In D dimensions, show that the density of states of particles with spin degeneracy g in a volume V is
g(k)dk=Γ(2D+1)(2π)DgVDπD/2kD−1dk.(25.31)
You may need to use the fact that the volume of a sphere of radius r in D dimensions is (see Appendix C.8)
Γ(2D+1)πD/2rD.(25.32)