Weak gravitational lensing: a compact object with arbitrary quadrupole moment immersed in plasma

TL;DR

This paper investigates how the quadrupole moment and plasma environment influence weak gravitational lensing around spherically symmetric compact objects, revealing increased image multiplicity and magnification effects.

Contribution

It introduces a model incorporating arbitrary quadrupole moments and plasma effects into gravitational lensing analysis, expanding understanding of light deflection in such environments.

Findings

Quadrupole moment parameter increases the number of images.

Plasma effects modify the deflection angle and magnification.

Presence of quadrupole enhances image magnification.

Abstract

We study weak gravitational lensing around a compact object with arbitrary quadrupole moment in the presence of plasma. The studied compact objects are considered to be spherically symmetric. The additional parameter $\epsilon$ regulating the quadrupole moment in the metric alters the deflection angle of light rays along with the plasma parameters. In the vacuum, the number of images due to the presence of the parameter $\epsilon$ increases and causes the increase of the magnification of the image source. The effects of uniform and nonuniform plasma on gravitational lensing around the compact object are also studied.