arXiv subjects

Kentaroh Yoshida

Publications and source records attributed to Kentaroh Yoshida.

At least 127 records · Page 7Linked to original sources

arXiv2006

Non-Relativistic AdS Branes and Newton-Hooke Superalgebra

We examine a non-relativistic limit of D-branes in AdS_5xS^5 and M-branes in AdS_{4/7}xS^{7/4}. First, Newton-Hooke superalgebras for the AdS branes are derived from AdSxS superalgebras as Inonu-Wigner contractions. It is shown that the directions along which the AdS-brane worldvolume extends are restricted by requiring that the isometry on the AdS-brane worldvolume and the Lorentz symmetry in the transverse space naturally extend to the super-isometry. We also derive Newton-Hooke superalgebras for pp-wave branes and show that the directions along which a brane worldvolume extends are restricted. Then the Wess-Zumino terms of the AdS branes are derived by using the Chevalley-Eilenberg cohomology on the super-AdSxS algebra, and the non-relativistic limit of the AdS-brane actions is considered. We show that the consistent limit is possible for the following branes: Dp (even,even) for p=1 mod 4 and Dp (odd,odd) for p=3 mod 4 in AdS_5xS^5, and M2 (0,3), M2 (2,1), M5 (1,5) and M5 (3,3) in AdS_{4}xS^{7} and S^{4}xAdS_{7}. We furthermore present non-relativistic actions for the AdS branes.

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arXiv2006

Dynamical aspects of the plane-wave matrix model at finite temperature

We study dynamical aspects of the plane-wave matrix model at finite temperature. One-loop calculation around general classical vacua is performed using the background field method, and the integration over the gauge field moduli is carried out both analytically and numerically. In addition to the trivial vacuum, which corresponds to a single M5-brane at zero temperature, we consider general static fuzzy-sphere type configurations. They are all 1/2 BPS, and hence degenerate at zero temperature due to supersymmetry. This degeneracy is resolved, however, at finite temperature, and we identify the configuration that gives the smallest free energy at each temperature. The Hagedorn transition in each vacuum is studied by using the eigenvalue density method for the gauge field moduli, and the free energy as well as the Polyakov line is obtained analytically near the critical point. This reveals the existence of fuzzy sphere phases, which may correspond to the plasma-ball phases in N=4 SU(\infty) SYM on S^1 X S^3. We also perform Monte Carlo simulation to integrate over the gauge field moduli. While this confirms the validity of the analytic results near the critical point, it also shows that the trivial vacuum gives the smallest free energy throughout the high temperature regime.

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arXiv2006

Noncommutative D-brane from Covariant AdS Superstring

We explore noncommutative D-branes in the AdS_5xS^5 background from the viewpoint of κ-invariance of a covariant open string action in the Green-Schwarz formulation. Boundary conditions to ensure the κ-invariance of the action lead to possible configurations of noncommutative D-branes. With this covariant method, we derive configurations of 1/4 BPS noncommutative D-branes. The resulting D-branes other than D-string are 1/4 BPS at any places, and the D-string is exceptional and it is 1/2 BPS at the origin and 1/4 BPS outside the origin. All of them are reduced to possible 1/4 BPS or 1/2 BPS AdS D-branes in the commutative limit or the strong magnetic flux limit. We also apply the same analysis to an open superstring in the pp-wave background and derive configurations of 1/4 BPS noncommutative D-branes in the pp-wave. These D-branes consistently related to AdS D-branes via the Penrose limit.

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arXiv2005

Open Spinning Strings and AdS/dCFT Duality

We consider open spinning string solutions on an AdS_4 x S^2-brane (D5-brane) in the bulk AdS_5 x S^5 background. By taking account of the breaking of SO(6)_R to SO(3)_H x SO(3)_V due to the presence of the AdS-brane, the open rotating string ansatz is discussed. We construct the elliptic folded/circular open string solutions in the SU(2) and the SL(2) sectors, so that they satisfy the appropriate boundary conditions. On the other hand, in the SU(2) sector of the gauge theory, we compute the matrix of anomalous dimension of the defect operator, which turns out to be the Hamiltonian of an open integrable spin chain. Then we consider the coordinate Bethe ansatz with arbitrary number of impurities, and compare the boundary condition of the Bethe wavefunction with that of the corresponding open string solution. We also discuss the Bethe ansatz for the open SL(2) spin chain with several supports from the string theory side. Then, in both SU(2) and SL(2) sectors, we analyze the Bethe equations in the thermodynamic limit and formulate the `doubling trick' on the Riemann surface associated with the gauge theory.

