  On the cosmological length scale, recent measurements by WMAP have validated
$\Lambda$CDM to a precision not see before in cosmology. Such is not the case
on galactic length scales, however, where the `cuspy-core' problem has
demonstrated our lack of understanding of structure formation. Here, we propose
a solution to the 'cuspy-core' problem based on the observation that with the
discovery of Dark Energy, $\Lambda_{DE}$, there is now a universal length
scale, $\lambda_{DE}=c/(\Lambda_{DE} G)^{1/2}$, associated with the universe.
This length scale allows for an extension of the geodesic equations of motion
that affects only the motion of massive test particles; the motion of massless
test particles are not affected, and such phenomenon as gravitational lensing
remain unchanged. An evolution equation for the density profile is derived, and
an effective free energy density functional for it is constructed. We
conjecture that the pseudoisothermal profile is preferred over the cusp-like
profile because it has a lower effective free energy. A cosmological check of
the theory is made using the observed rotational velocities and core sizes of
1393 spiral galaxies. We calculate $\sigma_8$ to be $0.68_{\pm0.11}$; this is
within experimental error of the WMAP value $0.761_{-0.048}^{+0.049}$. We then
calculate $R_{200}=270_{\pm 130}$ kpc, which is in agreement with observations.
We estimate the fractional density of matter that cannot be determined through
gravity to be $0.197_{\pm 0.017}$; this is nearly equal to the WMAP value for
the fractional density of nonbaryonic matter $0.196^{+0.025}_{-0.026}$. The
fractional density of matter that can be determined through gravity is then
calculated to be $0.041_{-0.031}^{+0.030}$; this is nearly equal to
$\Omega_B=0.0416_{-0.0039}^{+0.0038}$.
