Dark matter candidates: black holes and gravitationally bound black hole atoms in n-space

A comparison is made of a range of proposals to include free and bound black holes as either a small component or the dominant constituent of dark matter. The hypothesis that dark matter consists of atomic gravitationally bound primordial black holes is closely examined in 3-space, as well as in n-space. It is demonstrated that for dimensions greater than 3, stable gravitational or electrostatic atoms cannot be bound by energy constraints. The total number of degrees of freedom of a d-dimensional body in n-space is derived so that equipartition of energy may be applied in the early universe. Blackbody and Hawking radiation are generalized to n-space. A promising new approach to black hole entropy is presented.