Inspiral tests of general relativity and waveform geometry
Phys. Rev. D 114, 024059 – Published 22 July, 2026
DOI: https://doi.org/10.1103/nw3l-qld4
Abstract
The phase evolution of gravitational waves encodes critical information about the orbital dynamics of binary systems. In this work, we test the robustness of parametrized tests against unmodeled deviations from general relativity. We demonstrate that these parametrized tests are flexible and sensitive in detecting generic deviations in the waveform using the Cutler-Vallisneri bias formalism. This universality arises from examining the inherent geometry of the waveform signal and understanding how biases manifest. We show how Bayes factors are governed by the intrinsic geometry of the waveform signal manifold when parametrized tests are used to approximate generic violations of GR. We use the singular value decomposition to propose templates that are orthogonal to parametrized tests, identifying degeneracies and enhancing the detection of potential deviations. More broadly, the geometric framework developed here clarifies—at a fundamental level—how subtle waveform effects (including orbital eccentricity, spin precession, waveform systematics, and instrumental glitches) can mimic one another in data, and when they are intrinsically distinguishable.
