Scattering and absorption of a scalar field impinging on a charged black hole in the Einstein-Maxwell-dilaton theory

Understand

This study revisits the absorption and scattering process by which a massless scalar field impinges on a charged dilatonic black hole.

• First, we review the classical analysis to obtain the deflection angle and the differential scattering cross-section.
• Then, using the partial wave method, we determine the total absorption cross-section numerically in terms of the decoupling parameter called $M\omega$, finding that the amplitude of the dilatonic black hole is lower than the Reissner-Nordstr\"om one for mild frequencies.
• In the high-frequency limit, the absorption cross-section exhibits two different complex behaviors; the fine structure and the hyperfine structure.