2,614 research outputs found
The b Ghost of the Pure Spinor Formalism is Nilpotent
The ghost for world-sheet reparametrization invariance is not a fundamental
field in the pure spinor formalism. It is written as a combination of pure
spinor variables which have conformal dimension two and such that it commutes
with the BRST operator to give the world-sheet stress tensor. We show that the
ghost variable defined in this way is nilpotent since the OPE of b with itself
does not have singularities.Comment: 12 pages, harvmac-b. Minor change
First Massive State of the Superstring in Superspace
Using the manifestly spacetime supersymmetric description of the
four-dimensional open superstring, we construct the vertex operator in
superspace for the first massive state. This construction provides an N=1 D=4
superspace representation of the massive spin-2 multiplet.Comment: 7 pages late
Quantization of the Superstring with Manifest U(5) Super-Poincare Invariance
The superstring is quantized in a manner which manifestly preserves a U(5)
subgroup of the (Wick-rotated) ten-dimensional super-Poincar\'e invariance.
This description of the superstring contains critical N=2 worldsheet
superconformal invariance and is a natural covariantization of the
U(4)-invariant light-cone Green-Schwarz description.Comment: Added two comments on relation to light-cone gaug
Superstring Vertex Operators in an AdS_5 x S^5 Background
A quantizable action has recently been proposed for the superstring in an
AdS_5 x S^5 background with Ramond-Ramond flux. In this paper, we construct
physical vertex operators corresponding to on-shell fluctuations around the
AdS_5 x S^5 background. The structure of these AdS_5 x S^5 vertex operators
closely resembles the structure of the massless vertex operators in a flat
background.Comment: 13 pages harvmac (large
Super-Poincare Invariant Koba-Nielsen Formulas for the Superstring
The new spacetime-supersymmetric description of the superstring is used to
compute tree-level scattering amplitudes for an arbitrary number of massless
four-dimensional states. The resulting Koba-Nielsen formula is manifestly
SO(3,1) super-Poincare invariant and is easily generalized to scattering in the
presence of a D-brane.Comment: 11 pages harvma
Massive Superstring Vertex Operator in D=10 Superspace
Using the pure spinor formalism for the superstring, the vertex operator for
the first massive states of the open superstring is constructed in a manifestly
super-Poincar\'e covariant manner. This vertex operator describes a massive
spin-two multiplet in terms of ten-dimensional superfields.Comment: Added reference
One-Loop N-Point Superstring Amplitudes with Manifest d=4 Supersymmetry
The hybrid formalism for the superstring is used to compute one-loop
amplitudes with an arbitrary number of external d=4 supergravity states. These
one-loop N-point amplitudes are expressed as Koba-Nielsen-like formulas with
manifest d=4 supersymmetry.Comment: 18 pages harvma
Y-formalism and ghost in the Non-minimal Pure Spinor Formalism of Superstrings
We present the Y-formalism for the non-minimal pure spinor quantization of
superstrings. In the framework of this formalism we compute, at the quantum
level, the explicit form of the compound operators involved in the construction
of the ghost, their normal-ordering contributions and the relevant
relations among them. We use these results to construct the quantum-mechanical
ghost in the non-minimal pure spinor formalism. Moreover we show that this
non-minimal ghost is cohomologically equivalent to the non-covariant
ghost.Comment: 42 pages, no figure
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
The Ten-Dimensional Green-Schwarz Superstring is a Twisted Neveu-Schwarz-Ramond String
An action for the ten-dimensional Green-Schwarz superstring with N=2
worldsheet superconformal invariance has recently been used to calculate
superstring scattering amplitudes and prove their finiteness. In this paper, it
is shown that the N=2 stress-energy tensor for this Green-Schwarz action can be
constructed out of the stress-energy tensor and ghosts of the Neveu-
Schwarz-Ramond action by the standard twisting procedure. In other words, a
field redefinition is found from the GS matter fields into the NSR matter and
ghost fields which transforms the matter part of the two fermionic GS super-
conformal generators into the ghost and shifted BRST current of the NSR
string. In light-cone gauge, this field redefinition reduces to the usual one
relating the light-cone GS and NSR fields.
Although this proves the equivalence of physical vertex operators in the two
superstring formalisms, multiloop amplitudes are easier to calculate using the
Green-Schwarz formalism since manifest spacetime supersymmetry eliminates the
need for spin cuts, GSO projections, and cutoffs in moduli space.Comment: 6 pages plain Tex, KCL-TH-1
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