[Show abstract][Hide abstract] ABSTRACT: We use Hamiltonian methods to study curved domain walls and cosmologies. This leads naturally to first-order equations for all domain walls and cosmologies foliated by slices of maximal symmetry. For Minkowski and AdS-sliced domain walls (flat and closed FLRW cosmologies) we recover a recent result concerning their (pseudo)supersymmetry. We show how domain-wall stability is consistent with the instability of AdS vacua that violate the Breitenlohner-Freedman bound. We also explore the relationship to Hamilton-Jacobi theory and compute the wave-function of a 3-dimensional closed universe evolving towards de Sitter spacetime.
Physical Review D 12/2006; 74:125008. · 4.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The correspondence between domain-wall and cosmological solutions of gravity coupled to scalar fields is explained. Any domain wall solution that admits a Killing spinor is shown to correspond to a cosmology that admits a pseudo-Killing spinor: whereas the Killing spinor obeys a Dirac-type equation with hermitian `mass'-matrix, the corresponding pseudo-Killing spinor obeys a Dirac-type equation with a anti-hermitian `mass'-matrix. We comment on some implications of (pseudo)supersymmetry.
Journal of Physics A Mathematical and Theoretical 11/2006; 40(25). DOI:10.1088/1751-8113/40/25/S18 · 1.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The (2k+2)-dimensional Einstein-Yang-Mills equations for gauge group SO(2k) (or SU(2) for k=2 and SU(3) for k=3) are shown to admit a family of spherically-symmetric magnetic monopole solutions, for both zero and non-zero cosmological constant Lambda, characterized by a mass m and a magnetic-type charge. The k=1 case is the Reissner-Nordstrom black hole. The k=2 case yields a family of self-gravitating Yang monopoles. The asymptotic spacetime is Minkowski for Lambda=0 and anti-de Sitter for Lambda<0, but the total energy is infinite for k>1. In all cases, there is an event horizon when m>m_c, for some critical mass $m_c$, which is negative for k>1. The horizon is degenerate when m=m_c, and the near-horizon solution is then an adS_2 x S^{2k} vacuum. Comment: 16 pp. Extensive revision to include case of non-zero cosmological constant and implications for adS/CFT. Numerous additional references
[Show abstract][Hide abstract] ABSTRACT: We argue that the Wess-Zumino model with quartic superpotential admits stable static solutions in which three domain walls intersect at a junction. We derive an energy bound for such junctions and show that configurations saturating it preserve 14 supersymmetry.
[Show abstract][Hide abstract] ABSTRACT: A static minimal energy configuration of a super p-brane in a supersymmetric (n+1)-dimensional spacetime is shown to be a `generalized calibrated' submanifold. Calibrations in $\bE^{(1,n)}$ and $AdS_{n+1}$ are special cases. We present several M-brane examples. Comment: Revtex. 11 pp. Minor corrections made and references added. To appear in Phys. Rev. D
Physical Review D 05/1999; 60(10). DOI:10.1103/PhysRevD.60.106006 · 4.64 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We argue that the large n limit of the n-particle SU(1,1|2) superconformal Calogero model provides a microscopic description of the extreme Reissner–Nordström black hole in the near-horizon limit.
Physics Letters B 12/1998; 454(3-4-454):187-192. DOI:10.1016/S0370-2693(99)00266-X · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We discuss some general features of black holes of five-dimensional supergravity, such as the first law of black hole mechanics. We also discuss some special features of rotating supersymmetric black holes. In particular, we show that the horizon is a non-singular, and {\sl non-rotating}, null hypersurface whose intersection with a Cauchy surface is a squashed 3-sphere. We find the Killing spinors of the near-horizon geometry and thereby determine the near-horizon isometry supergroup.
