|
In mathematics, a compact quantum group is an abstract structure on a unital separable C *-algebra axiomatized from those that exist on the commutative C *-algebra of "continuous complex-valued functions" on a compact quantum group. The basic motivation for this theory comes from the following analogy. The space of complex-valued functions on a compact Hausdorff topological space forms a ''commutative'' C *-algebra. On the other hand, by the Gelfand Theorem, a commutative C *-algebra is isomorphic to the C *-algebra of continuous complex-valued functions on a compact Hausdorff topological space, and the topological space is uniquely determined by the C *-algebra up to homeomorphism. S. L. Woronowicz 〔Woronowicz, S.L. "Compact Matrix Pseudogrooups", Commun. Math. Phys. 111 (1987), 613-665〕 introduced the important concept of compact matrix quantum groups, which he initially called compact pseudogroups. Compact matrix quantum groups are abstract structures on which the "continuous functions" on the structure are given by elements of a C *-algebra. The geometry of a compact matrix quantum group is a special case of a noncommutative geometry. ==Formulation== For a compact topological group, , there exists a C *-algebra homomorphism : where is the minimal C *-algebra tensor product — the completion of the algebraic tensor product of and ) — such that : for all , and for all , where : for all and all . There also exists a linear multiplicative mapping :, such that : for all and all . Strictly speaking, this does not make into a Hopf algebra, unless is finite. On the other hand, a finite-dimensional representation of can be used to generate a *-subalgebra of which is also a Hopf *-algebra. Specifically, if : is an -dimensional representation of , then : for all , and : for all . It follows that the *-algebra generated by for all and for all is a Hopf *-algebra: the counit is determined by : for all (where is the Kronecker delta), the antipode is , and the unit is given by : 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「compact quantum group」の詳細全文を読む スポンサード リンク
|