Over an oriented even dimensional Riemannian manifold(M 2m ,ds2 ), in terms of the Levi-Civita connection form Ω and the canonical form Θ on the bundle of positive orthonormal frames, we give a detailed description ...Over an oriented even dimensional Riemannian manifold(M 2m ,ds2 ), in terms of the Levi-Civita connection form Ω and the canonical form Θ on the bundle of positive orthonormal frames, we give a detailed description of the twistor bundle Гm = SO(2m)/U(m)? J +(@#@ M,ds2 ) →M. The integrability on an almost complex structureJ compatible with the metric and the orientation, is shown to be equivalent to the fact that the corresponding cross section of the twistor bundle is holomorphic with respect toJ and the canonical almost complex structureJ 1 onJ +(M,ds2 ), by using moving frame theory. Moreover, for various metrics and a fixed orientation onM, a canonical bundle isomorphism is established. As a consequence, we generalize a celebrated theorem of LeBrun.展开更多
We study the symbology of planar Feynman integrals in dimensional regularization by considering geometric configurations in momentum twistor space corresponding to their leading singularities(LS). Cutting propagators ...We study the symbology of planar Feynman integrals in dimensional regularization by considering geometric configurations in momentum twistor space corresponding to their leading singularities(LS). Cutting propagators in momentum twistor space amounts to intersecting lines associated with loop and external dual momenta, including the special line associated with the point at infinity, which breaks dual conformal symmetry. We show that cross-ratios of intersection points on these lines, especially those on the infinity line, naturally produce symbol letters for Feynman integrals in D = 4-2∈, which include and generalize their LS. At one loop, we obtain all symbol letters using intersection points from quadruple cuts for integrals up to pentagon kinematics with two massive corners, which agree perfectly with canonical differential equation(CDE) results. We then obtain all two-loop letters, for up to four-mass box and one-mass pentagon kinematics, by considering more intersections arising from two-loop cuts. Finally we comment on how cluster algebras appear from this construction, and importantly how we may extend the method to non-planar integrals.展开更多
Using certain models of twistor surfaces for fields of force and the mathematical relationships that lie among fields, lines, surfaces and flows of energy, it has been designed and developed a flight electromagnetic t...Using certain models of twistor surfaces for fields of force and the mathematical relationships that lie among fields, lines, surfaces and flows of energy, it has been designed and developed a flight electromagnetic type system based on the synergic study of their electromagnetic field geodesics to generate vehicle levitation, suspension and movement without being in contact with the surface. The idea of such work is to obtain a new flight and impulse patent of an electromagnetic vehicle by principles of super-conduction and some laws of the current like Eddy currents and principles which are very similar to mechanics of sidereal objects like galaxies or stars under models of twistor surfaces. This vehicle will be controlled by one microchip that will be programmed by conscience operators algebra of electromagnetic type that leads to the flow of Eddy currents, the iso-rotations and suspension of the special geometrical characteristics vehicle, generating also on the vehicle structure certain “magnetic conscience” that provokes all movements like succeeding to the sidereal objects in the universe.展开更多
We discuss the twistor quantization problem for the classical system (V d ,A d ), represented by the phase space V d , identified with the Sobolev space H 0 1/2 (S 1,? d ) of half-differentiable vector functions on th...We discuss the twistor quantization problem for the classical system (V d ,A d ), represented by the phase space V d , identified with the Sobolev space H 0 1/2 (S 1,? d ) of half-differentiable vector functions on the circle, and the algebra of observables A d , identified with the semi-direct product of the Heisenberg algebra of V d and the algebra Vect(S 1) of tangent vector fields on the circle.展开更多
We introduce and study the concept of （weak） pseudotwistor for a nonlocal vertex algebra, as a generalization of the notion of twistor. We give the relations between pseudotwistors and twisting operators. Furthermor...We introduce and study the concept of （weak） pseudotwistor for a nonlocal vertex algebra, as a generalization of the notion of twistor. We give the relations between pseudotwistors and twisting operators. Furthermore, we study the inverse of an invertible weak pseudotwistor and the composition of two weak pseudotwistors.展开更多
In this paper we study surfaces in S^4 and their twistor Gauss maps.Some necessary and sufficient conditions that the twistor Gauss map is harmonic are given.We find many examples of nonisotropic harmonic maps from a ...In this paper we study surfaces in S^4 and their twistor Gauss maps.Some necessary and sufficient conditions that the twistor Gauss map is harmonic are given.We find many examples of nonisotropic harmonic maps from a surface to(?)P^3.展开更多