[Show abstract][Hide abstract] ABSTRACT: We present a new 1/8 supersymmetric intersecting M-brane solution of D=11 supergravity with two independent rotation parameters. The metric has a non-singular event horizon and the near-horizon geometry is AdS3×S3×S3×E2 (just as in the non-rotating case). We also present a method of determining the isometry supergroup of supergravity solutions from the Killing spinors and use it to show that for the near horizon solution it is D(2|1,α)×D(2|1,α) where α is the ratio of the two 3-sphere radii. We also consider various dimensional reductions of our solution, and the corresponding effect of these reductions on the Killing spinors and the isometry supergroups.
Physical Review D 11/1998; 59(2). DOI:10.1103/PhysRevD.59.025001 · 4.64 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An ‘algebraic’ approach to M-theory is briefly reviewed, and a proposal is made for a similar algebraic structure underlying the T9 compactification of ‘M(embrane) theory’, i.e. the M(atrix) model with area-preserving diffeomorphism gauge group.
[Show abstract][Hide abstract] ABSTRACT: Supersymmetric configurations of non-orthogonally intersecting M-5-branes can be obtained by rotation of one of a pair of parallel M-5-branes. Examples preserving and supersymmetry are reviewed.
[Show abstract][Hide abstract] ABSTRACT: We derive a bound on the energy of the general (p, q)-supersymmeric two-dimensional massive sigma-model with torsion, in terms of the topological and Noether charges that appear as central charges in its supersymmetry algebra. The bound is saturated by soliton solutions of first-order Bogomol'nyi-type equations. This generalizes results obtained previously for p = q models without torsion. We give examples of massive (1, 1) models with torsion that have a group manifold as a target space. We show that they generically have multiple vacua and find an explicit soliton solution of an SU(2) model. We also construct a new class of zero-torsion massive (4, 4) models with multiple vacua and soliton solutions. In addition, we compute the metrics on the one-soliton moduli spaces for those cases for which soliton solutions are known explicitly, and discuss their interpretation.
Nuclear Physics B 06/1998; 444(1-444):245-264. DOI:10.1016/0550-3213(95)00125-C · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It is argued that the type IIA 10-dimensional superstring theory is actually a compactified 11-dimensional supermembrane theory in which the fundamental supermembrane is identified with the soltionic membrane of 11-dimensional supergravity. The charged extreme black holes of the 10-dimensional type IIA string theory are interpreted as the Kaluza-Klein modes of 11-dimensional supergravity and the dual sixbranes as the analogue of Kaluza-Klein monopoles. All other p-brane solutions of the type IIA superstring theory are derived from the 11-dimensional membrane and its magnetic dual fivebrane soliton.
Physics Letters B 06/1998; 350(2-350):184-188. DOI:10.1016/0370-2693(95)00397-4 · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Generalized membrane solutions of D = 11 supergravity, for which the transverse space is a toric hyper-Kahler manifold, are shown to have IIB duals representing the intersection of parallel 3-branes with 5-branes whose orientations are determined by their charge vectors. These IIB solutions, which generically preserve 3/16 of the supersymmetry, can be further mapped to solutions of D = 11 supergravity representing the intersection of parallel membranes with any number of fivebranes at arbitrary angles. Alternatively, a subclass (corresponding to non-singular D = 11 solutions) can be mapped to solutions representing the intersection on a string of any number of D-5-branes at arbitrary angles, again preserving supersymmetry, as we verify in a special case by a quaternionic extension of the analysis of Berkooz, Douglas and Leigh. We also use similar methods to find new supersymmetric solutions of orthogonally intersecting branes.
Nuclear Physics B 09/1997; 500(1-3-500):133-162. DOI:10.1016/S0550-3213(97)00335-0 · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A manifestly S-dual, and ‘12 dimensional’, IIB superstring action with an Sl(2; ) doublet of ‘Born-Infeld’ fields is presented. The M-theory origin of the 12th dimension is the M-2-brane tension, which can be regarded as the flux of a 3-form worldvolume field strength. The latter is required by the fact that the M-2-brane can have a boundary on an M-5-brane.
