{"paper":{"title":"Advanced Virgo during the LIGO-Virgo-KAGRA fourth observing run","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"gr-qc","authors_text":"A Agapito, A Ain, A Allocca, A Amato, A Basti, A Bertolini, A Binetti, A Boudon, A Bozzi, A Brillet, A Buchicchio, A Buggiani, A Casallas-Lagos, A C Green, A Chincarini, A Chiummo, A Chopra, A Colombo, A Cozzumbo, A Daumas, A Demagny, A Depasse, A Domiciano De Souza, A E Koloniari, A Feo, A Fragkos, A Freise, A Gennai, A Ghinassi, A Goodwin-Jones, A Grado, A Ierardi, A I Renzini, A Karia, A Kr, A Lakhal, A Lartaux-Vollard, A Lema, A Longo, A Macquet, A Martini, A Masserot, A Moreso Serra, A Moscatello, A Nagar, A Nardecchia, A Nemmani, A Ouzriat, A Paoli, A Paolone, A Paquis, A Parisi, A Pasqualetti, A Perreca, A Pisarski, Archisman Ghosh, A Revilla-Pe, A Ricciardone, A Riminucci, A Rocchi, A Romero-Rodr, A Samajdar, A Sevrin, A Svizzeretto, A Syx, A Theodoropoulos, A Trapananti, A Trovato, A Van de Walle, A Veutro, A Vicer, B Banerjee, B D'Angelo, B Garaventa, B Haskell, B Kacskovics, B L Swinkels, B Mours, B Patricelli, B Revenu, B Sassolas, C-A Miritescu, C Amra, C Bellani, C Bradaschia, C Casentini, C de Melo, C De Rossi, C Diaz, C Gasbarra, C Gostiaux, C Grimaud, C Jacquet, C J Delgado Mendez, C Lazzaro, C Michel, C M Mow-Lowry, C Palomba, C Petrillo, C Turski, C Van Den Broeck, D Agarwal, D A Steer, D Barta, D Beltran-Martinez, D Bersanetti, D Buskulic, D Diksha, D Di Piero, D D'Urso, D Goupilliere, D Hegde, D Hofman, D Lumaca, D Nabari, D Nanadoumgar-Lacroze, D Pascucci, D Passuello, D Pesios, D Rosi, D Rozza, D Verkindt, E Benedetti, E Calloni, E Capocasa, E Cesarini, E Chassande-Mottin, E Coccia, E Codazzo, E Cuoco, E Fenyvesi, E Glowacki, E K Porter, E Kraja, E Maggio, E Majorana, E Milotti, E Minakaki, E N Tapia San Mart, E Placidi, E Polini, E Porcelli, E Ruiz Morales, E Tofani, E Tournefier, E Vallejo-Pag, E Van den Bossche, F Amicucci, F Arciprete, F Armato, F Attadio, F Aubin, F Barone, F Beirnaert, F Bianchi, F Bucci, F Carbognani, F Chiadini, F Cleva, F De Lillo, F De Marco, F De Matteis, F Diaz Guerra, F Di Renzo, F Fabrizi, F Fidecaro, F Flocco, F Frappez, F Frasconi, F Garufi, F Gautier, F Gittins, F Glotin, F Gulminelli, F Legger, F Liu, F Marion, F Martelli, F Muciaccia, F Nocera, F Pannarale, F Paoletti, F Piergiovanni, F Ricci, F Robinet, F Safai Tehrani, F Salemi, F Santoliquido, F Sarandrea, F Sorrentino, F Spada, F Travasso, F Vetrano, G A Iandolo, G A Prodi, G Avallone, G Balbi, G Baldi, G Ballardin, G Boileau, G Bruno, G Cagnoli, G Capoccia, G Capurri, G Cella, G Ciani, G Comp, G D, G Demasi, G Fern, G Gemme, G Greco, G Hemming, G Joubert, G Losurdo, G Mastropasqua, G M Guidi, G Montefusco, G Morras, G Oganesyan, G Papigkiotis, G Pierra, G Principe, G Qu, G Troian, G Vedovato, H Duval, H Einsle, H Heitmann, H J Bulten, H Narola, H Ubach, H van Haevermaet, H Vocca, I Bentara, I C F Wong, I Cordero-Carri, I Di Palma, I Fiori, I-L Ahrend, I M Pinto, I Nardecchia, I Rainho, I Takimoto Schmiegelow, I Tosta e Melo, J A Font, J A Lange, J Bezerra-Sobrinho, J Casanueva Diaz, J C Martins, J De Bolle, J Degallaix, J Ding, J F J van den Brand, J Garc, J Gargiulo, J Harms, J Heynen, J Irwin, J Janquart, J Kubisz, J Novak, J Perret, J-P Locquet, J Pomper, J-P Zendri, J Steinlechner, J Sun, J Suresh, J Tissino, J van Dongen, J V van Heijningen, J W Seo, J-Y Vinet, J Zhang, K Csuk, K Paul, K Schouteden, L A Corubolo, L Aiello, L Asprea, L Conti, L D'Onofrio, L Errico, L G Medeiros, L Honet, L Iampieri, L Lavezzi, Ll. M Mir, L Lunghini, L Massaro, L Maurin, L Mereni, L Mirasola, L Mobilia, L Muccillo, L Naticchioni, L Negri, L Papalini, L Piccari, L Pierini, L Pinard, L