Search

This paper classifies a class of holomorphic D-branes, closely related to framed torsion-free sheaves, on threefolds fibered in resolved ADE surfaces over a general curve C, in terms of representations with relations of a twisted Kronheimer–Nakajima-type quiver in the category Coh( C) of coherent sheaves on C. For the local Calabi–Yau case $$C\cong{\bf A}^1$$ and special choice of framing, one recovers the N = 1 ADE quiver studied by Cachazo–Katz–Vafa. [ABSTRACT FROM AUTHOR]

The authors give a complete classification of projective threefolds admitting a holomorphic conformal structure. A corollary is the complete list of projective threefolds, whose tangent bundle is a symmetric square. [ABSTRACT FROM AUTHOR]

Let X be an n-dimensional non-degenerated subvariety of PN with N ≥ 2n + 1. We give a rough classification for varieties X having Gn-1;n-defect. In case n = 3, we give a fine classification for smooth varieties X having G2,3-defect. [ABSTRACT FROM AUTHOR]