{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:QT2B4LMZ6VUM22VQB4L2EVYNPQ","short_pith_number":"pith:QT2B4LMZ","canonical_record":{"source":{"id":"1204.5936","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-04-26T14:25:06Z","cross_cats_sorted":[],"title_canon_sha256":"e24c0e9ba8c855ee54297e385705a0181ecd21647a79d94fa157f0d5c602d4f6","abstract_canon_sha256":"ca9bfd925bae4489f2b30e057daf1f326d1612b3d8f5c56381bc1df713cdcc6c"},"schema_version":"1.0"},"canonical_sha256":"84f41e2d99f568cd6ab00f17a2570d7c2afdfcbdca23438ad61670c4d5e3c463","source":{"kind":"arxiv","id":"1204.5936","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1204.5936","created_at":"2026-05-18T03:30:55Z"},{"alias_kind":"arxiv_version","alias_value":"1204.5936v2","created_at":"2026-05-18T03:30:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1204.5936","created_at":"2026-05-18T03:30:55Z"},{"alias_kind":"pith_short_12","alias_value":"QT2B4LMZ6VUM","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_16","alias_value":"QT2B4LMZ6VUM22VQ","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_8","alias_value":"QT2B4LMZ","created_at":"2026-05-18T12:27:18Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:QT2B4LMZ6VUM22VQB4L2EVYNPQ","target":"record","payload":{"canonical_record":{"source":{"id":"1204.5936","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-04-26T14:25:06Z","cross_cats_sorted":[],"title_canon_sha256":"e24c0e9ba8c855ee54297e385705a0181ecd21647a79d94fa157f0d5c602d4f6","abstract_canon_sha256":"ca9bfd925bae4489f2b30e057daf1f326d1612b3d8f5c56381bc1df713cdcc6c"},"schema_version":"1.0"},"canonical_sha256":"84f41e2d99f568cd6ab00f17a2570d7c2afdfcbdca23438ad61670c4d5e3c463","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:30:55.469989Z","signature_b64":"7p3yefVx6tF0tSMNs9zoOaqbFyOfIqJmSrlMawRy+H+tC5gopwehiJ9o9R0AxeYMG65FHV8q1dBx5WlPOaUtAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"84f41e2d99f568cd6ab00f17a2570d7c2afdfcbdca23438ad61670c4d5e3c463","last_reissued_at":"2026-05-18T03:30:55.469427Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:30:55.469427Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1204.5936","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T03:30:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"WVPBDg8ZUcWU66KTa07c9kQswJgLETMC7SFogV+Wu9Yr1gVyjSoPqNW+99ebV6D6tN47S8YEvWXwvzPXlU9gDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T01:24:23.648874Z"},"content_sha256":"14401a204fd98c4f803f983f34ad999e71667b48b9d521f07519e1744076e64f","schema_version":"1.0","event_id":"sha256:14401a204fd98c4f803f983f34ad999e71667b48b9d521f07519e1744076e64f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:QT2B4LMZ6VUM22VQB4L2EVYNPQ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Maximum-likelihood coherent-state quantum process tomography","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Aamir Anis, A. I. Lvovsky","submitted_at":"2012-04-26T14:25:06Z","abstract_excerpt":"Coherent-state quantum process tomography (csQPT) is a method of completely characterizing a quantum-optical \"black box\" by probing it with coherent states and performing homodyne measurements on the output [M. Lobino et al, Science 322, 563 (2008)]. We present a technique for csQPT that is fully based on statistical inference, specifically, quantum expectation-maximization. The method relies on the Jamiolkowski isomorphism and iteratively reconstructs the process tensor in the Fock basis directly from the experimental data. This approach permits incorporation of a priori constraints into the "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.5936","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T03:30:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"k9yhNLPBVx0a4Fk4FLHoY3CJy6kJxHwHPWBONCjxqVGJHPJxaxES8k2iXQPBm+9Fc76f/avSSinBD+BNddLSAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T01:24:23.649549Z"},"content_sha256":"8f95594f3a04978dd1965ee2ffa25bbe0f808fa3a670c948636714f32d0d6d9b","schema_version":"1.0","event_id":"sha256:8f95594f3a04978dd1965ee2ffa25bbe0f808fa3a670c948636714f32d0d6d9b"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QT2B4LMZ6VUM22VQB4L2EVYNPQ/bundle.json","state_url":"https://pith.science/pith/QT2B4LMZ6VUM22VQB4L2EVYNPQ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QT2B4LMZ6VUM22VQB4L2EVYNPQ/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-26T01:24:23Z","links":{"resolver":"https://pith.science/pith/QT2B4LMZ6VUM22VQB4L2EVYNPQ","bundle":"https://pith.science/pith/QT2B4LMZ6VUM22VQB4L2EVYNPQ/bundle.json","state":"https://pith.science/pith/QT2B4LMZ6VUM22VQB4L2EVYNPQ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QT2B4LMZ6VUM22VQB4L2EVYNPQ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:QT2B4LMZ6VUM22VQB4L2EVYNPQ","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"ca9bfd925bae4489f2b30e057daf1f326d1612b3d8f5c56381bc1df713cdcc6c","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-04-26T14:25:06Z","title_canon_sha256":"e24c0e9ba8c855ee54297e385705a0181ecd21647a79d94fa157f0d5c602d4f6"},"schema_version":"1.0","source":{"id":"1204.5936","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1204.5936","created_at":"2026-05-18T03:30:55Z"},{"alias_kind":"arxiv_version","alias_value":"1204.5936v2","created_at":"2026-05-18T03:30:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1204.5936","created_at":"2026-05-18T03:30:55Z"},{"alias_kind":"pith_short_12","alias_value":"QT2B4LMZ6VUM","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_16","alias_value":"QT2B4LMZ6VUM22VQ","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_8","alias_value":"QT2B4LMZ","created_at":"2026-05-18T12:27:18Z"}],"graph_snapshots":[{"event_id":"sha256:8f95594f3a04978dd1965ee2ffa25bbe0f808fa3a670c948636714f32d0d6d9b","target":"graph","created_at":"2026-05-18T03:30:55Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"Coherent-state quantum process tomography (csQPT) is a method of completely characterizing a quantum-optical \"black box\" by probing it with coherent states and performing homodyne measurements on the output [M. Lobino et al, Science 322, 563 (2008)]. We present a technique for csQPT that is fully based on statistical inference, specifically, quantum expectation-maximization. The method relies on the Jamiolkowski isomorphism and iteratively reconstructs the process tensor in the Fock basis directly from the experimental data. This approach permits incorporation of a priori constraints into the ","authors_text":"Aamir Anis, A. I. Lvovsky","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-04-26T14:25:06Z","title":"Maximum-likelihood coherent-state quantum process tomography"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.5936","kind":"arxiv","version":2},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:14401a204fd98c4f803f983f34ad999e71667b48b9d521f07519e1744076e64f","target":"record","created_at":"2026-05-18T03:30:55Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"ca9bfd925bae4489f2b30e057daf1f326d1612b3d8f5c56381bc1df713cdcc6c","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"quant-ph","submitted_at":"2012-04-26T14:25:06Z","title_canon_sha256":"e24c0e9ba8c855ee54297e385705a0181ecd21647a79d94fa157f0d5c602d4f6"},"schema_version":"1.0","source":{"id":"1204.5936","kind":"arxiv","version":2}},"canonical_sha256":"84f41e2d99f568cd6ab00f17a2570d7c2afdfcbdca23438ad61670c4d5e3c463","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"84f41e2d99f568cd6ab00f17a2570d7c2afdfcbdca23438ad61670c4d5e3c463","first_computed_at":"2026-05-18T03:30:55.469427Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:30:55.469427Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"7p3yefVx6tF0tSMNs9zoOaqbFyOfIqJmSrlMawRy+H+tC5gopwehiJ9o9R0AxeYMG65FHV8q1dBx5WlPOaUtAw==","signature_status":"signed_v1","signed_at":"2026-05-18T03:30:55.469989Z","signed_message":"canonical_sha256_bytes"},"source_id":"1204.5936","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:14401a204fd98c4f803f983f34ad999e71667b48b9d521f07519e1744076e64f","sha256:8f95594f3a04978dd1965ee2ffa25bbe0f808fa3a670c948636714f32d0d6d9b"],"state_sha256":"6a03ad602d6cbf86d58f662abc56b032febf5ecc7a16b7f2eae57337016f180c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"UFt32c8GfaXZW8aGFEKTDNy2PVQwmPbFC8Q3hHSGzFfh9cJr02Bh/y7Okc7t0WdnWtAkylZZwcj97TYSF/xiBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-26T01:24:23.652406Z","bundle_sha256":"722f21e3fe6f436de0f1963ab07a4877caa763584901b52accf9464a0132c5da"}}