3 research outputs found
Quantum AdS_5 x S^5 superstring in the AdS light-cone gauge
We consider the AdS_5 x S^5 superstring in the light-cone gauge adapted to a
massless geodesic in AdS5 in the Poincare patch. The resulting action has a
relatively simple structure which makes it a natural starting point for various
perturbative quantum computations. We illustrate the utility of this AdS
light-cone gauge action by computing the 1-loop and 2-loop corrections to the
null cusp anomalous dimension reproducing in a much simpler and efficient way
earlier results obtained in conformal gauge. This leads to a further insight
into the structure of the superstring partition function in non-trivial
background.Comment: 21pages, Late
Generalized scaling function from light-cone gauge AdS_5 x S^5 superstring
We revisit the computation of the 2-loop correction to the energy of a folded
spinning string in AdS_5 with an angular momentum J in S^5 in the scaling limit
log S, J >>1 with J / log S fixed. This correction gives the third term in the
strong-coupling expansion of the generalized scaling function. The computation,
using the AdS light-cone gauge approach developed in our previous paper, is
done by expanding the AdS_5 x S^5 superstring partition function near the
generalized null cusp world surface associated to the spinning string solution.
The result corrects and extends the previous conformal gauge result of
arXiv:0712.2479 and is found to be in complete agreement with the corresponding
terms in the generalized scaling function as obtained from the asymptotic Bethe
ansatz in arXiv:0805.4615 (and also partially from the quantum O(6) model and
the Bethe ansatz data in arXiv:0809.4952). This provides a highly nontrivial
strong coupling comparison of the Bethe ansatz proposal with the quantum AdS_5
x S^5 superstring theory, which goes beyond the leading semiclassical term
effectively controlled by the underlying algebraic curve. The 2-loop
computation we perform involves all the structures in the AdS light-cone gauge
superstring action of hep-th/0009171 and thus tests its ultraviolet finiteness
and, through the agreement with the Bethe ansatz, its quantum integrability. We
do most of the computations for a generalized spinning string solution or the
corresponding null cusp surface that involves both the orbital momentum and the
winding in a large circle of S^5.Comment: 50 pages, late
One-loop corrections to AdS_5 x S^5 superstring partition function via Pohlmeyer reduction
We discuss semiclassical expansions around a class of classical string
configurations lying in AdS_3 x S^1 using the Pohlmeyer-reduced from of the
AdS_5 x S^5 superstring theory. The Pohlmeyer reduction of the AdS_5 x S^5
superstring theory is a gauged Wess-Zumino-Witten model with an integrable
potential and two-dimensional fermionic fields. It was recently conjectured
that the quantum string partition function is equal to the quantum reduced
theory partition function. Continuing the previous paper (arXiv:0906.3800)
where arbitrary solutions in AdS_2 x S^2 and homogeneous solutions were
considered, we provide explicit demonstration of this conjecture at the
one-loop level for several string solutions in AdS_3 x S^1 embedded into AdS_5
x S^5. Quadratic fluctuations derived in the reduced theory for inhomogeneous
strings are equivalent to respective fluctuations found from the Nambu action
in the original string theory. We also show the equivalence of fluctuation
frequencies for homogeneous strings with both the orbital momentum and the
winding on a big circle of S^5.Comment: 45 pages, references added, minor correction