Vafa, Cumrun2019-09-221996Vafa, Cumrun. 1996. “Instantons on D-Branes.” Nuclear Physics B 463 (2–3): 435–42. https://doi.org/10.1016/0550-3213(96)00075-2.0169-68230550-32131873-1562http://nrs.harvard.edu/urn-3:HUL.InstRepos:41385068We consider type IIA compactification on K3. We show that the instanton subsectors of the worldvolume of N 4-branes wrapped around K3 lead to a Hagedorn density of BPS states in accord with heterotic-type IIA duality in 6 dimensions. We also find evidence that the correct framework to understand the results of Nakajima on the appearance of affine Kac-Moody algebras on the cohomology of moduli space of instantons on ALE spaces is in the context of heterotic-type IIA string duality.en-USJournal Article2019-09-2210.1016/0550-3213(96)00075-2