2025/03/12 by Kehagias, Alex, Perrone, Davide, Riotto, Antonio · 4 citations
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2503.09350
The Penrose limit connects a plane wave geometry to the photon ring of a black hole, where the quasi-normal modes are located in the eikonal limit. Utilizing this simplification, we analytically extract the quadratic-level non-linearities in the quasi-normal modes of a Schwarzschild black hole for the (ℓ×ℓ)→ 2ℓ channel. We demonstrate that this result is independent of ℓ and further confirm it through symmetry arguments.