English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Algebraic structure of a class of differential equations including Heun isshown to be related with the deformations of sl(2) algebra. These include bothquadratic and cubic ones. The finite dimensional representation of cubicalgebra is explicitly shown to describe a quasi-exactly solvable system, notconnected with sl(2) symmetry. Known finite dimensional representations ofsl(2) emerge under special conditions. We answer affirmatively the questionraised by Turbiner: Are there quasi- exactly solvable problems which can not berepresented in terms of sl(2) generators? and give the explicit deformedsymmetry underlying this system.

Quasi-Exact Solvability and Deformations of Sl(2) Algebra