125 research outputs found
On the Derivation of the Exact Slope Function
In this note we give a simple derivation of the exact slope function
conjectured by Basso for the anomalous dimensions of Wilson operators in the
sl2 sector of planar N=4 Super-Yang-Mills theory. We also discuss
generalizations of this result for higher charges and other sectors.Comment: 8pages. v2: minor corrections, JHEP versio
Analytic Solution of Bremsstrahlung TBA
We consider the quark--anti-quark potential on the three sphere or the
generalized cusp anomalous dimension in planar N=4 SYM. We concentrate on the
vacuum potential in the near BPS limit with units of R-charge.
Equivalently, we study the anomalous dimension of a super-Wilson loop with L
local fields inserted at a cusp. The system is described by a recently proposed
infinite set of non-linear integral equations of the Thermodynamic Bethe Ansatz
(TBA) type. That system of TBA equations is very similar to the one of the
spectral problem but simplifies a bit in the near BPS limit. Using techniques
based on the Y-system of functional equations we first reduced the infinite
system of TBA equations to a Finite set of Nonlinear Integral Equations
(FiNLIE). Then we solve the FiNLIE system analytically, obtaining a simple
analytic result for the potential! Surprisingly, we find that the system has
equivalent descriptions in terms of an effective Baxter equation and in terms
of a matrix model. At L=0, our result matches the one obtained before using
localization techniques. At all other L's, the result is new. Having a new
parameter, L, allows us to take the large L classical limit. We use the matrix
model description to solve the classical limit and match the result with a
string theory computation. Moreover, we find that the classical string
algebraic curve matches the algebraic curve arising from the matrix model.Comment: 50 pages, 5 figures. v2: references added, JHEP versio
Quark--anti-quark potential in N=4 SYM
We construct a closed system of equations describing the quark--anti-quark
potential at any coupling in planar N=4 supersymmetric Yang-Mills theory. It is
based on the Quantum Spectral Curve method supplemented with a novel type of
asymptotics. We present a high precision numerical solution reproducing the
classical and one-loop string predictions very accurately. We also analytically
compute the first 7 nontrivial orders of the weak coupling expansion.
Moreover, we study analytically the generalized quark--anti-quark potential
in the limit of large imaginary twist to all orders in perturbation theory. We
demonstrate how the QSC reduces in this case to a one-dimensional Schrodinger
equation. In the process we establish a link between the Q-functions and the
solution of the Bethe-Salpeter equation.Comment: 31 pages, 1 figure; v2: minor correcton
Quantum Spectral Curve at Work: From Small Spin to Strong Coupling in N=4 SYM
We apply the recently proposed quantum spectral curve technique to the study
of twist operators in planar N=4 SYM theory. We focus on the small spin
expansion of anomalous dimensions in the sl(2) sector and compute its first two
orders exactly for any value of the 't Hooft coupling. At leading order in the
spin S we reproduced Basso's slope function. The next term of order S^2
structurally resembles the Beisert-Eden-Staudacher dressing phase and takes
into account wrapping contributions. This expansion contains rich information
about the spectrum of local operators at strong coupling. In particular, we
found a new coefficient in the strong coupling expansion of the Konishi
operator dimension and confirmed several previously known terms. We also
obtained several new orders of the strong coupling expansion of the BFKL
pomeron intercept. As a by-product we formulated a prescription for the correct
analytical continuation in S which opens a way for deriving the BFKL regime of
twist two anomalous dimensions from AdS/CFT integrability.Comment: 53 pages, references added; v3: due to a typo in the coefficients C_2
and D_2 on page 29 we corrected the rational part of the strong coupling
predictions in equations (1.5-6), (6.22-24), (6.27-30) and in Table
Quantum folded string and integrability: from finite size effects to Konishi dimension
Using the algebraic curve approach we one-loop quantize the folded string
solution for the type IIB superstring in AdS(5)xS(5). We obtain an explicit
result valid for arbitrary values of its Lorentz spin S and R-charge J in terms
of integrals of elliptic functions. Then we consider the limit S ~ J ~ 1 and
derive the leading three coefficients of strong coupling expansion of short
operators. Notably, our result evaluated for the anomalous dimension of the
Konishi state gives 2\lambda^{1/4}-4+2/\lambda^{1/4}. This reproduces correctly
the values predicted numerically in arXiv:0906.4240. Furthermore we compare our
result using some new numerical data from the Y-system for another similar
state. We also revisited some of the large S computations using our methods. In
particular, we derive finite--size corrections to the anomalous dimension of
operators with small J in this limit.Comment: 20 pages, 1 figure; v2: references added, typos corrected; v3: major
improvement of the references; v4: Discussion of short operators is
restricted to the case n=1. This restriction does not affect the main results
of the pape
Tailoring Three-Point Functions and Integrability III. Classical Tunneling
We compute three-point functions between one large classical operator and two
large BPS operators at weak coupling. We consider operators made out of the
scalars of N=4 SYM, dual to strings moving in the sphere. The three-point
function exponentiates and can be thought of as a classical tunneling process
in which the classical string-like operator decays into two classical BPS
states. From an Integrability/Condensed Matter point of view, we simplified
inner products of spin chain Bethe states in a classical limit corresponding to
long wavelength excitations above the ferromagnetic vacuum. As a by-product we
solved a new long-range Ising model in the thermodynamic limit.Comment: 37 pages, 10 figure
- …