Gravitational Lensing by Dark Matter Caustics

Abstract

Dark matter caustics have specific density profiles and, therefore, precisely calculable gravitational lensing properties. We present a formalism which simplifies the relevant calculations, and apply it to four specific cases. In the first three, the line of sight is tangent to a smooth caustic surface. The curvature of the surface at the tangent point is positive, negative or zero. In the fourth case the line of sight passes near a cusp. For each we derive the map between the image and source planes. In some cases, a point source has multiple images and experiences infinite magnification when the images merge. Unfortunately, for the dark matter caustics expected in realistic galactic halo models, the angular resolution required to resolve the multiple images is not presently achievable. A more promising approach aims to observe the distortions caused by dark matter caustics in the images of extended sources such as radio jets.

36 pages, 11 figures

References in corpus (3)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Preliminary Maps and Basic Results
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Inflation

Cited by in corpus (14)

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• The Caustic Ring Model of the Milky Way Halo
• Caustics in growing Cold Dark Matter Haloes
• Flux Enhancement of Slow-moving Particles by Sun or Jupiter: Can they be Detected on Earth?
• Robustness of Discrete Flows and Caustics in Cold Dark Matter Cosmology
• Does the Second Caustic Ring of Dark Matter Cause the Monoceros Ring of Stars ?
• A further look at particle annihilation in dark matter caustics
• Probing dark matter caustics with weak lensing
• WIMP annihilation in caustics
• Gravitational Lensing and Structural Stability of Dark Matter Caustic Rings
• Dark Matter Caustics in Galaxy Clusters
• The gravitational force field of proto-pancakes
• Probing Cold Dark Matter Cusps by Gravitational Lensing
• Effects of a dark matter caustic passing through the Oort cloud