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arXiv2005

Graviton and Spherical Graviton Potentials in Plane-Wave Matrix Model - overview and perspective -

We briefly review our works for graviton and spherical graviton potentials in a plane-wave matrix model. To compute them, it is necessary to devise a configuration of the graviton solutions, since the plane-wave matrix model includes mass terms and hence the gravitons are not free particles as in the BFSS matrix model but harmonic oscillators or rotating particles. The configuration we proposed consists of a rotating graviton and an elliptically rotating graviton. It is applied to the two-body interaction of spherical gravitons in the SO(6) symmetric space, and then to that of point-like gravitons in the SO(3) symmetric space. In both cases the leading term of the resulting potential is 1/r^7. This result strongly suggests that the potentials should be closely related to the light-front eleven-dimensional supergravity linearized around the pp-wave background.

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arXiv2005

Point-Like Graviton Scattering in Plane-Wave Matrix Model

In a plane-wave matrix model we discuss a two-body scattering of gravitons in the SO(3) symmetric space. In this case the graviton solutions are point-like in contrast to the scattering in the SO(6) symmetric space where spherical membranes are interpreted as gravitons. We concentrate on a configuration in the 1-2 plane where a graviton rotates with a constant radius and the other one elliptically rotates. Then the one-loop effective action is computed by using the background field method. As the result, we obtain the 1/r^7-type interaction potential, which strongly suggests that the scattering in the matrix model would be closely related to that in the light-front eleven-dimensional supergravity.

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arXiv2005

Integrability and Higher Loops in AdS/dCFT Correspondence

We further study the correspondence between open semiclassical strings and long defect operators which is discussed in our previous work [hep-th/0410139]. We give an interpretation of the spontaneous symmetry breaking of SO(6)-> SO(3)_H x SO(3)_V from the viewpoint of the Riemann surface by following the argument of Minahan. Then we use the concrete form of the resolvent for a single cut solution and compute the anomalous dimension of operators dual to an open pulsating string at three-loop level. In the string side we obtain the energy of the open pulsating string solution by semiclassical analysis. Both results agree at two-loop level but we find a three-loop discrepancy.

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arXiv2005

Classical Integrability and Super Yangian of Superstring on AdS_5 x S^5

We discuss a classical integrability in the type IIB string theory on the AdS_5 x S^5 background. By using the Roiban-Siegel formulation of the superstring on the AdS_5 x S^5, we carefully treat the Wess-Zumino term and the constraint conditions intrinsic to the supersymmetric case, and construct explicitly non-local charges for a hidden infinite-dimensional symmetry. The existence of the symmetry is shown by Bena-Polchinski-Roiban. Then the super Yangian algebra is calculated. We also show the Serre relation ensuring the structure of the Hopf algebra. In addition, the classical integrability is discussed by constructing the Lax pair and the transfer matrix.

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arXiv2005

Bubbling 1/2 BPS Geometries and Penrose Limits

We discuss how to take a Penrose limit in bubbling 1/2 BPS geometries at the stage of a single function z(x_1,x_2,y). By starting from the z of the AdS_5 x S^5 we can directly derive that of the pp-wave via the Penrose limit. In that time the function z for the pp-wave with 1/R^2-corrections is obtained. We see that it surely reproduces the pp-wave with 1/R^2 terms. In addition we consider the Penrose limit in the configuration of the concentric rings.

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arXiv2005

Thermodynamic Behavior of Fuzzy Membranes in PP-Wave Matrix Model

We discuss a two-body interaction of membrane fuzzy spheres in a pp-wave matrix model at finite temperature by considering a fuzzy sphere rotates with a constant radius r around the other one sitting at the origin in the SO(6) symmetric space. This system of two fuzzy spheres is supersymmetric at zero temperature and there is no interaction between them. Once the system is coupled to the heat bath, supersymmetries are completely broken and non-trivial interaction appears. We numerically show that the potential between fuzzy spheres is attractive and so the rotating fuzzy sphere tends to fall into the origin. The analytic formula of the free energy is also evaluated in the large N limit. It is well approximated by a polylog-function.

