arXiv subjects

Mico Durdevic

Publications and source records attributed to Mico Durdevic.

18 recordsLinked to original sources

arXiv1996

First-Order Differential Calculi Over Multi-Braided Quantum Groups

A differential calculus of the first order over multi-braided quantum groups is developed. In analogy with the standard theory, left/right-covariant and bicovariant differential structures are introduced and investigated. Furthermore, antipodally covariant calculi are studied. The concept of the *-structure on a multi-braided quantum group is formulated, and in particular the structure of left-covariant *-covariant calculi is analyzed. A special attention is given to differential calculi covariant with respect to the action of the associated braid system. In particular it is shown that the left/right braided-covariance appears as a consequence of the left/right-covariance relative to the group action. Braided counterparts of all basic results of the standard theory are found.

q-alg↗

arXiv1996

General Frame Structures On Quantum Principal Bundles

A noncommutative-geometric generalization of the classical formalism of frame bundles is developed, incorporating into the theory of quantum principal bundles the concept of the Levi-Civita connection. The construction of a natural differential calculus on quantum principal frame bundles is presented, including the construction of the associated differential calculus on the structure group. General torsion operators are defined and analyzed. Illustrative examples are presented.

q-alg↗

arXiv1996

Quantum Principal Bundles and Their Characteristic Classes

A brief exposition of the general theory of characteristic classes of quantum principal bundles is given. The theory of quantum characteristic classes incorporates ideas of classical Weil theory into the conceptual framework of non-commutative differential geometry. A purely cohomological interpretation of the Weil homomorphism is given, together with a standard geometrical interpretation via quantum invariant polynomials. A natural spectral sequence is described. Some quantum phenomena appearing in the formalism are discussed.

q-alg↗

arXiv1996

Quantum Classifying Spaces and Universal Quantum Characteristic Classes

A construction of the noncommutative-geometric counterparts of classical classifying spaces is presented, for general compact matrix quantum structure groups. A quantum analogue of the classical concept of the classifying map is introduced and analyzed. Interrelations with the abstract algebraic theory of quantum characteristic classes are discussed. Various non-equivalent approaches to defining universal characteristic classes are outlined.

q-alg↗

arXiv1996

Quantum Gauge Transformations and Braided Structure on Quantum Principal Bundles

It is shown that every quantum principal bundle is braided, in the sense that there exists an intrinsic braid operator twisting the functions on the bundle. A detailed algebraic analysis of this operator is performed. In particular, it turns out that the braiding admits a natural extension to the level of arbitrary differential forms on the bundle. Applications of the formalism to the study of quantum gauge transformations are presented.

q-alg↗

arXiv1995

Braided Clifford Algebras as Braided Quantum Groups

The paper deals with braided Clifford algebras, understood as Chevalley-Kahler deformations of braided exterior algebras. It is shown that Clifford algebras based on involutive braids can be naturally endowed with a braided quantum group structure. Basic group entities are constructed explicitly.

q-alg↗

arXiv1995

Characteristic Classes of Quantum Principal Bundles

A noncommutative-geometric generalization of classical Weil theory of characteristic classes is presented, in the conceptual framework of quantum principal bundles. A particular care is given to the case when the bundle does not admit regular connections. A cohomological description of the domain of the Weil homomorphism is given. Relations between universal characteristic classes for the regular and the general case are analyzed. In analogy with classical geometry, a natural spectral sequence is introduced and investigated. The appropriate counterpart of the Chern character is constructed, for structures admitting regular connections. Illustrative examples and constructions are presented.

q-alg↗

arXiv1995

Quantum Principal Bundles and Tannaka-Krein Duality Theory

The structure of quantum principal bundles is studied, from the viewpoint of Tannaka-Krein duality theory. It is shown that if the structure quantum group is compact, principal G-bundles over a quantum space M are in a natural correspondence with certain contravariant functors defined on the category of finite-dimensional unitary representations of G, with the values in the category of finite projective bimodules over a *-algebra representing the base space.

q-alg↗

arXiv1995

On Framed Quantum Principal Bundles

A noncommutative-geometric formalism of framed principal bundles is sketched, in a special case of quantum bundles (over quantum spaces) possessing classical structure groups. Quantum counterparts of torsion operators and Levi-Civita type connections are analyzed. A construction of a natural differential calculus on framed bundles is described. Illustrative examples are presented.

