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Al. Zamolodchikov

Publications and source records attributed to Al. Zamolodchikov.

16 recordsLinked to original sources

Sinh-Gordon Boundary TBA and Boundary Liouville Reflection Amplitude

The ground state energy of the sinh-Gordon model defined on the strip is studied using the boundary thermodynamic Bethe ansatz equation. Its ultraviolet (small width of the strip) behavior is compared with the one obtained from the boundary Liouville reflection amplitude. The results are in perfect agreement in the allowable range of the parameters and provide convincing support for both approaches. We also describe how the ultraviolet limit of the effective central charge can exceed one in the parameter range when the Liouville zero mode forms a bound state.

hep-th

Bootstrap in Supersymmetric Liouville Field Theory. I. NS Sector

A four point function of basic Neveu-Schwarz exponential fields is constructed in the N = 1 supersymmetric Liouville field theory. Although the basic NS structure constants were known previously, we present a new derivation, based on a singular vector decoupling in the NS sector. This allows to stay completely inside the NS sector of the space of states, without referencing to the Ramond fields. The four-point construction involves also the NS blocks, for which we suggest a new recursion representation, the so-called elliptic one. The bootstrap conditions for this four point correlation function are verified numerically for different values of the parameters.

hep-th

Higher Equations of Motion in N = 1 SUSY Liouville Field Theory

Similarly to the ordinary bosonic Liouville field theory, in its N=1 supersymmetric version an infinite set of operator valued relations, the ``higher equations of motions'', holds. Equations are in one to one correspondence with the singular representations of the super Virasoro algebra and enumerated by a couple of natural numbers $(m,n)$. We demonstrate explicitly these equations in the classical case, where the equations of type $(1,n)$ survive and can be interpreted directly as relations for classical fields. General form of the higher equations of motion is established in the quantum case, both for the Neveu-Schwarz and Ramond series.

hep-th

Decay of Metastable Vacuum in Liouville Gravity

A decay of weakly metastable phase coupled to two-dimensional Liouville gravity is considered in the semiclassical approximation. The process is governed by the ``critical swelling'', where the droplet fluctuation favors a gravitational inflation inside the region of lower energy phase. This geometrical effect modifies the standard exponential suppression of the decay rate, substituting it with a power one, with the exponent becoming very large in the semiclassical regime. This result is compared with the power-like behavior of the discontinuity in the specific energy of the dynamical lattice Ising model. The last problem is far from being semiclassical, and the corresponding exponent was found to be 3/2. This exponent is expected to govern any gravitational decay into a vacuum without massless excitations. We conjecture also an exact relation between the exponent in this power-law suppression and the central charge of the stable phase.

hep-th

Gravitational Yang-Lee Model. Four Point Function

The four-point perturbative contribution to the spherical partition function of the gravitational Yang-Lee model is evaluated numerically. An effective integration procedure is due to a convenient elliptic parameterization of the moduli space. At certain values of the ``spectator'' parameter the Liouville four-point function involves a number of ``discrete terms'' which have to be taken into account separately. The classical limit, where only discrete terms contribute, is also discussed. In addition, we conjecture an explicit expression for this partition function at the ``second solvable point'' where the spectator matter is in fact another $M_{2/5}$ (Yang-Lee) minimal model.

hep-th

Perturbed Conformal Field Theory on Fluctuating Sphere

General properties of perturbed conformal field theory interacting with quantized Liouville gravity are considered in the simplest case of spherical topology. We discuss both short distance and large distance asymptotic of the partition function. The crossover region is studied numerically for a simple example of the perturbed Yang-Lee model, complemented in general with arbitrary conformal ``spectator'' matter. The latter is not perturbed and remains conformal along the flow, thus giving a control over the Liouville central charge. The partition function is evaluated numerically from combined analytic and perturbative information. In this paper we use the perturbative information up to third order. At special points the four-point integral can be evaluated and compared with our data. At the solvable point of minimal Liouville gravity we are in remarkably good agreement with the matrix model predictions. Possibilities to compare the result with random lattice simulations is discussed.

