8 research outputs found
Noncommutative N=2 Strings
We analyze open and mixed sector tree-level amplitudes of N=2 strings in a
space-time with (2,2) signature, in the presence of constant B field. The
expected topological nature of string amplitudes in the open sector is shown to
impose nontrivial constraints on the corresponding noncommutative field theory.
In the mixed sector, we first compute a 3-point function and show that the
corresponding field theory is written in terms of a generalized *-product. We
also analyze a 4-point function (A_{oooc}) of the mixed sector in Theta --->
infinity limit.Comment: 1+9 pages, LaTex, 1 ps figure; final version to appear in JHE
Bound States of String Networks and D-branes
We show the existence of non-threshold bound states of (p, q) string networks
and D3-branes, preserving 1/4 of the full type IIB supersymmetry, interpreted
as string networks dissolved in D3-branes. We also write down the expression
for the mass density of the system and discuss the extension of the
construction to other Dp-branes. Differences in our construction of string
networks with the ones interpreted as dyons in N=4 gauge theories are also
pointed out.Comment: 11 pages, latex, minor modifications (version to appear in Phys. Rev.
Lett.