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arXiv2005

Open Semiclassical Strings and Long Defect Operators in AdS/dCFT Correspondence

We consider defect composite operators in a defect superconformal field theory obtained by inserting an AdS_4 x S^2-brane in the AdS_5 x S^5 background. The one-loop dilatation operator for the scalar sector is represented by an integrable open spin chain. We give a description to construct coherent states for the open spin chain. Then, by evaluating the expectation value of the Hamiltonian with the coherent states in a long operator limit, a Landau-Lifshitz type of sigma model action is obtained. This action is also derived from the string action and hence we find a complete agreement in both SYM and string sides. We see that an SO(3)_H pulsating string solution is included in the action and its energy completely agrees with the result calculated in a different method. In addition, we argue that our procedure would be applicable to other AdS-brane cases.

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arXiv2005

Effective Potential in PP-Wave Geometry

We calculate effective potentials in scalar field theories on the maximally supersymmetric pp-wave background in ten dimensions. For this purpose we have to work in the light-cone formulation, and hence we introduce two methods to compute them in the light-cone frame. One is to use the Yan's formula for evaluating one-loop correction terms. The other is to introduce a cut-off for the light-cone momentum. These methods are also confirmed in the case of Minkowski spacetime.

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arXiv2005

Discrete Light-Cone Quantization in PP-Wave Background

We discuss the discrete light-cone quantization (DLCQ) of a scalar field theory on the maximally supersymmetric pp-wave background in ten dimensions. It has been shown that the DLCQ can be carried out in the same way as in the two-dimensional Minkowski spacetime. Then, the vacuum energy is computed by evaluating the vacuum expectation value of the light-cone Hamiltonian. The results are consistent with the effective potential obtained in our previous work [hep-th/0402028].

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arXiv2004

Membrane Fuzzy Sphere Dynamics in Plane-Wave Matrix Model

In plane-wave matrix model, the membrane fuzzy sphere extended in the SO(3) symmetric space is allowed to have periodic motion on a sub-plane in the SO(6) symmetric space. We consider a background configuration composed of two such fuzzy spheres moving on the same sub-plane and the one-loop quantum corrections to it. The one-loop effective action describing the fuzzy sphere interaction is computed up to the sub-leading order in the limit that the mean distance $r$ between two fuzzy spheres is very large. We show that the leading order interaction is of the 1/r^7 type and thus the membrane fuzzy spheres interpreted as giant gravitons really behave as gravitons.

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arXiv2004

D-branes of Covariant AdS Superstrings -- An Overview --

We briefly review a covariant analysis of D-branes of type IIB superstring on the AdS_5xS^5 background from the κ-invariance of the Green-Schwarz string action. The possible configurations of D-branes preserving half of supersymmetries are classified in both cases of AdS_5xS^5 and the pp-wave background.

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arXiv2004

Open M-branes on AdS_{4/7} x S^{7/4} Revisited

We proceed further with a study of open supermembrane on the AdS_{4/7} x S^{7/4} backgrounds. Open supermembrane can have M5-brane and 9-brane as Dirichlet branes. In AdS and pp-wave cases the configurations of Dirichlet branes are restricted. A classification of possible Dirichlet branes, which is given up to and including the fourth order of fermionic variable þin hep-th/0310035, is shown to be valid even at full order of þ. We also discuss open M5-brane on the AdS_{4/7} x S^{7/4}.

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arXiv2004

Notes on D-branes of Type IIB String on AdS_5 x S^5

We promote a study of D-branes of type IIB string on the AdS_5 x S^5 background. The possible D-branes preserving half of supersymmetries were classified up to and including the fourth order of fermionic variable þin our previous work [hep-th/0310228]. In this paper we show that our classification is still valid even at the full order of þ. This proof supplements our previous results and completes the classification of D-branes in the type IIB string theory on the AdS_5 x S^5.

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arXiv2004

D-branes of Covariant AdS Superstrings

We consider D-branes of open superstrings in the AdS_5 x S^5 background. The possible configurations of D-branes preserving half of supersymmetries are classified by analyzing the kappa-invariance of an open superstring in a covariant manner. We also revisit the classification of D-branes in the pp-wave background. It is shown that Penrose limits of the possible D-branes in the AdS_5 x S^5 give all of the D-branes in the pp-wave. In addition, 1/4 supersymmetric D-string, which is related to the D-string preserving 8 dynamical supersymmetries in the pp-wave, is presented. We also discuss the relation between our branes and the AdS branes in a brane probe analysis.

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