https://doi.org/10.1140/epjc/s10052-025-15167-w
Regular Article - Theoretical Physics
Constraints on the Sen black hole mass and charge from quasi-periodic oscillations
1
Al-Farabi Kazakh National University, Al-Farabi av. 71, 050040, Almaty, Kazakhstan
2
Università di Camerino, Via Madonna delle Carceri 9, 62032, Camerino, Italy
3
ICRANet, Piazza della Repubblica 10, 65122, Pescara, Italy
a
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Received:
21
August
2025
Accepted:
4
December
2025
Published online:
29
December
2025
Abstract
We analyze quasi-periodic oscillation data from selected X-ray binary systems hosting black holes. To model the spacetime geometry, we resort to the static Sen solution—originally derived in the framework of heterotic string theory—which reduces to the Schwarzschild spacetime for vanishing electric charge. By fitting the observed frequencies within the relativistic precession model, we constrain the mass and charge parameters of the Sen black hole and discuss their astrophysical implications, particularly in distinguishing classical black holes from their string-inspired counterparts.
© The Author(s) 2025
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