705 research outputs found
Regularizing Cubic Open Neveu-Schwarz String Field Theory
After introducing non-minimal variables, the midpoint insertion of Y\bar Y in
cubic open Neveu-Schwarz string field theory can be replaced with an operator
N_\rho depending on a constant parameter \rho. As in cubic open superstring
field theory using the pure spinor formalism, the operator N_\rho is invertible
and is equal to 1 up to a BRST-trivial quantity. So unlike the linearized
equation of motion Y\bar Y QV=0 which requires truncation of the Hilbert space
in order to imply QV=0, the linearized equation N_\rho QV=0 directly implies
QV=0.Comment: 6 pages harvmac, added footnote and referenc
Manifest Electromagnetic Duality in Closed Superstring Field Theory
The free action for massless Ramond-Ramond fields is derived from closed
superstring field theory using the techniques of Siegel and Zwiebach. For the
uncompactified Type IIB superstring, this gives a manifestly Lorentz-covariant
action for a self-dual five-form field strength. Upon compactification to four
dimensions, the action depends on a U(1) field strength from 4D N=2
supergravity. However, unlike the standard Maxwell action, this action is
manifestly invariant under the electromagnetic duality transformation which
rotates into .Comment: Added three references and corrected one footnote. 15 pages harvma
Vanishing Theorems for the Self-Dual N=2 String
It is proven that up to possible surface terms, the only non-vanishing
momentum-dependent amplitudes for the self-dual N=2 string in are the
tree-level two and three-point functions, and the only non-vanishing
momentum-independent amplitudes are the one-loop partition function and the
tree-level two and four-point functions. The calculations are performed using
the topological prescription developed in an earlier paper with Vafa. As in
supersymmetric non-renormalization theorems, the vanishing proof is based on a
relationship between the zero-momentum dilaton and axion.Comment: 8 pages te
Quantization of the Type II Superstring in a Curved Six-Dimensional Background
A sigma model action with N=2 D=6 superspace variables is constructed for the
Type II superstring compactified to six curved dimensions with Ramond-Ramond
flux. The action can be quantized since the sigma model is linear when the
six-dimensional spacetime is flat. When the six-dimensional spacetime is
, the action reduces to one found earlier with Vafa and
Witten.Comment: 13 pages harvmac te
Superspace Effective Actions for 4D Compactifications of Heterotic and Type II Superstrings
Two-dimensional sigma models are defined for the new manifestly spacetime
supersymmetric description of four-dimensional compactified superstrings. The
resulting target-superspace effective action is constrained by the way the
spacetime dilaton couples to the worldsheet curvature: For the heterotic
superstring, the worldsheet curvature couples to the real part of a chiral
multiplet, and for Type II it couples to the real part of the sum of a vector
multiplet and a tensor hypermultiplet.
For the Type II superstring, this contradicts the standard folklore that only
a hypermultiplet counts string-loops, explains the peculiar dilaton coupling of
Ramond-Ramond fields, and allows the effective action to be easily written in
N=2 4D superspace. It also implies that vector multiplet interactions get no
quantum corrections, while hypermultiplet interactions can only get corrections
if mirror symmetry is non-perturbatively broken.Comment: 45 p. (Replaced sentence on non-local terms and added 2 references
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