framed bundles; affine bundles; quot scheme vector bundles on projective surfaces; stable coherent sheaves; moduli spaces; gauge field theory; Donaldson polynomials; Seiberg-Witten invariants; Grauert-Mülich theorem; semi-stable sheaves; geometric invariant theory; conformal quantum field theory; Verlinde formula; Seiberg-Witten theory; Picard groups; determinantal line bundles; Gieseker-Maruyama moduli spaces; Donaldson-Uhlenbeck compactification; differential forms on moduli spaces of stable sheaves; birational properties 