Let $U(n)$ denote the unitary group (this is a manifold of dimension $n^2$). Let 
$$
{\cal D} \subset U(n)
$$ 
denote the subspace of those matrices having
a non-trivial $(+1)$-eigenspace. 

**Background:** It is known that $\cal D$ has vanishing homology
in dimension $n^2$. It is also not difficult to show that $H_{n^2-1}({\cal D}) \cong \Bbb Z$. Furthermore, it is known that ${\cal D}$ has the structure of a finite CW complex of dimension $n^2-1$.

For $g\in {\cal D}$, define the *local homology* by
$$
H_{n^2-1}({\cal D}\, |\, g;\Bbb Q) := H_{n^2-1}({\cal D},{\cal D} \setminus g;\Bbb Q)\, .
$$

**Question:** For arbitrary $g\in {\cal D}$ is the rank of this group known? 

If yes, can anyone provide a reference?

**Remark:**
Based on a direct computation when $n=2$, it seems reasonable to conjecture that the rank of $H_{n^2-1}({\cal D}\, |\, g;\Bbb Q)$ is equal to the dimension of the $(+1)$-eigenspace of $g$ (i.e., the multiplicity of the eigenvalue +1).