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1998, Physical Review D
Using twistor methods we derive a generating function which leads to the hyperkähler metric on a deformation of the Atiyah-Hitchin monopole moduli space. This deformation was first considered by Dancer through the quotient construction and is related to a charge two monopole configuration in a completely broken SU (3) gauge theory. The manifold and metric are the first members of a family of hyperkähler manifolds which are deformations of the D k rational singularities of C 2 .
Commun Math Phys, 1996
The Legendre transform and its generalizations, originally found in supersymmetric sigma-models, are techniques that can be used to give local constructions of hyperkähler metrics. We give a twistor space interpretation to the generalizations of the Legendre transform construction. The Atiyah-Hitchin metric on the moduli space of two monopoles is used as a detailed example.
Letters in Mathematical Physics, 2009
We study general linear perturbations of a class of 4d real-dimensional hyperkähler manifolds obtainable by the (generalized) Legendre transform method. Using twistor methods, we show that deformations can be encoded in a set of holomorphic functions of 2d + 1 variables, as opposed to the functions of d + 1 variables controlling the unperturbed metric. Such deformations generically break all tri-holomorphic isometries of the unperturbed metric. Geometrically, these functions generate the symplectomorphisms which relate local complex Darboux coordinate systems in different patches of the twistor space. The deformed Kähler potential follows from these data by a Penrose-type transform. As an illustration of our general framework, we determine the leading exponential deviation of the Atiyah-Hitchin manifold away from its negative mass Taub-NUT limit.
Advances in Theoretical and Mathematical Physics, 2019
In 2009 Gaiotto, Moore and Neitzke presented a new construction of hyperkähler metrics on the total spaces of certain complex integrable systems, represented as a torus fibration M over a base space B, except for a divisor D in B, in which the torus fiber degenerates into a nodal torus. The hyperkähler metric g is obtained via solutions Xγ of a Riemann-Hilbert problem. We interpret the Kontsevich-Soibelman Wall Crossing Formula as an isomonodromic deformation of a family of RH problems, therefore guaranteeing continuity of Xγ at the walls of marginal stability. The technical details about solving the different classes of Riemann-Hilbert problems that arise here are left to a second article. To extend this construction to singular fibers, we use the Ooguri-Vafa case as our model and choose a suitable gauge transformation that allow us to define an integral equation defined at the degenerate fiber, whose solutions are the desired Darboux coordinates Xγ. We show that these functions yield a holomorphic symplectic form ̟(ζ), which, by Hitchin's twistor construction, constructs the desired hyperkähler metric.
Communications in Mathematical Physics, 1997
We use the HyperKähler quotient of flat space to obtain some monopole moduli space metrics in explicit form. Using this new description, we discuss their topology, completeness and isometries. We construct the moduli space metrics in the limit when some monopoles become massless, which corresponds to non-maximal symmetry breaking of the gauge group. We also introduce a new family of HyperKähler metrics which, depending on the "mass parameter" being positive or negative, give rise to either the asymptotic metric on the moduli space of many SU (2) monopoles, or to previously unknown metrics. These new metrics are complete if one carries out the quotient of a non-zero level set of the moment map, but develop singularities when the zero-set is considered. These latter metrics are of relevance to the moduli spaces of vacua of three dimensional gauge theories for higher rank gauge groups. Finally, we make a few comments concerning the existence of closed or bound orbits on some of these manifolds and the integrability of the geodesic flow.
The construction of new hyper-Kähler manifolds by taking the infinite monopole mass limit of certain Bogomol'nyi-Prasad-Sommerfield monopole moduli spaces is considered. The one-parameter family of hyper-Kähler manifolds due to Dancer is shown to be an example of such manifolds. A new family of fixed monopole spaces is constructed. They are the moduli spaces of four SU 4 monopoles, in the infinite mass limit of two of the monopoles. These manifolds are shown to be nonsingular when the fixed monopole positions are distinct.
Journal of High Energy Physics, 2012
In type IIB string compactifications on a Calabi-Yau threefold, the hypermultiplet moduli space $ {\mathcal{M}_H} $ must carry an isometric action of the modular group SL(2, $ \mathbb{Z} $ ), inherited from the S-duality symmetry of type IIB string theory in ten dimensions. We investigate how this modular symmetry is realized at the level of the twistor space of $ {\mathcal{M}_H} $ , and construct a general class of SL(2, $ \mathbb{Z} $ )-invariant quaternion-Kähler metrics with two commuting isometries, parametrized by a suitably covariant family of holomorphic transition functions. This family should include $ {\mathcal{M}_H} $ corrected by D3-D1-D(-1)-instantons (with five-brane corrections ignored) and, after taking a suitable rigid limit, the Coulomb branch of five-dimensional $ \mathcal{N} = {2} $ gauge theories compactified on a torus, including monopole string instantons. These results allow us to considerably simplify the derivation of the mirror map between type IIA and II...
