible ways to investigate various phase transitions such as metal-insulator, magnetic and orbital order-disorder transitions without the minus sign problem. As an application, a two-band model is investigated by the projection QMC method and the ground state properties of this model are presented.
description: 10 pages LaTeX including 2 PS figures, to appear in J.Phys.Soc.Jpn
Dolichopus sidorenkoi Negrobov, Maslova et Selivanova 2011
Creators: name: Grichanov, I. Ya.
name: Selivanova, O. O.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Dolichopodidae
Dolichopus
Dolichopus sidorenkoi

description: Dolichopus sidorenkoi Negrobov, Maslova et Selivanova, 2011
 DISTRIBUTION. Endemic to Shumshu Island (Negrobov et al., 2011).
description: Published as part of Grichanov, I. Ya. & Selivanova, O. O., 2022, The long-legged flies (Diptera: Dolichopodidae) from Kurile Islands, with description of a new species of the genus Sciapus Zeller, 1842, pp. 7-24 in Far Eastern Entomologist 445 on page 13, DOI: 10.25221/fee.445.2, http://zenodo.org/record/7166752
Short-range plasma model for intermediate spectral statistics
Creators: name: Bogomolny, E.
name: Gerland, U.
name: Schmit, C.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We propose a plasma model for spectral statistics displaying level repulsion without long-range spectral rigidity, i.e. statistics intermediate between random matrix and Poisson statistics similar to the ones found numerically at the critical point of the Anderson metal-insulator transition in disordered systems and in certain dynamical systems. The model emerges from Dysons one-dimensional gas corresponding to the eigenvalue distribution of the classical random matrix ensembles by restricting the logarithmic pair interaction to a finite number $k$ of nearest neighbors. We calculate analytically the spacing distributions and the two-level statistics. In particular we show that the number variance has the asymptotic form $Σ^2(L)\simχL$ for large $L$ and the nearest-neighbor distribution decreases exponentially when $s\to \infty$, $P(s)\sim\exp (-Λs)$ with $Λ=1/χ=kβ+1$, where $β$ is the inverse temperature of the gas ($β=$1, 2 and 4 for the orthogonal, unitary and symplectic symmetry class respectively). In the simplest case of $k=β=1$, the model leads to the so-called Semi-Poisson statistics characterized by particular simple correlation functions e.g. $P(s)=4s\exp(-2s)$. Furthermore we investigate the spectral statistics of several pseudointegrable quantum billiards numerically and compare them to the Semi-Poisson statistics.
description: 24 pages, 4 figures
Dynamical Instabilities of the Randall-Sundrum Model
Creators: name: Boehm, Timon
name: Durrer, Ruth
name: van de Bruck, Carsten
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: FOS: Physical sciences

description: We derive dynamical equations to describe a single 3-brane containing fluid matter and a scalar field coupling to the dilaton and the gravitational field in a five dimensional bulk. First, we show that a scalar field or an arbitrary fluid on the brane cannot evolve to cancel the cosmological constant in the bulk. Then we show that the Randall-Sundrum model is unstable under small deviations from the fine-tuning between the brane tension and the bulk cosmological constant and even under homogeneous gravitational perturbations. Implications for brane world cosmologies are discussed.
description: 12 pages, 2 figures
Dolichopus stackelbergi Smirnov 1948
Creators: name: Grichanov, I. Ya.
name: Selivanova, O. O.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Dolichopodidae
Dolichopus
Dolichopus stackelbergi

description: Dolichopus stackelbergi Smirnov, 1948
DISTRIBUTION. This species was described from Primorsky Krai of Russia and was recorded from Kuriles without definite locality (Negrobov, 1991: 116).
description: Published as part of Grichanov, I. Ya. & Selivanova, O. O., 2022, The long-legged flies (Diptera: Dolichopodidae) from Kurile Islands, with description of a new species of the genus Sciapus Zeller, 1842, pp. 7-24 in Far Eastern Entomologist 445 on page 13, DOI: 10.25221/fee.445.2, http://zenodo.org/record/7166752
Geodesic Completeness of Orthogonally Transitive Cylindrical Spacetimes
Creators: name: Fernandez-Jambrina, Leonardo
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper a theorem is derived in order to provide a wide sufficient condition for an orthogonally transitive cylindrical spacetime to be singularity-free. The applicability of the theorem is tested on examples provided by the literature that are known to have regular curvature invariants.
description: 9 pages, to appear in Journal of Mathematical Physics
Density of Superfluid Helium Droplets
Creators: name: Harms, Jan
name: Toennies, J. Peter
name: Dalfovo, Franco
Publisher: name: arXiv
Year: 1997
Subjects: subject: Condensed Matter (cond-mat)
subject: FOS: Physical sciences

