Tensionless string spectra on AdS3 Gaberdiel, Matthias R.; Gopakumar, Rajesh
The journal of high energy physics,
05/2018, Letnik:
2018, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A
bstract
The spectrum of superstrings on AdS
3
× S
3
×
M
4
with pure NS-NS flux is analysed for the background where the radius of the AdS space takes the minimal value (
k
= 1). Both for
M
4
= S
3
...× S
1
and
M
4
=
T
4
we show that there is a special set of physical states, coming from the bottom of the spectrally flowed continuous representations, which agree in precise detail with the single particle spectrum of a free symmetric product orbifold. For the case of AdS
3
× S
3
×
T
4
this relies on making sense of the world-sheet theory at
k
= 1, for which we make a concrete proposal. We also comment on the implications of this striking result.
The worldsheet dual of the symmetric product CFT Eberhardt, Lorenz; Gaberdiel, Matthias R.; Gopakumar, Rajesh
The journal of high energy physics,
04/2019, Letnik:
2019, Številka:
4
Journal Article
Recenzirano
Odprti dostop
A
bstract
Superstring theory on
AdS
3
×
S
3
×
T
4
with the smallest amount of NS-NS flux (“
k
= 1”) is shown to be dual to the spacetime CFT given by the large
N
limit of the free symmetric product ...orbifold Sym
N
T
4
. To define the worldsheet theory at
k
= 1, we employ the hybrid formalism in which the AdS
3
× S
3
part is described by the
p
s
u
1
,
1
|
2
1
WZW model (which is well defined). Unlike the case for
k
≥ 2, it turns out that the string spectrum at
k
= 1 does
not
exhibit the long string continuum, and perfectly matches with the large
N
limit of the symmetric product. We also demonstrate that the fusion rules of the symmetric orbifold are reproduced from the worldsheet perspective. Our proposal therefore affords a tractable worldsheet description of a tensionless limit in string theory, for which the dual CFT is also explicitly known.
Deriving the AdS3/CFT2 correspondence Eberhardt, Lorenz; Gaberdiel, Matthias R.; Gopakumar, Rajesh
The journal of high energy physics,
02/2020, Letnik:
2020, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A
bstract
It was recently argued that string theory on AdS
3
×
S
3
×
𝕋
4
with one unit (
k
= 1) of NS-NS flux is exactly dual to the symmetric orbifold CFT Sym
N
(𝕋
4
). In this paper we show how ...to directly relate the
n
-point correlators of the two sides to one another. In particular, we argue that the correlators of the world-sheet theory are delta-function- localised in string moduli space to those configurations that allow for a holomorphic covering map of the S
2
-boundary of AdS
3
by the world-sheet. This striking feature can be seen both from a careful Ward identity analysis, as well as from semi-classically exact AdS
3
solutions that are pinned to the boundary. The world-sheet correlators therefore have exactly the same structure as in the Lunin-Mathur construction of symmetric orbifold CFT correlators in terms of a covering surface — which now gets identified with the world-sheet. Together with the results of
1
,
2
this essentially demonstrates how the
k
= 1 AdS
3
string theory becomes equivalent to the spacetime orbifold CFT in the genus expansion.
For string theory on AdS3 with pure NS-NS flux a complete set of DDF operators is constructed, from which one can read off the symmetry algebra of the spacetime CFT. Together with an analysis of the ...spacetime spectrum, this allows us to show that the long string sector of superstring theory on AdS3×S3×T4 for generic NS-NS flux is described by the symmetric orbifold of (N=4Liouville theory)×T4. For the case of minimal flux (k=1), the Liouville factor disappears, and we just obtain the symmetric orbifold of T4, thereby giving further support to a previous claim. We also show that a similar analysis can be done for bosonic string theory on AdS×3X.