Physics Letters B 05/1997; 409(1-4-409):131-135. DOI:10.1016/S0370-2693(97)00862-9 · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The M-theory interpretation of certain D = 10 IIA p-branes implies the existence of worldvolume Kaluza-Klein modes which are expected to appear as 0-brane/p-brane bound states preserving of the spacetime supersymmetry. We construct the corresponding solutions of the effective supergravity theory for p = 1,4, and show that no such solution exists for p = 8.
Physics Letters B 09/1996; 393(1-2-393):59-64. DOI:10.1016/S0370-2693(96)01614-0 · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We present the magnetic duals of Güven's electric-type solutions of D = 11 supergravity preserving or of the D = 11 supersymmetry. We interpret the electric solutions as n orthogonal intersecting membranes and the magnetic solutions as n orthogonal intersecting 5-branes, with n = 2, 3; these cases obey the general rule that p-branes can self-intersect on (p − 2)-branes. On reduction to D = 4 these solutions become electric or magnetic dilaton black holes with dilaton coupling constant a = 1 (for n = 2) or (for n = 3). We also discuss the reduction to D = 10.
Physics Letters B 03/1996; 380(3-4-380):273-279. DOI:10.1016/0370-2693(96)00506-0 · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A review is given of the implications of supersymmetric black holes for the non-perturbative formulation of toroidally compactified superstrings, with particular emphasis on symmetry enhancement at special vacua and S-duality of the heterotic string.
[Show abstract][Hide abstract] ABSTRACT: We investigate the compactification of D = 11 supergravity to D = 5,4,3, on compact manifolds of holonomy SU(3) (Calabi-Yau), G2, and Spin(7), respectively, making use of examples of the latter two cases found recently by Joyce. In each case the lower dimensional theory is a Maxwell/Einstein supergravity theory. We find evidence for an equivalence, in certain cases, with heterotic string compactifications from D = 10 to D = 5,4,3, on compact manifolds of holonomy SU(2) (K3 × S1), SU(3), and G2, respectively. Calabi-Yau manifolds with Hodge numbers h1,1 = h1,2 = 19 play a significant role in the proposed equivalences.
Physics Letters B 06/1995; 357(3-357):300-306. DOI:10.1016/0370-2693(95)00929-F · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We show that the exact static, i.e. ‘anti-gravitating’, magnetic multi monopole solutions of the Einstein/Maxwell/dilaton-YM/Higgs equations found by Kastor, London, Traschen, and the authors, for arbitrary non-zero dilaton coupling constant a, are equivalent to the string theory BPS magnetic monopole solutions of Harvey and Liu when . For this value of a, the monopole solutions also solve the equations of five-dimensional supergravity/YM theory. We also discuss some features of the dyon solutions obtained by boosting in the fifth dimension and some features of the moduli space of anti-gravitating multi-monopoles.
Physics Letters B 06/1995; 356(4-356):472-478. DOI:10.1016/0370-2693(95)00850-K · 6.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The conjectured equivalence of the heterotic string to a K3 compactified type IIA superstring is combined with the conjectured equivalence of the latter to a compactified 11-dimensional supermembrane to derive a string membrane duality in seven dimensions; the membrane is a soliton of the string theory and vice versa. A prediction of this duality is that the heterotic string is a K3 compactification of the solitonic 11-dimensional fivebrane. It is verified that the worldsheet action of the D = 10 heterotic string is indeed obtainable by K3 compactification of the worldvolume action of the 11-dimensional fivebrane, and it is suggested how the worldvolume action of the D = 11 supermebrane may be similarly obtained by T3 compactification of the worldvolume action of a D = 10 heterotic fivebrane. Generalizations to D = 8 string-threebrane and membrane-membrane duality are also discussed.
Physics Letters B 04/1995; 354(3-4-354):247-255. DOI:10.1016/0370-2693(95)00649-6 · 6.13 Impact Factor