arXiv subjects

Yu Nakayama

Publications and source records attributed to Yu Nakayama.

168 records · Page 10Linked to original sources

arXiv2004

Liouville Field Theory -- A decade after the revolution

We review recent developments (up to January 2004) of the Liouville field theory and its matrix model dual. This review consists of three parts. In part I, we review the bosonic Liouville theory. After briefly reviewing the necessary background, we discuss the bulk structure constants (the DOZZ formula) and the boundary states (the FZZT brane and the ZZ brane). Various applications are also presented. In part II, we review the supersymmetric extension of the Liouville theory. We first discuss the bulk structure constants and the branes as in the bosonic Liouville theory, and then we present the matrix dual descriptions with some applications. In part III, the Liouville theory on unoriented surfaces is reviewed. After introducing the crosscap state, we discuss the matrix model dual description and the tadpole cancellation condition. This review also includes some original material such as the derivation of the conjectured dual action for the N = 2 Liouville theory from other known dualities and the comparison of the Liouville crosscap state with the c = 0 unoriented matrix model. This is based on my master's thesis submitted to Department of Physics, Faculty of Science, University of Tokyo on January 2004.

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arXiv2004

Zamolodchikov relations and Liouville hierarchy in SL(2,R)_k WZNW model

We study the connection between Zamolodchikov operator-valued relations in Liouville field theory and in the SL(2,R)_k WZNW model. In particular, the classical relations in SL(2,R)_k can be formulated as a classical Liouville hierarchy in terms of the isotopic coordinates, and their covariance is easily understood in the framework of the AdS_3/CFT_2 correspondence. Conversely, we find a closed expression for the classical Liouville decoupling operators in terms of the so called uniformizing Schwarzian operators and show that the associated uniformizing parameter plays the same role as the isotopic coordinates in SL(2,R)_k. The solutions of the j-th classical decoupling equation in the WZNW model span a spin j reducible representation of SL(2,R). Likewise, we show that in Liouville theory solutions of the classical decoupling equations span spin j representations of SL(2,R), which is interpreted as the isometry group of the hyperbolic upper half-plane. We also discuss the connection with the Hamiltonian reduction of SL(2,R)_k WZNW model to Liouville theory.

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arXiv2004

Boundary States for the Rolling D-branes in NS5 Background

In this paper we construct the time dependent boundary states describing the ``rolling D-brane solutions'' in the NS5 background discovered recently by Kutasov by means of the classical DBI analysis. We first survey some aspects of non-compact branes in the NS5 background based on known boundary states in the N=2 Liouville theory. We consider two types of non-compact branes, one of which is BPS and the other is non-BPS but stable. Then we clarify how to Wick-rotate the non-BPS one appropriately. We show that the Wick-rotated boundary state realizes the correct trajectory of rolling D-brane in the classical limit, and leads to well behaved spectral densities of open strings due to the existence of non-trivial damping factors of energy. We further study the cylinder amplitudes and the emission rates of massive closed string modes.

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arXiv2004

The Liouville Geometry of N=2 Instantons and the Moduli of Punctured Spheres

We study the instanton contributions of N=2 supersymmetric gauge theory and propose that the instanton moduli space is mapped to the moduli space of punctured spheres. Due to the recursive structure of the boundary in the Deligne-Knudsen-Mumford stable compactification, this leads to a new recursion relation for the instanton coefficients, which is bilinear. Instanton contributions are expressed as integrals on M_{0,n} in the framework of the Liouville F-models. This also suggests considering instanton contributions as a kind of Hurwitz numbers and also provides a prediction on the asymptotic form of the Gromov-Witten invariants. We also interpret this map in terms of the geometric engineering approach to the gauge theory, namely the topological A-model, as well as in the noncritical string theory framework. We speculate on the extension to nontrivial gravitational background and its relation to the uniformization program. Finally we point out an intriguing analogy with the self-dual YM equations for the gravitational version of SU(2) where surprisingly the same Hauptmodule of the SW solution appears.

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arXiv2003

Effective Gauge Degrees of Freedom and the (Non)existence of the Glueball Superpotential

We propose an efficient way to obtain a correct Veneziano-Yankielowicz type integration constant of the effective glueball superpotential $W_{eff}(S,g,Λ)$, even for massless theories. Applying our method, we show some $\mathcal{N} = 1$ theories do not have such an effective glueball superpotential, even though they have isolated vacua. In these cases, $S = 0$ typically.

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arXiv2003

Tadpole Cancellation in Unoriented Liouville Theory

The tadpole cancellation in the unoriented Liouville theory is discussed. Using two different methods -- the free field method and the boundary-crosscap state method, we derive one-loop divergences. Both methods require two D1-branes with the symplectic gauge group to cancel the orientifold tadpole divergence. However, the finite part left is different in each method and this difference is studied. We also discuss the validity of the free field method and the possible applications of our result.

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