43,630 research outputs found

    3-Body Dynamics in a (1+1) Dimensional Relativistic Self-Gravitating System

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    The results of our study of the motion of a three particle, self-gravitating system in general relativistic lineal gravity is presented for an arbitrary ratio of the particle masses. We derive a canonical expression for the Hamiltonian of the system and discuss the numerical solution of the resulting equations of motion. This solution is compared to the corresponding non-relativistic and post-Newtonian approximation solutions so that the dynamics of the fully relativistic system can be interpretted as a correction to the one-dimensional Newtonian self-gravitating system. We find that the structure of the phase space of each of these systems yields a large variety of interesting dynamics that can be divided into three distinct regions: annulus, pretzel, and chaotic; the first two being regions of quasi-periodicity while the latter is a region of chaos. By changing the relative masses of the three particles we find that the relative sizes of these three phase space regions changes and that this deformation can be interpreted physically in terms of the gravitational interactions of the particles. Furthermore, we find that many of the interesting characteristics found in the case where all of the particles share the same mass also appears in our more general study. We find that there are additional regions of chaos in the unequal mass system which are not present in the equal mass case. We compare these results to those found in similar systems.Comment: latex, 26 pages, 17 figures, high quality figures available upon request; typos and grammar correcte

    Critical dynamics of nonconserved NN-vector model with anisotropic nonequilibrium perturbations

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    We study dynamic field theories for nonconserving NN-vector models that are subject to spatial-anisotropic bias perturbations. We first investigate the conditions under which these field theories can have a single length scale. When N=2 or N4N \ge 4, it turns out that there are no such field theories, and, hence, the corresponding models are pushed by the bias into the Ising class. We further construct nontrivial field theories for N=3 case with certain bias perturbations and analyze the renormalization-group flow equations. We find that the three-component systems can exhibit rich critical behavior belonging to two different universality classes.Comment: Included RG analysis and discussion on new universality classe

    Mass Hierarchy, Mixing, CP-Violation and Higgs Decay---or Why Rotation is Good for Us

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    The idea of a rank-one rotating mass matrix (R2M2) is reviewed detailing how it leads to ready explanations both for the fermion mass hierarchy and for the distinctive mixing patterns between up and down fermion states, which can be and have been tested against experiment and shown to be fully consistent with existing data. Further, R2M2 is seen to offer, as by-products: (i) a new solution of the strong CP problem in QCD by linking the theta-angle there to the Kobayashi-Maskawa CP-violating phase in the CKM matrix, and (ii) some novel predictions of possible anomalies in Higgs decay observable in principle at the LHC. A special effort is made to answer some questions raised.Comment: 47 pages, 9 figure

    Topological dilaton black holes

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    In four-dimensional spacetime, when the two-sphere of black hole event horizons is replaced by a two-dimensional hypersurface with zero or negative constant curvature, the black hole is referred to as a topological black hole. In this paper we present some exact topological black hole solutions in the Einstein-Maxwell-dilaton theory with a Liouville-type dilaton potential.Comment: 8 pages, Revtex, no figure

    Exact Black Hole and Cosmological Solutions in a Two-Dimensional Dilaton-Spectator Theory of Gravity

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    Exact black hole and cosmological solutions are obtained for a special two-dimensional dilaton-spectator (ϕψ\phi-\psi) theory of gravity. We show how in this context any desired spacetime behaviour can be determined by an appropriate choice of a dilaton potential function V(ϕ)V(\phi) and a ``coupling function'' l(ϕ)l(\phi) in the action. We illustrate several black hole solutions as examples. In particular, asymptotically flat double- and multiple- horizon black hole solutions are obtained. One solution bears an interesting resemblance to the 2D2D string-theoretic black hole and contains the same thermodynamic properties; another resembles the 4D4D Reissner-Nordstrom solution. We find two characteristic features of all the black hole solutions. First the coupling constants in l(ϕ)l(\phi) must be set equal to constants of integration (typically the mass). Second, the spectator field ψ\psi and its derivative ψ\psi^{'} both diverge at any event horizon. A test particle with ``spectator charge" ({\it i.e.} one coupled either to ψ\psi or ψ\psi^{'}), will therefore encounter an infinite tidal force at the horizon or an ``infinite potential barrier'' located outside the horizon respectively. We also compute the Hawking temperature and entropy for our solutions. In 2D2D FRWFRW cosmology, two non-singular solutions which resemble two exact solutions in 4D4D string-motivated cosmology are obtained. In addition, we construct a singular model which describes the 4D4D standard non-inflationary big bang cosmology (bigbangradiationdustbig-bang\rightarrow radiation\rightarrow dust). Motivated by the similaritiesbetween 2D2D and 4D4D gravitational field equations in FRWFRW cosmology, we briefly discuss a special 4D4D dilaton-spectator action constructed from the bosonic part of the low energy heterotic string action andComment: 34 pgs. Plain Tex, revised version contains some clarifying comments concerning the relationship between the constants of integration and the coupling constants

    Generic master equations for quasi-normal frequencies

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    Generic master equations governing the highly-damped quasi-normal frequencies [QNFs] of one-horizon, two-horizon, and even three-horizon spacetimes can be obtained through either semi-analytic or monodromy techniques. While many technical details differ, both between the semi-analytic and monodromy approaches, and quite often among various authors seeking to apply the monodromy technique, there is nevertheless widespread agreement regarding the the general form of the QNF master equations. Within this class of generic master equations we can establish some rather general results, relating the existence of "families" of QNFs of the form omega_{a,n} = (offset)_a + i n (gap) to the question of whether or not certain ratios of parameters are rational or irrational.Comment: 23 pages; V2: Minor additions, typos fixed. Matches published versio

    ADI splitting schemes for a fourth-order nonlinear partial differential equation from image processing

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    We present directional operator splitting schemes for the numerical solution of a fourth-order, nonlinear partial differential evolution equation which arises in image processing. This equation constitutes the H−1-gradient flow of the total variation and represents a prototype of higher-order equations of similar type which are popular in imaging for denoising, deblurring and inpainting problems. The efficient numerical solution of this equation is very challenging due to the stiffness of most numerical schemes. We show that the combination of directional splitting schemes with implicit time-stepping provides a stable and computationally cheap numerical realisation of the equation
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