Download or read book On the Structure of Principal Subspaces of Standard Modules for Affine Lie Algebras of Type A written by Christopher Michael Sadowski and published by . This book was released on 2014 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using the theory of vertex operator algebras and intertwining operators, we obtain presentations for the principal subspaces of all the standard $widehat{goth{sl}(3)}$-modules. Certain of these presentations had been conjectured and used in work of Calinescu to construct exact sequences leading to the graded dimensions of certain principal subspaces. We prove the conjecture in its full generality for all standard $widehat{goth{sl}(3)}$-modules. We then provide a conjecture for the case of $widehat{goth{sl}(n)}$, $n ge 4$. In addition, we construct completions of certain universal enveloping algebras and provide a natural setting for families of defining relations for the principal subspaces of standard modules for untwisted affine Lie algebras. We also use the theory of vertex operator algebras and intertwining operators, along with conjecturally assumed presentations for certain principal subspaces, to construct exact sequences among principal subspaces of certain standard $widehat{mathfrak{sl}(n)}$-modules, $n ge 3$. As a consequence, we obtain the multigraded dimensions of the principal subspaces $W(k_1Lambda_1 + k_2 Lambda_2)$ and $W(k_{n-2}Lambda_{n-2} + k_{n-1} Lambda_{n-1})$. This generalizes earlier work by Calinescu on principal subspaces of standard $widehat{mathfrak{sl}(3)}$-modules, where similar assumptions were made.