Black hole horizons must be veiled by photon spheres

التفاصيل البيبلوغرافية
العنوان: Black hole horizons must be veiled by photon spheres
المؤلفون: Carballo-Rubio, Raúl, Eichhorn, Astrid
سنة النشر: 2024
المجموعة: Astrophysics
General Relativity and Quantum Cosmology
مصطلحات موضوعية: General Relativity and Quantum Cosmology, Astrophysics - High Energy Astrophysical Phenomena
الوصف: Horizons and bound photon orbits are defining features of black holes that translate into key features of black hole images. We present a purely geometric proof that spherically symmetric, isolated objects with horizons in gravity theories with null-geodesic propagation of light must display bound photon orbits forming a photon sphere. Identifying the key elements of the proof, we articulate a simpler argument that carries over to more general situations with modified light propagation and implies the existence of equatorial spherical photon orbits in axisymmetric spacetimes with reflection symmetry. We conclude that the \emph{non-}observation of photon rings with very-large-baseline interferometry would be a very strong indication against a horizon, irrespective of whether or not the image shows a central brightness depression.
Comment: 10 pages, 2 figures, Honorable Mention in the Gravity Research Foundation 2024 Awards for Essays on Gravitation
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2405.08872
رقم الأكسشن: edsarx.2405.08872
قاعدة البيانات: arXiv