Abstract:
To study the representation category of the triplet $W$-algebra
$\boldsymbol{\mathcal{W}}(p)$
that is the symmetry of the $(1,p)$ logarithmic conformal field theory model,
we propose the equivalent category $\EuScript{C}_p$ of finite-dimensional
representations of the restricted quantum group
$\overline{\EuScript{U}}_{\!\mathfrak{q}} s\ell(2)$ at
$\mathfrak{q}=e^{{i\pi}/{p}}$. We fully describe the category $\EuScript{C}_p$ by classifying all
indecomposable representations. These are exhausted by projective modules and
three series of representations that are essentially described by
indecomposable representations of the Kronecker quiver. The equivalence of
the $\boldsymbol{\mathcal{W}}(p)$- and
$\overline{\EuScript{U}}_{\!\mathfrak{q}} s\ell(2)$-representation categories is conjectured for
all $p\ge2$ and proved for $p=2$. The implications include identifying the quantum group center with the logarithmic conformal field theory center and
the universal $R$-matrix with the braiding matrix.
Keywords:Kazhdan–Lusztig correspondence, quantum groups, logarithmic conformal field theories, indecomposable representations.