In the realm of theoretical physics and gravitational research, Maxence Corman, Llibert Aresté Saló, and Katy Clough from the University of Amsterdam have been delving into the complexities of black hole binaries within the framework of shift-symmetric Einstein-scalar-Gauss-Bonnet gravity. Their recent study, published in the journal Physical Review D, explores how these binaries behave differently compared to the predictions of general relativity, particularly in the late stages of their merger.
The researchers focused on black hole binaries in shift-symmetric Einstein-scalar-Gauss-Bonnet gravity, a modified theory of gravity that includes additional scalar fields and higher-order curvature terms. In this framework, stationary black holes possess a non-vanishing scalar charge, which influences their dynamics during the inspiral phase. The study found that the phase evolution of these binaries is modified by several effects, primarily an additional scalar dipole radiation that enters at the -1 Post-Newtonian (PN) order. This effect initially accelerates the inspiral compared to general relativity when corrections up to 2PN are included.
However, the researchers discovered that in the late stages of the merger, the orbital dynamics are altered in such a way that the overall effect is a decelerated merger phase for the modified gravity case. This deceleration is attributed to changes in the conservative dynamics, where more energy must be emitted in scalar-Gauss-Bonnet gravity to induce a given change in frequency. This leads to a distinctive switch between a faster and slower frequency evolution relative to general relativity as the binary approaches merger.
The findings suggest that existing constraints on the theory, which are obtained assuming PN approximations apply up to merger or based on order-by-order approximations that neglect backreaction effects on the metric, may need to be revisited. The study highlights the importance of including non-linear effects that modify the gravitational sector in the strong field regime.
For the energy industry, while this research is primarily theoretical and does not have immediate practical applications, it contributes to our understanding of fundamental physics and the behavior of black holes. This knowledge can inform the development of more accurate models for astrophysical phenomena, which in turn can enhance our understanding of the universe and potentially lead to advancements in energy-related technologies that rely on precise gravitational measurements, such as those used in energy exploration and monitoring.
Source: Corman, M., Aresté Saló, L., & Clough, K. (2023). Black hole binaries in shift-symmetric Einstein-scalar-Gauss-Bonnet gravity experience a slower merger phase. Physical Review D.
This article is based on research available at arXiv.