We study harmonic maps from Riemann surfaces M to the loop spacesΩG of compact Lie groups G,using the twistor approach.We conjecture that harmonic maps of the Riemann sphere CP^1 intoΩG are related to Yang-Mills G-f...We study harmonic maps from Riemann surfaces M to the loop spacesΩG of compact Lie groups G,using the twistor approach.We conjecture that harmonic maps of the Riemann sphere CP^1 intoΩG are related to Yang-Mills G-fields on R^4.展开更多
The twistor kinematic-energy model of the space-time and the kinematic-energy tensor as the energy-matter tensor in relativity are considered to demonstrate the possible behavior of gravity as gravitational waves that...The twistor kinematic-energy model of the space-time and the kinematic-energy tensor as the energy-matter tensor in relativity are considered to demonstrate the possible behavior of gravity as gravitational waves that derive of mass-energy source in the space-time and whose contorted image is the spectrum of the torsion field acting in the space-time. The energy of this field is the energy of their second curvature. Likewise, it is assumed that the curvature energy as spectral curvature in the twistor kinematic frame is the curvature in twistor-spinor framework, which is the mean result of this work. This demonstrates the lawfulness of the torsion as the indicium of the gravitational waves in the space-time. A censorship to detect gravitational waves in the space-time is designed using the curvature energy.展开更多
We study the concept of module twistor for a module over an algebra. This concept provides a unifying framework for various deformed constructions of modules over algebras, such as module R-matrices,(n-factor iterated...We study the concept of module twistor for a module over an algebra. This concept provides a unifying framework for various deformed constructions of modules over algebras, such as module R-matrices,(n-factor iterated) twisted tensor products and L-R-twisted tensor products of algebras. Among the main results,we find the relations among these constructions. Furthermore, we study some properties of module twistors.展开更多
We study conformal minimal two-spheres immersed into the quaternionic projective spaceℍP^(n) by using the twistor map.We present a method to construct new minimal two-spheres with constant curvature inℍP^(n),based on ...We study conformal minimal two-spheres immersed into the quaternionic projective spaceℍP^(n) by using the twistor map.We present a method to construct new minimal two-spheres with constant curvature inℍP^(n),based on the minimal property and horizontal condition of Veronese map in complex projective space.Then we construct some concrete examples of conformal minimal two-spheres inℍP^(n) with constant curvature 2/n,n=4,5,6,respectively.Finally,we prove that there exist conformal minimal two-spheres with constant curvature 2/n inℍP^(n)(n≥7).展开更多
On the base of differential biquatemions algebra and theories of generalized functions the biquaternionic wave equation of general type is considered under vector representation of its structural coefficient. Its gene...On the base of differential biquatemions algebra and theories of generalized functions the biquaternionic wave equation of general type is considered under vector representation of its structural coefficient. Its generalized decisions in the space of tempered generalized functions are constructed. The elementary twistors and twistor fields are built and their properties are investigated. Introduction. The proposed by V.P. Hamilton quatemions algebra [1] and its complex extension - biquaternions algebra are very convenient mathematical tool for the description of many physical processes. At presence these algebras have been actively used in in the work of various authors to solve a number of problems in electrodynamics, quantum mechanics, solid mechanics and field theory. The properties of these algebras are actively studied in the framework of the theory of Clifford algebras. In the papers [2, 3] the differential algebra of biquatemions has been elaborated for construction of generalized solutions of the biquaternionic wave （biwave） equations. The particular types of biwave equations were considered, which are equivalent to the systems of Maxwell and Dirac equations and their generalizations, their biquaternionic decisions also were constructed. Here the biwave equation is considered with vector structural coefficient which is biquaternionic generalization of Dirac equations. Their generalized solutions in the space of tempered distributions are defined and their properties are researched.展开更多
The author studies the properties and applications of quasi-Killing spinors and quasi-twistor spinors and obtains some vanishing theorems. In particular, the author classifies all the types of quasi-twistor spinors on...The author studies the properties and applications of quasi-Killing spinors and quasi-twistor spinors and obtains some vanishing theorems. In particular, the author classifies all the types of quasi-twistor spinors on closed Riemannian spin manifolds. As a consequence, it is known that on a locally decomposable closed spin manifold with nonzero Ricci curvature, the space of twistor spinors is trivial. Some integrability condition for twistor spinors is also obtained.展开更多
基金This work was supported partially by the National Natural Science Foundation of China(Grant No.10131020)Outstanding Youth Foundation of China No.19925103 and No.10229101the“973”.
