“…The geometry and topology of these moduli spaces have been extensively studied. General results include the nonemptiness (see 21,18,13]), generic smoothness and irreducibility (see 3,8,27,10,24,11,25]), and variations of these moduli spaces (see 12,14,6,9,23]). There are also some speci c results for these moduli spaces over particular surfaces (see 4,5,16,18,19,26,28] for some of the papers).…”