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Kazuyuki Furuuchi

Publications and source records attributed to Kazuyuki Furuuchi.

At least 37 records · Page 2Linked to original sources

Non-Linearly Extended Self-Dual Relations From The Nambu-Bracket Description Of M5-Brane In A Constant C-Field Background

The derivation of the self-dual relations for the two-form gauge field in the Nambu-bracket description of M5-brane in a constant C-field background initiated in arXiv:0907.4596 is completed by including contributions from all the fields in the M5-brane action. The result is used to examine Seiberg-Witten map of the BPS conditions for the string solitons, up to the first order in the expansion by the parameter $g$ which characterizes the strength of the interactions through the Nambu-bracket.

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String solitons in the M5-brane worldvolume with a Nambu-Poisson structure and Seiberg-Witten map

We analyze BPS equations for string-like configurations derived from the M5-brane worldvolume action with a Nambu-Poisson structure constructed in arXiv:0804.3629, arXiv:0805.2898. We solve the BPS equations up to the first order in the parameter $g$ which characterizes the strength of the Nambu-Poisson bracket. We compare our solutions to previously constructed BPS string solitons in the conventional description of M5-brane in a constant three-form background via Seiberg-Witten map, and find agreement.

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Supersymmetric reduced models with a symmetry based on Filippov algebra

Generalizations of the reduced model of super Yang-Mills theory obtained by replacing the Lie algebra structure to Filippov $n$-algebra structures are studied. Conditions for the reduced model actions to be supersymmetric are examined. These models are related with what we call $\{cal N}_{min}=2$ super $p$-brane actions.

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Lectures On AdS-CFT At Weak 't Hooft Coupling At Finite Temperature

This is an introductory lecture note aiming at providing an overview of the AdS-CFT correspondence at weak 't Hooft coupling at finite temperature. The first aim of this note is to describe the equivalence of three interesting thermodynamical phenomena in theoretical physics, namely, Hawking-Page transition to black hole geometry, deconfinement transition in gauge theories, and vortex condensation on string worldsheets. The Hawking-Page transition and the deconfinement transition in weakly coupled gauge theories are briefly reviewed. Emphasis is on the study of 't Hooft-Feynman diagrams in the large $N$ gauge theories, which are supposed to describe closed string worldsheets and probe the above equivalence. Nature of the 't Hooft-Feynman diagrams at finite temperature is analyzed, both in the Euclidean signature (the imaginary time formalism) and in the Lorentzian signature (the real time formalism). The second aim of this note is to give an introduction to the real time formalism applied to AdS-CFT.

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M-Theory Superalgebra From Multiple Membranes

We investigate space-time supersymmetry of the model of multiple M2-branes proposed by Bagger-Lambert and Gustavsson. When there is a central element in Lie 3-algebra, the model possesses an extra symmetry shifting the fermions in the central element. Together with the original worldvolume supersymmetry transformation, we construct major part of the eleven dimensional space-time super-Poincaré algebra with central extensions. Implications to transverse five-branes in the matrix model for M-theory are also discussed.

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Matrix Model For Polyakov Loops, String Field Theory In The Temporal Gauge, Winding String Condensation In Anti-de Sitter Space And Field Theory Of D-branes

Closed string field theory is constructed by stochastically quantizing a matrix model for Polyakov loops that describes phases of a large N gauge theory at finite temperature. Coherent states in this string field theory describes winding string condensation which has been expected to cause a topology change from thermal AdS geometry to AdS-Schwarzschild black hole geometry. D-branes in this closed string field theory is also discussed. Slightly extended version of a talk given at CosPA 2007, Nov.13-15, Taipei, Taiwan.

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Matrix Model For Polyakov Loops, String Field Theory In The Temporal Gauge, And Winding String Condensation In Anti-de Sitter Space

It has recently been shown that the low energy dynamics of the large $N$ gauge theory on $S^3$ at finite temperature reduces to a one-matrix model, where the matrix is given by the holonomy of the gauge field around the Euclidean time direction compactified on a circle. On the other hand, there is a prescription for constructing a closed string field theory in the temporal gauge from a given one-matrix model via loop equations. I identify the closed string field theory in the temporal gauge constructed from the above matrix model as effective closed string field theory that describes the propagations of closed strings in the radial and Euclidean time directions in the bulk. Then I argue that a coherent state in this string field theory describes winding string condensation, which has been expected to cause the topology change from the thermal AdS geometry to the AdS-Schwarzschild black hole geometry.

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Confined Phase In The Real Time Formalism And The Fate Of The World Behind The Horizon

In the real time formulation of finite temperature field theories, one introduces an additional set of fields (type-2 fields) associated to each field in the original theory (type-1 field). In hep-th/0106112, in the context of the AdS-CFT correspondence, Maldacena interpreted type-2 fields as living on a boundary behind the black hole horizon. However, below the Hawking-Page transition temperature, the thermodynamically preferred configuration is the thermal AdS without a black hole, and hence there are no horizon and boundary behind it. This means that when the dual gauge theory is in confined phase, the type-2 fields cannot be associated with the degrees of freedom behind the black hole horizon. I argue that in this case the role of the type-2 fields is to make up bulk type-2 fields of classical closed string field theory on AdS at finite temperature in the real time formalism.

