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48 results for twistor method

Paper constructs multivalued harmonic functions on R^3 using twistor methods.

problem Constructing multivalued harmonic functions on R^3.
method Twistor methods to construct multivalued harmonic functions.
result Found a family of multivalued harmonic functions with branching sets as ellipses and quadratic growth at infinity.

The paper proves unique properties of Riemannian twistor spaces under specific curvature conditions.

problem Characterizing Riemannian twistor spaces under vanishing curvature conditions.
method Moving frame method, classification, and nonexistence proofs.
result The only twistor space with parallel Bochner tensor is CP3\mathbb{CP}^3.

Study of CR twistor model Q2,2Q^{2,2} and its sections.

problem Classify and describe projective lines and hyperplane sections of the CR twistor model.
method Explicit projective methods, classification of lines and sections, use of involution jj.
result Complete relative classification of smooth quadric sections and explicit non-spherical CR structures.

The study generalizes twistor spinors to Kähler manifolds and finds bilinear form equations.

problem Generalizing twistor spinors to Kähler manifolds.
method Finding differential equations and reducing them to conformal Killing-Yano equations.
result Bilinear forms of Kählerian twistor spinors reduce to Kählerian conformal Killing-Yano equations under certain conditions.

Explains conformal maps using twistor lifts and provides a factorization method.

problem Understanding and analyzing conformal maps from a surface to Euclidean 4-space.
method Uses twistor lifts and differential factorization to explain and analyze conformal maps.
result Obtains a local factorization of the differential of a conformal map.

Researchers derive symmetry operators from twistor spinors in curved spacetime.

problem Deriving symmetry operators for gauged twistor spinors in curved backgrounds.
method Using gauged twistor spinors and conformal Killing-Yano forms, symmetry operators are constructed.
result Symmetry operators can be obtained from ordinary twistor spinors in constant curvature backgrounds.

The study bounds and characterizes surfaces containing smooth conics and twistor fibers in a flag threefold.

problem Bounding and characterizing surfaces containing smooth conics and twistor fibers in a flag threefold.
method Analyzing the family of smooth conics and using algebraic properties to construct surfaces.
result The only smooth cases of surfaces containing infinitely many twistor fibers are of bidegree (1,1).

We give a new proof that the sphere S^6 does not admit an integrable orthogonal complex structure, as in \cite{LeBrun}, following the methods from twistor theory. We present the twistor space of a pseudo-sphere S^{2n}_{2q}=SO_{2p+1,2q}/SO_{2p,2q} as a pseudo-Kähler symmetric space. We then consider orthogonal complex s…

2005-09-20abs ↗pdf ↗

On a Kähler spin manifold Kählerian twistor spinors are a natural analogue of twistor spinors on Riemannian spin manifolds. They are defined as sections in the kernel of a first order differential operator adapted to the Kähler structure, called Kählerian twistor (Penrose) operator. We study Kählerian twistor spinors a…

2008-12-17abs ↗pdf ↗

Harmonic spinors linked to twistor spinors via potential forms and conformal Killing-Yano forms.

problem Connecting harmonic spinors and twistor spinors using mathematical operators.
method Constructing symmetry operators from conformal Killing-Yano forms and finding transformation operators between twistor and harmonic spinors in terms of potential forms.
result Operators transforming gauged twistor spinors to gauged harmonic spinors and algebraic conditions for Seiberg-Witten equations solutions.

In a recent paper (math.DG/0701278) we constructed a series of new Moishezon twistor spaces which is a kind of variant of the famous LeBrun twistor spaces. In this paper we explicitly give projective models of another series of Moishezon twistor spaces on nCP^2 for arbitrary n>2, which can be regarded as a generalizati…

2007-05-01abs ↗pdf ↗

In this paper we investigate a family of Moishezon twistor spaces on the connected sum of 4 complex projective planes, which can be regarded as a direct generalization of the twistor spaces on 3CP^2 of double solid type studied by Poon and Kreussler-Kurke. These twistor spaces have a natural structure of double coverin…

2010-09-16abs ↗pdf ↗

Study on surfaces in flag threefold with constraints on twistor fibers.

problem Understanding the arrangement and existence of twistor fibers in surfaces of specific bidegree.
method Analyzing surfaces of bidegree (1,d) in the flag threefold, proving existence and non-existence of twistor fibers.
result Existence and non-existence of surfaces containing specific numbers of twistor fibers, with improved results for d=2 and d=3.

The paper defines a new twistor space for Riemannian manifolds with even Clifford structures.

problem No specific problem stated; the focus is on a new mathematical structure.
method Introduced a new twistor space for Riemannian manifolds with even Clifford structures.
result Constructed almost complex structures on the twistor space for parallel even Clifford structures and proved integrability in some cases.

