arXiv subjects

Machiko Hatsuda

Publications and source records attributed to Machiko Hatsuda.

45 records · Page 3Linked to original sources

arXiv2001

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 kappa-transformations, infinite reducibility and kappa-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 the 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.

hep-th↗

arXiv2001

Open Superstring Theory and Superalgebra of the Brane Antibrane System

Open superstring theory is formulated in terms of a nondegenerate supertranslation algebra. A supercharge for a tachyonic superstring can be also defined classically by taking into account the leakage of the supercurrent which is compensated by fermionic and bosonic auxiliary fields. The anticommutator of two supercharges of the tachyonic superstring does not contain the zero eigenvalue and so this string is not a BPS state. Brane-antibrane annihilation scenarios are described by these superalgebras defined on the sum of world-volumes of a D-brane, an anti-D-brane and a tachyonic superstring.

hep-th↗

arXiv2000

Nondegenerate Super-Anti-de Sitter Algebra and a Superstring Action

We construct an Anti-de Sitter(AdS) algebra in a nondegenerate superspace. Based on this algebra we construct a covariant kappa-symmetric superstring action, and we examine its dynamics: Although this action reduces to the usual Green-Schwarz superstring action in flat limit, the auxiliary fermionic coordinates of the nondegenerate superspace becomes dynamical in the AdS background.

hep-th↗

arXiv2000

BPS states carrying fermionic brane charges

The Green-Siegel central extension of superalgebras for BPS branes is studied. In these cases commutators of usual bosonic brane charges only with the broken supersymmetry charges allow this central extension. We present an interpretation of these fermionic central charges as fermionic brane charges, and show that they take nonzero values for a nontrivial fermionic boundary condition. Such fermionic coordinates solutions are determined by equations of motion in a suitable gauge condition which manifests Nambu-Goldstone fermionic modes as well as bosonic modes in the static gauge. We also show that some modes of dilatino fields couple with the fermionic brane currents.

hep-th↗

arXiv1999

Electric-Magnetic Duality Invariant Lagrangians

We find general non-linear lagrangians of a U(1) field invariant under electric-magnetic duality. They are characterized by an arbitrary function and go to the Maxwell theory in the weak field limit. We give some explicit examples which are generalizations of the Born-Infeld theory.

hep-th↗

arXiv1999

SO(2,1) Covariant IIB Superalgebra

We propose a type IIB super-Poincare algebra with SO(2,1) covariant central extension. Together with SO(2,1) and SO(9,1) generators, a SO(2,1) triplet (momenta), a Majorana-spinor doublet (supercharges) and a Rarita-Schwinger central charge generate a group, G. We consider a coset G/H where H=(SO(2) x Lorentz), and the SL(2,R) 2-form doublet is obtained by the coset construction. It is shown that U(1) connections, whose strengths are associated with 2-forms, are recognized as coordinates of the enlarged space. We suggest that this is the fundamental algebra governing the superstring theories which explains the IIB SL(2,R) duality and geometrical origin of U(1) fields.

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arXiv1998

Canonical Formulation of IIB D-branes

We find Wess-Zumino actions for kappa invariant IIB D-branes in the explicit form. A simple and compact expression is obtained by the grace of spinor variables which are defined as power series of differential forms. Once explicit form of the Wess-Zumino actions is determined, global supersymmetry (SUSY) charges and constraint equations including local supersymmetry (kappa) generators can be determined. The SUSY algebra and the central charges are also calculated explicitly.

hep-th↗

arXiv1998

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 D-p-branes into the first class and the 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.

hep-th↗

arXiv1998

Covariant Quantization of The Super-D-string

We present the covariant BRST quantization of the super-D-string. The non-vanishing supersymmetric U(1) field strength ${\cal F}$ is essential for the covariant quantization of the super-D-string as well as for its static picture. A SO(2) parameter parametrizes a family of local supersymmetric (kappa symmetric) systems including the super-D-string with ${\cal F}\ne 0$ and the Green-Schwarz superstring with ${\cal F}= 0$. We suggest that $E^1$ (canonical conjugate of U(1) gauge field) plays a role of the order parameter in the Green-Schwarz formalism: the super-D-string exists for $E^1 \ne 0$ while the fundamental Green-Schwarz superstring exists only for $E^1 =0$.

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