The Universal Askey-Wilson Algebra and the Equitable Presentation of   $U_q(\mathfrak{sl}_2)$
  Around 1992 A. Zhedanov introduced the Askey-Wilson algebra AW(3). Recently we introduced a central extension $\Delta$ of AW(3) called the universal Askey-Wilson algebra. In this paper we discuss a connection between $\Delta$ and the quantum algebra $U_q(\mathfrak{sl}_2)$. Our main result is an algebra injection from $\Delta$ into a relative of $U_q(\mathfrak{sl}_2)$; the relative is obtained from $U_q(\mathfrak{sl}_2)$ by adjoining three mutually commuting indeterminates. We describe the injection using the equitable presentation of $U_q(\mathfrak{sl}_2)$ 
Paul Terwilliger
math.QA math.RA