arXiv subjects

Kiyoshi Kamimura

Publications and source records attributed to Kiyoshi Kamimura.

At least 55 records · Page 3Linked to original sources

arXiv2004

Wess-Zumino terms for AdS D-branes

We show that Wess-Zumino terms for D-p branes with p>0 in the Anti-de Sitter (AdS) space are given in terms of "left-invariant" currents on the super-AdS group or the "expanded" super-AdS group. As a result there is no topological extension of the super-AdS algebra. In the flat limit the global Lorentz rotational charges of the AdS space turn out to be brane charges of the supertranslation algebra representing the BPS mass. We also show that a D-instanton is described by the GL(1) degree of freedom in the Roiban-Siegel formalism based on the GL(4|4)/[Sp(4)xGL(1)]^2 coset.

hep-th↗

arXiv2004

Physical Degrees of Freedom of Non-local Theories

We analyze the physical (reduced) space of non-local theories, around the fixed points of these systems, by analyzing: i) the Hamiltonian constraints appearing in the 1+1 formulation of those theories, ii) the symplectic two form in the surface on constraints. P-adic string theory for spatially homogeneous configurations has two fixed points. The physical phase space around $q=0$ is trivial, instead around $q=\frac 1g$ is infinite dimensional. For the special case of the rolling tachyon solutions it is an infinite dimensional lagrangian submanifold. In the case of string field theory, at lowest truncation level, the physical phase space of spatially homogeneous configurations is two dimensional around $q=0$, which is the relevant case for the rolling tachyon solutions, and infinite dimensional around $q=\frac {M^2}g$.

hep-th↗

arXiv2003

osp(1|32) and Extensions of super-AdS_5 X S^5 algebra

The super-AdS_5 X S^5 and the four-dimensional N=4 superconformal algebras play important roles in superstring theories. It is often discussed the roles of the osp(1|32) algebra as a maximal extension of the superalgebras in flat background. In this paper we show that the su(2,2|4), the super-AdS_5 X S^5 algebra or the superconformal algebra, is not a restriction of the osp(1|32) though the bosonic part of the former is a subgroup of the latter. There exist only two types of u(1) extension of the super-AdS_5 X S^5 algebra if the bosonic AdS_5 X S^5 covariance is imposed. Possible significance of the results is also discussed briefly.

hep-th↗

arXiv2002

Gauge invariant action for superstring in Ramond-Ramond plane-wave background

We present a gauge invariant action for a superstring in the plane wave background with Ramond-Ramond (RR) five-form flux. The Wess-Zumino term is given explicitly in a bilinear form of the left invariant currents by introducing a fermionic center to define the nondegenerate group metric. The reparametrization invariance generators, whose combinations are conformal generators, and fermionic constraints, half of which generate kappa-symmetry, are obtained. Equations of motion are obtained in conformal invariant and background covariant manners.

hep-th↗

arXiv2002

Super-PP-wave Algebra from Super-AdS x S Algebras in Eleven-dimensions

Maximally supersymmetric spacetime algebras in eleven-dimensions, which are the isometry superalgebras of Minkowski space, AdS_7 x S^4, AdS_4 x S^7 and pp-wave background, are related by Inonu-Wigner contractions. The super-AdS_{4(7)} x S^{7(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.

hep-th↗

arXiv2002

From Super-AdS_5xS^5 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-AdS_5xS^5 algebra. The super-AdS_5xS^5 algebra allows introducing two contraction parameters; the one for the Penrose limit to the maximally supersymmetric pp-wave algebra and the AdS_5xS^5 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.

hep-th↗

arXiv2001

Gauge Transformations and Weak Lax Equation

We consider several integrable systems from a standpoint of the SL(2,R) invariant gauge theory. In the Drinfeld-Sokorov gauge, we get a one parameter family of nonlinear equations from zero curvature conditions. For each value of the parameter the equation is described by weak Lax equations. It is transformed to a set of coupled equations which pass the Painlevé test and are integrable for any integer values of the parameter. Performing successive gauge transformations (the Miura transformations) on the system of equations we obtain a series of nonlinear equations.

nlin.SI↗

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

Gauge and BRST Generators for Space-Time Non-commutative U(1) Theory

The Hamiltonian (gauge) symmetry generators of non-local (gauge) theories are presented. The construction is based on the d+1 dimensional space-time formulation of d dimensional non-local theories. The procedure is applied to U(1) space-time non-commutative gauge theory. In the Hamiltonian formalism the Hamiltonian and the gauge generator are constructed. The nilpotent BRST charge is also obtained. The Seiberg-Witten map between non-commutative and commutative theories is described by a canonical transformation in the superphase space and in the field-antifield space. The solutions of classical master equations for non-commutative and commutative theories are related by a canonical transformation in the antibracket sense.

hep-th↗

arXiv2000

Hamiltonian Formalism for Space-time Non-commutative Theories

Space-time non-commutative theories are non-local in time. We develop the Hamiltonian formalism for non-local field theories in d space-time dimensions by considering auxiliary d+1 dimensional field theories which are local with respect to the evolution time. The Hamiltonian path integral quantization is considered and the Feynman rules in the Lagrangian formalism are derived. The case of non-commutative ϕ^3 theory is considered as an example.

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

T-duality Covariance of SuperD-branes

T-duality realized on SuperD-brane effective actions probing in constant $G_{mn}$ and $b_{mn}$ backgrounds is studied from a pure world volume point of view. It is proved that requiring {\em T-duality covariance} of such actions ``fixes'' the T-duality transformations of the world volume dynamical fields, and consequently, of the NS-NS and R-R coupling superfields. The analysis is extended to uncover the mapping of the symmetry structure associated with these SuperD-brane actions. In particular, we determine the T-duality transformation properties of kappa symmetry and supersymmetry, which allow us to prove that bosonic supersymmetric world volume solitons of the original theory generate, through T-duality, the expected ones in the T-dual theory. The latter proof is generalized to arbitrary bosonic backgrounds. We conclude with some comments on extensions of our approach to arbitrary kappa symmetric backgrounds, non-BPS D-branes and non-abelian SuperD-branes.

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.

hep-th↗

arXiv1998

Electric-Magnetic Duality Rotations and Invariance of Actions

For D=4 theories of a single U(1) gauge field strength coupled to gravity and matters, we show that the electric-magnetic duality can be formulated as an invariance of the actions. The symmetry is associated with duality rotation acting directly on the gauge field. The rotation is constructed in flat space, and an extension to curved spaces is also given. It is non-local and non-covariant, yet generates off-shell extended transformation of the field strength. The algebraic condition of Gaillard and Zumino turns out to be a necessary and sufficient condition for the invariance of actions. It may be used as a guiding principle in constructing self-dual actions in string and field theories.

hep-th↗

arXiv1998

Self-duality in Super D3-brane Action

We establish self-duality of super D3-brane theory as an exact symmetry of the action both in the Lagrangian and Hamiltonian formalism. In the Lagrangian formalism, the action is shown to satisfy the Gaillard-Zumino condition. This algebraic relation is recognized in our previous paper to be a necessary and sufficient condition for generic action of U(1) gauge field strength coupled with gravity and matters to be self-dual. For the super D3-brane action, SO(2) duality transformation of a world-volume gauge field should be associated with SO(2) rotation of fermionic brane coordinates in N=2 SUSY multiplet. This SO(2) duality symmetry is lifted to SL(2,R) symmetry in the presence of a dilaton and an axion background fields. In the canonical formalism, we show that the duality rotation is described by a canonical transformation, and the Hamiltonian of the D3-brane action is invariant under the transformation.

hep-th↗

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↗