q-alg↗

arXiv1995

Quantum Principal Bundles as Hopf-Galois Extensions

It is shown that every quantum principal bundle with a compact structure group is a Hopf-Galois extension. This property naturally extends to the level of general differential structures, so that every differential calculus over a quantum principal bundle with a compact structure group is a graded-differential variant of the Hopf-Galois extension.

q-alg↗

arXiv1995

Geometry of Quantum Principal Bundles I

A theory of principal bundles possessing quantum structure groups and classical base manifolds is presented. Structural analysis of such quantum principal bundles is performed. A differential calculus is constructed, combining differential forms on the base manifold with an appropriate differential calculus on the structure quantum group. Relations between the calculus on the group and the calculus on the bundle are investigated. A concept of (pseudo)tensoriality is formulated. The formalism of connections is developed. In particular, operators of horizontal projection, covariant derivative and curvature are constructed and analyzed. Generalizations of the first structure equation and of the Bianchi identity are found. Illustrative examples are presented.

q-alg↗

arXiv1995

Quantum Principal Bundles and Corresponding Gauge Theories

A generalization of classical gauge theory is presented, in the framework of a noncommutative-geometric formalism of quantum principal bundles over smooth manifolds. Quantum counterparts of classical gauge bundles, and classical gauge transformations, are introduced and investigated. A natural differential calculus on quantum gauge bundles is constructed and analyzed. Kinematical and dynamical properties of corresponding gauge theories are discussed.

q-alg↗

arXiv1994

Clifford Algebras and Spinors for Arbitrary Braids

General braided counterparts of classical Clifford algebras are introduced and investigated. Braided Clifford algebras are defined as Chevalley-Kahler deformations of the corresponding braided exterior algebras. Analogs of the spinor representations are studied, generalizing classical Cartan's approach. It is shown that, under certain assumptions concerning the braiding, the spinor representation is faithful and irreducible, as in the classical theory.

q-alg↗

arXiv1994

On Braided Quantum Groups

A braided generalization of the concept of Hopf algebra (quantum group) is presented. The generalization overcomes an inherent geometrical inhomogeneity of quantum groups, in the sense of allowing completely pointless objects. All braid-type equations appear as a consequence of initial axioms. Braided counterparts of basic algebraic relations between fundamental entities of the standard theory are found.

q-alg↗

arXiv1994

On Differential Structures on Quantum Principal Bundles

A constructive approach to differential calculus on quantum principal bundles is presented. The calculus on the bundle is built in an intrinsic manner, starting from given graded (differential) *-algebras representing horizontal forms on the bundle and differential forms on the base manifold, together with a family of antiderivations acting on horizontal forms, playing the role of covariant derivatives of regular connections. In this conceptual framework, a natural differential calculus on the structure quantum group is described.

q-alg↗

arXiv1994

Geometry of Quantum Principal Bundles II-Extended Version

A general noncommutative-geometric theory of principal bundles is presented. Quantum groups play the role of structure groups. General quantum spaces play the role of base manifolds. A differential calculus on quantum principal bundles is studied. In particular, algebras of horizontal and verticalized differential forms on the bundle are introduced and investigated. The formalism of connections is developed. Operators of horizontal projection, covariant derivative and curvature are constructed and analyzed. A quantum generalization of classical Weil's theory of characteristic classes is sketched. Quantum analogs of infinitesimal gauge transformations are studied. Illustrative examples and constructions are presented.

q-alg↗

arXiv1994

Classical Spinor Structures on Quantum Spaces

A noncommutative-geometric generalization of the classical concept of spinor structure is presented. This is done in the framework of the formalism of quantum principal bundles. In particular, analogs of the Dirac operator and the Laplacian are introduced and analyzed. A general construction of examples of quantum spaces with a spinor structure is presented.

q-alg↗

arXiv1993

Quantum Principal Bundles

A noncommutative-geometric generalization of the theory of principal bundles is sketched. A differential calculus over corresponding quantum principal bundles is analysed. The formalism of connections is presented. In particular, operators of covariant derivative and horizontal projection are described and analysed. Quantum counterparts for the Bianchi identity and the Weil's homomorphism are found. Illustrative examples are considered. (Lecture presented at the XXII-th Conference on Differential Geometric Methods in Theoretical Physics, Ixtapa-Zihuatanejo, Mexico, September 1993).

hep-th↗