1,269 research outputs found
Born-Infeld Dynamics in Uniform Electric Field
We investigate various properties of classical configurations of the
Born-Infeld theory in a uniform electric field. This system is involved with
dynamics of (F,Dp) bound states, which are bound states of fundamental strings
and Dp-branes. The uniform electric field can be treated as a constraint on the
asymptotic behavior of the fields on the brane. BPS configurations in this
theory correspond to fundamental strings attached to the (F,Dp) bound state,
and are found to be stable due to force balance. Fluctuations around these
stable configurations are subject to appropriate Dirichlet and Neumann boundary
conditions which are identical with the ones deduced from the ordinary
worldsheet description of the attached string. Additionally, non-BPS solutions
are studied and related physics are discussed.Comment: 16 pages, 2 figures ; references adde
Generalized Supersymetric Boundary State
Following our previous paper (hep-th/9909027), we generalize a supersymmetric
boundary state so that arbitrary configuration of the gauge field coupled to
the boundary of the worldsheet is incorpolated. This generalized boundary state
is BRST invariant and satisfy the non-linear boundary conditions with
non-constant gauge field strength. This boundary state contains divergence
which is identical with the loop divergence in a superstring sigma model. Hence
vanishing of the beta function in the superstring sigma model corresponds to a
well-defined boundary state with no divergence. The coupling of a single closed
superstring massless mode with multiple open string massless modes is encoded
in the boundary state, and we confirm that derivative correction to the D-brane
action in this sector vanishes up to the first non-trivial order
O(alpha'(derivative)^2). Combining T-dualities, we incorpolate also general
configurations of the scalar fields on the D-brane, and construct boundary
states representing branes stuck to another D-brane, with use of BIon
configuration.Comment: 27 pages, LaTeX, 1 eps figure, typos correcte
Branes Ending On Branes In A Tachyon Model
In a tachyon model proposed by Minahan and Zwiebach and derived in the
boundary string field theory, we construct various new solutions which
correspond to nontrivial brane configurations in string theory. Our solutions
include Dp-D(p-2) bound states, (F, Dp) bound states, string junctions,
D(p-2)-branes ending on a Dp-brane, D(p-2)-branes suspended between parallel
Dp-branes and their non-commutative generalizations. We find the Bogomol'nyi
bounds and the BPS equations for some of our solutions, and check the physical
consistency of our solutions with the D-brane picture by looking at the
distributions of their energies and RR-charges in space. We also give
conjectures for a few other brane configurations.Comment: 19 pages, LaTeX, minor corrections and references adde
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