Twistor correspondences for R-invariant indefinite self-dual conformal structures on R^4 are established explicitly. These correspondences are written down by using a natural integral transform from functions on a two dimensional cylinder to functions on the flat Lorentz space R^{1,2} which is related to the wave equat…

2012-01-17abs ↗pdf ↗

In this paper we investigate Moishezon twistor spaces which have a structure of double covering over a very simple rational threefold. These spaces can be regarded as a direct generalization of the twistor spaces studied by Poon and Kreussler-Kurke to the case of arbitrary signature. In particular, the branch divisor o…

2011-09-26abs ↗pdf ↗

The paper embeds CR manifolds into twistor spaces and constructs neutral hyperkähler metrics.

problem Embedding CR manifolds into twistor spaces and constructing neutral hyperkähler metrics.
method Embedding a real analytic twistor CR manifold into the twistor space of a Poincaré-Einstein metric, constructing the associated Fefferman ambient metric as a neutral hyperkähler metric.
result The construction of neutral hyperkähler metrics associated with twistor CR manifolds.

We compute the hessian of the natural Hermitian form successively on the Calabi family of a hyperkähler manifold, on the twistor space of a 4-dimensional anti-self-dual Riemannian manifold and on the twistor space of a quaternionic Kähler manifold. We show a strong convexity property of the cycle space of twistor lines…

2012-02-01abs ↗pdf ↗

Study shows algebraic dimension of certain twistor spaces is limited to 1 or 0.

problem Limiting the algebraic dimension of twistor spaces over n#CP^2.
method Analyzing the fundamental system as a pencil and proving constraints on algebraic dimension.
result Twistor spaces over n#CP^2 with algebraic dimension 2 have either empty or single fundamental system.

Researchers develop new symmetry operators from conformal Killing-Yano forms.

problem Constructing symmetry operators for twistor spinors in conformally-flat backgrounds.
method Using conformal Killing-Yano forms and graded Lie algebra structure, the researchers extended conformal superalgebras to include twistor spinors.
result Extended conformal superalgebras that include twistor spinors and conformal Killing-Yano forms are constructed.

In this paper we discuss the twistor equation in Lorentzian spin geometry. In particular, we explain the local conformal structure of Lorentzian manifolds, which admit twistor spinors inducing lightlike Dirac currents. Furthermore, we derive all local geometries with singularity free twistor spinors that occur up to di…

2003-05-04abs ↗pdf ↗

In contrast to the classical twistor spaces whose fibres are 2-spheres, we introduce twistor spaces over manifolds with almost quaternionic structures of the second kind in the sense of P. Libermann whose fibres are hyperbolic planes. We discuss two natural almost complex structures on such a twistor space and their ho…

2003-12-18abs ↗pdf ↗

This article gives a study of the higher-dimensional Penrose transform between conformally invariant massless fields on space-time and cohomology classes on twistor space, where twistor space is defined to be the space of projective pure spinors of the conformal group. We focus on the 6-dimensional case in which twisto…

2011-11-10abs ↗pdf ↗

The paper establishes a connection between superminimal surfaces and Lagrangian submanifolds in twistor spaces.

problem Understanding the geometric relationship between superminimal surfaces and Lagrangian submanifolds in twistor spaces.
method Proves a bijective correspondence between superminimal surfaces and Lagrangian submanifolds of twistor spaces, using specific constructions and projections.
result Produces many Lagrangian submanifolds of twistor spaces that are also minimal.

Generalizes twistor lines for complex tori, introducing new non-compact curves.

problem Understanding the structure of complex tori through twistor lines.
method Introducing and studying two new types of non-compact analytic curves in the period domain of complex tori.
result Analytic properties of compactifications of curves, preservation of cohomology classes, and twistor path connectivity.

It is shown that there exist non-singular cubic surfaces in CP^3 containing 5 twistor lines. This is the maximum number of twistor fibres that a non-singular cubic can contain. Cubic surfaces in CP^3 with 5 twistor lines are classified up to transformations preserving the conformal structure of S^4.

2012-12-12abs ↗pdf ↗

Biholomorphisms of transport twistor spaces are rigid under certain conditions.

problem Rigidity of biholomorphisms in transport twistor spaces.
method Proof of rigidity for biholomorphisms between transport twistor spaces of simple or Anosov surfaces.
result Biholomorphisms are rigid, up to constant rescaling and the antipodal map, being lifts of orientation-preserving isometries.

Study geometric structures on twistor and reflector spaces of paraquaternionic contact manifolds.

problem Geometric structures on paraquaternionic contact manifolds.
method Investigate fiber bundles (twistor and reflector spaces) over paraquaternionic contact manifolds.
result Intrinsic geometric structures on twistor and reflector spaces are always integrable.

We deal here with the geometry of the twistor fibration $\mathcal{Z} \to \bb{S}^3_1$ over the De Sitter 3-space. The total space Z\mathcal{Z} is a five dimensional reductive homogeneous space with two canonical invariant almost CR structures. Fixed the normal metric on Z\mathcal{Z} we study the harmonic map equation …

2009-10-29abs ↗pdf ↗