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Large N Reductions and Holography

The large $N$ reductions in gauge theories are identified with dimensional reductions with homogeneous distribution of the eigenvalues of the gauge field, and it is used to identify the corresponding closed string descriptions in the Maldacena duality. When one does not take the zero-radii limit, the large $N$ reductions are naturally extended to the equivalences between the gauge theories and the "generalized" reduced models, which naturally contain the notion of T-dual equivalence. In the dual gravitational description, T-duality relates two type IIB supergravity solutions, the near horizon geometry of D3-branes, and the near horizon geometry of D-instantons densely and homogeneously distributing on the dual torus. This is the holographic description of the generalized large $N$ reductions. A new technique for calculating correlation functions of local gauge invariant single trace operators from the reduced models is also given.

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From Free Fields to AdS -- Thermal Case

We analyze the reorganization of free field theory correlators to closed string amplitudes investigated in hep-th/0308184 hep-th/0402063 hep-th/0409233 hep-th/0504229 in the case of Euclidean thermal field theory and study how the dual bulk geometry is encoded on them. The expectation value of Polyakov loop, which is an order parameter for confinement-deconfinement transition, is directly reflected on the dual bulk geometry. The dual geometry of confined phase is found to be AdS space periodically identified in Euclidean time direction. The gluing of Schwinger parameters, which is a key step for the reorganization of field theory correlators, works in the same way as in the non-thermal case. In deconfined phase the gluing is made possible only by taking the dual geometry correctly. The dual geometry for deconfined phase does not have a non-contractible circle in the Euclidean time direction.

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Holomorphically Covariant Matrix Models

We present a method to construct matrix models on arbitrary simply connected oriented real two dimensional Riemannian manifolds. The actions and the path integral measure are invariant under holomorphic transformations of matrix coordinates.

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Generally Covariant Actions for Multiple D-branes

We develop a formalism that allows us to write actions for multiple D-branes with manifest general covariance. While the matrix coordinates of the D-branes have a complicated transformation law under coordinate transformations, we find that these may be promoted to (redundant) matrix fields on the transverse space with a simple covariant transformation law. Using these fields, we define a covariant distribution function (a matrix generalization of the delta function which describes the location of a single brane). The final actions take the form of an integral over the curved space of a scalar single-trace action built from the covariant matrix fields, tensors involving the metric, and the covariant distribution function. For diagonal matrices, the integral localizes to the positions of the individual branes, giving N copies of the single-brane action.

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Non-commutative Space And Chan-Paton Algebra In Open String Field Algebra

There are several equivalent descriptions for constant B-field background of open string. The background can be interpreted as constant B-field as well as constant gauge field strength or infinitely many D-branes with non-commuting Chan-Paton matrices. In this article, the equivalence of these open string theories is studied in Witten's cubic open string field theory. Through the map between these equivalent descriptions, both algebra of non-commutative coordinates as well as Chan-Paton matrix algebra are identified with subalgebras of open string field algebra.

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Comma Vertex and String Field Algebra

We study the matter part of the algebra of open string fields using the 3-string vertex over the sliver state, which we call ``comma vertex''. By generalizing this comma vertex to the $N$-string overlap, we obtain a closed form of the Neumann coefficients in the $N$-string vertex and discuss its relation to the oscillator representation of wedge states.

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Dp-D(p+4) in Noncommutative Yang-Mills

An anti-self-dual instanton solution in Yang-Mills theory on noncommutative ${\R}^4$ with an anti-self-dual noncommutative parameter is constructed. The solution is constructed by the ADHM construction and it can be treated in the framework of the IIB matrix model. In the IIB matrix model, this solution is interpreted as a system of a Dp-brane and D(p+4)-branes, with the Dp-brane dissolved in the worldvolume of the D(p+4)-branes. The solution has a parameter that characterises the size of the instanton. The zero of this parameter corresponds to the singularity of the moduli space. At this point, the solution is continuously connected to another solution which can be interpreted as a system of a Dp-brane and D(p+4)-branes, with the Dp-brane separated from the D(p+4)-branes. It is shown that even when the parameter of the solution comes to the singularity of the moduli space, the gauge field itself is non-singular. A class of multi-instanton solutions is also constructed.

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Equivalence of Projections as Gauge Equivalence on Noncommutative Space

Projections play crucial roles in the ADHM construction on noncommutative $\R^4$. In this article a framework for the description of equivalence relations between projections is proposed. We treat the equivalence of projections as ``gauge equivalence'' on noncommutative space. We find an interesting application of this framework to the study of U(2) instanton on noncommutative $\R^4$: A zero winding number configuration with a hole at the origin is ``gauge equivalent'' to the noncommutative analog of the BPST instanton. Thus the ``gauge transformation'' in this case can be understood as a noncommutative resolution of the singular gauge transformation in ordinary $\R^4$.

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Instantons on Noncommutative R^4 and Projection Operators

I carefully study noncommutative version of ADHM construction of instantons, which was proposed by Nekrasov and Schwarz. Noncommutative ${\bf R}^4$ is described as algebra of operators acting in Fock space. In ADHM construction of instantons, one looks for zero-modes of Dirac-like operator. The feature peculiar to noncommutative case is that these zero-modes project out some states in Fock space. The mechanism of these projections is clarified when the gauge group is U(1). I also construct some zero-modes when the gauge group is U(N) and demonstrate that the projections also occur, and the mechanism is similar to the U(1) case. A physical interpretation of the projections in IIB matrix model is briefly discussed.

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