{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:OT22AYEKLK4XWVT47XFRSX5OM5","short_pith_number":"pith:OT22AYEK","canonical_record":{"source":{"id":"2504.15737","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2025-04-22T09:31:55Z","cross_cats_sorted":["eess.SP","math.IT"],"title_canon_sha256":"9ce6ce5ead2a293721290fb964cf68f54c71603a484521c56d7c1953cf362862","abstract_canon_sha256":"50e2212c7fa9b0e986eed4e883743162a87e9ccef97e907aa631d3bed14039f8"},"schema_version":"1.0"},"canonical_sha256":"74f5a0608a5ab97b567cfdcb195fae6779bdc121fe0c662c2f0c73c590008cd5","source":{"kind":"arxiv","id":"2504.15737","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2504.15737","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"arxiv_version","alias_value":"2504.15737v1","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2504.15737","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"pith_short_12","alias_value":"OT22AYEKLK4X","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"pith_short_16","alias_value":"OT22AYEKLK4XWVT4","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"pith_short_8","alias_value":"OT22AYEK","created_at":"2026-07-05T10:52:29Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:OT22AYEKLK4XWVT47XFRSX5OM5","target":"record","payload":{"canonical_record":{"source":{"id":"2504.15737","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2025-04-22T09:31:55Z","cross_cats_sorted":["eess.SP","math.IT"],"title_canon_sha256":"9ce6ce5ead2a293721290fb964cf68f54c71603a484521c56d7c1953cf362862","abstract_canon_sha256":"50e2212c7fa9b0e986eed4e883743162a87e9ccef97e907aa631d3bed14039f8"},"schema_version":"1.0"},"canonical_sha256":"74f5a0608a5ab97b567cfdcb195fae6779bdc121fe0c662c2f0c73c590008cd5","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T10:52:29.276635Z","signature_b64":"7fZft9WQf5873N4OIzofT28Mfa4aFYJnMmjCd+g5B7nVT/7OcBMhDk+e7ki9uazfGtnGE14yUur1zZ2zbk/dBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"74f5a0608a5ab97b567cfdcb195fae6779bdc121fe0c662c2f0c73c590008cd5","last_reissued_at":"2026-07-05T10:52:29.276140Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T10:52:29.276140Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2504.15737","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T10:52:29Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rs6OnrYcZChyjtNVil7kZ4k9oJyjFFocSG4wB2HxWRJAkRxdsPah2Y7kCOhqmMXDxsnLIUUHgwj8eS630chwCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-17T18:27:06.114878Z"},"content_sha256":"13f76ac2cc0a116fb118aa49da0833780f8cd9f6c92fd2b77b98f4d2b027619f","schema_version":"1.0","event_id":"sha256:13f76ac2cc0a116fb118aa49da0833780f8cd9f6c92fd2b77b98f4d2b027619f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:OT22AYEKLK4XWVT47XFRSX5OM5","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Energy-Efficient SIM-assisted Communications: How Many Layers Do We Need?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["eess.SP","math.IT"],"primary_cat":"cs.IT","authors_text":"Bo Ai, Chau Yuen, Enyu Shi, Jiancheng An, Jiayi Zhang, Marco Di Renzo","submitted_at":"2025-04-22T09:31:55Z","abstract_excerpt":"The stacked intelligent metasurface (SIM), comprising multiple layers of reconfigurable transmissive metasurfaces, is becoming an increasingly viable solution for future wireless communication systems. In this paper, we explore the integration of SIM in a multi-antenna base station for application to downlink multi-user communications, and a realistic power consumption model for SIM-assisted systems is presented. Specifically, we focus on maximizing the energy efficiency (EE) for hybrid precoding design, i.e., the base station digital precoding and SIM wave-based beamforming. Due to the non-co"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2504.15737","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2504.15737/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T10:52:29Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"TiTdIBBG5j9l8JKnRyOgXqQkZbcQaJZC5F1Z40GZRnekOr7V6O8dt/osNtKuLiY4Pm5LNbtnx2HIPW4X7DZhAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-17T18:27:06.115874Z"},"content_sha256":"d9a8270c9e864afcd210c1619249bba52a83e2fc24dcb64efece2fa2a22bba12","schema_version":"1.0","event_id":"sha256:d9a8270c9e864afcd210c1619249bba52a83e2fc24dcb64efece2fa2a22bba12"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OT22AYEKLK4XWVT47XFRSX5OM5/bundle.json","state_url":"https://pith.science/pith/OT22AYEKLK4XWVT47