Li\'enard--Wiechert fields in AdS and flat-space antipodal matching from geodesic-centered Coulombic data

Sarthak Duary

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arXiv · 2607.05395

Li\'enard--Wiechert fields in AdS and flat-space antipodal matching from geodesic-centered Coulombic data

Sarthak Duary

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Abstract

We present a geometric derivation of Li\'enard--Wiechert fields in flat-space and AdS, emphasizing the origin of antipodal matching. In flat-space, the field of a uniformly moving charge is rewritten in coordinates centered on the source timelike geodesic. In this frame the charge is at rest and the solution is Coulombic, so the matching of the leading data at null infinity arises from describing a static field in a non-centered frame. We extend this construction to global AdS, where uniform motion is replaced by motion along a timelike geodesic. Starting from the static Coulomb solution at the center, we reconstruct the field of a freely moving charge in arbitrary global coordinates using embedding-space invariants. The resulting closed-form field obeys exact antipodal covariance in the bulk, and its boundary null-fringe limit reproduces the usual flat-space antipodal matching relation. We also describe an image-charge interpretation: the flat-space Coulomb field is represented after conformal compactification by an image singularity at spatial infinity, while the AdS Coulomb seed may be viewed as a charge together with an opposite image charge in a reflected copy. Together, these perspectives give a unified picture of Coulombic Li\'enard--Wiechert fields, antipodal matching, and the AdS-to-flat-space limit.

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Sarthak Duary. 2026-07-06. Li\'enard--Wiechert fields in AdS and flat-space antipodal matching from geodesic-centered Coulombic data. https://arxiv.org/abs/2607.05395

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