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

We derive a geometric representation of couplings between spin degrees offreedom and gauge fields within the worldline approach to quantum field theory.We combine the string-inspired methods of the worldline formalism with elementsof the loop-space approach to gauge theory. In particular, we employ the loop(or area) derivative operator on the space of all holonomies which canimmediately be applied to the worldline representation of the effective action.This results in a spin factor that associates the information about spin with"zigzag" motion of the fluctuating field. Concentrating on the case of quantumelectrodynamics in external fields, we obtain a purely geometric representationof the Pauli term. To one-loop order, we confirm our formalism by rederivingthe Heisenberg-Euler effective action. Furthermore, we give closed-formworldline representations for the all-loop order effective action to lowestnontrivial order in a small-N_f expansion.Comment: 18 pages, v2: references added, minor changes, matches PRD versio

Geometry of spin-field coupling on the worldline