The initial value problem for linearized gravitational perturbations of the Schwarzschild naked singularity
The initial value problem for linearized gravitational perturbations of the Schwarzschild naked singularity
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DOI:
10.1088/0264-9381/26/21/215002
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发表时间:
2009-11-07
影响因子:
3.5
通讯作者:
Gleiser, Reinaldo J.
中科院分区:
文献类型:
--
作者:
Dotti, Gustavo;Gleiser, Reinaldo J.
The coupled equations for the scalar modes of the linearized Einstein equations around Schwarzschild's spacetime were reduced by Zerilli to a (1+1) wave equation partial derivative(2)Psi(z)/partial derivative t(2) + H Psi(z) = 0, where H = partial derivative(2)/partial derivative x(2) + V (x) is the Zerilli 'Hamiltonian' and x is the tortoise radial coordinate. From its definition, for smoothmetric perturbations the field Psi(z) is singular at r(s) = -6M/(l-1)(l+2), with l being the mode harmonic number. The equation Psi(z) obeys is also singular, since V has a second- order pole at rs. This is irrelevant to the black hole exterior stability problem, where r > 2M > 0, and r(s) < 0, but it introduces a non- trivial problem in the naked singular case where M < 0, then rs > 0, and the singularity appears in the relevant range of r (0 < r < infinity). We solve this problem by developing a new approach to the evolution of the even mode, based on a new gauge invariant function, (Psi) over cap, that is a regular function of the metric perturbation for any value of M. The relation of (Psi) over cap to Psi(z) is provided by an intertwiner operator. The spatial pieces of the (1+1) wave equations that (Psi) over cap and Psi(z) obey are related as a supersymmetric pair of quantum Hamiltonians H and (H) over cap. For M < 0, has a regular potential and a unique self-adjoint extension in a domain D defined by a physically motivated boundary condition at r = 0. This allows us to address the issue of evolution of gravitational perturbations in this non- globally hyperbolic background. This formulation is used to complete the proof of the linear instability of the Schwarzschild naked singularity, by showing that a previously found unstable mode belongs to a complete basis of (H) over cap in D, and thus is excitable by generic initial data. This is further illustrated by numerically solving the linearized equations for suitably chosen initial data.