Quantized coordinate ring

introduction

• $\mathfrak{g}$ : simple Lie algebra over $\mathbb{C}$
• $G$ : connected, simply-connected simple algebraic group with Lie algebra $\mathfrak{g}$

dual of quantized enveloping algebras

QEA

• $q\in \mathbb{C}^{\times}$ not a root of 1
• $U_q:=U_q(\mathfrak{g})=\langle k_i^{\pm},e_i,f_i :i\in I \rangle$ : quantum enveloping algebra

quantized coordinate algebra

• $U_q^{*}=\operatorname{Hom}_{\mathbb{Q}(q)}(U_q,\mathbb{Q}(q))$
• $A_q(\mathfrak{g}):=\{\varphi \in U_q^{*} | \dim U_q \varphi, \dim \varphi U_q <\infty \}$
  • also denoted by $\mathbb{C}_q[G]$
• We call $A_q(\mathfrak{g})$ the quantized coordinate ring

comodules and modules

• $\mathbb{C}_q[G]$-comodules = locally finite $U_q(\mathfrak{g})$-modules of type 1

thm (Soibelman)

cluster theory

• Monoidal categorifications of cluster algebras
• $\mathbb{C}[N]$ is Hopf dual to $U(\mathfrak{n})$ where $\mathfrak{n}=Lie(N)$
• Ringel, Lusztig : Geometric realization of $U_q(\mathfrak{n})$ via constructible sheaves on varieties of $\mathbb{C}Q$-modules
• Lusztig : Geometric realization of $U(n)$ via constructible functions on varieties of $\Lambda$-modules
• Geiss-Leclerc-S : Dualizing Lusztig's construction, get a cluster character

related items

• Q-boson algebras