@article {2008,
	title = {Existence of conformal metrics with constant $Q$-curvature},
	journal = {Ann. of Math. 168 (2008) 813-858},
	number = {SISSA;70/2004/M},
	year = {2008},
	abstract = {Given a compact four dimensional manifold, we prove existence of conformal metrics with constant $Q$-curvature under generic assumptions. The problem amounts to solving a fourth-order nonlinear elliptic equation with variational structure. Since the corresponding Euler functional is in general unbounded from above and from below, we employ topological methods and minimax schemes, jointly with a compactness result by the second author.},
	url = {http://hdl.handle.net/1963/2308},
	author = {Zindine Djadli and Andrea Malchiodi}
}
