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Do relativistic corrections affect microlensing amplification?

Junya Ebina·Takeaki Osuga·Hideki Asada·Masumi Kasai
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Abstract

Studies of gravitational microlensing are usually based on the lens equation, which is valid only to first order in the gravitational constant $G$. However, the amplification factor of microlensing is a second-order quantity with respect to $G$. Despite this fact, conventional studies are still based on the lowest-order lens equation. Then the question naturally arises: Why are these conventional studies justified? We carefully study the relativistic correction to the amplification factor at $O(G^2)$. We show that the amplification factor for each image is corrected. However, the total amplification remains unchanged at this order.

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Junya Ebina, Takeaki Osuga, Hideki Asada, Masumi Kasai. 2000-11-16. Do relativistic corrections affect microlensing amplification?. https://doi.org/10.1143/ptp.104.1317

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