Shadow and Optical Imaging in Einstein-Maxwell-Dilaton Black Hole

Fuente: arXiv
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Main Authors: Qin, Junlin, Gong, Hong-Er, Wang, Yusen, Mai, Zhan-Feng, Wu, Bofeng, Guo, Sen, Liang, Enwei
Format: Preprint
Published: 2025
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_version_ 1866912764805513216
author Qin, Junlin
Gong, Hong-Er
Wang, Yusen
Mai, Zhan-Feng
Wu, Bofeng
Guo, Sen
Liang, Enwei
author_facet Qin, Junlin
Gong, Hong-Er
Wang, Yusen
Mai, Zhan-Feng
Wu, Bofeng
Guo, Sen
Liang, Enwei
contents This paper investigates photon motion in black hole of Einstein-Maxwell-dilaton theory, exploring black hole shadows and observational characteristics under various accretion models. We first give the relation of the event horizon, photon sphere, and critical impact parameter in terms of the magnetic charge $q$. We then use the Event Horizon Telescope data to constrain $q$. For the two spherical accretion models, the infalling scenario yields a darker shadow due to the Doppler effect. However, the shadow radius remains unchanged for different models. In the case of an optically thin, geometrically thin disk accretion model, the observed brightness is predominantly determined by direct emission. The lensing ring provides a secondary contribution to the intensity, whereas the photon ring's emission is negligible. The widths of the lensing and photon rings exhibit a positive correlation with the magnetic charge $q$. Additionally, within the disk model framework, the black hole shadow radius is found to depend on the specific emission model.
format Preprint
id arxiv_https___arxiv_org_abs_2512_13114
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Shadow and Optical Imaging in Einstein-Maxwell-Dilaton Black Hole
Qin, Junlin
Gong, Hong-Er
Wang, Yusen
Mai, Zhan-Feng
Wu, Bofeng
Guo, Sen
Liang, Enwei
General Relativity and Quantum Cosmology
This paper investigates photon motion in black hole of Einstein-Maxwell-dilaton theory, exploring black hole shadows and observational characteristics under various accretion models. We first give the relation of the event horizon, photon sphere, and critical impact parameter in terms of the magnetic charge $q$. We then use the Event Horizon Telescope data to constrain $q$. For the two spherical accretion models, the infalling scenario yields a darker shadow due to the Doppler effect. However, the shadow radius remains unchanged for different models. In the case of an optically thin, geometrically thin disk accretion model, the observed brightness is predominantly determined by direct emission. The lensing ring provides a secondary contribution to the intensity, whereas the photon ring's emission is negligible. The widths of the lensing and photon rings exhibit a positive correlation with the magnetic charge $q$. Additionally, within the disk model framework, the black hole shadow radius is found to depend on the specific emission model.
title Shadow and Optical Imaging in Einstein-Maxwell-Dilaton Black Hole
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2512.13114