@article {2014,
	title = {N = 2 Quiver Gauge Theories on A-type ALE Spaces},
	number = {Letters in mathematical physics;volume 105; issue 3; pages 401-445;},
	year = {2014},
	publisher = {Springer},
	abstract = {We survey and compare recent approaches to the computation of the partition functions and correlators of chiral BPS observables in N = 2 gauge theories on ALE spaces based on quiver varieties and the minimal resolution Xk of the Ak-1 toric singularity C2/Zk, in light of their recently conjectured duality with two-dimensional coset conformal field theories. We review and elucidate the rigorous constructions of gauge theories for a particular family of ALE spaces, using their relation to the cohomology of moduli spaces of framed torsion-free sheaves on a suitable orbifold compactification of Xk. We extend these computations to generic N = 2 superconformal quiver gauge theories, obtaining in these instances new constraints on fractional instanton charges, a rigorous proof of the Nekrasov master formula, and new quantizations of Hitchin systems based on the underlying Seiberg{\textendash}Witten geometry.},
	doi = {10.1007/s11005-014-0734-x},
	url = {http://urania.sissa.it/xmlui/handle/1963/34719},
	author = {Ugo Bruzzo and Francesco Sala and Richard J. Szabo}
}