文摘Over an oriented even dimensional Riemannian manifold(M 2m ,ds2 ), in terms of the Levi-Civita connection form Ω and the canonical form Θ on the bundle of positive orthonormal frames, we give a detailed description of the twistor bundle Гm = SO(2m)/U(m)? J +(@#@ M,ds2 ) →M. The integrability on an almost complex structureJ compatible with the metric and the orientation, is shown to be equivalent to the fact that the corresponding cross section of the twistor bundle is holomorphic with respect toJ and the canonical almost complex structureJ 1 onJ +(M,ds2 ), by using moving frame theory. Moreover, for various metrics and a fixed orientation onM, a canonical bundle isomorphism is established. As a consequence, we generalize a celebrated theorem of LeBrun.
基金supported by the New Cornerstone Science Foundation through the XPLORER PRIZEthe National Natural Science Foundation of China(Grant Nos. 12225510, 11935013, 12047503, and 12247103)。
文摘We study the symbology of planar Feynman integrals in dimensional regularization by considering geometric configurations in momentum twistor space corresponding to their leading singularities(LS). Cutting propagators in momentum twistor space amounts to intersecting lines associated with loop and external dual momenta, including the special line associated with the point at infinity, which breaks dual conformal symmetry. We show that cross-ratios of intersection points on these lines, especially those on the infinity line, naturally produce symbol letters for Feynman integrals in D = 4-2∈, which include and generalize their LS. At one loop, we obtain all symbol letters using intersection points from quadruple cuts for integrals up to pentagon kinematics with two massive corners, which agree perfectly with canonical differential equation(CDE) results. We then obtain all two-loop letters, for up to four-mass box and one-mass pentagon kinematics, by considering more intersections arising from two-loop cuts. Finally we comment on how cluster algebras appear from this construction, and importantly how we may extend the method to non-planar integrals.
文摘Using certain models of twistor surfaces for fields of force and the mathematical relationships that lie among fields, lines, surfaces and flows of energy, it has been designed and developed a flight electromagnetic type system based on the synergic study of their electromagnetic field geodesics to generate vehicle levitation, suspension and movement without being in contact with the surface. The idea of such work is to obtain a new flight and impulse patent of an electromagnetic vehicle by principles of super-conduction and some laws of the current like Eddy currents and principles which are very similar to mechanics of sidereal objects like galaxies or stars under models of twistor surfaces. This vehicle will be controlled by one microchip that will be programmed by conscience operators algebra of electromagnetic type that leads to the flow of Eddy currents, the iso-rotations and suspension of the special geometrical characteristics vehicle, generating also on the vehicle structure certain “magnetic conscience” that provokes all movements like succeeding to the sidereal objects in the universe.
基金supported by the RFBR(Grant Nos.06-02-04012,08-01-00014)the program of Support of Scientific Schools(Grant No.NSH-3224.2008.1)Scientific Program of RAS"Nonlinear Dynamics"
文摘We discuss the twistor quantization problem for the classical system (V d ,A d ), represented by the phase space V d , identified with the Sobolev space H 0 1/2 (S 1,? d ) of half-differentiable vector functions on the circle, and the algebra of observables A d , identified with the semi-direct product of the Heisenberg algebra of V d and the algebra Vect(S 1) of tangent vector fields on the circle.
基金This work was supported in part by the National Natural Science Foundation of China （Grant Nos. 11201285, 11371238） and a grant of the First-class Discipline of Universities in Shanghai.
文摘We introduce and study the concept of （weak） pseudotwistor for a nonlocal vertex algebra, as a generalization of the notion of twistor. We give the relations between pseudotwistors and twisting operators. Furthermore, we study the inverse of an invertible weak pseudotwistor and the composition of two weak pseudotwistors.
