Absorption of fixed scalar in scattering off 4D N = 4 black holes

We perform the perturbation analysis of the black holes in the 4D, N = 4 supergravity. Analysis around the black holes reveals a complicated mixing between the dilation and other fields (metric and two U(1) Maxwell fields). It turns out that considering both s-wave (l = 0) and higher momentum modes (l ≠ 0), the dilaton as a fixed scalar is the only propagating mode when P = Q, h1 = h2 = 0 and F = −G = 2ϕ. We calculate the absorption cross-section for scattering of low frequency waves of fixed scalar and U(1) Maxwell fields off the extremal black hole.