• waves on a hyperbolic plane

    From Roland Franzius@21:1/5 to matmzc%hofstra.edu@gtempaccount.com on Mon Nov 23 15:02:13 2015
    <matmzc%hofstra.edu@gtempaccount.com> wrote:

    Hi all.  On any smooth surface one can use the metric to define
    Christoffel symbols, define a covariant derivative, and a covariant
    Laplacian which one can use to set up a wave equation.  For no
    particular reason it occurred to me that one might get interesting
    solutions of the wave equation on the hyperbolic plane or in hyperbolic 3-space.  A Google search didn't turn up anything.  Does anyone know of
    any relevant literature?  I set up the wave equation for the unit disk
    in the Poincare and Klein metrics, but in both cases I got a mess that
    seems unsolvable (by humble me anyways).  Any thoughts on this?  Or
    perhaps my idea that the problem is worth looking into was overly
    optimistic?


    Its standard.

    The geometry is rotional invariant and in polar or spherical
    coordinates
    the scalar wave equation separates readily producing products of the 2d
    or 3d the angular momentum operator times a solution of the radial
    function that solves the radial equation
    omega^2 psi - f(r)-1 d_r f(r) d_r psi  + l^2/r^2  psi = m^2 psi

    where "l^2" is an eigenvalue of the angular momentum operator squared,
    in  3D eg

    L^2 = -csc tetha d_theta sin tetha  d_theta + m^2/(sin theta)^2

    The exact form depends on dimension of course.

    Google eg on scholar.google.com

    https://books.google.de/books?hl=de&lr=&id=rIM8AAAAIAAJ&oi=fnd&pg=PA91&d q=metrics+on+the+hyperbolic+plane&ots=imtAYtaYru&sig=jZ93XruOzaGTEnIFxKK 3sI3Q5KU#v=onepage&q=metrics%20on%20the%20hyperbolic%20plane&f=false


    --

    Roland Franzius

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  • From matmzc%hofstra.edu@gtempaccount.com@21:1/5 to All on Sun Nov 22 17:08:59 2015
    Hi all.  On any smooth surface one can use the metric to define
    Christoffel symbols, define a covariant derivative, and a covariant
    Laplacian which one can use to set up a wave equation.  For no
    particular reason it occurred to me that one might get interesting
    solutions of the wave equation on the hyperbolic plane or in hyperbolic 3-space.  A Google search didn't turn up anything.  Does anyone know of
    any relevant literature?  I set up the wave equation for the unit disk
    in the Poincare and Klein metrics, but in both cases I got a mess that
    seems unsolvable (by humble me anyways).  Any thoughts on this?  Or
    perhaps my idea that the problem is worth looking into was overly
    optimistic?

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