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- Adawi, Tom, 1970, et al.
(författare)
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Goldstone tensor modes
- 1998
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Ingår i: J. High Energy Phys. 9902:001,1999.
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Tidskriftsartikel (refereegranskat)abstract
- In the context of brane solutions of supergravity, we discuss a general method to introduce collective modes of any spin by exploiting a particular way of breaking symmetries. The method is applied to the D3, M2 and M5 branes and we derive explicit expressions for how the zero-modes enter the target space fields, verify normalisability in the transverse directions and derive the corresponding field equations on the brane. In particular, the method provides a clear understanding of scalar, spinor, and rank r tensorial Goldstone modes, chiral as well as non-chiral, and how they arise from the gravity, Rarita-Schwinger, and rank r+1 Kalb-Ramond tensor gauge fields, respectively. Some additional observations concerning the chiral tensor modes on the M5 brane are discussed.
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3. |
- Adawi, Tom, 1970, et al.
(författare)
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Superembeddings, nonlinear supersymmetry and five-branes
- 1997
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Ingår i: Int.J.Mod.Phys.A13:4691-4716,1998.
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Tidskriftsartikel (refereegranskat)abstract
- We examine general properties of superembeddings, i.e., embeddings of supermanifolds into supermanifolds. The connection between an embedding procedure and the method of non-linearly realised supersymmetry is clarified, and we demonstrate how the latter arises as a special case of the former. As an illustration, the super-5-brane in 7 dimensions, containing a self-dual 3-form world-volume field strength, is formulated in both languages, and provides an example of a model where the embedding condition does not suffice to put the theory on-shell.
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- Bandos, Igor, et al.
(författare)
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Towards a complete twistorization of the heterotic string
- 1994
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Ingår i: Mod.Phys.Lett.A9 (1994) 2987.
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Tidskriftsartikel (refereegranskat)abstract
- In D=3,4,6 and 10 space-time dimensions considered is a string model invariant under transformations of N=1 space-time supersymmetry and n=D-2 local worldsheet supersymmetry with the both Virasoro constraints solved in the twistor form. The twistor solution survives in a modified form even in the presence of the heterotic fermions.
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5. |
- Bao, Ling, 1980, et al.
(författare)
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A note on topological M5-branes and string-fivebrane duality
- 2008
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Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708. ; 2008:6, s. 11-
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Tidskriftsartikel (refereegranskat)abstract
- We derive the stability conditions for the M5-brane in topological M-theory using k-symmetry. The non-linearly self-dual 3-form on the world-volume is necessarily non-vanishing, as is the case also for the 2-form field strengths on coisotropic branes in topological string theory. It is demonstrated that the self-duality is consistent with the stability conditions, which are solved locally in terms of a tensor in the representation 6 of SU(3) subset of G(2). The double dimensional reduction of the M5-brane is the D4-brane, and its direct reduction is an NS5-brane. We show that the equation of motion for the 3-form on the NS5-brane wrapping a Calabi-Yau space is exactly the Kodaira-Spencer equation, providing support for a string-fivebrane duality in topological string theory.
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6. |
- Bao, Ling, 1980, et al.
(författare)
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A Note on Topological M5-branes and String-Fivebrane Duality
- 2006
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We derive the stability conditions for the M5-brane in topological M-theory using kappa-symmetry. The non-linearly self-dual 3-form on the world-volume is necessarily non-vanishing, as is the case also for the 2-form field strengths on coisotropic branes in topological string theory. It is demonstrated that the self-duality is consistent with the stability conditions, which are solved locally in terms of a tensor in the representation 6 of SU(3) in G_2. The double dimensional reduction of the M5-brane is the D4-brane, and its direct reduction is an NS5-brane. We show that the equation of motion for the 3-form on the NS5-brane wrapping a Calabi-Yau space is exactly the Kodaira-Spencer equation, providing support for a string-fivebrane duality in topological string theory.
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7. |
- Bao, Ling, 1980, et al.
