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arXiv · 2602.04502

Trapped photon region in the phase space of sub-extremal Kerr-Newman and Kerr-Sen spacetimes

Carla Cederbaum·Karim Mosani
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Abstract

We analyse the geometry and topology of the trapped photon region in the domain of outer communication of sub-extremal Kerr-Newman and Kerr-Sen spacetimes. Specifically, we show that its projection to the (co-)tangent bundle forms a five-dimensional submanifold with topology $SO(3)\times \mathbb{R}^2$ in each setup. The proof adapts the method of Cederbaum and Jahns for sub-extremal Kerr spacetime.

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Carla Cederbaum, Karim Mosani. 2026-02-04. Trapped photon region in the phase space of sub-extremal Kerr-Newman and Kerr-Sen spacetimes. https://arxiv.org/abs/2602.04502

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