Corrective effect of many-body interactions in dynamical friction

Understand

Dynamical friction is a fundamental and important phenomenon in astrophysics.

• The Chandrasekhar formula is a well-known analytical estimation of the effect.
• However, current astrophysicists have realized that the formula is not correct in some cases because of several approximations dared in the formulation and/or complex non-linearities in the real universe.
• For example, it has been indicated that the dynamical friction doesn't work in cored density profiles (constant density in the central region) despite that the Chandrasekhar formula predicts drag force even in the constant densities.