description: The classical integral cross sections of large superfluid 4He_N droplets and the number of atoms in the droplets (N=10^3-10^4) have been measured in molecular beam scattering experiments. These measurements are found to be in good agreement with the cross sections predicted from density functional calculations of the radial density distributions with a 10-90 % surface thickness of 5.7Å. By using a simple model for the density profile of the droplets a thickness of about 6-8Åis extracted directly from the data.
description: 27 pages, REVTeX, 5 postscript figures
Large N wormhole approach to spacetime foam
Creators: name: Garattini, Remo
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: A simple model of spacetime foam, made by $N$ wormholes in a semiclassical approximation, is taken under examination. We show that the qualitative behaviour of the fluctuation of the metric conjectured by Wheeler is here reproduced.
description: Revtex 3.0, 12 pages, accepted in Phys. Lett. B, Acknowledgements included
On the topology and area of higher dimensional black holes
Creators: name: Cai, Mingliang
name: Galloway, Gregory J.
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: Over the past decade there has been an increasing interest in the study of black holes, and related objects, in higher (and lower) dimensions, motivated to a large extent by developments in string theory. The aim of the present paper is to obtain higher dimensional analogues of some well known results for black holes in 3+1 dimensions. More precisely, we obtain extensions to higher dimensions of Hawking's black hole topology theorem for asymptotically flat ($Λ=0$) black hole spacetimes, and Gibbons' and Woolgar's genus dependent, lower entropy bound for topological black holes in asymptotically locally anti-de Sitter ($Λ<0$) spacetimes. In higher dimensions the genus is replaced by the so-called $σ$-constant, or Yamabe invariant, which is a fundamental topological invariant of smooth compact manifolds.
description: 15 pages, Latex2e; typos corrected, a convention clarified, resulting in the simplification of certain formulas, other improvements
Cyclotron lines in highly magnetized neutron stars
Creators: name: Staubert, R.
name: Trümper, J.
name: Kendziorra, E.
name: Klochkov, D.
name: Postnov, K.
name: Kretschmar, P.
name: Pottschmidt, K.
name: Haberl, F.
name: Rothschild, R. E.
name: Santangelo, A.
name: Wilms, J.
name: Kreykenbohm, I.
name: Fürst, F.
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Cyclotron lines, also called cyclotron resonant scattering features (CRSF) are spectral features, generally appearing in absorption, in the X-ray spectra of objects containing highly magnetized neutron stars, allowing the direct measurement of the magnetic field strength in these objects. Cyclotron features are thought to be due to resonant scattering of photons by electrons in the strong magnetic fields. The main content of this contribution focusses on electron cyclotron lines as found in accreting X-ray binary pulsars (XRBP) with magnetic fields on the order of several 1012 Gauss. Also, possible proton cyclotron lines from single neutron stars with even stronger magnetic fields are briefly discussed.With regard to electron cyclotron lines, we present an updated list of XRBPs that show evidence of such absorption lines. The first such line was discovered in a 1976 balloon observation of the accreting binary pulsar Hercules X-1, it is considered to be the first direct measurement of the magnetic field of a neutron star. As of today (mid 2018), we list 36 XRBPs showing evidence of one ore more electron cyclotron absorption line(s). A few have been measured only once and must be confirmed (several more objects are listed as candidates). In addition to the Tables of objects, we summarize the evidence of variability of the cyclotron line as a function of various parameters (especially pulse phase, luminosity and time), and add a discussion of the different observed phenomena and associated attempts of theoretical modeling. We also discuss our understanding of the underlying physics of accretion onto highly magnetized neutron stars. For proton cyclotron lines, we present tables with seven neutron stars and discuss their nature and the physics in these objects.
description: 32 pages, 15 figures, 8 Tables, accepted by A&A 2018
A geometric approach to singularity confinement and algebraic entropy
Creators: name: Takenawa, Tomoyuki
Publisher: name: arXiv
Year: 2000
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: A geometric approach to the equation found by Hietarinta and Viallet, which satisfies the singularity confinement criterion but exhibits chaotic behavior, is presented. It is shown that this equation can be lifted to an automorphism of a certain rational surface and can therefore be considered to be the action of an extended Weyl group of indefinite type. A method to calculate its algebraic entropy by using the theory of intersection numbers is presented.
description: 9 pages, 1 figure, LaTeX file
Single-exterior black holes
Creators: name: Louko, Jorma
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: We discuss quantum properties of the single-exterior, geon-type black (and white) holes that are obtained from the Kruskal spacetime and the spinless Banados-Teitelboim-Zanelli hole via a quotient construction that identifies the two exterior regions. For the four-dimensional geon, the Hartle-Hawking type state of a massless scalar field is thermal in a limited sense, but there is a discrepancy between Lorentzian and Riemannian derivations of the geon entropy. For the three-dimensional geon, the state induced for a free conformal scalar field on the conformal boundary is similarly thermal in a limited sense, and the correlations in this state provide support for the holographic hypothesis in the context of asymptotically anti-de Sitter black holes in string theory.
description: 16 pages, LaTeX with cl2emult.cls, 6 eps figures. (Lectures at the XXXV Karpacz Winter School)
Topological asymmetry in the damping-pairing contribution of electron-boson scattering
Creators: name: Varelogiannis, Georgios
name: Peter, Martin
Publisher: name: arXiv
Year: 1997
Subjects: subject: Condensed Matter (cond-mat)
subject: FOS: Physical sciences

