@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}
}
@article {11011,
	title = {Nonabelian Lie algebroid extensions},
	number = {SISSA preprint;06/2014/mate},
	year = {2013},
	abstract = {<p>We classify nonabelian extensions of Lie algebroids in the holomorphic or algebraic category, and introduce and study a spectral sequence that one can attach to any such extension and generalizes the Hochschild-Serre spectral sequence associated to an ideal in a Lie algebra. We compute the differentials of the spectral sequence up to $d_2$</p>},
	keywords = {Lie algebroids, nonabelian extensions, spectral sequences},
	author = {Ugo Bruzzo and Igor Mencattini and Pietro Tortella and Vladimir Rubtsov}
}
@article {2007,
	title = {Numerically flat Higgs vector bundles},
	number = {SISSA;39/2005/FM},
	year = {2007},
	abstract = {After providing a suitable definition of numerical effectiveness for Higgs bundles, and a related notion of numerical flatness, in this paper we prove, together with some side results, that all Chern classes of a Higgs-numerically flat Higgs bundle vanish, and that a Higgs bundle is Higgs-numerically flat if and only if it is has a filtration whose quotients are flat stable Higgs bundles. We also study the relation between these numerical properties of Higgs bundles and (semi)stability.},
	doi = {10.1142/S0219199707002526},
	url = {http://hdl.handle.net/1963/1757},
	author = {Ugo Bruzzo and Beatriz Grana-Otero}
}
@article {2006,
	title = {Normal bundles to Laufer rational curves in local Calabi-Yau threefolds},
	number = {SISSA;88/2005/FM},
	year = {2006},
	abstract = {We prove a conjecture by F. Ferrari. Let X be the total space of a nonlinear deformation of a rank 2 holomorphic vector bundle on a smooth rational curve, such that X has trivial canonical bundle and has sections. Then the normal bundle to such sections is computed in terms of the rank of the Hessian of a suitably defined superpotential at its critical points.},
	doi = {10.1007/s11005-006-0057-7},
	url = {http://hdl.handle.net/1963/1785},
	author = {Ugo Bruzzo and Antonio Ricco}
}
