Theoretical Physics Implications of the Binary Black-Hole Mergers GW150914 and GW151226

By N. Yunes, Kent Yagi, Frans Pretorius. 2016

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The gravitational wave observations GW150914 and GW151226 by Advanced LIGO provide the first opportunity to learn about physics in the extreme gravity environment of coalescing binary black holes. The LIGO Scientific Collaboration and the Virgo Collaboration have verified that this observation is consistent with Einstein’s theory of general relativity, constraining the presence of certain parametric anomalies in the signal. This paper expands their analysis to a larger class of anomalies, highlighting the inferences that can be drawn on nonstandard theoretical physics mechanisms that could otherwise have affected the observed signals. We find that these gravitational wave events constrain a plethora of mechanisms associated with the generation and propagation of gravitational waves, including the activation of scalar fields, gravitational leakage into large extra dimensions, the variability of Newton’s constant, the speed of gravity, a modified dispersion relation, gravitational Lorentz violation and the strong equivalence principle. Though other observations limit many of these mechanisms already, GW150914 and GW151226 are unique in that they are direct probes of dynamical strong-field gravity and of gravitational wave propagation. We also show that GW150914 constrains inferred properties of exotic compact object alternatives to Kerr black holes. We argue, however, that the true potential for GW150914 to both rule out exotic objects and constrain physics beyond general relativity is severely limited by the lack of understanding of the coalescence regime in almost all relevant modified gravity theories. This event thus significantly raises the bar that these theories have to pass, both in terms of having a sound theoretical underpinning and reaching the minimal level of being able to solve the equations of motion for binary merger events. We conclude with a discussion of the additional inferences that can be drawn if the lower-confidence observation of an electromagnetic counterpart to GW150914 holds true, or such a coincidence is observed with future events; this would provide dramatic constraints on the speed of gravity and gravitational Lorentz violation.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/6e440550f043417ecf9806688059ab2dfc9b6736

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Citations in the corpus

• Dynamical boson stars (2012, background): “Much work has already appeared examining the implications of these initial detections [369, 366, 4].”
• Holomorphic classical limit for spin effects in gravitational and electromagnetic scattering (2017, background): “In this context, the motivation for these problems stems from the always increasing interest in the measurement of gravitational waves as definitive tests of GR, which has led to the acclaimed first detection by LIGO in 2016 [9, 10].”
• Bayesian inference for compact binary coalescences with bilby: validation and application to the first LIGO–Virgo gravitational-wave transient catalogue (2020, background): “…Belczynski et al. 2018; Bavera et al. 2020), the equation of state of neutron-star matter (Abbott et al. 2018c; Most et al. 2018; Essick et al. 2020; Abbott et al. 2020b), and the nature of gravity (Yunes & Siemens 2013; Abbott et al. 2016b; Yunes et al. 2016; Abbott et al. 2019i; Isi et al. 2019).”
• Search for New Physics with Atoms and Molecules (2017, background): “Theoretical physics implications of the observed binary black-hole mergers and probes of new physics and cosmology enabled by the detection of the gravitational waves are described by Yunes et al. (2016).”
• Gravitational wave decay into dark energy (2018, background): “provide an energy-dependent phase-velocity) at a level in principle detectable by current gravitational waves experiments [36, 37].”
• Tests for the existence of black holes through gravitational wave echoes (2017, background): “[42] Yunes, N and Yagi, K and Pretorius, F, Theoretical Physics Implications of the Binary Black-Hole Mergers GW150914 and GW151226.”
• Dark Energy in Light of Multi-Messenger Gravitational-Wave Astronomy (2018, background): “For instance, with the first two events it was possible to limit the presence of scalar hair (Yunes et al., 2016).”
• Hořava gravity at a Lifshitz point: A progress report (2017, background): “C, the healthy extension, it is shown that the theory is self-consistent and also consistent not only with solar system tests and cosmological observations, but also with the binary pulsar and gravitational wave observations [152, 153, 155].”