Caustic ring singularity

Journal Article · Wed Sep 01 04:00:00 EDT 1999 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.60.063501· OSTI ID:6470936

Sikivie, P ^[1]

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1. Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

I investigate the caustics produced by the fall of collisionless dark matter in and out of a galaxy in the limit of negligible velocity dispersion. The outer caustics are spherical shells enveloping the galaxy. The inner caustics are rings. These are located near where the particles with the most angular momentum are at their distance of closest approach to the galactic center. The surface of a caustic ring is a closed tube whose cross section is a D[sub [minus]4] catastrophe. It has three cusps amongst which exists a discrete Z[sub 3] symmetry. A detailed analysis is given in the limit where the flow of particles is axially and reflection symmetric and where the transverse dimensions of the ring are small compared to the ring radius. Five parameters describe the caustic in that limit. The relations between these parameters and the initial velocity distribution of the particles are derived. The structure of the caustic ring is used to predict the shape of the bump produced in a galactic rotation curve by a caustic ring lying in the galactic plane. [copyright] [ital 1999] [ital The American Physical Society]

• OSTI ID: 6470936
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Vol. 60:6; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

661300* -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GALAXIES
MATTER
NONLUMINOUS MATTER
SYMMETRY