This is the second part of a project concerning variation of stability and chamber structure for ADHM invariants of curves. Wallcrossing formulas for such invariants are derived using the theory of stack function RingelHall algebras constructed by Joyce and the theory of generalized DonaldsonThomas invariants of Joyce and Song. It is shown that these formulas imply the BPS rationality conjectur...

A discussão incide sobre o modo como Lacan, em distintos trabalhos do seu ensino, a partir de Joyce relaciona corpo palavra com topologia nós.

If M is a quaternionic manifold and P is an S 1-instanton over M , then Joyce constructed a hypercomplex manifold we call P (M) over M. These hypercomplex manifolds admit a U(2)-action of a special type permuting the complex structures. We show that up to double covers, all such hypercomplex manifolds arise in this way. Examples, including that of a hypercomplex structure on SU(3), show the nec...