Optical Signatures of q-deformed solution in Einstein-Maxwell-dilaton Gravity

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Sakkawattana, Chawit, Promsiri, Chatchai, Ponglertsakul, Supakchai
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915698471600128
author Sakkawattana, Chawit
Promsiri, Chatchai
Ponglertsakul, Supakchai
author_facet Sakkawattana, Chawit
Promsiri, Chatchai
Ponglertsakul, Supakchai
contents We consider null geodesics in the background of spherically symmetric object in Einstein-Maxwell-Dilaton (EMD) theory with coupling function $f(Φ)=e^{-2λΦ}$. The spherical solution is characteristically described by dilaton coupling $λ$, integrated dilaton flux $D$ and magnetic charge $P$. Then, we derive geodesic equations by using the Hamilton-Jacobi approach. The radial photon orbital equation on equatorial plane and effective potential are analyzed. The total deflection angle and trajectories of photon as a function of impact parameter $b$ are plotted with the variation of $λ,D$ and $P$. Furthermore, the relation between photon ring's width and the Lyapunov exponent is also explored. In addition, we use the Gralla-Lupsasca-Marrone (GLM) model to model intensity profile of optically thin accretion disk around the object. Hence, we construct optical images of the object surrounded by three distinct emission profiles. Lastly, we investigate the radius of innermost stable circular orbit (ISCO) for timelike geodesics.
format Preprint
id arxiv_https___arxiv_org_abs_2512_23551
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Optical Signatures of q-deformed solution in Einstein-Maxwell-dilaton Gravity
Sakkawattana, Chawit
Promsiri, Chatchai
Ponglertsakul, Supakchai
General Relativity and Quantum Cosmology
We consider null geodesics in the background of spherically symmetric object in Einstein-Maxwell-Dilaton (EMD) theory with coupling function $f(Φ)=e^{-2λΦ}$. The spherical solution is characteristically described by dilaton coupling $λ$, integrated dilaton flux $D$ and magnetic charge $P$. Then, we derive geodesic equations by using the Hamilton-Jacobi approach. The radial photon orbital equation on equatorial plane and effective potential are analyzed. The total deflection angle and trajectories of photon as a function of impact parameter $b$ are plotted with the variation of $λ,D$ and $P$. Furthermore, the relation between photon ring's width and the Lyapunov exponent is also explored. In addition, we use the Gralla-Lupsasca-Marrone (GLM) model to model intensity profile of optically thin accretion disk around the object. Hence, we construct optical images of the object surrounded by three distinct emission profiles. Lastly, we investigate the radius of innermost stable circular orbit (ISCO) for timelike geodesics.
title Optical Signatures of q-deformed solution in Einstein-Maxwell-dilaton Gravity
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2512.23551