Exact Gravitational Wave Signatures from Colliding Extreme Black Holes

Understand

The low-energy dynamics of any system admitting a continuum of static configurations is approximated by slow motion in moduli (configuration) space.

• Here, following Ferrell and Eardley, this moduli space approximation is utilized to study collisions of two maximally charged Reissner--Nordstr{\"o}m black holes of arbitrary masses, and to compute analytically the gravitational radiation generated by their scattering or coalescence.
• The motion remains slow even though the fields are strong, and the leading radiation is quadrupolar.
• A simple expression for the gravitational waveform is derived and compared at early and late times to expectations.