description: We make a harmonic analysis of the pairing and damping contribution of a finite $k$ range isotropic electron-phonon (or other boson) scattering in an anisotropic two-dimensional electronic system. We show that the pairing contribution of the anisotropic part of the electronic system can be much larger than its damping contribution enhancing significantly T_c. The higher is the order of the harmonic of the electronic anisotropy, smaller is its damping contribution and higher can be the asymmetry in its damping-pairing contribution. This could explain the puzzle of a much broader quasiparticle peak in the n-doped than in the p-doped cuprates, their smaller T_c's being also attributed to larger damping effects.
description: LATEX file and 3 Postscript figures
Dualities versus Singularities
Creators: name: Banks, Tom
name: Fischler, Willy
name: Motl, Lubos
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 show that a subgroup of the modular group of M-theory compactified on a ten torus, implies the Lorentzian structure of the moduli space, that is usually associated with naive discussions of quantum cosmology based on the low energy Einstein action. This structure implies a natural division of the asymptotic domains of the moduli space into regions which can/cannot be mapped to Type II string theory or 11D Supergravity (SUGRA) with large radii. We call these the safe and unsafe domains. The safe domain is the interior of the future light cone in the moduli space while the unsafe domain contains the spacelike region and the past light cone. Within the safe domain, apparent cosmological singularities can be resolved by duality transformations and we briefly provide a physical picture of how this occurs. The unsafe domains represent true singularities where all field theoretic description of the physics breaks down. They violate the holographic principle. We argue that this structure provides a natural arrow of time for cosmology. All of the Kasner solutions, of the compactified SUGRA theory interpolate between the past and future light cones of the moduli space. We describe tentative generalizations of this analysis to moduli spaces with less SUSY.
description: JHEP LaTeX, 23 pages, 1 eps-figure. Five references, a paragraph at the beginning of section 3 and an appendix added
The Coupling of Gravity to Spin and Electromagnetism
Creators: name: Finster, Felix
name: Smoller, Joel
name: Yau, Shing-Tung
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The coupled Einstein-Dirac-Maxwell equations are considered for a static, spherically symmetric system of two fermions in a singlet spinor state. Stable soliton-like solutions are shown to exist, and we discuss the regularizing effect of gravity from a Feynman diagram point of view.
description: 5 pages, LaTeX, 2 figures
the contribution of traditional elders in conflict resolution and peacebuilding in Banadir region, Somalia 1991 – 2016 in Somalia
Creators: name: Said, Abdi Bare
Publisher: name: Zenodo
Year: 2025
Subjects: the contribution
traditional elders
in conflict resolution and
peacebuilding in Banadir region, Somalia 1991 – 2016 in Somalia

