{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"581116070d42eabf6e43396cd030557b4949a6ce6c003a502f109d5a810c2754","created":"2026-10-03T07:18:02Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","ec960d90ef6443b334f903e8c930243add5a04b385f93a9075b8c991e11006cd"],"salt":"39f12f9f282017416dd3d349b8e1170230c270f0b1cbc43a8c6e053a2f85deed","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"amo.ultralight-dm-fifth-forces.scalar-photon-coupling","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"Scalar ultralight dark matter is one candidate answer to dark matter identity","parent_revision":"ec960d90ef6443b334f903e8c930243add5a04b385f93a9075b8c991e11006cd","relation":"special_case"}],"plain":"A scalar dark matter field (a field with no direction, like temperature) oscillating at its mass frequency would make $\\alpha$ oscillate. Networks of clocks can look for this oscillation over a huge range of masses.","posed_since":"","precise":"For scalar dark matter $\\phi$ of mass $m_{\\phi}$ in 1e-23 to 1e-15 eV with local density $0.4\\,\\mathrm{GeV}\\,\\mathrm{cm}^{-3}$ and dimensionless linear coupling $d_{\\gamma}$ to the photon (called $d_e$ in the Damour-Donoghue convention, unrelated to the electron EDM), determine whether $d_{\\gamma}$ is nonzero below present limits from clock comparisons and the MICROSCOPE equivalence-principle bound, by searching for oscillations of optical-clock frequency ratios at angular frequency $m_{\\phi} c^2/\\hbar$.","problem_ref":null,"references":"","settled_by":"Clock-ratio time series (optical, nuclear or highly charged ion clocks, including space clocks) that improve on the MICROSCOPE-derived $d_{\\gamma}$ limit across the mass range, or show a coherent oscillation seen at two sites.","status_note":"","title":"Scalar ultralight dark matter coupled to photons: detect or exclude","topic_ref":"65dd591d9a6aea57b124c4aa9efd99b0deceb1c7733b697b5b72544d315d1ba0"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"f2e8af267a742dec7cae14681589dd6f2e9caec76c9e10b934f0dc3382593f02","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"f463a076902e57910f6112d6d36b16bdf2fb05e841cd109d88284975f076b4b3","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"dbIJMt8oHu1sAMPqIM_NleShb_al7E_EIVMF0dT1diEVjAtPznh1dBTbDbc59yEigG9Thjz5NvHRhJy9M7byAA"},"schema":"pubphys.envelope/1"},"record_hash":"f2e8af267a742dec7cae14681589dd6f2e9caec76c9e10b934f0dc3382593f02","leaf_index":1245}