Journal of Geometry and Physics, 2015
We give an explicit formula for the quaternionic Kähler metrics obtained by the HK/QK correspondence. As an application, we give a new proof of the fact that the Ferrara-Sabharwal metric as well as its one-loop deformation is quaternionic Kähler. A similar explicit formula is given for the analogous (K/K) correspondence between Kähler manifolds endowed with a Hamiltonian Killing vector field. As an example, we apply this formula in the case of an arbitrary conical Kähler manifold. Contents 1 The Swann bundle revisited 4
Communications in Mathematical Physics, 2010
We extend the twistor methods developed in our earlier work on linear deformations of hyperkähler manifolds [1] to the case of quaternionic-Kähler manifolds. Via Swann's construction, deformations of a 4d-dimensional quaternionic-Kähler manifold M are in one-to-one correspondence with deformations of its 4d + 4-dimensional hyperkähler cone S. The latter can be encoded in variations of the complex symplectomorphisms which relate different locally flat patches of the twistor space Z S , with a suitable homogeneity condition that ensures that the hyperkähler cone property is preserved. Equivalently, we show that the deformations of M can be encoded in variations of the complex contact transformations which relate different locally flat patches of the twistor space Z M of M, bypassing the Swann bundle and its twistor space. We specialize these general results to the case of quaternionic-Kähler metrics with d + 1 commuting isometries, obtainable by the Legendre transform method, and linear deformations thereof. We illustrate our methods for the hypermultiplet moduli space in string theory compactifications at tree-and one-loop level. Contents
Journal of Mathematical Physics, 2010
Four-dimensional quaternion-Kähler metrics, or equivalently self-dual Einstein spaces M, are known to be encoded locally into one real function h subject to Przanowski's heavenly equation. We elucidate the relation between this description and the usual twistor description for quaternion-Kähler spaces. In particular, we show that the same space M can be described by infinitely many different solutions h, associated with different complex ͑local͒ submanifolds on the twistor space, and therefore to different ͑local͒ integrable complex structures on M. We also study quaternion-Kähler deformations of M and, in the special case where M has a Killing vector field, show that the corresponding variations in h are related to eigenmodes of the conformal Laplacian on M. We exemplify our findings on the four-sphere S 4 , the hyperbolic plane H 4 , and on the "universal hypermultiplet," i.e., the hypermultiplet moduli space in type IIA string compactified on a rigid Calabi-Yau threefold.
Communications in Mathematical Physics, 2010
We describe the relation between supersymmetric σ-models on hyperkähler manifolds, projective superspace, and twistor space. We review the essential aspects and present a coherent picture with a number of new results.
Nonlinearity, 1996
We consider 3-monopoles symmetric under inversion symmetry. We show that the moduli space of these monopoles is an Atiyah-Hitchin submanifold of the 3monopole moduli space. This allows what is known about 2-monopole dynamics to be translated into results about the dynamics of 3-monopoles. Using a numerical ADHMN construction we compute the monopole energy density at various points on two interesting geodesics. The first is a geodesic over the two-dimensional rounded cone submanifold corresponding to right angle scattering and the second is a closed geodesic for three orbiting monopoles.
1996
The moduli space describing the low-energy dynamics of BPS multi-monopoles for several charge configurations is presented. We first prove the conjectured form of the moduli space of n − 1 distinct monopoles in a spontaneously broken SU (n) gauge theory. We further propose the solution where one of the charge components has two units, hence asymptotically corresponds to embeddings of two monopoles of one charge type and the rest different. The latter hyperkähler metrics possess features of the two-monopole Atiyah-Hitchin metric. We also conjecture classes of solutions to multi-monopole moduli spaces with arbitrary charge and no more than two units in each component, which models the gluing together of Atiyah-Hitchin metrics. Our approach here uses the generalized Legendre transform technique to find the new hyperkähler manifolds and rederive previously conjectured ones.
Modern Physics Letters A, 2000
Using a geometric realization of the SU (2) R symmetry and a procedure of factorisation of the gauge and SU (2) R charges, we study the small instanton singularities of the Higgs branch of supersymmetric U (1) r gauge theories with eight supercharges. We derive new solutions for the moduli space of vacua preserving manifestly the eight supercharges. In particular, we obtain an extension of the ordinary ADE singularities for hyperKahler manifolds and show that the classical moduli space of vacua is in general given by cotangent bundles of compact weighted projective spaces.
