D. Pollack, COMPACTNESS RESULTS FOR COMPLETE METRICS OF CONSTANT POSITIVE SCALAR CURVATURE ON SUBDOMAINS OF S(N), Indiana University mathematics journal, 42(4), 1993, pp. 1441-1456
In this paper we prove that the set of metrics conformal to the standa
rd metric on S(n)\{P1,...,P(k)}, where {p1,...,p(k)} is an arbitrary s
et of k > 1 points, is compact in the C(m,alpha) topology, provided th
e Dilational Pohozaev invariants are bounded away from zero. Such metr
ics are necessarily complete on S(n)\{p1,...,p(k)} and asymptotic, at
each singular point, to one of the periodic, spherically symmetric sol
utions on the positive n-dimensional half cylinder, which are known as
Delaunay metrics. The Pohozaev invariants are defined at each singula
r point, and their dilational component is shown to be equal to a dime
nsional constant times the Hamiltonian energy of the asymptotic Delaun
ay metric. We also address the issue of convergence when the invariant
s tend to zero for a proper subset of the singular points.