Current Density Distributions and a Supersymmetric Action for Interacting Brane Systems

We propose a method to obtain a manifestly supersymmetric action functional for interacting brane systems. It is based on the induced map of the worldvolume of low-dimensional branes into the worldvolume of the space-time filling brane ((D-1)-brane), which may be either dynamical or auxiliary, and implies an identification of Grassmann coordinate fields of lower dimensional branes with an image of the Grassmann coordinate fields of that (D-1)-brane. With this identification the covariant current distribution forms with support on the superbrane worldvolumes become invariant under the target space supersymmetry and can be used to write the coupled superbrane action as an integral over the D-dimensional manifolds ((D-1)-brane worldvolume). We compare the equations derived from this new ('Goldstone fermion embedded') action with the ones produced by a more straightforward generalization of the free brane actions based on the incorporation of the boundary terms with Lagrange multipliers ('superspace embedded' action). We find that both procedures produce the same equations of motion and thus justify each other. Both actions are presented explicitly for the coupled system of a D=10 super-D3-brane and a fundamental superstring which ends on the super-D3-brane.Comment: 14 pages, latex, no figure

Superstring in doubled superspace

The covariant and kappa-symmetric action for superstring in direct product of two flat D=10 N=1 superspaces is presented. It is given by the sum of supersymmetric generalization of two copies of chiral boson actions constructed with the use of the Pasti-Sorokin-Tonin (PST) technique. The chirality of 8 `left' bosons and 8 `left' fermions and the anti-chirality of their `right' counterparts are obtained as gauge fixed version of the equations of motion, so that the physical degrees of freedom are essentially those of the II Green-Schwarz superstring. Our action is manifestly T-duality invariant as the fields describing oscillating and winding modes enter it on equal footing.Comment: 4+1 pages. V2: Misprints corrected, references adde

Exceptional field theories, superparticles in an enlarged 11D superspace and higher spin theories

Recently proposed exceptional field theories (EFTs) making manifest the duality $E_{n(n)}$ symmetry, first observed as nonlinearly realized symmetries of the maximal $d=3,4,...,9$ supergravity ($n=11-d$) and containing 11D and type IIB supergravity as sectors, were formulated in enlarged spacetimes. In the case of $E_{7(7)}$ EFT such an enlarged spacetime can be identified with the bosonic body of the $d=4$ central charge superspace $\Sigma^{(60|32)}$, the ${\cal N}=8$ $d=4$ superspace completed by 56 additional bosonic coordinates associated to central charges of the maximal $d=4$ supersymmetry algebra. In this paper we show how the hypothesis on the relation of all the known $E_{n(n)}$ EFTs, including $n=8$, with supersymmetry leads to the conjecture on existence of 11D exceptional field theory living in 11D tensorial central charge superspace $\Sigma^{(528|32)}$ and underlying all the $E_{n(n)}$ EFTs with $n=2,...,8$, and probably the double field theory (DFT). We conjecture the possible form of the section conditions of such an 11D EFT and show that quite generic solutions of these can be generated by superparticle models the ground states of which preserve from one half to all but one supersymmetry. The properties of these superparticle models are briefly discussed. We argue that, upon quantization, their quantum states should describe free massless non-conformal higher spin fields in D=11. We also discuss some relevant representations of the M-theory superalgebra which, in the present context, describes supersymmetry of the 11D EFT.Comment: 33 pages. V2: references added. V3: 42 pages. Minor corrections. New sections 3.3 and 5 added. Published in NP

On Lagrangian approach to self-dual gauge fields in spacetime of nontrivial topology

We study the Lagrangian description of chiral bosons, p-form gauge fields with (anti-)self-dual gauge field strengths, in D=2p+2 dimensional spacetime of nontrivial topology. We show that the manifestly Lorentz and diffeomorphism invariant Pasti-Sorokin-Tonin (PST) approach is consistent and produces the (anti-)self-duality equation also in topologically nontrivial spacetime. We discuss in what circumstances the nontrivial topology makes difference between two disconnected, `da-timelike' and `da-spacelike' branches of the PST system, the gauge fixed version of which are described by not manifestly invariant Henneaux-Teitelboim (HT) and Perry-Schwarz (PS) actions, respectively.Comment: 1+36 pages, JHEP class. V2: references added, misprints corrected, to appear in JHE