Machiko Hatsuda

From super-AdS5×S5 algebra to super-pp-wave algebra

The isometry algebras of the maximally supersymmetric solutions of IIB supergravity are derived by the Inonu–Wigner contractions of the super-AdS5×S5 algebra. The super-AdS5×S5 algebra allows introducing two contraction parameters; the one for the Penrose limit to the maximally supersymmetric pp-wave algebra and the AdS5×S5 radius for the flat limit. The fact that the Jacobi identity of three supercharges holds irrespectively of these parameters reflects the fact that the number of supersymmetry is not affected under both contractions.

Noncommutative superspace, supermatrix and lowest Landau level

By using graded (super-)Lie algebras, we can construct noncommutative superspace on curved homogeneous manifolds. In this paper, we take a flat limit to obtain flat noncommutative superspace. We particularly consider d=2 and d=4 superspaces based on the graded Lie algebras osp(1|2), su(2|1) and psu(2|2). Jacobi identities of supersymmetry algebras and associativities of star products are automatically satisfied. Covariant derivatives which commute with supersymmetry generators are obtained and chiral constraints can be imposed. We also discuss that these noncommutative superspaces can be understood as constrained systems analogous to the lowest Landau level system.

Super-pp-wave algebra from super-AdS×S algebras in eleven dimensions

Abstract Maximally supersymmetric spacetime algebras in eleven dimensions, which are the isometry superalgebras of Minkowski space, AdS7×S4, AdS4×S7 and pp-wave background, are related by Inonu–Wigner contractions. The super-AdS4(7)×S7(4) algebras allow to introduce two contraction parameters, the one for the flat limit to the super-Poincare algebra and the other for a Penrose limit to the super-pp-wave algebra. Under these contractions supersymmetries are maintained because the Jacobi identity of three supercharges holds for any values of contraction parameters.

Wess-Zumino term for AdS superstring

We examine a bilinear form Wess-Zumino term for a superstring in anti-de Sitter (AdS) spaces. This is composed of two parts; a bilinear term in superinvariant currents and a total derivative bilinear term which is required for the pseudo-superinvariance of the Wess-Zumino term. The covariant supercharge commutator containing a string charge is also obtained.

Classical AdS superstring mechanics

We analyze the anti-de Sitter (AdS) superparticle and superstring systems described in terms of supermatrix valued coordinates proposed by Roiban and Siegel. This approach gives simple symmetry transformations and equations of motion. We examine their κ-transformations, infinite reducibility and κ-gauge fixing conditions. A closed first class constraint set for the AdS superparticle is GL(4|4) covariant and keeping superconformal symmetry manifestly. For the AdS superstring σ-dependence breaks the GL(4|4) covariance, where supercovariant derivatives and currents satisfy an inhomogeneous GL(4|4). A closed first class constraint set for the AdS superstring turns out to be the same as the one for a superstring in flat space, namely ABCD constraints.

CANONICAL FORMULATION OF IIB D-BRANES

Abstract We find Wess-Zumino actions for kappa invariant type IIB D-branes in explicit forms. A simple and compact expression is obtained by the use of spinor variables which are defined as power series of differential forms. Using the Wess-Zumino actions we develop the canonical formulation and find the complete set of the constraint equations for generic type IIB D p -branes. The conserved global supersymmetry charges are determined and the algebra containing the central charges can be obtained explicitly.

Electric-magnetic duality invariant Lagrangians

Abstract We find general non-linear Lagrangians invariant under the electric-magnetic duality. They are characterized by an arbitrary function and are reduced to the Maxwell theory in weak field limit. We present some explicit examples that include generalizations of the Born–Infeld theory.

Wess-Zumino actions for IIA D-branes and their supersymmetries

We present Wess-Zumino actions for general IIA D p-branes in explicit forms. We perform the covariant and irreducible separation of the fermionic constraints of IIA Dp-branes into first class and second class. A necessary condition which guarantees this separation is discussed. The generators of the local supersymmetry (kappa symmetry) and the kappa algebra are obtained. We also explicitly calculate the conserved charge of the global supersymmetry (SUSY) and the SUSY algebra which contains topological charges.

The regularized phase space path integral measure for a scalar field coupled to gravity

Abstract The path integral measure for a scalar field coupled to gravity in phase space is examined by constructing regulators for the jacobians, and explicitly computing Einstein, Weyl and other anomalies. The anomalies in phase space are independent of the choice of path integral variables (“the measure”) and this shows that one can simultaneously satisfy the requirements of unitarity and absence of Einstein anomalies. For the corresponding configuration space measures we find that different measures give different anomalies, but these anomalies are all related to each other by local counterterms.

Superspace with manifest T-duality from type II superstring

A bstractA superspace formulation of type II superstring background with manifest T-duality symmetry is presented. This manifestly T-dual formulation is constructed in a space spanned by two sets of nondegenerate super-Poincaré algebras. Supertorsion constraints are obtained from consistency of the κ-symmetric Virasoro constraints. All superconnections and vielbein fields are solved in terms of a prepotential which is one of the vielbein components. AdS5×S5 background is explained in this formulation.