Topological D-branes and commutative algebra

Non-commutative branes in D-brane backgrounds

We study Myers world-volume effective action of coincident D-branes. We investigate a system of N0 D0-branes in the near horizon geometry of Dp-branes with p = 2 or p = 4. The choice of coordinates can make the action simplified and tractable. For p = 4, we show that a certain point-like D0-brane configuration solving equations of motion of the action can expand to form a fuzzy two-sphere witho...

Topological Born-Infeld Actions and D-Branes

We propose that the effective field theories of certain wrapped D-branes are given by topological actions based on Born-Infeld theory. In particular, we present a Born-Infeld version of the Abelian Donaldson-Witten theory. We then consider wrapping D3 branes on calibrated submanifolds and for the Calabi-Yau four-fold case, discuss how the resulting theory could give rise to a Born-Infeld versio...

Commutative Algebra Commutative Algebra : General

A Construction of Commutative D-branes from Lower Dimensional Non-BPS D-branes

We construct an exact soliton, which represents a BPS Dp-brane, in a boundary string field theory action of infinitely many non-BPS D(p − 1)-branes. Furthermore, we show that this soliton can be regarded as an exact soliton in the full string field theory. The world-volume theory of the BPS Dp-brane constructed in this way becomes usual gauge theory on commutative R, instead of non-commutative ...

D-branes and the Non-commutative Structure of Quantum Spacetime

A worldsheet approach to the study of non-abelian D-particle dynamics is presented based on viewing matrix-valued D-brane coordinate fields as coupling constants of a deformed σ-model which defines a logarithmic conformal field theory. The shortdistance structure of spacetime is shown to be naturally captured by the Zamolodchikov metric on the corresponding moduli space which encodes the geomet...