BPS correlators for AdS3/CFT2 Gaberdiel, Matthias R.; Nairz, Beat
The journal of high energy physics,
09/2022, Letnik:
2022, Številka:
9
Journal Article
Recenzirano
Odprti dostop
A
bstract
The BPS correlators of the symmetric product orbifold Sym
N
(𝕋
4
) are reproduced from the dual worldsheet theory describing strings on AdS
3
×
S
3
×
𝕋
4
with minimal (
k
= 1) NS-NS flux. ...More specifically, we show that the worldsheet duals of the symmetric orbifold BPS states can be identified with their lift to the covering surface, thereby making the matching of the correlators essentially manifest. We also argue that the argument can be generalised to arbitrary descendants, using suitable DDF operators on the worldsheet.
A
bstract
The worldsheet string theory dual to free 4d
N
= 4 super Yang-Mills theory was recently proposed in
1
. It is described by a free field sigma model on the twistor space of AdS
5
× S
5
, ...and is a direct generalisation of the corresponding model for tensionless string theory on AdS
3
× S
3
. As in the case of AdS
3
, the worldsheet theory contains spectrally flowed representations. We proposed in
1
that in each such sector only a finite set of generalised zero modes (‘wedge modes’) are physical. Here we show that after imposing the appropriate residual gauge conditions, this worldsheet description reproduces precisely the spectrum of the planar gauge theory. Specifically, the states in the sector with
w
units of spectral flow match with single trace operators built out of
w
super Yang-Mills fields (‘letters’). The resulting physical picture is a covariant version of the BMN light-cone string, now with a finite number of twistorial string bit constituents of an essentially topological worldsheet.
Higher spins & strings Gaberdiel, Matthias R.; Gopakumar, Rajesh
The journal of high energy physics,
11/2014, Letnik:
2014, Številka:
11
Journal Article
Recenzirano
Odprti dostop
A
bstract
It is natural to believe that the free symmetric product orbifold CFT is dual to the tensionless limit of string theory on AdS
3
× S
3
×
T
4
. At this point in moduli space, string theory ...is expected to contain a Vasiliev higher spin theory as a subsector. We confirm this picture explicitly by showing that the large level limit of the
N
=4 cosets of arXiv:1305.4181, that are dual to a higher spin theory on AdS
3
, indeed describe a closed subsector of the symmetric product orbifold. Furthermore, we reorganise the full partition function of the symmetric product orbifold in terms of representations of the higher spin algebra (or rather its
W
∞
extension). In particular, the unbroken stringy symmetries of the tensionless limit are captured by a large chiral algebra which we can describe explicitly in terms of an infinite sum of
W
∞
representations, thereby exhibiting a vast extension of the conventional higher spin symmetry.
Free field world-sheet correlators for AdS3 Dei, Andrea; Gaberdiel, Matthias R.; Gopakumar, Rajesh ...
The journal of high energy physics,
02/2021, Letnik:
2021, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A
bstract
We employ the free field realisation of the
psu
1
1
2
1
world-sheet theory to constrain the correlators of string theory on AdS
3
×
S
3
×
𝕋
4
with unit NS-NS flux. In particular, we ...directly obtain the unusual delta function localisation of these correlators onto branched covers of the boundary S
2
by the (genus zero) world-sheet — this is the key property which makes the equivalence to the dual symmetric orbifold manifest. In our approach, this feature follows from a remarkable ‘incidence relation’ obeyed by the correlators, which is reminiscent of a twistorial string description. We also illustrate our results with explicit computations in various special cases.
String theory as a higher spin theory Gaberdiel, Matthias R.; Gopakumar, Rajesh
The journal of high energy physics,
09/2016, Letnik:
2016, Številka:
9
Journal Article
Recenzirano
Odprti dostop
A
bstract
The symmetries of string theory on
AdS
3
×
S
3
×
T
4
at the dual of the symmetric product orbifold point are described by a so-called Higher Spin Square (HSS). We show that the massive ...string spectrum in this background organises itself in terms of representations of this HSS, just as the matter in a conventional higher spin theory does so in terms of representations of the higher spin algebra. In particular, the entire untwisted sector of the orbifold can be viewed as the Fock space built out of the multiparticle states of a
single
representation of the HSS, the so-called ‘minimal’ representation. The states in the twisted sector can be described in terms of tensor products of a novel family of representations that are somewhat larger than the minimal one.
PDF
