82 research outputs found

### New Superstring Isometries and Hidden Dimensions

We explore the hierarchy of hidden space-time symmetries of noncritical
strings in RNS formalism, realized nonlinearly. Under these symmetry
transformations the variation of the matter part of the RNS action is cancelled
by that of the ghost part. These symmetries, referred to as the
$\alpha$-symmetries, are induced by special space-time generators, violating
the equivalence of ghost pictures. We classify the $\alpha$-symmetry generators
in terms of superconformal ghost cohomologies $H_{n}\sim{H_{-n-2}}(n\geq{0})$
and associate these generators with a chain of hidden space-time dimensions,
with each ghost cohomology $H_{n}\sim{H_{-n-2}}$ ``contributing'' an extra
dimension. Namely, we show that each ghost cohomology $H_{n}\sim{H_{-n-2}}$ of
non-critical superstring theory in $d$-dimensions contains $d+n+1$
$\alpha$-symmetry generators and the generators from
$H_{k}\sim{H_{-k-2}},1\leq{k}\leq{n}$, combined together, extend the space-time
isometry group from the naive $SO(d,2)$ to $SO(d+n,2)$. In the simplest case of
$n=1$ the $\alpha$-generators are identified with the extra symmetries of the
$2T$-physics formalism, also known to originate from a hidden space-time
dimension.Comment: 26 pages typos correcte

### String Theory and Emergent AdS Geometry in Higher Spin Field Theories

We analyze the Weyl invariance constraints on higher spin vertex operators in
open superstring theory describing massless higher spin gauge field excitations
in d-dimensional space-time. We show that these constraints lead to low-energy
equations of motion for higher spin fields in AdS space, with the leading order
beta-function for the higher spin fields producing Fronsdal's operator in
$AdS_{d+1}$, despite that the higher spin vertex operators are originally
defined in flat background. The correspondence between the $\beta$-function in
string theory and $AdS_{d+1}$ Fronsdal operators in space-time is found to be
exact for $d=4$, while for other space-time dimensions it requires
modifications of manifest expressions for the higher spin vertex operators.
We argue that the correspondence considered in this paper is the leading
order of more general isomorphism between Vasiliev's equations and equations of
motion of extended open string field theory (OSFT), generalized to include the
higher spin operators.Comment: 28 page

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