D-brane solutions in noncommutative gauge theory on fuzzy sphere

Noncommutative gauge theory on a fuzzy sphere was obtained by Alekseev, Recknagel, and Schomerus as describing the low energy dynamics of a spherical D2 brane in S-3 with the background b field. We identify a subset of solutions of this theory which are analogues of "unstable" solitons on a noncommutative flat D2 brane found by Aganagic et al. Analogously to the flat case, these solutions can be interpreted as describing D0 branes "not yet dissolved" by the D2 brane. We confirm this interpretation by showing the precise agreement of the binding energy computed in the noncommutative and ordinary Born-Infeld descriptions. We then study the stability of the solution describing a single D0 brane off a D2 brane. Similarly to the flat case, we find an instability when the D0 brane is located close to the D2 brane. We furthermore obtain the complete mass spectrum of 0-2 fluctuations. which thus gives a prediction for the low energy spectrum of the 0-2 conformal field theory in S-3. We also discuss in detail how the instability to a formation of the fuzzy sphere modifies the usual Higgs mechanism for a small separation between the branes.