XFRSX5OM5/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OT22AYEKLK4XWVT47XFRSX5OM5/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":"2026-08-17T18:27:06Z","links":{"resolver":"https://pith.science/pith/OT22AYEKLK4XWVT47XFRSX5OM5","bundle":"https://pith.science/pith/OT22AYEKLK4XWVT47XFRSX5OM5/bundle.json","state":"https://pith.science/pith/OT22AYEKLK4XWVT47XFRSX5OM5/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OT22AYEKLK4XWVT47XFRSX5OM5/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:OT22AYEKLK4XWVT47XFRSX5OM5","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":"50e2212c7fa9b0e986eed4e883743162a87e9ccef97e907aa631d3bed14039f8","cross_cats_sorted":["eess.SP","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2025-04-22T09:31:55Z","title_canon_sha256":"9ce6ce5ead2a293721290fb964cf68f54c71603a484521c56d7c1953cf362862"},"schema_version":"1.0","source":{"id":"2504.15737","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2504.15737","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"arxiv_version","alias_value":"2504.15737v1","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2504.15737","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"pith_short_12","alias_value":"OT22AYEKLK4X","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"pith_short_16","alias_value":"OT22AYEKLK4XWVT4","created_at":"2026-07-05T10:52:29Z"},{"alias_kind":"pith_short_8","alias_value":"OT22AYEK","created_at":"2026-07-05T10:52:29Z"}],"graph_snapshots":[{"event_id":"sha256:d9a8270c9e864afcd210c1619249bba52a83e2fc24dcb64efece2fa2a22bba12","target":"graph","created_at":"2026-07-05T10:52:29Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2504.15737/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The stacked intelligent metasurface (SIM), comprising multiple layers of reconfigurable transmissive metasurfaces, is becoming an increasingly viable solution for future wireless communication systems. In this paper, we explore the integration of SIM in a multi-antenna base station for application to downlink multi-user communications, and a realistic power consumption model for SIM-assisted systems is presented. Specifically, we focus on maximizing the energy efficiency (EE) for hybrid precoding design, i.e., the base station digital precoding and SIM wave-based beamforming. Due to the non-co","authors_text":"Bo Ai, Chau Yuen, Enyu Shi, Jiancheng An, Jiayi Zhang, Marco Di Renzo","cross_cats":["eess.SP","math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2025-04-22T09:31:55Z","title":"Energy-Efficient SIM-assisted Communications: How Many Layers Do We Need?"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2504.15737","kind":"arxiv","version":1},"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":"sha256:13f76ac2cc0a116fb118aa49da0833780f8cd9f6c92fd2b77b98f4d2b027619f","target":"record","created_at":"2026-07-05T10:52:29Z","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":"50e2212c7fa9b0e986eed4e883743162a87e9ccef97e907aa631d3bed14039f8","cross_cats_sorted":["eess.SP","math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2025-04-22T09:31:55Z","title_canon_sha256":"9ce6ce5ead2a293721290fb964cf68f54c71603a484521c56d7c1953cf362862"},"schema_version":"1.0","source":{"id":"2504.15737","kind":"arxiv","version":1}},"canonical_sha256":"74f5a0608a5ab97b567cfdcb195fae6779bdc121fe0c662c2f0c73c590008cd5","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"74f5a0608a5ab97b567cfdcb195fae6779bdc121fe0c662c2f0c73c590008cd5","first_computed_at":"2026-07-05T10:52:29.276140Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T10:52:29.276140Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"7fZft9WQf5873N4OIzofT28Mfa4aFYJnMmjCd+g5B7nVT/7OcBMhDk+e7ki9uazfGtnGE14yUur1zZ2zbk/dBQ==","signature_status":"signed_v1","signed_at":"2026-07-05T10:52:29.276635Z","signed_message":"canonical_sha256_bytes"},"source_id":"2504.15737","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:13f76ac2cc0a116fb118aa49da0833780f8cd9f6c92fd2b77b98f4d2b027619f","sha256:d9a8270c9e864afcd210c1619249bba52a83e2fc24dcb64efece2fa2a22bba12"],"state_sha256":"2a036f1d292f1100eb7bbc575c06d7b8c426048dd7ae141781e7fd3c8a2bfb4c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uQ2VjKb4wpzWfjV7O0XUxEekHXCE46qKgkyTkx6uY0kaVze1DG74iX+vwX5GDeG/RN0cOjYUzCXiJSV9ipw/BQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-17T18:27:06.121472Z","bundle_sha256":"6caff36c2781ba4f9825b8a5b96641269947fe7635939585f4d1dfffdee83f1b"}}