description: ABSTRACT

In Somalia, the phenomenon of conflicts has been persistent since the collapse of Said Abdi Barreregime in 1991. Peace building initiatives by international, national and local actors have intervened atdifferent levels to address these conflicts. Existing research into peace building and reconciliation has marginally discussed roles of traditional elders in the Banadir region of Somalia. This study examined the contribution of traditional elders in conflict resolution and peace building in the Banadir region, Somalia, 1991 - 2016. The main objectives of the study were to examine the role of elders in the reconciliation and mediation process in the Banadir region of Somalia, 1991 - to 2004, to discuss peace-building initiatives led by elders in the Banadir region, Somalia, 2005 - 2016, and finally, to assess the challenges faced by elders in conflict resolution and peace building in Banadir region of Somalia, 1991 - 2016. Mediation theory and conflict transformation theory were used to analyze andpresent data. The study used a descriptive research design. The target population of this research were; traditional elders, religious leaders, civil society leaders, youth and government officers. In this study, the respondents were chosen based on non-probability sampling procedure, notably purposive sampling. The study established that since 1991 traditional elders immensely contributed to peace building in Banadir region, Somalia. The study established that the greatest challenge traditional elders experience in peace building was the inability of the elders to enforce agreements reached during conflict reconciliation among groups who were in conflict. This study recommends that the federal government of Somalia develop and enact a policy and or legislative framework that provide enforcement mechanisms for peace building processes enacted by Traditional elders.
Exact Results for the BTZ Black Hole
Creators: name: Birmingham, Danny
name: Sachs, Ivo
name: Sen, Siddhartha
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: In this review, we summarize exact results for the three-dimensional BTZ black hole. We use rigorous mathematical results to clarify the general structure and properties of this black hole spacetime and its microscopic description. In particular, we study the formation of the black hole by point particle collisions, leading to an exact analytic determination of the Choptuik scaling parameter. We also show that a `No Hair Theorem' follows immediately from a mathematical theorem of hyperbolic geometry, due to Sullivan. A microscopic understanding of the Bekenstein-Hawking entropy, and decay rate for massless scalars, is shown to follow from standard results of conformal field theory.
description: 24 pages, Latex, Review article to appear in Int. J. Mod. Phys. D, v2 additional references
Classical and Quantum Hamiltonian Ratchets
Creators: name: Schanz, Holger
name: Otto, Marc-Felix
name: Ketzmerick, Roland
name: Dittrich, Thomas
Publisher: name: arXiv
Year: 2000
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We explain the mechanism leading to directed chaotic transport in Hamiltonian systems with spatial and temporal periodicity. We show that a mixed phase space comprising both regular and chaotic motion is required and derive a classical sum rule which allows to predict the chaotic transport velocity from properties of regular phase-space components. Transport in quantum Hamiltonian ratchets arises by the same mechanism as long as uncertainty allows to resolve the classical phase-space structure. We derive a quantum sum rule analogous to the classical one, based on the relation between quantum transport and band structure.
description: published version
A time varying speed of light as a solution to cosmological puzzles
Creators: name: Albrecht, Andreas
name: Magueijo, Joao
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the cosmological implications of light travelling faster in the early Universe. We propose a prescription for deriving corrections to the cosmological evolution equations while the speed of light $c$ is changing. We then show how the horizon, flatness, and cosmological constant problems may be solved. We also study cosmological perturbations in this scenario and show how one may solve the homogeneity and isotropy problems. As it stands, our scenario appears to most easily produce extreme homogeneity, requiring structure to be produced in the Standard Big Bang epoch. Producing significant perturbations during the earlier epoch would require a rather careful design of the function $c(t)$. The large entropy inside the horizon nowadays can also be accounted for in this scenario.
description: To be published in Physical Review D. Note added referring to John Moffat's early work on VSL theories
Corner Transfer Matrix Algorithm for Classical Renormalization Group
Creators: name: Nishino, Tomotoshi
name: Okunishi, Kouichi
Publisher: name: arXiv
Year: 1997
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We report a real-space renormalization group (RSRG) algorithm, which is formulated through Baxter's corner transfer matrix (CTM), for two-dimensional (d = 2) classical lattice models. The new method performs the renormalization group transformation according to White's density matrix algorithm, so that variational free energies are minimized within a restricted degree of freedom m. As a consequence of the renormalization, spin variables on each corner of CTM are replaced by a m-state block spin variable. It is shown that the thermodynamic functions and critical exponents of the q = 2, 3 Potts models can be precisely evaluated by use of the renormalization group method.
description: 20 pages, 10 ps figures, JPSJ style files are included
Gauge Invariances and Phases of Massive Higher Spins in (A)dS
Creators: name: Deser, S.
name: Waldron, A.
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: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The (m^2,Λ) plane of spin s>1 massive fields in (A)dS backgrounds is shown to consist of separate phases, divided by lines of novel ``partially massless'' gauge theories that successively remove helicities, starting from the lowest, 0 or +/-(1/2). The norms of the excluded states flip as the gauge lines are crossed and only the region containing the massive Minkowski theory is unitary. The partially massless gauge theories are unitary or not, depending on the ordering of the gauge lines. This ``level splitting'' of massless Minkowski gauge theories is specific to non-zero Λ.
description: 10 pages, LaTeX
Twisted spinors on Schwarzschild and Reissner-Nordstrom black holes
Creators: name: Goncharov, Yu. P.
Publisher: name: arXiv
Year: 1999
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We describe twisted configurations of spinor field on the Schwarzschild and Reissner-Nordström black holes that arise due to existence of the twisted spinor bundles over the standard black hole topology. From a physical point of view the appearance of spinor twisted configurations is linked with the natural presence of Dirac monopoles that play the role of connections in the complex line bundles corresponding to the twisted spinor bundles. Possible application to the Hawking radiation is also outlined.
description: 10 pages, LaTeX with using elsart.sty
Cosmologies with Varying Light-Speed
Creators: name: Barrow, John D.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We analyse a generalisation of general relativity that incorporates a cosmic time-variation of the velocity of light in vacuum, $c,$ and the Newtonian gravitation 'constant', $G,$ proposed by Albrecht and Maguejo. We find exact solutions for Friedmann universes and determine the rate of variation of $c$ required to solve the flatness and classical cosmological constant problems. Potential problems with this approach to the resolution of the flatness and classical cosmological constant problems are highlighted. Reformulations are suggested which give the theory a more desirable limit as a theory of varying $G$ in the limit of constant $c$ and its relationship to theories with varying electron charge and constant $c$ are discussed.
description: latex file. 19 pages
$E\otimes e$ Jahn-Teller Effect in $C_{70}^{3-}$ Systems
Creators: name: Tian, Lin
name: Yi, Ya-Sha
name: Wang, Chui-Lin
name: Su, Zhao-Bin
Publisher: name: arXiv
Year: 1997
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The electron-phonon interaction in $C_{70}$ anions is studied by making use of a lattice relaxation approach. We find there exists a Jahn-Teller effect in $C_{70}^{3-}$ system, due to an extra electron being doped to the double degenerate $E_{1}^{''}$ state. As a result of this effect, the original $D_{5h}$ symmetry of the ground state becomes unstable, which causes distortion of the lattice configuration. The only symmetry maintained in the final state of the relaxation is the $x-y$ plane reflection symmetry. We further find that besides the Jahn-Teller active $A_{1}^{'}, A_{2}^{'}, E_{2}^{'}$ modes, the non-Jahn-Teller active $E_{1}^{'}$ vibrations also contribute to the relaxation process, which come from the nonlinear effect and are two or three orders smaller than those of the Jahn-Teller active modes. We suggest that the $C_{70}^{3-}$ molecule is a promising Berry Phase candidate in this effective $E \otimes e$ Jahn-Teller system.
description: 14 pages, to appear in Mod. Phys. Lett. B (1997)
Replacing Biot – An Energy-Conserved Model of Poroelasticity
Creators: name: biot-bazant, figshare admin
name: Couples, Gary
Publisher: name: The Biot-Bazant Conference
Year: 2021
Subjects: subject: 91402 Geomechanics and Resources Geotechnical Engineering
subject: FOS: Environmental engineering
subject: Mechanics

