Multicloud solutions with massless and massive monopoles

Certain spontaneously broken gauge theories contain massless magnetic monopoles. These are realized classically as clouds of non-Abelian fields surrounding one or more massive monopoles. In order to gain a better understanding of these clouds, we study BPS solutions with four massive and six massless monopoles in an SU(6) gauge theory. We develop an algebraic procedure, based on the Nahm construction, that relates these solutions to previously known examples. Explicit implementation of this procedure for a number of limiting cases reveals that the six massless monopoles condense into four distinct clouds, of two different types. By analyzing these limiting solutions, we clarify the correspondence between clouds and massless monopoles, and infer a set of rules that describe the conditions under which a finite size cloud can be formed. Finally, we identify the parameters entering the general solution and describe their physical significance.Comment: 58 pages, 5 figure

New supersymmetric solutions of N=2, D=5 gauged supergravity with hyperscalars

We construct new supersymmetric solutions, including AdS bubbles, in an N=2 truncation of five-dimensional N=8 gauged supergravity. This particular truncation is given by N=2 gauged supergravity coupled to two vector multiples and three incomplete hypermultiplets, and was originally investigated in the context of obtaining regular AdS bubble geometries with multiple active R-charges. We focus on cohomogeneity-one solutions corresponding to objects with two equal angular momenta and up to three independent R-charges. Curiously, we find a new set of zero and negative mass solitons asymptotic to AdS_5/Z_k, for k \ge 3, which are everywhere regular without closed timelike curves.Comment: Latex 3 times, 42 page

Monopoles and clusters

We define and study certain hyperkaehler manifolds which capture the asymptotic behaviour of the SU(2)-monopole metric in regions where monopoles break down into monopoles of lower charges. The rate at which these new metrics approximate the monopole metric is exponential, as for the Gibbons-Manton metric.Comment: v2.: relation to calorons mentioned; added explanation

Twistors and Black Holes

Motivated by black hole physics in N=2, D=4 supergravity, we study the geometry of quaternionic-Kahler manifolds M obtained by the c-map construction from projective special Kahler manifolds M_s. Improving on earlier treatments, we compute the Kahler potentials on the twistor space Z and Swann space S in the complex coordinates adapted to the Heisenberg symmetries. The results bear a simple relation to the Hesse potential \Sigma of the special Kahler manifold M_s, and hence to the Bekenstein-Hawking entropy for BPS black holes. We explicitly construct the ``covariant c-map'' and the ``twistor map'', which relate real coordinates on M x CP^1 (resp. M x R^4/Z_2) to complex coordinates on Z (resp. S). As applications, we solve for the general BPS geodesic motion on M, and provide explicit integral formulae for the quaternionic Penrose transform relating elements of H^1(Z,O(-k)) to massless fields on M annihilated by first or second order differential operators. Finally, we compute the exact radial wave function (in the supergravity approximation) for BPS black holes with fixed electric and magnetic charges.Comment: 47 pages, v2: typos corrected, reference added, v3: minor change

A Kummer construction for gravitational instantons

We give a simple and uniform construction of essentially all known deformation classes of gravitational instantons with ALF, ALG or ALH asymptotics and nonzero injectivity radius. We also construct new ALH Ricci flat metrics asymptotic to the product of a real line with a flat 3-manifold.Comment: The construction of locally hyperkahler ALH spaces is corrected and complete

Obstructions to the Existence of Sasaki-Einstein Metrics

We describe two simple obstructions to the existence of Ricci-flat Kahler cone metrics on isolated Gorenstein singularities or, equivalently, to the existence of Sasaki-Einstein metrics on the links of these singularities. In particular, this also leads to new obstructions for Kahler-Einstein metrics on Fano orbifolds. We present several families of hypersurface singularities that are obstructed, including 3-fold and 4-fold singularities of ADE type that have been studied previously in the physics literature. We show that the AdS/CFT dual of one obstruction is that the R-charge of a gauge invariant chiral primary operator violates the unitarity bound.Comment: 35 pages, 1 figure; references and a footnote adde

The management of case reviews A guide and model process for Area Child Protection Committees

SIGLEAvailable from British Library Document Supply Centre-DSC:f99/2072 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Dihedral singularities and gravitational instantons

SIGLEAvailable from British Library Document Supply Centre- DSC:9106.16(CU-DAMTP--92/19) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Bianchi IX Kahler surfaces

SIGLEAvailable from British Library Document Supply Centre- DSC:9106.16(CU-DAMTP--92-60) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Nahm data and SU(3) monopoles

Available from British Library Document Supply Centre- DSC:9106.16(CU-DAMTP--91-44) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo