Jian-Ge Zhou

Super 0-brane and GS superstring actions on AdS2 × S2

The super 0-brane and GS superstring actions on AdS2 × S2 background with 2-form flux are constructed by taking a supercoset approach. We find that the super 0-brane action contains two parameters which are interpreted as the electric and magnetic charges of the super 0-brane. The obtained super 0-brane action describes the BPS saturated dyonic superparticle moving on AdS2 × S2 background. The WZ action contains the required coupling with 2-form flux. For GS superstring, we find the string action on AdS2 × S2 takes the same form as those in AdS3 × S3 and AdS5 × S5 with RR field background.

Fermionic zero mode and string creation between D4-branes at angles

Abstract We study the creation of a fundamental string between D4-branes at angles in string theory. It is shown that R(−1) F part of the one-loop potential of open string changes its sign due to the change of fermionic zero-mode vacua when the branes cross each other. As a result the effective potential is independent of the angles when supersymmetry is partially unbroken, and leads to a consistent picture that a fundamental string is created in the process. We also discuss the s-rule in the configuration. The same result is obtained from the one-loop potential for the orthogonal D4-branes with non-zero field strength. The result is also confirmed from the tension obtained by deforming the Chern-Simons term on one D4-brane, which is induced by another tilted D4-brane.

Euclidean path integral, D0-branes and Schwarzschild black holes in Matrix theory

The partition function in Matrix theory is constructed by the Euclidean path integral method. The D0-branes, which move around in the finite region with a typical size of Schwarzschild radius, are chosen as the background. The mass and entropy of the system obtained from the partition function contain the parameters of the background. After averaging the mass and entropy over the parameters, we find that they match the properties of 11D Schwarzschild black holes. The period β of Euclidean time can be identified with the reciprocal of the boosted Hawking temperature. The entropy S is shown to be proportional to the number N of Matrix theory partons, which is a consequence of the D0-brane background.

TOWARDS THE CLASSIFICATION OF NONMARGINAL BOUND STATES OF M-BRANES AND THEIR CONSTRUCTION RULES

We present a systematic analysis of possible bound states of M-brane solutions (including waves and monopoles) by using the solution generating technique of reduction fo M-brane to 10 dimensions, use of T-duality and then lifting back to 11 dimensions. We summarize a list of bound states for one- and two-charge cases including tilted brane solutions. Construction rules for these nonmarginal solutions are also discussed.

REALIZATION OF D4-BRANES AT ANGLES IN SUPER YANG-MILLS THEORY

Abstract An explicit solution in super Yang-Mills theory, which after T-duality describes two sets of D4-branes at angles, is constructed. The gauge configuration possesses 3/16 unbroken supersymmetry for the equal magnitudes of field strengths, and can be considered as the counterpart of the solution of D=11 supergravity with the same amount of supersymmetry in the solutions given by Gauntlett et al. The energy of the Born-Infeld action of the gauge configuration gives further evidence for the geometrical interpretation as two sets of D4-branes at angles. The energy of super Yang-Mills theory is shown to coincide with that of M(atrix) theory. This fact shows that the configuration with 3/16 supersymmetry can be realized in M(atrix) theory, which describes two sets of longitudinal M5-branes (with common string direction) at angles.

AdS3/CFT correspondence, Poincaré vacuum state and greybody factors in BTZ black holes

Abstract The greybody factors in BTZ black holes are evaluated from 2D CFT in the spirit of AdS3/CFT correspondence. The initial state of black holes in the usual calculation of greybody factors by effective CFT is described as Poincare vacuum state in 2D CFT. The normalization factor which cannot be fixed in the effective CFT without appealing to string theory is shown to be determined by the normalized bulk-to-boundary Green function. The relation among the greybody factors in different dimensional black holes is exhibited. Two kinds of (h, h )=(1,1) operators which couple with the boundary value of massless scalar field are discussed.

Thermalization of Poincare vacuum state and fermion emission from AdS(3) black holes in bulk boundary correspondence

The greybody factors for spin ½ particles in the BTZ black holes are discussed from 2D CFT in bulk-boundary correspondence. It is found that the initial state of spin ½ particle in the BTZ black holes can be described by the Poincare vacuum state in boundary 2D CFT, and the nonlinear coordinate transformation causes the thermalization of the Poincare vacuum state. For special case, our results for the greybody factors agree with the semiclassical calculation.

Spacetime superalgebra in AdS 4 × S 7 via the supermembrane probe

The spacetime superalgebra via the supermembrane probe in the background of AdS_4 \times S^7 is discussed to the lowest order in the spinor coordinate

Spacetime superalgebra inAdS4×S7via the supermembrane probe

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Spacetime Superalgebra in AdS_4 \times S^7 via Supermembrane Probe

. To obtain the correct spacetime superalgebras, all