{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"cbbed6f6d3869d185da459ef9cff1b5628f49933dd21f5ca22b03f2ce5b1d89a","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","f2e8af267a742dec7cae14681589dd6f2e9caec76c9e10b934f0dc3382593f02"],"salt":"220d1fd44441a21495904229425e8c3916db4b7b87ca72eab59ea029d03c8eb0","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":"2","parents":[],"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 $10^{-23}$ to $10^{-15}$ 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":"f2e8af267a742dec7cae14681589dd6f2e9caec76c9e10b934f0dc3382593f02","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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"8bd3ecffd118918c3daef6538000ab99d618a1c8c598258dd28827d91e35c97e","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"a47576ec0200a0329e2dd7b717a6949d63f20440358411bc50687dcbccac995b","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"_7lwabzdaJhaBAyZTTqsKr9S_eLMLYCbxlJDgmXzGAVwNdF8XkEDHOt6FPwzi_1zZi7kzTC9xz1e-LB29LygCQ"},"schema":"pubphys.envelope/1"},"record_hash":"8bd3ecffd118918c3daef6538000ab99d618a1c8c598258dd28827d91e35c97e","leaf_index":2288}