Supersymmetric and Kappa-invariant Coincident D0-Branes

We propose a generic supersymmetric and kappa-invariant action for describing coincident D0-branes with non-abelian matter fields on their worldline. The action is shown to be in agreement with the Matrix Theory limit of the ND0-brane effective action.Comment: JHEP style, 1+8 page

A Twistor Formulation of the Non-Heterotic Superstring with Manifest Worldsheet Supersymmetry

We propose a new formulation of the $D=3$ type II superstring which is manifestly invariant under both target-space $N=2$ supersymmetry and worldsheet $N=(1,1)$ super reparametrizations. This gives rise to a set of twistor (commuting spinor) variables, which provide a solution to the two Virasoro constraints. The worldsheet supergravity fields are shown to play the r\^ole of auxiliary fields.Comment: 21p., LaTe

A twistor-like D=10 superparticle action with manifest N=8 world-line supersymmetry

We propose a new formulation of the $D=10$ Brink-Schwarz superparticle which is manifestly invariant under both the target-space super-Poincar\'e group and the world-line local $N=8$ superconformal group. This twistor-like construction naturally involves the sphere $S^8$ as a coset space of the $D=10$ Lorentz group. The action contains only a finite set of auxiliary fields, but they appear in unusual trilinear combinations. The origin of the on-shell $D=10$ fermionic $\kappa$ symmetry of the standard Brink-Schwarz formulation is explained. The coupling to a $D=10$ super-Maxwell background requires a new mechanism, in which the electric charge appears only on shell as an integration constant.Comment: 22pages, standard LATEX fil

Quantization of the Chern-Simons Coupling Constant

We investigate the quantum consistency of p-form Maxwell-Chern-Simons electrodynamics in 3p+2 spacetime dimensions (for p odd). These are the dimensions where the Chern--Simons term is cubic, i.e., of the form FFA. For the theory to be consistent at the quantum level in the presence of magnetic and electric sources, we find that the Chern--Simons coupling constant must be quantized. We compare our results with the bosonic sector of eleven dimensional supergravity and find that the Chern--Simons coupling constant in that case takes its corresponding minimal allowed value.Comment: 15 pages, 1 figure, JHEP3.cls. Equation (8.6) corrected and perfect agreement with previous results is obtaine

Q7-branes and their coupling to IIB supergravity

We show how, by making use of a new basis of the IIB supergravity axion-dilaton coset, SL(2,R)/SO(2), 7-branes that belong to different conjugacy classes of the duality group SL(2,R) naturally couple to IIB supergravity with appropriate source terms characterized by an SL(2,R) charge matrix Q. The conjugacy classes are determined by the value of the determinant of Q. The (p,q) 7-branes are the branes in the conjugacy class detQ = 0. The 7-branes in the conjugacy class detQ > 0 are labelled by three numbers (p,q,r) which parameterize the matrix Q and will be called Q7-branes. We construct the full bosonic Wess--Zumino term for the Q7-branes. In order to realize a gauge invariant coupling of the Q7-brane to the gauge fields of IIB supergravity it is necessary to introduce an SL(2,R) doublet of two distinct Born--Infeld fields on the Q7-brane world-volume.Comment: 31 pages, Latex fil

New supersymmetric AdS4 type II vacua

Building on our recent results on dynamic SU(3)xSU(3) structures we present a set of sufficient conditions for supersymmetric AdS4xM6 backgrounds of type IIA/IIB supergravity. These conditions ensure that the background solves, besides the supersymmetry equations, all the equations of motion of type II supergravity. The conditions state that the internal manifold is locally a codimension-one foliation such that the five dimensional leaves admit a Sasaki-Einstein structure. In type IIA the supersymmetry is N=2, and the total six-dimensional internal space is locally an S^2 bundle over a four-dimensional Kaehler-Einstein base; in IIB the internal space is the direct product of a circle and a five-dimensional squashed Sasaki-Einstein manifold. Given any five-dimensional Sasaki-Einstein manifold we construct the corresponding families of type IIA/IIB vacua. The precise profiles of all the fields are determined at the solution and depend on whether one is in IIA or in IIB. In particular the background does not contain any sources, all fluxes (including the Romans mass in IIA) are generally non-zero, and the dilaton and warp factor are non-constant.Comment: 19 pages; clarifications added, version to appear in JHE

New Superembeddings for Type II Superstrings

Possible ways of generalization of the superembedding approach for the supersurfaces with the number of Grassmann directions being less than the half of that for the target superspace are considered on example of Type II superstrings. Focus is on n=(1,1) superworldsheet embedded into D=10 Type II superspace that is of the interest for establishing a relation with the NSR string.Comment: 26 pages, LaTeX, JHEP.cls and JHEP.bst style files are used; v2: misprints corrected, comments, acknowledgments, references adde

On superembedding approach to type IIB 7-branes

In search for a dynamical description of Q7-branes, which were known as solutions of supergravity equations and then conjectured to be dynamical objects of type IIB string theory, we study the superembedding description of 7-branes in curved type IIB supergravity superspace. With quite minimal and natural assumptions we have found that there is no place for Q7-branes as dynamical branes in superembedding approach. Our study might give implications for the old-standing problem of the covariant and supersymmetric description of multiple Dp-brane systems.Comment: LaTeX, 40 pages, no figures. V2: 44 pages, misprints corrected, minor cosmetic changes, improvements and extensions of discussion, in particular in the parts devoted to derivation of D7-brane equations of motion (Sec. 3) and in Secs. 4.2; appendices E,F added, footnote on page 30 extended, conclusions remain the same. V3. More misprints correcte

Reducible higher-spin multiplets in flat and AdS spaces and their geometric frame-like formulation

We consider the frame-like formulation of reducible sets of totally symmetric bosonic and fermionic higher-spin fields in flat and AdS backgrounds of any dimension, that correspond to so-called higher-spin triplets resulting from the string-inspired BRST approach. The explicit relationship of the fields of higher-spin triplets to the higher-spin vielbeins and connections is found. The gauge invariant actions are constructed including, in particular, the reducible (i.e. triplet) higher-spin fermion case in AdS_D space.Comment: 1+49 pages, This is an essentially extended version of the contribution to the volume dedicated to the 60th birthday anniversary of Joseph Buchbinder; v2 FIAN Preprint No and references adde

Kappa-symmetry for coincident D-branes

A kappa-symmetric action for coincident D-branes is presented. It is valid in the approximation that the additional fermionic variables, used to incorporate the non-abelian degrees of freedom, are treated classically. The action is written as a Bernstein-Leites integral on the supermanifold obtained from the bosonic worldvolume by adjoining the extra fermions. The integrand is a very simple extension of the usual Green-Schwarz action for a single brane; all symmetries, except for kappa, are manifest, and the proof of kappa-symmetry is very similar to the abelian case.Comment: 18 pages. References adde