{"artifact_id":"L1-168","layer":"L1","title":"Event Horizon Telescope (VLBI) Imaging","domain":"Astronomy","sub_domain":"Radio interferometry","physics_fingerprint":{"L_DAG":4.5,"title":"Event Horizon Telescope (VLBI) Imaging","domain":"Astronomy","carrier":"radio_wave","primitives":["F.fourier.nufft","S.closure.phase","O.regularize","O.chi2.visibility"],"sub_domain":"Radio interferometry","noise_model":"thermal_gaussian","problem_class":"nonlinear_inverse","solution_space":"2D_brightness_temperature","difficulty_delta":5,"integration_axis":"uv_plane","sensing_mechanism":"vlbi_sparse_aperture"},"observable_profile":{"metric":"chi2_reduced","regime":"Existence of the recovered 2D_brightness_temperature is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by declared priors. Stability is conditionally stable (kappa_eff ~= 1000); station_gain_error dominates the stability cliff; the remaining mismatch parameters contribute higher-order bias terms. Thermal gaussian sets the irreducible data-fidelity floor.","secondary":"image_fidelity_score"},"size_tiers":{"center_spec":{"omega":{"H":64,"W":64,"N_baselines":15,"uv_fraction":0.001,"noise_sigma_Jy":0.1},"input_format":"measurement_only","problem_class":"nonlinear_inverse","forward_operator":"vlbi_sparse_aperture","epsilon_fn_center":"1.2 chi2_reduced"},"omega_bounds":{"H":[32,512],"W":[32,512],"N_baselines":[6,50],"uv_fraction":[0.0001,0.01],"noise_sigma_Jy":[0.01,1.0]},"epsilon_bounds":{"chi2_reduced":[0.8,3.0]},"allowed_problem_classes":["nonlinear_inverse"],"allowed_omega_dimensions":["H","W","N_baselines","uv_fraction","noise_sigma_Jy"],"allowed_forward_operators":["vlbi_sparse_aperture"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":1000000.0,"metric":"chi2_reduced"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0xc117659285882e17ebe99e1e597e0872c212d4fd5da6b7b9bde35261efd32c2b","chain_tx_hash":"0x6ce6ec74df271331b2949e1d1555e365520aa5620795915d1b2370904d5daa35","chain_block":41554244}