{"work":{"id":"b27bc4fc-4268-4e2e-92fc-46bb6fd01e3e","openalex_id":null,"doi":null,"arxiv_id":"1407.3789","raw_key":null,"title":"New Symmetries of Massless QED","authors":null,"authors_text":"T","year":2014,"venue":"hep-th","abstract":"An infinite number of physically nontrivial symmetries are found for abelian gauge theories with massless charged particles. They are generated by large $U(1)$ gauge transformations that asymptotically approach an arbitrary function $\\varepsilon(z,\\bar{z})$ on the conformal sphere at future null infinity ($\\mathscr I^+$) but are independent of the retarded time. The value of $\\varepsilon$ at past null infinity ($\\mathscr I^-$) is determined from that on $\\mathscr I^+$ by the condition that it take the same value at either end of any light ray crossing Minkowski space. The $\\varepsilon\\neq$ constant symmetries are spontaneously broken in the usual vacuum. The associated Goldstone modes are zero-momentum photons and comprise a $U(1)$ boson living on the conformal sphere. The Ward identity associated with this asymptotic symmetry is shown to be the abelian soft photon theorem.","external_url":"https://arxiv.org/abs/1407.3789","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-06-29T12:13:27.240166+00:00","pith_arxiv_id":"1407.3789","created_at":"2026-05-10T23:35:49.853056+00:00","updated_at":"2026-06-29T12:13:27.240166+00:00","title_quality_ok":false,"display_title":"New Symmetries of Massless QED","render_title":"New Symmetries of Massless QED"},"hub":{"state":{"work_id":"b27bc4fc-4268-4e2e-92fc-46bb6fd01e3e","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":13,"external_cited_by_count":null,"distinct_field_count":3,"first_pith_cited_at":"2025-01-13T08:53:58+00:00","last_pith_cited_at":"2026-05-27T02:38:39+00:00","author_build_status":"not_needed","summary_status":"needed","contexts_status":"needed","graph_status":"needed","ask_index_status":"not_needed","reader_status":"not_needed","recognition_status":"not_needed","updated_at":"2026-06-30T01:59:28.536157+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":6}],"polarity_counts":[{"context_polarity":"background","n":6}],"runs":{},"summary":{},"graph":{},"authors":[]}}