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

Two types of Carrollian field theories are shown to emerge from finitecurrent-current deformations of toroidal CFT$_{2}$'s when the deformationcoupling is precisely fixed, up to a sign. In both cases the energy andmomentum densities fulfill the BMS$_{3}$ algebra. Applying these results to thebosonic string, one finds that the electric-like deformation (positivecoupling) reduces to the standard tensionless string. The magnetic-likedeformation (negative coupling) yields to a new theory, still beingrelativistic, devoid of tension and endowed with an "inner Carrollianstructure". Classical solutions describe a sort of "self-interacting nullparticle" moving along generic null curves of the original background metric,not necessarily geodesics. This magnetic-like theory is also shown to berecovered from inequivalent limits in the tension of the bosonic string.Electric- and magnetic-like deformations of toroidal CFT$_{2}$'s can be seen tocorrespond to limiting cases of continuous exactly marginal (trivial)deformations spanned by an SO(1,1) automorphism of the current algebra. Thus,the absolute value of the current-current deformation coupling is shown to bebounded. When the bound saturates, the deformation ceases to be exactlymarginal, but still retains the full conformal symmetry in two alternativeultrarelativistic regimes.

BMS$_{3}$ (Carrollian) field theories from a bound in the coupling of current-current deformations of CFT$_{2}$