description: This publication is part of the proceedings of the Biot-Bažant Conference on Engineering Mechanics and Physics of Porous Materials, which took place virtually on June 1-3, 2021. It contains a one-page abstract and the video of the talk that was given at the conference.
D7.1 Impact Master Plan
Creators: name: AUSTRALO
Publisher: name: Zenodo
Year: 2023

description: This deliverable outlines the planning of the dissemination, communication, exploitation and standardisation strategies for the EXA4MIND Horizon Europe project. This planning will be of relevance throughout the duration of the project and will be revisited periodically as it progresses.

EXA4MIND is an initiative funded by the European Union’s Horizon Europe Research and Innovation programme under grant agreement N° 101092944
HERA for AIAA Electrified Aircraft Technologies Intergation
Creators: name: Ascione, Vittorio
name: Digiulio, Massimiliano
name: Piscopo, Giuseppe
Publisher: name: Zenodo
Year: 2025

description: The year 2025 began with a notable event for HERA—the AIAA SciTech Forum in Orlando, FL. The Clean Aviation Special Session on "Innovative Aircraft Concepts and Novel Configurations" was chaired by Jurij Sodja, Assistant Professor of Aerospace Engineering at TU Delft. This session featured a presentation titled "HERA – Hybrid-Electric Regional Architecture" by Massimiliano Di Giulio, Giuseppe Piscopo, and Vittorio Ascione from Leonardo.
OccFeat: Self-supervised Occupancy Feature Prediction for Pretraining BEV Segmentation Networks (peer-reviewed poster)
Creators: name: Czech Technical University
Publisher: name: Zenodo
Year: 2024

description: Acknowledgement: This research received the support of EXA4MIND project, funded by a European Union ́s Horizon Europe Re- search and Innovation Programme, under Grant Agreement N° 101092944. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the granting authority can be held responsible for them.