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A. B. Zamolodchikov

Publications and source records attributed to A. B. Zamolodchikov.

12 recordsLinked to original sources
arXiv2016

On space of integrable quantum field theories

We study deformations of 2D Integrable Quantum Field Theories (IQFT) which preserve integrability (the existence of infinitely many local integrals of motion). The IQFT are understood as "effective field theories", with finite ultraviolet cutoff. We show that for any such IQFT there are infinitely many integrable deformations generated by scalar local fields $X_s$, which are in one-to-one correspondence with the local integrals of motion; moreover, the scalars $X_s$ are built from the components of the associated conserved currents in a universal way. The first of these scalars, $X_1$, coincides with the composite field $(T{\bar T})$ built from the components of the energy-momentum tensor. The deformations of quantum field theories generated by $X_1$ are "solvable" in a certain sense, even if the original theory is not integrable. In a massive IQFT the deformations $X_s$ are identified with the deformations of the corresponding factorizable S-matrix via the CDD factor. The situation is illustrated by explicit construction of the form factors of the operators $X_s$ in sine-Gordon theory. We also make some remarks on the problem of UV completeness of such integrable deformations.

hep-th↗
arXiv2010

Quantum Sine(h)-Gordon Model and Classical Integrable Equations

We study a family of classical solutions of modified sinh-Gordon equation, $\partial_z\partial_{\bar z} η-\re^{2η}+p(z)\,p({\bar z})\ \re^{-2η}=0$ with $p(z)=z^{2α}-s^{2α}$. We show that certain connection coefficients for solutions of the associated linear problem coincide with the $Q$-function of the quantum sine-Gordon $(α>0)$ or sinh-Gordon $(α<-1)$ models.

math-ph↗
arXiv2009

On mass spectrum in 't Hooft's 2D model of mesons

We study 't Hooft's integral equation determining the meson masses M_n in multicolor QCD_2. In this note we concentrate on developing an analytic method, and restrict our attention to the special case of quark masses m_1=m_2=g/\sqrtπ. Among our results is systematic large-n expansion, and exact sum rules for M_n. Although we explicitly discuss only the special case, the method applies to the general case of the quark masses, and we announce some preliminary results for m_1=m_2.

hep-th↗
arXiv2008

On Correlation Numbers in 2D Minimal Gravity and Matrix Models

We test recent results for the four-point correlation numbers in Minimal Liouville Gravity against calculations in the one-Matrix Models, and find full agreement. In the process, we construct the resonance transformation which relates coupling parameters of the Liouville Gravity with the couplings of the Matrix Models, up to the terms of the order 4. We also conjecture the general form of this transformation.

hep-th↗
arXiv2005

Dual Form of the Paperclip Model

The ``paperclip model'' is 2D model of Quantum Field Theory with boundary interaction defined through a special constraint imposed on the boundary values of massless bosonic fields (hep-th/0312168). Here we argue that this model admits equivalent ``dual'' description, where the boundary constraint is replaced by special interaction of the boundary values of the bosonic fields with an additional boundary degree of freedom. The dual form involves the topological theta-angle in explicit way.

hep-th↗
arXiv2005

Paperclip at $θ=π$

We study the ``paperclip'' model of boundary interaction with the topological angle $θ$ equal to $π$. We propose exact expression for the disk partition function in terms of solutions of certain ordinary differential equation. Large distance asymptotic form of the partition function which follows from this proposal makes it possible to identify the infrared fixed point of the paperclip boundary flow at $θ=π$.

hep-th↗
arXiv2003

Integrable Circular Brane Model and Coulomb Charging at Large Conduction

We study a model of 2D QFT with boundary interaction, in which two-component massless Bose field is constrained to a circle at the boundary. We argue that this model is integrable at two values of the topological angle, $θ=0$ and $θ=π$. For $θ=0$ we propose exact partition function in terms of solutions of ordinary linear differential equation. The circular brane model is equivalent to the model of quantum Brownian dynamics commonly used in describing the Coulomb charging in quantum dots, in the limit of small dimensionless resistance $g_0$ of the tunneling contact. Our proposal translates to partition function of this model at integer charge.

hep-th↗
arXiv2003

Integrable Model of Boundary Interaction: The Paperclip

We consider a model of 2D quantum field theory on a disk, whose bulk dynamics is that of a two-component free massless Bose field (X,Y), and interaction occurs at the boundary, where the boundary values (X_B, Y_B) are constrained to special curve - the ``paperclip brane''. The interaction breaks conformal invariance, but we argue that it preserves integrability. We propose exact expression for the disk partition function (and more general overlap amplitudes < P | B > of the boundary state with all primary states) in terms of solutions of certain ordinary linear differential equations.

hep-th↗
arXiv1998

Integrable Structure of Conformal Field Theory III. The Yang-Baxter Relation

In this paper we fill some gaps in the arguments of our previous papers [hep-th/9412229,hep-th/9604044]. In particular, we give a proof that the L operators of Conformal Field Theory indeed satisfy the defining relations of the Yang-Baxter algebra. Among other results we present a derivation of the functional relations satisfied by ${\bf T}$ and ${\bf Q}$ operators and a proof of the basic analyticity assumptions for these operators used in [hep-th/9412229,hep-th/9604044].

hep-th↗
arXiv1996

Integrable Quantum Field Theories in Finite Volume: Excited State Energies

We develop a method of computing the excited state energies in Integrable Quantum Field Theories (IQFT) in finite geometry, with spatial coordinate compactified on a circle of circumference R. The IQFT ``commuting transfer-matrices'' introduced by us (BLZ) for Conformal Field Theories (CFT) are generalized to non-conformal IQFT obtained by perturbing CFT with the operator $Φ_{1,3}$. We study the models in which the fusion relations for these ``transfer-matrices'' truncate and provide closed integral equations which generalize the equations of Thermodynamic Bethe Ansatz to excited states. The explicit calculations are done for the first excited state in the ``Scaling Lee-Yang Model''.

hep-th↗
arXiv1995

Structure Constants and Conformal Bootstrap in Liouville Field Theory

An analytic expression is proposed for the three-point function of the exponential fields in the Liouville field theory on a sphere. In the classical limit it coincides with what the classical Liouville theory predicts. Using this function as the structure constant of the operator algebra we construct the four-point function of the exponential fields and verify numerically that it satisfies the conformal bootstrap equations, i.e., that the operator algebra thus defined is associative. We consider also the Liouville reflection amplitude which follows explicitly from the structure constants.

hep-th↗