ByElle Pop

Branes and Geometry in String and M
We review the recent developments in the theory of multiple M2 branes and 3 algebras leading to multiple D2 brane theories. The inclusion of flux terms for the supersymmetric BLG and ABJM theories of closed M2 branes is discussed and then generalised to open M2 branes. Here the boundary condition is derived and different BPS configurations are examined where we find a mass deformed Basu Harvey equation for the M2 M5 system. The Lorentzian 3 algebra is then employed for obtaining a theory of D2 branes in a flux background, we then obtain the new fuzzy funnel solution of the system of D2 D4 branes in a flux. Matrix theories and their compactifications as well as noncommutative geometry and noncommutative gauge theories are reviewed with a discussion of their generalisations to three replica bolsa hermes dimensions to be used to describe the M theory three form potential. A new feature of string theory is then obtained called the quantum Nambu geometry (QNG). It is found by considering the action for D1 strings in a RR flux background and we demonstrate that there is a large flux double scaling limit where the action is dominated by a Chern Simons Myers coupling term. A classical solution to this is the quantised spacetime known as the quantum Nambu geometry. Various matrix models are obtained from this action, these are the large flux dominated terms of the full actions for the corresponding matrix models. The QNG gives rise to an expansion of D1 strings to D4 branes in the IIA theory, so we obtain an action for the large flux terms for this action which is verified by a dimensional reduction of the PST action describing M5 branes. We make a generalisation of the D4 brane action to describe M5 branes using a duality. We are describing the 3 form self dual field strength of a non abelian generalisation of the PST action.

## About the author