https://doi.org/10.1140/epjc/s10052-025-15116-7
Comment
Comments on the non-existence of unified hoop conjecture
1
Department of Mathematics, Kidderpore College, 2, Pitamber Sircar Lane, 700023, Kolkata, WB, India
2
Zel’dovich International Center for Astrophysics, M. Akmullah Bashkir State Pedagogical University, 3A, October Revolution Street, 450008, Ufa, RB, Russia
a
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Received:
4
July
2025
Accepted:
25
November
2025
Published online:
3
December
2025
In a recent article, Hod (Eur Phys J C 80:982, 2020) has concluded the non-existence, heretofore unnoticed, of a unified Thorne’s hoop conjecture that holds for the quasi-local mass, 
for static Reissner–Nordstrőm black hole, but does not hold for the spinning electrically charged Kerr–Newman black holes, when the same quasi-local mass is used. While the conclusion is correct and important, we wish to point out a curious exception for which the conjecture holds in a unified way for both the static and spinning tidal charged 4d braneworld black holes of string theory, when the mass in the conjecture is the same quasi-local mass.
© The Author(s) 2025
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