49,688 research outputs found

    Classification of Triadic Chord Inversions Using Kohonen Self-organizing Maps

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    In this paper we discuss the application of the Kohonen Selforganizing Maps to the classification of triadic chords in inversions and root positions. Our motivation started in the validation of Schönberg´s hypotheses of the harmonic features of each chord inversion. We employed the Kohonen network, which has been generally known as an optimum pattern classification tool in several areas, including music, to verify that hypothesis. The outcomes of our experiment refuse the Schönberg´s assumption in two aspects: structural and perceptual/functional

    Synchronization of Kauffman networks

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    We analyze the synchronization transition for a pair of coupled identical Kauffman networks in the chaotic phase. The annealed model for Kauffman networks shows that synchronization appears through a transcritical bifurcation, and provides an approximate description for the whole dynamics of the coupled networks. We show that these analytical predictions are in good agreement with numerical results for sufficiently large networks, and study finite-size effects in detail. Preliminary analytical and numerical results for partially disordered networks are also presented.Comment: 10 pages, 9 figure

    Fractional Exclusion Statistics and the Universal Quantum of Thermal Conductance: A Unifying Approach

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    We introduce a generalized approach to one-dimensional (1D) conduction based on Haldane's concept of fractional statistics (FES) and the Landauer formulation of transport theory. We show that the 1D ballistic thermal conductance is independent of the statistics obeyed by the carriers and is governed by the universal quantum (π2kB2T)/(3h) (\pi^2 k^2_B T)/(3h) in the degenerate regime. By contrast, the electrical conductance of FES systems is statistics-dependent. This work unifies previous theories of electron and phonon systems and explains an interesting commonality in their behavior.Comment: 7 pages (Tex source file) + 2 ps figure

    Big brake singularity is accommodated as an exotic quintessence field

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    We describe a big brake singularity in terms of a modified Chaplygin gas equation of state p=(\ga_{m}-1)\rho+\al\ga_{m}\rho^{-n}, accommodate this late-time event as an exotic quintessence model obtained from an energy-momentum tensor, and focus on the cosmological behavior of the exotic field, its kinetic energy and the potential energy. At the background level, the exotic field does not blow up whereas its kinetic energy and potential both grow without limit near the future singularity. We evaluate the classical stability of this background solution by examining the scalar perturbations of the metric along with the inclusion of entropy perturbation in the perturbed pressure. Within the Newtonian gauge, the gravitational field approaches a constant near the singularity plus additional regular terms. When the perturbed exotic field is associated with \al>0 the perturbed pressure and contrast density both diverge, whereas the perturbed exotic field and the divergence of the exotic field's velocity go to zero exponentially. When the perturbed exotic field is associated with \al<0 the contrast density always blows up, but the perturbed pressure can remain bounded. In addition, the perturbed exotic field and the divergence of the exotic field's velocity vanish near the big brake singularity. We also briefly look at the behavior of the intrinsic entropy perturbation near the singular event.Comment: 11 pages, no figures. Accepted for its publication in PR

    Detecting bifurcation values at infinity of real polynomials

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    We present a new approach for estimating the set of bifurcation values at infinity. This yields a significant shrinking of the number of coefficients in the recent algorithm introduced by Jelonek and Kurdyka for reaching critical values at infinity by rational arcs

    Dark matter, dark energy, and dark radiation coupled with a transversal interaction

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    We investigate a cosmological scenario with three interacting components that includes dark matter, dark energy, and radiation in the spatially flat Friedmann-Robertson-Walker universe. We introduce a 3-dimensional internal space, the interaction vector Q=(Qx,Qm,Qr)\mathbf{Q}=(Q_{x}, Q_{m}, Q_{r}) satisfying the constraint plane Qx+Qm+Qr=0Q_{x}+ Q_{m}+ Q_{r}=0, the barotropic index vector \boldmath {\gamma}=(\ga_x,\ga_m,\ga_r) and select a transversal interaction vector Qt\mathbf{Q_t} in a sense that \mathbf{Q_t}\cdot \boldmath {\gamma}=0=0. We exactly solve the source equation for a linear Qt\mathbf{Q_t}, that depends on the total energy density and its derivatives up to third order, and find all the component energy densities. We obtain a large set of interactions for which the source equation admits a power law solution and show its asymptotic stability by constructing the Lyapunov function. We apply the χ2\chi^{2} method to the observational Hubble data for constraining the cosmic parameters, and analyze the amount of dark energy in the radiation era for the above linear Qt\mathbf{Q_t}. It turns to be that our model fulfills the severe bound of Ωx(z1100)<0.1\Omega_{x}(z\simeq 1100)<0.1 and is consistent with the future constraints achievable by Planck and CMBPol experiments.Comment: 9 pages, 4 figures. Accepted for publication in Physical Review
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