939 research outputs found

    Dephasing representation: Employing the shadowing theorem to calculate quantum correlation functions

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    Due to the Heisenberg uncertainty principle, various classical systems differing only on the scale smaller than Planck's cell correspond to the same quantum system. This fact is used to find a unique semiclassical representation without the Van Vleck determinant, applicable to a large class of correlation functions expressible as quantum fidelity. As in the Feynman path integral formulation of quantum mechanics, all contributing trajectories have the same amplitude: that is why it is denoted the ``dephasing representation.'' By relating the present approach to the problem of existence of true trajectories near numerically-computed chaotic trajectories, the approximation is made rigorous for any system in which the shadowing theorem holds. Numerical implementation only requires computing actions along the unperturbed trajectories and not finding the shadowing trajectories. While semiclassical linear-response theory was used before in quasi-integrable and chaotic systems, here its validity is justified in the most generic, mixed systems. Dephasing representation appears to be a rare practical method to calculate quantum correlation functions in nonuniversal regimes in many-dimensional systems where exact quantum calculations are impossible.Comment: 5 pages, 1 figure, to appear in Phys. Rev. E (R

    Holder Shadowing on Finite Intervals

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    For any θ,ω>1/2\theta, \omega > 1/2 we prove that, if any dd-pseudotrajectory of length 1/dω\sim 1/d^{\omega} of a diffeomorphism fC2f\in C^2 can be dθd^{\theta}-shadowed by an exact trajectory, then ff is structurally stable. Previously it was conjectured by Hammel-Grebogi-Yorke that for θ=ω=1/2\theta = \omega = 1/2 this property holds for a wide class of non-uniformly hyperbolic diffeomorphisms. In the proof we introduce the notion of sublinear growth property for inhomogenious linear equations and prove that it implies exponential dichotomy.Comment: 19 pages. Minor change

    Hopf type rigidity for thermostats

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    We show a Hopf type rigidity for thermostats without conjugate points on a 2-torusComment: 9 pages; minor revisions to reflect published versio

    Absolute Continuity Theorem for Random Dynamical Systems on RdR^d

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    In this article we provide a proof of the so called absolute continuity theorem for random dynamical systems on RdR^d which have an invariant probability measure. First we present the construction of local stable manifolds in this case. Then the absolute continuity theorem basically states that for any two transversal manifolds to the family of local stable manifolds the induced Lebesgue measures on these transversal manifolds are absolutely continuous under the map that transports every point on the first manifold along the local stable manifold to the second manifold, the so-called Poincar\'e map or holonomy map. In contrast to known results, we have to deal with the non-compactness of the state space and the randomness of the random dynamical system.Comment: 46 page

    Pseudo-Anosov flows in toroidal manifolds

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    We first prove rigidity results for pseudo-Anosov flows in prototypes of toroidal 3-manifolds: we show that a pseudo-Anosov flow in a Seifert fibered manifold is up to finite covers topologically equivalent to a geodesic flow and we show that a pseudo-Anosov flow in a solv manifold is topologically equivalent to a suspension Anosov flow. Then we study the interaction of a general pseudo-Anosov flow with possible Seifert fibered pieces in the torus decomposition: if the fiber is associated with a periodic orbit of the flow, we show that there is a standard and very simple form for the flow in the piece using Birkhoff annuli. This form is strongly connected with the topology of the Seifert piece. We also construct a large new class of examples in many graph manifolds, which is extremely general and flexible. We construct other new classes of examples, some of which are generalized pseudo-Anosov flows which have one prong singularities and which show that the above results in Seifert fibered and solvable manifolds do not apply to one prong pseudo-Anosov flows. Finally we also analyse immersed and embedded incompressible tori in optimal position with respect to a pseudo-Anosov flow.Comment: 44 pages, 4 figures. Version 2. New section 9: questions and comments. Overall revision, some simplified proofs, more explanation

    Stable Flags and the Riemann-Hilbert Problem

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    We tackle the Riemann-Hilbert problem on the Riemann sphere as stalk-wise logarithmic modifications of the classical R\"ohrl-Deligne vector bundle. We show that the solutions of the Riemann-Hilbert problem are in bijection with some families of local filtrations which are stable under the prescribed monodromy maps. We introduce the notion of Birkhoff-Grothendieck trivialisation, and show that its computation corresponds to geodesic paths in some local affine Bruhat-Tits building. We use this to compute how the type of a bundle changes under stalk modifications, and give several corresponding algorithmic procedures.Comment: 39 page

    Analyticity of the SRB measure for a class of simple Anosov flows

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    We consider perturbations of the Hamiltonian flow associated with the geodesic flow on a surface of constant negative curvature. We prove that, under a small perturbation, not necessarely of Hamiltonian character, the SRB measure associated to the flow exists and is analytic in the strength of the perturbation. An explicit example of "thermostatted" dissipative dynamics is constructed.Comment: 23 pages, corrected typo

    Black Hole Thermodynamics in Carath\'eodory's Approach

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    We show that, in the framework of Carath\'eodory's approach to thermodynamics, one can implement black hole thermodynamics by realizing that there exixts a quasi-homogeneity symmetry of the Pfaffian form \deq representing the infinitesimal heat exchanged reversibly by a Kerr-Newman black hole; this allow us to calculate readily an integrating factor, and, as a consequence, a foliation of the thermodynamic manifold can be recovered.Comment: 10 pages; elsart styl

    Hyperbolic Chaos of Turing Patterns

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    We consider time evolution of Turing patterns in an extended system governed by an equation of the Swift-Hohenberg type, where due to an external periodic parameter modulation long-wave and short-wave patterns with length scales related as 1:3 emerge in succession. We show theoretically and demonstrate numerically that the spatial phases of the patterns, being observed stroboscopically, are governed by an expanding circle map, so that the corresponding chaos of Turing patterns is hyperbolic, associated with a strange attractor of the Smale-Williams solenoid type. This chaos is shown to be robust with respect to variations of parameters and boundary conditions.Comment: 4 pages, 4 figure

    On a problem of A. Weil

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    A topological invariant of the geodesic laminations on a modular surface is constructed. The invariant has a continuous part (the tail of a continued fraction) and a combinatorial part (the singularity data). It is shown, that the invariant is complete, i.e. the geodesic lamination can be recovered from the invariant. The continuous part of the invariant has geometric meaning of a slope of lamination on the surface.Comment: to appear Beitr\"age zur Algebra und Geometri
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