User Tools

Site Tools


compact_matrix_quantum_group

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
compact_matrix_quantum_group [2020/01/02 11:59]
amang [Original version by Woronowicz]
compact_matrix_quantum_group [2021/11/23 11:56] (current)
Line 4: Line 4:
  
 ===== Definition ===== ===== Definition =====
-The term **compact matrix quantum group** only makes sense with reference to a certain dimension ​ $N\in \N$. Two definitions appear in the literature, the orginal one by Woronowicz from [(:​ref:​Wor87)] and an equivalent alternative formulation. ​+The term **compact matrix quantum group** ​(or **CMQG** for short) ​only makes sense with reference to a certain dimension ​ $N\in \N$. Two definitions appear in the literature, the orginal one by Woronowicz from [(:​ref:​Wor87)] and an equivalent alternative formulation. ​
  
 Both define a compact matrix quantum group $G$ as a pair $(A,u)$ of a $C^\ast$-algebra $A$ and a matrix $u$ with entries in $A$. In keeping with the general paradigm of non-commutative topology, $A$ is usually referred to as the //algebra of continuous functions// $C(G)$ //on// $G$ even if $A$ is non-commutative. Both define a compact matrix quantum group $G$ as a pair $(A,u)$ of a $C^\ast$-algebra $A$ and a matrix $u$ with entries in $A$. In keeping with the general paradigm of non-commutative topology, $A$ is usually referred to as the //algebra of continuous functions// $C(G)$ //on// $G$ even if $A$ is non-commutative.
Line 16: Line 16:
   * there exists a linear antimultiplicative mapping $S:​\mathscr{A}\to \mathscr{A}$ with $S(S(a^\ast)^\ast)=a$ for all $a\in \mathscr{A}$ and with $\sum_{k=1}^N S(u_{i,​k})u_{k,​j}=\delta_{i,​j}I$ and $\sum_{k=1}^N u_{i,​k}S(u_{k,​j})=\delta_{i,​j}I$ for all $i,​j=1,​\ldots,​N$,​ where $I$ is the unit of $A$.   * there exists a linear antimultiplicative mapping $S:​\mathscr{A}\to \mathscr{A}$ with $S(S(a^\ast)^\ast)=a$ for all $a\in \mathscr{A}$ and with $\sum_{k=1}^N S(u_{i,​k})u_{k,​j}=\delta_{i,​j}I$ and $\sum_{k=1}^N u_{i,​k}S(u_{k,​j})=\delta_{i,​j}I$ for all $i,​j=1,​\ldots,​N$,​ where $I$ is the unit of $A$.
  
-If so, then $\Delta$ and $S$ are uniquely determined. They are called the //​comultiplication//​ and the //​antipode//​ (or //​coinverse//​),​ respectively. And $u$ is called the //​fundamental corepresentation (matrix)//​. +If so, then $\Delta$ and $S$ are uniquely determined ​by [(:​ref:​Wor87)]. They are called the //​comultiplication//​ and the //​antipode//​ (or //​coinverse//​),​ respectively. And $u$ is called the //​fundamental corepresentation (matrix)//​. 
-==== Alternative ​version ​ ====+==== Equivalent alternative ​version ​ ====
 A **compact** $N\!\times\! N$**-matrix quantum group** is a pair $(A,u)$ such that  A **compact** $N\!\times\! N$**-matrix quantum group** is a pair $(A,u)$ such that 
   * $A$ is a unital $C^\ast$-algebra, ​   * $A$ is a unital $C^\ast$-algebra, ​
Line 27: Line 27:
 Here also, of course, $\Delta$ and //u// are referred to as the //​comultiplication//​ and //​fundamental corepresentation (matrix)//, respectively. Here also, of course, $\Delta$ and //u// are referred to as the //​comultiplication//​ and //​fundamental corepresentation (matrix)//, respectively.
 ===== Compact matrix quantum groups as compact quantum groups ===== ===== Compact matrix quantum groups as compact quantum groups =====
-Given a compact matrix quantum group $(A,u)$ with comultiplication $\Delta$ the pair $(A,​\Delta)$ is a [[compact quantum group]].+Given a compact matrix quantum group $(A,u)$ with comultiplication $\Delta$ the pair $(A,​\Delta)$ is a [[compact quantum group]] by [(:​ref:​Wor98)].
  
 ===== Comparing compact matrix quantum groups ===== ===== Comparing compact matrix quantum groups =====
Line 51: Line 51:
 )] )]
  
 +[( :ref:Wor98 >>
 +author ​  :​Stanisław L. Woronowicz
 +title :Compact quantum groups
 +booktitle: Quantum symmetries/​Symétries quantiques. Proceedings of the Les Houches summer school, Session LXIV, Les Houches, France, August 1st -- September 8th, 1995
 +editor ​  :​Connes,​ Alain
 +pages    :845--884
 +year     :1998
 +)]
compact_matrix_quantum_group.1577966397.txt.gz · Last modified: 2021/11/23 11:56 (external edit)