Rolland, L Salconi, L Silenzi, L Silvestri, L Smith, L Tao, L Trozzo, L Zhizhong, L Zimmermann, M-A Bizouard, M A Dicorato, M Andia, M A Palaia, M Assiduo, M Ballelli, M Baratti, M Barsuglia, M Bawaj, M Bazzan, M Bejger, M Bilicki, M Bitossi, M Bloch, M Boldrini, M Branchesi, M Carpinelli, M Cie, M Cifaldi, M C Tringali, M Cusinato, M De Laurentis, M Di Cesare, M Di Giovanni, M Drago, M Dubois, M Esposito, M Fays, M Galimberti, M Gosselin, M Granata, M Haney, M Ianni, M J Szczepa, M Lalleman, M L Brozzetti, M Le Jean, M Lenti, M Leonardi, M Lequime, M Lethuillier, M Lopez Portilla, M Lorenzini, M Lorusso, M Magnozzi, M Mancarella, M Mantovani, M Mapelli, M Martinez, M Montani, M Oertel, M Panzeri, M Pichot, M Piendibene, M Pillas, M Pinto, M Polo, M Pracchia, M Punturo, M Razzano, M Ricci, M Sall, M Salom, M Schoor, M Schulz, M Scialpi, M Seglar-Arroyo, M Serra, M Spera, M Suchenek, M Tacca, M Tagliazucchi, M T Hartman, M Toffano, M Turconi, M Vacatello, M Valentini, M van Dael, M van der Kolk, M van der Sluys, M Vardaro, M Vereecken, M Was, M Wils, M Wright, M Zanatta, M Zeoli, M Zerrad, N Arnaud, N Avdeev, N Baldicchi, N Borghi, N Busdon, N Christensen, N Franchini, N Lajili, N Letendre, N Man, N Sanchis-Gual, N Stergioulas, N Tamanini, N van Remortel, N Villanueva Espinosa, N Yadav, O Bulashenko, O Dorosh, O Freitas, P Astone, P Cerd, P Chessa, P Ciecielag, P Davis, P-F Cohadon, P Figura, P Garc, P Iosif, P Jaranowski, P J S Silva, P Leaci, P Prosperi, P Prosposito, P Puppo, P Rapagnani, P Ruggi, P Saffarieh, P Sassi, P Spinicelli, P T H Pang, P Tiwari, P Van Hove, P Verdier, R Bonnand, R Buscicchio, R Cabrita, R Cavalieri, R De Pietri, R De Rosa, R De Simone, R Flaminio, R Gouaty, R Lemrani Alaoui, R Oliveira, R Poggiani, R R Cuzinatto, R Romano, R Travaglini, S Antier, S Assis de Souza Melo, S Babak, S Bagnasco, S Baimukhametova, S Bera, S Biot, S Chaty, S Clesse, S Corezzi, S Cortese, S Dall'Osso, S Dal Pra, S Danilishin, S D'Antonio, S Della Torre, S Dhage, S Di Pace, S Ferraiuolo, S Galaudage, S Gomez Lopez, S Harikumar, S Hild, S Jaraba, S Koley, S Kuroyanagi, S Lexmond, S L Kranzhoff, S Maenaut, S Marchetti, S Marsat, S Mastrogiovanni, S Nadji, S Nissanke, S Ronchini, S Roy, S Sajith Menon, S Salvador, S S Madekar, S Soares de Albuquerque Filho, S Steinlechner, S Sudhagar, S Vallero, S Venikoudis, S Verma, S Viret, T Andri, T Baka, T Bertheas, T Briant, T Bulik, T C K Ng, T Dal Canton, T Fernandes, T G F Li, T Jacquot, T Regimbau, T Sainrat, T Wouters, T Zelenova, U Dupletsa, V Biancalana, V Boschi, V Dattilo, V Ernst, V Fafone, V Fiumara, V Gennari, V Granata, Virgo Collaboration: F Acernese, V Loriette, V Mangano, V Martinez, V Milotti, V Napolano, V Pierro, V Sequino, V Sordini, V Spagnuolo, W Ali, W Amar, W Chaibi, W Del Pozzo, W-F Hsu, W Kiendrebeogo, X Garrido, Y Bothra, Y Guo, Y Minenkov, Y Zhao, Z Wu","submitted_at":"2026-07-29T13:02:00Z","abstract_excerpt":"From April 10, 2024 to November 18, 2025 Advanced Virgo participated in the fourth observing run of the network of gravitational-wave detectors, together with Advanced LIGO and KAGRA. For this observing run Advanced Virgo has completed its design optical configuration with the installation of a signal recycling mirror. In this paper we describe the challenges encountered in commissioning this optical configuration, alongside the other upgrades performed between the third and fourth observing run. The Virgo detector operated with a 68.9% duty cycle and with an angle-averaged median range to bin"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.26872","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/2607.26872/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"}