Frequency Shift in Binary Lensing System

TL;DR

This paper explores the frequency shift effect in binary gravitational microlensing, deriving its magnitude and assessing its potential for constraining lens parameters through observational methods.

Contribution

It extends the application of the frequency shift effect to binary microlensing and derives its magnitude during lensing and caustic crossing.

Findings

Frequency shift magnitude is approximately 10^{-12}.

Cross-Correlation methods may detect the frequency shift.

Provides additional constraints for binary lens parameters.

Abstract

Gravitational microlensing with binary lensing is one of the channels for detecting exoplanets. Due to the degeneracy of the lens parameters for the binary microlensing, additional features such as parallax and finite-size effects need to identify the lens parameters. The frequency-shift effect as the relativistic analogy of the gravity assist for the photons, is an extra observation that provides additional constraint between the lens parameters . In this work, we extend the application of the frequency shift effect to binary microlensing and derive the frequency shift during the lensing and caustic crossing. The frequency shift for the binary lens is of the order of ${\Delta\nu}/{\nu}\sim 10^{-12}$. We also investigate the feasibility of detecting this effect by employing Cross-Correlation methods .