Gravitons, inflatons, twisted bits: A noncommutative bestiary

In this work, we examine ideas connected with the noncommutativity of spacetime and its realizations in string theory. Motivated by Matrix Theory and the AdS-CFT correspondence, we propose a survey of selected noncommutative objects, assessing their implications for inflation, gauge theory duals, and solvable backgrounds. Our initial pair of examples, related to the Myers effect, incorporate elements of so-called "giant graviton" behavior. In the first, the formation of an extended, supersymmetry-restoring domain wall from point-brane sources in a flux background is related to a nonperturbative process of brane-flux annihilation. In the second, we reexamine these phenomena from a cosmological vantage, investigating the prospect of slow-roll inflation in the noncommutative configuration space of multiple d-branes. For our third and final example, we turn to the solvable pp-wave background, outlining a combinatorial, permutation-based approach to string physics which interpolates between gauge theory and worldsheet methods. This "string bit" language will allow us to find exact agreement between Yang-Mills theory in the large R-charge sector and string field theory on the light cone, resolving some previous discrepancies in the literature.