Lecture Notes in Physics, 1995
Communications in Mathematical Physics, 2018
We advocate that the generalized Kronheimer construction of the Kähler quotient crepant resolution M ζ -→ C 3 /Γ of an orbifold singularity where Γ ⊂ SU(3) is a finite subgroup naturally defines the field content and the interaction structure of a superconformal Chern-Simons Gauge Theory. This latter is supposedly the dual of an M2-brane solution of D = 11 supergravity with C × M ζ as transverse space. We illustrate and discuss many aspects of this type of constructions emphasizing that the equation p p p∧ p p p = 0 which provides the Kähler analogue of the holomorphic sector in the hyperKähler moment map equations canonically defines the structure of a universal superpotential in the CS theory. Furthermore the kernel D Γ of the above equation can be described as the orbit with respect to a quiver Lie group G Γ of a special locus that has also a universal definition. We provide an extensive discussion of the relation between the coset manifold G Γ /F Γ , the gauge group F Γ being the maximal compact subgroup of the quiver group, the moment map equations and the first Chern classes of the so named tautological vector bundles that are in one-to-one correspondence with the nontrivial irreps of Γ. These first Chern classes are represented by (1,1)-forms on M ζ and provide a basis for the cohomology group H 2 (M ζ ). We also discuss the relation with conjugacy classes of Γ and we provide the explicit construction of several examples emphasizing the role of a generalized McKay correspondence. The case of the ALE manifold resolution of C 2 /Γ singularities is utilized as a comparison term and new formulae related with the complex presentation of Gibbons-Hawking metrics are exhibited.
Physics Letters B, 1988
Using recently established results on the superconformal moduli space and their relation to the geometry of N= 2 SUGRA, we give an explicit formula for the K~ihler potential for the chiral multiplets associated to deformation of the K~hler class [ ( 1, 1 ) forms]. The formula holds for all compactifications on (2, 2) systems and it requires only topological informations about the internal superconformal theory (i.e. the intersection numbers). The metric turns out to be the unique K~hler metric which is conformal to the one proposed by Strominger some time ago. From this fact we infer that the cone in H2(K, Dq) consisting of K~ihler classes coincides with a class of convex cones whose remarkable geometrical properties were already noticed in the contexts of N= 2 supergravity and Jordan algebras. Our formula gives a closed expression for this K~ihler cone.
Journal Fur Die Reine Und Angewandte Mathematik, 2004
The target space of a (4,0) supersymmetric two-dimensional sigma model with Wess-Zumino term has a connection with totally skew-symmetric torsion and holonomy contained in Sp(n)Sp(1) (resp. Sp(n)), QKT (resp. HKT)-spaces. We study the geometry of QKT, HKT manifold and their twistor spaces. We show that the Swann bundle of a QKT manifold admits a HKT structure with special symmetry if and only if the twistor space of the QKT manifold admits an almost hermitian structure with totally skew-symmetric Nijenhuis tensor, thus connecting two structures arising from quantum field theories and supersymmetric sigma models with Wess-Zumino term.
Journal of High Energy Physics, 2015
We use the twistorial construction of D-instantons in Calabi-Yau compactifications of type II string theory to compute an explicit expression for the metric on the hypermultiplet moduli space affected by these non-perturbative corrections. In this way we obtain an exact quaternion-Kähler metric which is a non-trivial deformation of the local c-map. In the four-dimensional case corresponding to the universal hypermultiplet, our metric fits the Tod ansatz and provides an exact solution of the continuous Toda equation. We also analyze the fate of the curvature singularity of the perturbative metric by deriving an S-duality invariant equation which determines the singularity hypersurface after inclusion of the D(-1)-instanton effects.
Nuclear Physics B, 2001
We obtain a simple explicit expression for the hyper-Kähler Calabi metric on the cotangent bundle of CP n+1 , for all n, in which it is constructed as a metric of cohomogeneity one with SU (n + 2)/U (n) principal orbits. These results enable us to obtain explicit expressions for an L 2-normalisable harmonic 4-form in D = 8, and an L 2-normalisable harmonic 6-form in D = 12. We use the former in order to obtain an explicit resolved M2-brane solution, and we show that this solution is invariant under all three of the supersymmetries associated with the covariantly-constant spinors in the 8-dimensional Calabi metric. We give some discussion of the corresponding dual N = 3 three-dimensional field theory. Various other topics are also addressed, including superpotentials for the Calabi metrics and the metrics of exceptional G 2 and Spin(7) holonomy in D = 7 and D = 8. We also present complex and quaternionic conifold constructions, associated with the cone metrics whose resolutions are provided by the Stenzel T * S n+1 and Calabi T * CP n+1 metrics. In the latter case we relate the construction to the hyper-Kähler quotient. We then use the hyper-Kähler quotient to give a quaternionic rederivation of the Calabi metrics.
Communications in Mathematical Physics, 1987
We describe two constructions of hyperkahler manifolds, one based on a Legendre transform, and one on a symplectic quotient. These constructions arose in the context of supersymmetric nonlinear σ-models, but can be described entirely geometrically. In this general setting, we attempt to clarify the relation between supersymmetry and aspects of modern differential geometry, along the way reviewing many basic and well known ideas in the hope of making them accessible to a new audience.
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