Skip to main content
Unpublished Paper
Dynamics of the DBI Spike Soliton
  • David Kastor, University of Massachusetts - Amherst
  • Jennie Traschen, University of Massachusetts - Amherst

We compare oscillations of a fundamental string ending on a D3-brane in two different settings: (1) a test-string radially threading the horizon of an extremal black D3-brane and (2) the spike soliton of the DBI effective action for a D3-brane. Previous work has shown that overall transverse modes of the test-string appear as l=0 modes of the transverse scalar fields of the DBI system. We identify DBI world-volume degrees of freedom that have dynamics matching those of the test-string relative transverse modes. We show that there is a map, resembling T-duality, between relative and overall transverse modes for the test-string that interchanges Neumann and Dirichlet boundary conditions and implies equality of the absorption coefficients for both modes. We give general solutions to the overall and relative transverse parts of the DBI coupled gauge and scalar system and calculate absorption coefficients for the higher angular momentum modes in the low frequency limit. We find that there is a nonzero amplitude for l>0 modes to travel out to infinity along the spike, demonstrating that the spike remains effectively 3+1-dimensional.

Publication Date
December 28, 1999
This is the pre-published version harvested from The published version is located at
Citation Information
David Kastor and Jennie Traschen. "Dynamics of the DBI Spike Soliton" PHYSICAL REVIEW D (1999)
Available at: