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arXiv · hep-th/9612248

Wavy Strings: Black or Bright?

Nemanja Kaloper·Robert C. Myers·Harold Roussel
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Abstract

Recent developments in string theory have brought forth a considerable interest in time-dependent hair on extended objects. This novel new hair is typically characterized by a wave profile along the horizon and angular momentum quantum numbers $l,m$ in the transverse space. In this work, we present an extensive treatment of such oscillating black objects, focusing on their geometric properties. We first give a theorem of purely geometric nature, stating that such wavy hair cannot be detected by any scalar invariant built out of the curvature and/or matter fields. However, we show that the tidal forces detected by an infalling observer diverge at the `horizon' of a black string superposed with a vibration in any mode with $l \ge 1$. The same argument applied to longitudinal ($l=0$) waves detects only finite tidal forces. We also provide an example with a manifestly smooth metric, proving that at least a certain class of these longitudinal waves have regular horizons.

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Nemanja Kaloper, Robert C. Myers, Harold Roussel. 1996-12-30. Wavy Strings: Black or Bright?. https://doi.org/10.1103/physrevd.55.7625

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