arXiv subjects
Publications and source records attributed to Takashi Yokono.
We found a gravity solution of p+1 dimensional extended object with SO(p)xSO(9-p) symmetry which has zero pressure and zero dilaton charge. We expect that this object is a residual tachyon dust after tachyon condensation of brane and anti-brane system discussed by Sen, recently. We also discuss the Hawking temperature and some properties of this object.
We study the O3-plane in the conifold. On the D3-brane world-volume we obtain SO x USp gauge theory that exhibits a duality cascade phenomenon. The orientifold projection is determined on the type IIB string side, and corresponds to that of O4-plane on the dual type IIA side. We show that SUGRA solutions of Klebanov-Tseytlin and Klebanov-Strassler survive under the projection. We also investigate the orientifold projection in the generalized conifolds, and verify desired features of the O4-projection in the type IIA picture.
We investigate a near-horizon geometry of NS5-branes wrapping on a Riemann surface, which asymptotically approaches to linear dilaton backgrounds. We concretely find a fully localized solution of the near-horizon geometry of intersecting NS5-branes. We also discuss a relation to a description of Landau-Ginzburg theories.
We study the relation between intersecting NS5-branes whose intersection is smoothed out and the deformed conifold in terms of the supergravity solution. We solve the condition of preserved supersymmetry on a metric inspired by the deformed conifold metric and obtain a solution of the NS5-branes which is delocalized except for one of the overall transverse directions. The solution has consistent properties with other configurations obtained by string dualities.
The production of string charge during a crossing of certain oriented D-branes is studied. We compute the string charge in the system of a probe D2-brane and a background D6-brane by use of the equations of motion in the ten-dimensions. We confirm the creation of string charge as inflow from the background D6-brane.
We consider brane configurations in elliptic models which represent softly broken N=4 USp(2 N_c) and SO(N_c) theory. We generalize the notion of the O4 plane, so that it is compatible with the symmetry in the covering space of the elliptic models. By using this notion of the O4 plane, we find the curve for softly broken N=4 USp(2 N_c) and that for SO(N_c) theory as infinite series expansions. For the USp case, we can present the expansion as a polynomial.
We investigate the brane exchange in the framework of N=2 MQCD by using a specific family of M fivebrane configurations relevant to describe the baryonic branch root. An exchange of M fivebranes is realized in the Taub-NUT geometry and controlled by the moduli parameter of the configurations. This family also provides two different descriptions of the root. These descriptions are examined carefully using the Taub-NUT geometry. It is shown that they have the same baryonic branch and are shifted each other by the brane exchange.
We study configurations of a single $M$ fivebrane in the geometry ${\bf R}^7 \times Q$ where $Q$ is the Taub-NUT space. Taking the IIA limit at each value of their modulus, two possibilities of the IIA configuration are revealed. One consists of a NS fivebrane and a D sixbrane while the other consists of a NS fivebrane, a D sixbrane and a D fourbrane. In the latter case the fourbrane is shown to be suspended by the fivebrane and the sixbrane. This appearance of fourbrane can be interpreted in Type IIA picture as the result of the crossing of the fivebrane and the sixbrane
Higgs branch of N=2 SQCD is studied from the M theory viewpoint. With a differential geometrical proof of the s-rule besides an investigation on the global symmetry of M theory brane configurations, an exact description of the baryonic and non-baryonic branches in terms of M theory is presented. The baryonic branch root is also studied. The ``electric'' and ``magnetic'' descriptions of the root are shown to be related with each other by the brane exchange in M theory.