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Effective Field Theory for Extreme Mass Ratio Binaries
Clifford Cheung1, Julio Parra-Martinez1,2, Ira Z Rothstein3
1Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125, USA.
Physical Review Letters
|March 15, 2024
Summary
We developed a new theory for how two bodies interact gravitationally, considering their mass difference. This approach accurately calculates gravitational dynamics, including effects from additional fields.
Area of Science:
- Gravitational physics
- Effective field theories
- General relativity
Background:
- Understanding gravitational interactions between massive bodies is crucial in astrophysics and cosmology.
- Previous models often simplified the mass ratio or did not fully account for self-force effects.
Purpose of the Study:
- To derive an effective field theory for gravitationally interacting point particles using a mass-ratio expansion (self-force expansion).
- To compute conservative dynamics at third post-Minkowskian order, incorporating scalar and vector fields.
Main Methods:
- Developed an effective field theory based on the self-force expansion.
- Incorporated geodesic deviation and fluctuation gravitons.
- Included a heavy body recoil operator.
- Calculated dynamics at third post-Minkowskian order.
Main Results:
- Derived the 0SF dynamics from geodesic motion in a Schwarzschild background.
- Accounted for 1SF and higher corrections through perturbations and a recoil operator.
- Computed new results for conservative dynamics in the presence of scalar and vector fields.
Conclusions:
- The derived effective field theory provides a systematic framework for studying binary systems with disparate masses.
- The inclusion of a heavy body recoil operator is essential for accurate self-force calculations.
- The results offer a more complete description of gravitational interactions, applicable to various astrophysical scenarios.
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