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 Tools annual

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 Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We revisit the critical two-dimensional Ashkin-Teller model, i.e. the$\mathbb{Z}_2$ orbifold of the compactified free boson CFT at $c=1$. We solvethe model on the plane by computing its three-point structure constants andproving crossing symmetry of four-point correlation functions. We do this notonly for affine primary fields, but also for Virasoro primary fields, i.e.higher twist fields and degenerate fields.  This leads us to clarify the analytic properties of Virasoro conformal blocksand fusion kernels at $c=1$. We show that blocks with a degenerate channelfield should be computed by taking limits in the central charge, rather than inthe conformal dimension. In particular, Al. Zamolodchikov's simple explicitexpression for the blocks that appear in four-twist correlation functions isonly valid in the non-degenerate case: degenerate blocks, starting with theidentity block, are more complicated generalized theta functions.

Analytic conformal bootstrap and Virasoro primary fields in the Ashkin-Teller model