(författare)
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Aspects of higher curvature terms and U-duality
- 2007
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Ingår i: Classical and Quantum Gravity. - : IOP Publishing. - 0264-9381 .- 1361-6382. ; 25:9
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Tidskriftsartikel (refereegranskat)abstract
- We discuss various aspects of dimensional reduction of gravity with theEinstein-Hilbert action supplemented by a lowest order deformation formed asthe Riemann tensor raised to powers two, three or four. In the case of R^2 wegive an explicit expression, and discuss the possibility of extended cosetsymmetries, especially SL(n+1,Z) for reduction on an n-torus to threedimensions. Then we start an investigation of the dimensional reduction of R^3and R^4 by calculating some terms relevant for the coset formulation, aiming inparticular towards E_8(8)/(Spin(16)/Z_2) in three dimensions and aninvestigation of the derivative structure. We emphasise some issues concerningthe need for the introduction of non-scalar automorphic forms in order torealise certain expected enhanced symmetries.
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8. |
- Bao, Ling, 1980, et al.
(författare)
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Membranes for Topological M-Theory
- 2005
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Ingår i: Journal of High Energy Physics.
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Tidskriftsartikel (refereegranskat)abstract
- We formulate a theory of topological membranes on manifolds with G_2 holonomy. The BRST charges of the theories are the superspace Killing vectors (the generators of global supersymmetry) on the background with reduced holonomy G_2. In the absence of spinning formulations of supermembranes, the starting point is an N=2 target space supersymmetric membrane in seven euclidean dimensions. The reduction of the holonomy group implies a twisting of the rotations in the tangent bundle of the branes with ``R-symmetry'' rotations in the normal bundle, in contrast to the ordinary spinning formulation of topological strings, where twisting is performed with internal U(1) currents of the N=(2,2) superconformal algebra. The double dimensional reduction on a circle of the topological membrane gives the strings of the topological A-model (a by-product of this reduction is a Green-Schwarz formulation of topological strings). We conclude that the action is BRST-exact modulo topological terms and fermionic equations of motion. We discuss the role of topological membranes in topological M-theory and the relation of our work to recent work by Hitchin and by Dijkgraaf et al.
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9. |
- Bao, Ling, 1980, et al.
(författare)
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U-Duality and the Compactified Gauss-Bonnet Term
- 2007
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Ingår i: Journal of High Energy Physics.
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Tidskriftsartikel (refereegranskat)abstract
- We present the complete toroidal compactification of the Gauss-Bonnet Lagrangian from D dimensions to D-n dimensions. Our goal is to investigate the resulting action from the point of view of the "U-duality" symmetry SL(n+1,R) which is present in the tree-level Lagrangian when D-n=3. The analysis builds upon and extends the investigation of the paper [arXiv:0706.1183], by computing in detail the full structure of the compactified Gauss-Bonnet term, including the contribution from the dilaton exponents. We analyze these exponents using the representation theory of the Lie algebra sl(n+1,R) and determine which representation is the relevant one for quadratic curvature corrections. By interpreting the result of the compactification as a leading term in a large volume expansion of an SL(n+1,Z)-invariant action, we conclude that the overall exponential dilaton factor should not be included in the representation structure. As a consequence, all dilaton exponents correspond to weights of sl(n+1,R), which, nevertheless, remain on the positive side of the root lattice.
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10. |
- Bengtsson, Anders K.H., et al.
(författare)
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Particles, superparticles and twistors
- 1987
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Ingår i: Phys. Rev. D36 (1987) 1766.
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Tidskriftsartikel (refereegranskat)abstract
- The covariant Green-Schwarz action for a superstring has never been quantized covariantly. The physics behind this is discussed. We then consider the corresponding point-particle action in four dimensions, and write down a master action from which it can be obtained as a gauge choice: the ‘‘space-time gauge.’’ There is also a ‘‘twistor gauge,’’ in which covariant quantization is straightforward (as noted previously by Shirafuji).
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