0000000000164012

AUTHOR

Igor A. Bandos

Twistor string as tensionless superstring

6 pages.-- PACS nrs.: 11.30.Pb, 11.25.-w, 11.10.Kk, 12.60.Jv.-- ISI Article Identifier: 000247103400009.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-th/0702133

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D=4 supergravity dynamically coupled to superstring in a superfield Lagrangian approach

We elaborate a full superfield description of the interacting system of dynamical D=4, N=1 supergravity and dynamical superstring. As far as minimal formulation of the simple supergravity is used, such a system should contain as well the tensor (real linear) multiplet which describes the dilaton and the two-superform gauge field whose pull-back provides the Wess-Zumino term for the superstring. The superfield action is given by the sum of the Wess-Zumino action for D=4, N=1 superfield supergravity, the superfield action for the tensor multiplet in curved superspace and the Green-Schwarz superstring action. The latter includes the coupling to the tensor multiplet both in the Nambu-Goto and i…

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Generalized curvature and the equations of D=11 supergravity

It is known that, for zero fermionic sector, the bosonic equations of Cremmer-Julia-Scherk eleven-dimensional supergravity can be collected in a compact expression which is a condition on the curvature of the generalized connection. Here we peresent the equation which collects all the bosonic equations of D=11 supergravity when the gravitino is nonvanishing.

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On the underlying gauge group structure of D=11 supergravity

The underlying gauge group structure of D=11 supergravity is revisited (see paper for detailed abstract).

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Lorentz harmonics and superfield action. D=10, N=1 superstring

We propose a new version of the superfield action for a closed D=10, N=1 superstring where the Lorentz harmonics are used as auxiliary superfields. The incorporation of Lorentz harmonics into the superfield action makes possible to obtain superfield constraints of the induced worldsheet supergravity as equations of motion. Moreover, it becomes evident that a so-called 'Wess-Zumino part' of the superfield action is basically a Lagrangian form of the generalized action principle. We propose to use the second Noether theorem to handle the essential terms in the transformation lows of hidden gauge symmetries, which remove dynamical degrees of freedom from the Lagrange multiplier superfield.

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On the absence of BPS preonic solutions in IIA and IIB supergravities

We consider the present absence of 31 out of 32 supersymmetric solutions in supergravity i.e., of solutions describing BPS preons. A recent result indicates that (bosonic) BPS preonic solutions do not exist in type IIB supergravity. We reconsider this analysis by using the G-frame method, extend it to the IIA supergravity case, and show that there are no (bosonic) preonic solutions for type IIA either. For the classical D=11 supergravity no conclusion can be drawn yet, although the negative IIA results permit establishing the conditions that preonic solutions would have to satisfy. For supergravities with `stringy' corrections, the existence of BPS preonic solutions remains fully open.

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BPS preons in M-theory and supergravity

7 pages.-- PACS nrs.: 11.30.Pb, 11.25.-w, 04.65.+e, 11.10.Kk.-- ISI Article Identifier: 000247103400029.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-th/0702099

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Spinor moving frame, M0-brane covariant BRST quantization and intrinsic complexity of the pure spinor approach

To exhibit the possible origin of the inner complexity of the Berkovits's pure spinor approach, we consider the covariant BRST quantization of the D=11 massless superparticle (M0-brane) in its spinor moving frame or twistor-like Lorentz harmonics formulation. The presence of additional twistor-like variables (spinor harmonics) allows us to separate covariantly the first and the second class constraints. After taking into account the second class constraints by means of Dirac brackets and after further reducing the first class constraints algebra, the dynamical system is described by the cohomology of a simple BRST charge associated to the d=1, n=16 supersymmetry algebra. The calculation of …

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D=11massless superparticle covariant quantization, pure spinor BRST charge and hidden symmetries

We consider the covariant quantization of the D=11 massless superparticle (M0-brane) in the spinor moving frame or twistor-like Lorentz harmonics formulation. The action involves the set of 16 constrained 32 component Majorana spinors, the spinor Lorentz harmonics parametrizing (as homogeneous coordinates, modulo gauge symmetries) the celestial sphere S9. There presence allows us to separate covariantly the first and the second class constraints of the model. After taking into account the second class constraints by means of Dirac brackets and after further reducing the first class constraints algebra, the system is described in terms of a simple BRST charge associated to the d=1, n=16 supe…

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Superembedding Approach and S-Duality. A unified description of superstring and super-D1-brane

It is proved that a basic superembedding equation for the 2-dimensional worldsheet superspace $\S^{(2|8+8)}$ embedded into D=10 type IIB superspace $M^{(10|16+16)}$ provides a universal, S-duality invariant description of a fundamental superstring and super-D1-brane. We work out generalized action principle, obtain superfield equations of motion for both these objects and find how the S-duality transformations relate the superfield equations of superstring and super-D1-brane. The superembedding of 6-dimensional worldsheet superspace $\S^{(6|16)}$ into the D=10 type IIB superspace will probably provide a similar universal description for the set of type IIB super-NS5-brane, super-D5-brane an…

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Aspects of D-brane Dynamics in Supergravity Backgrounds with Fluxes, Kappa-symmetry and Equations of Motion. Part IIB

We derive and carry out a detailed analysis of the equations of motion of the type IIB D branes in generic supergravity backgrounds with fluxes making account of the worldvolume Born-Infeld gauge field and putting a special emphasis on the structure of the Dirac equation for Dp brane fermionic modes. We present an explicit form of the worldvolume field equations for each of the Dp branes (p=1,3,5,7,9) in the cases in which the Neveu-Schwarz flux and the Ramond-Ramond p-form flux along the Dp-brane worldvolume are zero and the supergravity backgrounds do not necessarily induce the worldvolume Born-Infeld flux. We then give several examples of D3, D5 and D7 brane configurations in which the w…

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BPS preons and higher spin theory in D=4, 6, 10

We briefly review here the notion of BPS preons, the hypothetical constituents of M-theory, emphasizing its generalization to arbitrary dimensions D and its relation to higher spin theories in D=4,6 and 10.

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The Space Filling Dirichlet 3-Brane in N=2, D=4 Superspace

We discuss a four-dimensional Volkov-Akulov supersymmetric theory on a D3-brane with N=2 supersymmetry broken down to N=1.

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