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All Journal Spektra: Jurnal Fisika dan Aplikasinya
Ramadhan, H. S.
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Aerospace Engineering Electrical & Electronics Engineering Energy Materials Science & Nanotechnology Physics

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Enhanced Approaches to Gravitational Lensing: A Regular Charged Black Hole in Weak Field Limit Din, H. M. U.; Ramadhan, H. S.
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 2 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 2, August 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.092.03

Abstract

Gravitational lensing, an integral aspect of general relativity, profoundly impacts our understanding of black holes (BH’s). The presence of a centered singularity resulting from gravitational collapse is a fundamental characteristic of a BH. Nonetheless, the exploitation of non-linear electrodynamics (NLED) divulges the emphatic concept of non-singularity. Our analysis primarily focuses on calculating the deflection angle in the weak field approximation, deliberately excluding the original spacetime configuration. The photon’s effective geometry is typically linked to NLED. Instead, a photon traverses an effective null geodesic that aligns with the geometry of a regular metric. The findings reveal an additional term in the deflection angle compared to the Reissner-Nordström (RN) metric, evidenced by a shifted positional displacement of the tertiary image associated with a regular BH. This study succinctly encapsulates these findings, positioning them within the extensive terminology ambient to BH’s singularity and GL, thus edifying the scientific memoir with precise astrophysical insights.
Exploring Weak Gravitational Lensing Effects by a Regular Black Hole Durrani, A. K.; Ramadhan, H. S.
Spektra: Jurnal Fisika dan Aplikasinya Vol. 9 No. 2 (2024): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 9 Issue 2, August 2024
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.092.02

Abstract

Gravitational lensing is one of the physical consequences of Einstein’s general theory of relativity, which has been observationally confirmed. This work aims to study the weak gravitational lensing scenario where the lens is a spherically symmetric, charged-nonsingular black hole that asymptotically behaves as the Reissner-Nordström (RN). The difference exists in the higher-order expansion. Therefore, the metric function of the regular charged black hole is expanded up to the fourth order, and the deflection angle is calculated. The thin lens equation is used, leading to five images: two imaginary and three real images. The exact positions of the images and magnification properties are calculated by providing the physical parameters such as mass, charge, and distances. Our calculation shows that the third image position shifted away from the optical axis. The formalism is applied to the case of a supermassive black hole located at the center of our galaxy with the assumption that it has an electric charge.
Co-Authors Din, H. M. U. Durrani, A. K.