4,604 research outputs found

    Exact solution for two unequal counter-rotating black holes

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    The complete solution for two unequal counter-rotating black holes separated by a massless strut, is developed in terms of four arbitrary parameters involving two quantities \sigma 1 and \sigma 2 as the half length of the two rods representing the black hole horizons, the total mass M and the relative distance R between the centers of the horizons. A further attempt for describing the explicit form of this solution in terms of the physical parameters: The two Komar masses M1 and M2, Komar angular momenta per unit mass a1 and a2 (a1 and a2 have opposite sign), and the coordinate distance R, guided us to a 4-parameter subclass in which the five physical parameters satisfy a simple algebraic relation and the interaction force in this scheme looks like Schwarzschild type.Comment: This paper has been withdrawn for changes on i

    Hidden Symmetries, AdS_D x S^n, and the lifting of one-time-physics to two-time-physics

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    The massive non-relativistic free particle in d-1 space dimensions has an action with a surprizing non-linearly realized SO(d,2) symmetry. This is the simplest example of a host of diverse one-time-physics systems with hidden SO(d,2) symmetric actions. By the addition of gauge degrees of freedom, they can all be lifted to the same SO(d,2) covariant unified theory that includes an extra spacelike and an extra timelike dimension. The resulting action in d+2 dimensions has manifest SO(d,2) Lorentz symmetry and a gauge symmetry Sp(2,R) and it defines two-time-physics. Conversely, the two-time action can be gauge fixed to diverse one-time physical systems. In this paper three new gauge fixed forms that correspond to the non-relativistic particle, the massive relativistic particle, and the particle in AdS_(d-n) x S^n spacetime will be discussed. The last case is discussed at the first quantized and field theory levels as well. For the last case the popularly known symmetry is SO(d-n-1,2) x SO(n+1), but yet we show that it is symmetric under the larger SO(d,2). In the field theory version the action is symmetric under the full SO(d,2) provided it is improved with a quantized mass term that arises as an anomaly from operator ordering ambiguities. The anomalous cosmological term vanishes for AdS_2 x S^0 and AdS_n x S^n (i.e. d=2n). The strikingly larger symmetry could be significant in the context of the proposed AdS/CFT duality.Comment: Latex, 23 pages. The term "cosmological constant" that appeared in the original version has been changed to "mass term". My apologies for the confusio

    The Fractality of the Hydrodynamic Modes of Diffusion

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    Transport by normal diffusion can be decomposed into the so-called hydrodynamic modes which relax exponentially toward the equilibrium state. In chaotic systems with two degrees of freedom, the fine scale structure of these hydrodynamic modes is singular and fractal. We characterize them by their Hausdorff dimension which is given in terms of Ruelle's topological pressure. For long-wavelength modes, we derive a striking relation between the Hausdorff dimension, the diffusion coefficient, and the positive Lyapunov exponent of the system. This relation is tested numerically on two chaotic systems exhibiting diffusion, both periodic Lorentz gases, one with hard repulsive forces, the other with attractive, Yukawa forces. The agreement of the data with the theory is excellent

    The fractality of the relaxation modes in deterministic reaction-diffusion systems

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    In chaotic reaction-diffusion systems with two degrees of freedom, the modes governing the exponential relaxation to the thermodynamic equilibrium present a fractal structure which can be characterized by a Hausdorff dimension. For long wavelength modes, this dimension is related to the Lyapunov exponent and to a reactive diffusion coefficient. This relationship is tested numerically on a reactive multibaker model and on a two-dimensional periodic reactive Lorentz gas. The agreement with the theory is excellent

    A Two-Form Formulation of the Vector-Tensor Multiplet in Central Charge Superspace

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    A two-form formulation for the N=2 vector-tensor multiplet is constructed using superfield methods in central charge superspace. The N=2 non-Abelian standard supergauge multiplet in central charge superspace is also discussed, as is with the associated Chern-Simons form. We give the constraints, solve the Bianchi identities and present the action for a theory of the vector-tensor multiplet coupled to the non-Abelian supergauge multiplet via the Chern-Simons form.Comment: 16 pages, LaTeX2e with AMS-LaTe

    Fractals and dynamical chaos in a random 2D Lorentz gas with sinks

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    Two-dimensional random Lorentz gases with absorbing traps are considered in which a moving point particle undergoes elastic collisions on hard disks and annihilates when reaching a trap. In systems of finite spatial extension, the asymptotic decay of the survival probability is exponential and characterized by an escape rate, which can be related to the average positive Lyapunov exponent and to the dimension of the fractal repeller of the system. For infinite systems, the survival probability obeys a stretched exponential law of the form P(c,t)~exp(-Ct^{1/2}). The transition between the two regimes is studied and we show that, for a given trap density, the non-integer dimension of the fractal repeller increases with the system size to finally reach the integer dimension of the phase space. Nevertheless, the repeller remains fractal. We determine the special scaling properties of this fractal.Comment: 40 pages, 10 figures, preprint for Physica
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