Dynamical Decay of Brane-Antibrane and Dielectric Brane

TL;DR

This paper investigates the decay processes of unstable brane systems using effective field theories, providing explicit decay widths and new solutions for brane nucleation relevant to string theory and cosmology.

Contribution

It offers explicit calculations of decay widths for brane-antibrane pairs and dielectric branes, introducing new solutions and insights into their decay mechanisms.

Findings

Decay width for brane-antibrane pair proportional to exp(-l^{p+1} T_{Dp})

Identification of bubble nucleation as decay mechanism for brane-antibrane annihilation

New doughnut-shaped solutions for dielectric brane nucleation from nothing

Abstract

Using D-brane effective field theories, we study dynamical decay of unstable brane systems : (i) a parallel brane-antibrane pair with separation l and (ii) a dielectric brane. In particular we give explicitly the decay width of these unstable systems, and describe how the decay proceeds after the tunnel effect. The decay (i) is analysed by the use of a tachyon effective action on the Dp-Dpbar. A pair annihilation starts by nucleation of a bubble of a tachyon domain wall which represents a throat connecting these branes, and the tunneling decay width is found to be proportional to exp(-l^{p+1} T_{Dp}). We study also the decay leaving topological defects corresponding to lower-dimensional branes, which may be relevant for recent inflationary braneworld scenario. As for the decay (ii), first we observe that Dp-branes generically ``curl up'' in a nontrivial RR field strength. Using this viewpoint, we compute the decay width of the dielectric D2-branes by constructing relevant Euclidean bounce solutions in the shape of a funnel. We also give new solutions in doughnut shape which are involved with nucleation of dielectric branes from nothing.