基金Supported by the National Natural Science Foundation of China and the Science Foundation of Zhejiang Province.
文摘In this paper we study surfaces in S^4 and their twistor Gauss maps.Some necessary and sufficient conditions that the twistor Gauss map is harmonic are given.We find many examples of nonisotropic harmonic maps from a surface to(?)P^3.
基金This work was partly supported by the RFBR(Grant Nos.04-01-00236,06-02-04012)by the program of Support of Scientific Schools(Grant No.1542.2003.1)by the Scientific Program of RAS"Nonlinear Dynamics"
文摘We study harmonic maps from Riemann surfaces M to the loop spacesΩG of compact Lie groups G,using the twistor approach.We conjecture that harmonic maps of the Riemann sphere CP^1 intoΩG are related to Yang-Mills G-fields on R^4.
文摘The twistor kinematic-energy model of the space-time and the kinematic-energy tensor as the energy-matter tensor in relativity are considered to demonstrate the possible behavior of gravity as gravitational waves that derive of mass-energy source in the space-time and whose contorted image is the spectrum of the torsion field acting in the space-time. The energy of this field is the energy of their second curvature. Likewise, it is assumed that the curvature energy as spectral curvature in the twistor kinematic frame is the curvature in twistor-spinor framework, which is the mean result of this work. This demonstrates the lawfulness of the torsion as the indicium of the gravitational waves in the space-time. A censorship to detect gravitational waves in the space-time is designed using the curvature energy.
基金supported by National Natural Science Foundation of China (Grant Nos. 11201285 and 11371238)the First-class Discipline of Universities in Shanghai
文摘We study the concept of module twistor for a module over an algebra. This concept provides a unifying framework for various deformed constructions of modules over algebras, such as module R-matrices,(n-factor iterated) twisted tensor products and L-R-twisted tensor products of algebras. Among the main results,we find the relations among these constructions. Furthermore, we study some properties of module twistors.
基金This work was supported in part by the National Natural Science Foundation of China(Grant No.11871450).
文摘We study conformal minimal two-spheres immersed into the quaternionic projective spaceℍP^(n) by using the twistor map.We present a method to construct new minimal two-spheres with constant curvature inℍP^(n),based on the minimal property and horizontal condition of Veronese map in complex projective space.Then we construct some concrete examples of conformal minimal two-spheres inℍP^(n) with constant curvature 2/n,n=4,5,6,respectively.Finally,we prove that there exist conformal minimal two-spheres with constant curvature 2/n inℍP^(n)(n≥7).
文摘On the base of differential biquatemions algebra and theories of generalized functions the biquaternionic wave equation of general type is considered under vector representation of its structural coefficient. Its generalized decisions in the space of tempered generalized functions are constructed. The elementary twistors and twistor fields are built and their properties are investigated. Introduction. The proposed by V.P. Hamilton quatemions algebra [1] and its complex extension - biquaternions algebra are very convenient mathematical tool for the description of many physical processes. At presence these algebras have been actively used in in the work of various authors to solve a number of problems in electrodynamics, quantum mechanics, solid mechanics and field theory. The properties of these algebras are actively studied in the framework of the theory of Clifford algebras. In the papers [2, 3] the differential algebra of biquatemions has been elaborated for construction of generalized solutions of the biquaternionic wave （biwave） equations. The particular types of biwave equations were considered, which are equivalent to the systems of Maxwell and Dirac equations and their generalizations, their biquaternionic decisions also were constructed. Here the biwave equation is considered with vector structural coefficient which is biquaternionic generalization of Dirac equations. Their generalized solutions in the space of tempered distributions are defined and their properties are researched.
基金supported by the National Natural Science Foundation of China(Nos.11301202,11571131)
文摘The author studies the properties and applications of quasi-Killing spinors and quasi-twistor spinors and obtains some vanishing theorems. In particular, the author classifies all the types of quasi-twistor spinors on closed Riemannian spin manifolds. As a consequence, it is known that on a locally decomposable closed spin manifold with nonzero Ricci curvature, the space of twistor spinors is trivial. Some integrability condition for twistor spinors is also obtained.
