### Abstract

The caustics of high-frequency wave propagation may be classified using catastrophe theory. The wavefield in the vicinity of any caustic is described by the corresponding diffraction catastrophe. The singularity index, β, is a measure of the rate at which such a wavefield diverges as ω→∞ at the point where all control parameters and moduli are set equal to zero. It is shown that away from this point β also describes a balance between two different measures of the unfolding of the wavefield in each control direction, β = σ_{n}ρ{variant}_{n}. The indices σ_{n} and ρ{variant}_{n} describe, respectively, the rate at which individual ray arrivals separate in time and decay as a function of control parameter.

Original language | English (US) |
---|---|

Pages (from-to) | 107-110 |

Number of pages | 4 |

Journal | Wave Motion |

Volume | 9 |

Issue number | 1 |

DOIs | |

State | Published - Jan 1987 |

### ASJC Scopus subject areas

- Modeling and Simulation
- Physics and Astronomy(all)
- Computational Mathematics
- Applied Mathematics