hep-th

On the Three-point Function in Minimal Liouville Gravity

The problem of the structure constants of the operator product expansions in the minimal models of conformal field theory is revisited. We rederive these previously known constants and present them in the form particularly useful in the Liouville gravity applications. Analytic relation between our expression and the structure constant in Liouville field theory is discussed. Finally we present in general form the three- and two-point correlation numbers on the sphere in the minimal Liouville gravity.

hep-th

Higher Equations of Motion in Liouville Field Theory

An infinite set of operator-valued relations in Liouville field theory is established. These relations are enumerated by a pair of positive integers $(m,n)$, the first $(1,1)$ representative being the usual Liouville equation of motion. The relations are proven in the framework of conformal field theory on the basis of exact structure constants in the Liouville operator product expansions. Possible applications in 2D gravity are discussed.

hep-th

Scaling Lee-Yang Model on a Sphere. I. Partition Function

Some general properties of perturbed (rational) CFT in the background metric of symmetric 2D sphere of radius $R$ are discussed, including conformal perturbation theory for the partition function and the large $R$ asymptotic. The truncated conformal space scheme is adopted to treat numerically perturbed rational CFT's in the spherical background. Numerical results obtained for the scaling Lee-Yang model lead to the conclusion that the partition function is an entire function of the coupling constant. Exploiting this analytic structure we are able to describe rather precisely the ``experimental'' truncated space data, including even the large $R$ behavior, starting only with the CFT information and few first terms of conformal perturbation theory.

hep-th

Liouville field theory on a pseudosphere

Liouville field theory is considered with boundary conditions corresponding to a quantization of the classical Lobachevskiy plane (i.e. euclidean version of $AdS_2$). We solve the bootstrap equations for the out-vacuum wave function and find an infinite set of solutions. This solutions are in one to one correspondence with the degenerate representations of the Virasoro algebra. Consistency of these solutions is verified by both boundary and modular bootstrap techniques. Perturbative calculations lead to the conclusion that only the ``basic'' solution corresponding to the identity operator provides a ``natural'' quantization of the Lobachevskiy plane.

hep-th

On the Thermodynamic Bethe Ansatz Equation in Sinh-Gordon Model

Two implicit periodic structures in the solution of sinh-Gordon thermodynamic Bethe ansatz equation are considered. The analytic structure of the solution as a function of complex $θ$ is studied to some extent both analytically and numerically. The results make a hint how the CFT integrable structures can be relevant in the sinh-Gordon and staircase models. More motivations are figured out for subsequent studies of the massless sinh-Gordon (i.e. Liouville) TBA equation.

hep-th

Boundary Liouville Field Theory I. Boundary State and Boundary Two-point Function

Liouville conformal field theory is considered with conformal boundary. There is a family of conformal boundary conditions parameterized by the boundary cosmological constant, so that observables depend on the dimensional ratios of boundary and bulk cosmological constants. The disk geometry is considered. We present an explicit expression for the expectation value of a bulk operator inside the disk and for the two-point function of boundary operators. We comment also on the properties of the degenrate boundary operators. Possible applications and further developments are discussed. In particular, we present exact expectation values of the boundary operators in the boundary sin-Gordon model.

hep-th

Expectation values of descendent fields in the sine-Gordon model

We obtain exactly the vacuum expectation values $<(\partialϕ)^2 ({\bar\partial}ϕ) e^{iαϕ}>$ in the sine-Gordon model and $ $ in $Φ_{1,3}$ perturbed minimal CFT. We discuss applications of these results to short-distance expansions of two-point correlation functions.

hep-th

Expectation values of local fields in Bullough-Dodd model and integrable perturbed conformal field theories

Exact expectation values of the fields e^{aϕ} in the Bullough-Dodd model are derived by adopting the ``reflection relations'' which involve the reflection S-matrix of the Liouville theory, as well as special analyticity assumption. Using this result we propose explicit expressions for expectation values of all primary operators in the c<1 minimal CFT perturbed by the operator Φ_{1,2} or Phi_{2,1}. Some results concerning the $Φ_{1,5}$ perturbed minimal models are also presented.

hep-th

Painleve III and 2D Polymers

Recently the scaling function of the dilute non-contractible self-avoiding 2D polymer loop on a cylinder was related to the Painleve III transcendent. Using the perturbation theory, the thermidynamic Bethe ansatz and numerical calculations we argue a similar relation for the contractible self-avoiding loop.

hep-th