Yusuke Kimura

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It is shown that a covariant derivative on any d-dimensional manifold M can be mapped to a set of d operators acting on the space of functions defined on the principal Spin(d)-bundle over M. In other words, any d-dimensional manifold can be described in terms of d operators acting on an infinite-dimensional space. Therefore it is natural to introduce a new(More)
We consider a reduced model of four-dimensional Yang-Mills theory with a mass term. This matrix model has two classical solutions, two-dimensional fuzzy sphere and two-dimensional fuzzy torus. These classical solutions are constructed by embedding them into three or four dimensional flat space. They exist for finite size matrices, that is, the number of the(More)
Matrix descriptions of higher dimensional spherical branes are investigated. It is known that a fuzzy 2k-sphere is described by the coset space SO(2k + 1)/U (k) and has some extra dimensions. It is shown that a fuzzy 2k-sphere is comprised of n k(k−1) 2 spherical D(2k − 1)-branes and has a fuzzy 2(k − 1)-sphere at each point. We can understand the(More)
We propose gauge theory operators built using a complex Matrix scalar which are dual to brane-anti-brane systems in AdS 5 × S 5 , in the zero coupling limit of the dual Yang-Mills. The branes involved are half-BPS giant gravitons. The proposed operators dual to giant-anti-giant configurations satisfy the appropriate orthogonality properties. Projection(More)
D0-branes are unstable in the presence of an R-R field strength background. A fuzzy two-sphere is classically stable under such a background, this phenomenon being called the Myers effect. We analyze this effect from the viewpoint of tachyon condensation. It is explicitly shown that a fuzzy two-sphere is realized by the condensation of tachyons which appear(More)
It is known that noncommutative Yang-Mills is equivalent to IIB matrix model with a noncommutative background, which is interpreted as a twisted reduced model. In non-commutative Yang-Mills, long range interactions can be seen in nonplanar diagrams after integrating high momentum modes. These interactions can be understood as block-block interactions in the(More)
This paper proposes a framework for analyzing legal sentences including itemized or referential expressions. Thus far, we have developed a system for translating legal documents into logical formu-lae. Although our system basically converts words and phrases in a target sentence into predicates in a logical formula, it generates some useless predicates for(More)
It is well-known that coordinates of a charged particle in the presence of a monopole background become noncommutative. In this paper, we study the motion of a charged particle moving on a supersphere in the presence of a supermonopole. We construct a supermonopole by using a supersymmetric extension of the first Hopf map. We investigate algebras of angular(More)