required to be highly coherent and correlated with ${r_\mathrm{soi}}$ already before the black hole growth. Our coreless galaxies do not provide evidence for this. Second, adiabatic black hole growth steepens the central light profile [@Young80] and thus cannot explain the formation of cores in the first place. Core creation through dynamical friction-driven angular momentum transfer from infalling objects [@Goerdt10] and core expansion in reaction to gas ejection by an active galactic nucleus [@Martizzi12] are unlikely as well. These processes are not directly linked to the mass of the central black hole and hence cannot explain the fact that cores sizes correlate tightly with ${M_\bullet}$ [@Rusli13b]. These processes might, however, be important for less massive, fast-rotating core galaxies [e.g. @Krajnovic13].

Core Formation by Binary Black Holes
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@Quinlan97 studied the response of a galaxy’s orbital anisotropy and its 3D density profile to a central, equal-mass black hole binary, starting from isotropic systems with various inner logarithmic density slopes. We fit core radii ${r_b}$ to their simulations with black hole masses in the range ${M_\bullet}= (0.005 -
0.02) \, M_\mathrm{tot}$, and initial slopes $\gamma = \{-1,-2\}$, typical for power-law ellipticals. To ensure compatibility with the core radii measured in real galaxies, the 