991 research outputs found
Critical Collapse of the Massless Scalar Field in Axisymmetry
We present results from a numerical study of critical gravitational collapse
of axisymmetric distributions of massless scalar field energy. We find
threshold behavior that can be described by the spherically symmetric critical
solution with axisymmetric perturbations. However, we see indications of a
growing, non-spherical mode about the spherically symmetric critical solution.
The effect of this instability is that the small asymmetry present in what
would otherwise be a spherically symmetric self-similar solution grows. This
growth continues until a bifurcation occurs and two distinct regions form on
the axis, each resembling the spherically symmetric self-similar solution. The
existence of a non-spherical unstable mode is in conflict with previous
perturbative results, and we therefore discuss whether such a mode exists in
the continuum limit, or whether we are instead seeing a marginally stable mode
that is rendered unstable by numerical approximation.Comment: 11 pages, 8 figure
Continuous Self-Similarity and -Duality
We study the spherically symmetric collapse of the axion/dilaton system
coupled to gravity. We show numerically that the critical solution at the
threshold of black hole formation is continuously self-similar. Numerical and
analytical arguments both demonstrate that the mass scaling away from
criticality has a critical exponent of .Comment: 17 pages, harvmac, six figures uuencoded in separate fil
Critical Collapse of a Complex Scalar Field with Angular Momentum
We report a new critical solution found at the threshold of axisymmetric
gravitational collapse of a complex scalar field with angular momentum. To
carry angular momentum the scalar field cannot be axisymmetric; however, its
azimuthal dependence is defined so that the resulting stress energy tensor and
spacetime metric are axisymmetric. The critical solution found is
non-spherical, discretely self-similar with an echoing exponent of 0.42 (+-
4%), and exhibits a scaling exponent of 0.11 (+- 10%) in near critical
collapse. Our simulations suggest that the solution is universal (within the
imposed symmetry class), modulo a family-dependent constant phase in the
complex plane.Comment: 4 pages, 4 figure
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