Abstract:
We study the groups of conformal transformations of $n$-dimensional
pseudo-Riemannian orbifolds $({\mathcal N},g)$ as $n\geq 3$.
We extend the Alekseevskii method for studying conformal transformation groups of
Riemannian manifolds to pseudo-Riemannian orbifolds. We show that
a conformal pseudo-Riemannian geometry is induced on each stratum of such orbifold. Due to this,
for $k\in\{0,1\}\cup\{3,\ldots,n-1\}$, we obtain exact estimates for the dimensions of the conformal
transformation groups of $n$-dimensional pseudo-Riemannian orbifolds admitting $k$-dimensional
stratum with essential groups of conformal transforms.
A key fact in obtaining these estimates is that each connected transformation group of an
orbifold preserves every connected component of each its stratum.
The influence of stratification of $n$-dimensional pseudo-Riemann orbifold
to the similarity transformation group of this orbifold is also studied for $n\geq 2$.
We prove that the obtained estimates for the dimension of the complete essential groups of conformal
transformations and the similarity transformation groups of $n$-dimensional pseudo-Riemann orbifolds are sharp; this is done by adducing corresponding examples of locally flat pseudo-Riemannian orbifolds.