P.K. Townsend

University of Cambridge, Cambridge, England, United Kingdom

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Publications (49)253.57 Total impact

  • Source
    K. Skenderis · P. K. Townsend
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    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.
    Full-text · Article · Dec 2006 · Physical Review D
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    Kostas Skenderis · Paul K Townsend
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    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.
    Full-text · Article · Nov 2006 · Journal of Physics A Mathematical and Theoretical
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    G. W. Gibbons · P. K. Townsend
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    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
    Full-text · Article · Apr 2006 · Classical and Quantum Gravity
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    Paul K. Townsend
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    ABSTRACT: The relevance of calibrations, and `generalized' calibrations, to supersymmetric M-brane configurations and their associated field theories is reviewed, with emphasis on applications to domain walls and domain wall junctions of D = 4,N = 1 supersymmetric field theories.
    Preview · Article · Mar 2000 · Classical and Quantum Gravity
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    G. W. Gibbons · P. K. Townsend
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    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.
    Full-text · Article · Aug 1999 · Physical Review Letters
  • Martin Cederwall · P. K. Townsend
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    ABSTRACT: We present a manifestly Sl(2; Z)-covariant action for the type IIB superstring, and prove -symmetry for on-shell IIB supergravity backgrounds. 1. Introduction The Type IIB superstring theory has D=10 IIB supergravity as its effective field theory. Until a few years ago, the Sl(2; R) invariance of the latter [1,2] was thought to be an artefact of the field theory approximation to string theory, but it is now believed that IIB superstring theory is itself an approximation to some underlying non-perturbative theory in which an Sl(2; Z) subgroup of Sl(2; R) survives as a symmetry [3,4]. To the extent to which this theory can be said to be a string theory it describes an entire Sl(2; Z) orbit of `(p; q)' strings [5,6] with the (1,0) string being the Green-Schwarz (GS) IIB superstring and the (0,1) string the D-string. This explains why both the usual IIB superstring action, and that of the D-string, break Sl(2; Z) (the action for the `fundamental' string breaks the full group, while the ...
    No preview · Article · May 1999
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    J. Gutowski · G. Papadopoulos · P. K. Townsend
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    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
    Full-text · Article · May 1999 · Physical Review D
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    G.W. Gibbons · P.K. Townsend
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    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.
    Full-text · Article · Dec 1998 · Physics Letters B
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    Jerome P Gauntlett · Robert C Myers · Paul K Townsend
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    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.
    Preview · Article · Nov 1998 · Classical and Quantum Gravity
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    J. P. Gauntlett · R. C. Myers · P. K. Townsend
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    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.
    Preview · Article · Nov 1998 · Physical Review D
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    P.K. Townsend
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    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.
    Preview · Article · Nov 1998 · Nuclear Physics B - Proceedings Supplements
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    P.K. Townsend
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    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.
    Preview · Article · Jul 1998 · Nuclear Physics B - Proceedings Supplements
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    G. Papadopoulos · P.K. Townsend
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    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.
    Full-text · Article · Jun 1998 · Nuclear Physics B
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    P.K. Townsend
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    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.
    Preview · Article · Jun 1998 · Physics Letters B
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    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.
    Full-text · Article · Sep 1997 · Nuclear Physics B
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    Martin Cederwall · Paul K Townsend
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    ABSTRACT: We present a manifestly Sl(2; Z)-covariant action for the type IIB superstring, and prove -symmetry for on-shell IIB supergravity backgrounds. 1. Introduction The Type IIB superstring theory has D=10 IIB supergravity as its effective field theory. Until a few years ago, the Sl(2; R) invariance of the latter [1,2] was thought to be an artefact of the field theory approximation to string theory, but it is now believed that IIB superstring theory is itself an approximation to some underlying non-perturbative theory in which an Sl(2; Z) subgroup of Sl(2; R) survives as a symmetry [3,4]. To the extent to which this theory can be said to be a string theory it describes an entire Sl(2; Z) orbit of `(p; q)' strings [5,6] with the (1,0) string being the Green-Schwarz (GS) IIB superstring and the (0,1) string the D-string. This explains why both the usual IIB superstring action, and that of the D-string, break Sl(2; Z) (the action for the `fundamental' string breaks the full group, while the ...
    Full-text · Article · Aug 1997 · Journal of High Energy Physics
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    P.K. Townsend
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    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.
    Preview · Article · May 1997 · Physics Letters B
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    G. Papadopoulos · P.K. Townsend
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    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.
    Full-text · Article · Sep 1996 · Physics Letters B
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    G. Papadopoulos · P.K. Townsend
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    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.
    Full-text · Article · Mar 1996 · Physics Letters B
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    P.K. Townsend
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    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.
    Preview · Article · Oct 1995 · Nuclear Physics B - Proceedings Supplements

Publication Stats

5k Citations
253.57 Total Impact Points

Institutions

  • 1986-2006
    • University of Cambridge
      • Department of Applied Mathematics and Theoretical Physics
      Cambridge, England, United Kingdom
  • 1993
    • University of California, Santa Barbara
      • Kavli Institute for Theoretical Physics
      Santa Barbara, California, United States