Get quick answers to your questions about the article from our AI researcher chatbot
{'id': 'https://openalex.org/W2950257145', 'doi': 'https://doi.org/10.1088/1475-7516/2007/11/002', 'title': 'Greisen–Zatsepin–Kuzmin photons above 10 EeV', 'display_name': 'Greisen–Zatsepin–Kuzmin photons above 10 EeV', 'publication_year': 2007, 'publication_date': '2007-11-05', 'ids': {'openalex': 'https://openalex.org/W2950257145', 'doi': 'https://doi.org/10.1088/1475-7516/2007/11/002', 'mag': '2950257145'}, 'language': 'en', 'primary_location': {'is_oa': False, 'landing_page_url': 'https://doi.org/10.1088/1475-7516/2007/11/002', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S120662888', 'display_name': 'Journal of Cosmology and Astroparticle Physics', 'issn_l': '1475-7516', 'issn': ['1475-7508', '1475-7516'], 'is_oa': False, 'is_in_doaj': False, 'is_core': True, 'host_organization': 'https://openalex.org/P4310311669', 'host_organization_name': 'Institute of Physics', 'host_organization_lineage': ['https://openalex.org/P4310311669'], 'host_organization_lineage_names': ['Institute of Physics'], 'type': 'journal'}, 'license': None, 'license_id': None, 'version': None, 'is_accepted': False, 'is_published': False}, 'type': 'article', 'type_crossref': 'journal-article', 'indexed_in': ['arxiv', 'crossref', 'datacite'], 'open_access': {'is_oa': True, 'oa_status': 'green', 'oa_url': 'http://arxiv.org/pdf/0706.2181', 'any_repository_has_fulltext': True}, 'authorships': [{'author_position': 'first', 'author': {'id': 'https://openalex.org/A5014300395', 'display_name': 'Graciela B. Gelmini', 'orcid': 'https://orcid.org/0000-0001-8401-1505'}, 'institutions': [{'id': 'https://openalex.org/I161318765', 'display_name': 'University of California, Los Angeles', 'ror': 'https://ror.org/046rm7j60', 'country_code': 'US', 'type': 'education', 'lineage': ['https://openalex.org/I161318765']}], 'countries': ['US'], 'is_corresponding': False, 'raw_author_name': 'Graciela Gelmini', 'raw_affiliation_strings': ['Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547, USA'], 'affiliations': [{'raw_affiliation_string': 'Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547, USA', 'institution_ids': ['https://openalex.org/I161318765']}]}, {'author_position': 'middle', 'author': {'id': 'https://openalex.org/A5004815685', 'display_name': 'O. Kalashev', 'orcid': 'https://orcid.org/0000-0002-7982-1842'}, 'institutions': [{'id': 'https://openalex.org/I161318765', 'display_name': 'University of California, Los Angeles', 'ror': 'https://ror.org/046rm7j60', 'country_code': 'US', 'type': 'education', 'lineage': ['https://openalex.org/I161318765']}], 'countries': ['US'], 'is_corresponding': False, 'raw_author_name': 'Oleg Kalashev', 'raw_affiliation_strings': ['Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547, USA', 'INR RAS, 60th October Anniversary Prospekt 7a, 117312 Moscow, Russia'], 'affiliations': [{'raw_affiliation_string': 'Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095-1547, USA', 'institution_ids': ['https://openalex.org/I161318765']}, {'raw_affiliation_string': 'INR RAS, 60th October Anniversary Prospekt 7a, 117312 Moscow, Russia', 'institution_ids': []}]}, {'author_position': 'last', 'author': {'id': 'https://openalex.org/A5036192202', 'display_name': 'D. Semikoz', 'orcid': 'https://orcid.org/0000-0001-6417-1560'}, 'institutions': [{'id': 'https://openalex.org/I187986737', 'display_name': 'Collège de France', 'ror': 'https://ror.org/04ex24z53', 'country_code': 'FR', 'type': 'education', 'lineage': ['https://openalex.org/I187986737']}], 'countries': ['FR'], 'is_corresponding': False, 'raw_author_name': 'Dmitry V Semikoz', 'raw_affiliation_strings': ['APC, College de France, 11 place Marcelin Berthelot, Paris 75005, France', 'INR RAS, 60th October Anniversary Prospekt 7a, 117312 Moscow, Russia'], 'affiliations': [{'raw_affiliation_string': 'APC, College de France, 11 place Marcelin Berthelot, Paris 75005, France', 'institution_ids': ['https://openalex.org/I187986737']}, {'raw_affiliation_string': 'INR RAS, 60th October Anniversary Prospekt 7a, 117312 Moscow, Russia', 'institution_ids': []}]}], 'institution_assertions': [], 'countries_distinct_count': 2, 'institutions_distinct_count': 2, 'corresponding_author_ids': [], 'corresponding_institution_ids': [], 'apc_list': None, 'apc_paid': None, 'fwci': 1.629, 'has_fulltext': True, 'fulltext_origin': 'pdf', 'cited_by_count': 21, 'citation_normalized_percentile': {'value': 0.776777, 'is_in_top_1_percent': False, 'is_in_top_10_percent': False}, 'cited_by_percentile_year': {'min': 88, 'max': 89}, 'biblio': {'volume': '2007', 'issue': '11', 'first_page': '002', 'last_page': '002'}, 'is_retracted': False, 'is_paratext': False, 'primary_topic': {'id': 'https://openalex.org/T10818', 'display_name': 'Astrophysics and Cosmic Phenomena', 'score': 1.0, 'subfield': {'id': 'https://openalex.org/subfields/3106', 'display_name': 'Nuclear and High Energy Physics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}, 'topics': [{'id': 'https://openalex.org/T10818', 'display_name': 'Astrophysics and Cosmic Phenomena', 'score': 1.0, 'subfield': {'id': 'https://openalex.org/subfields/3106', 'display_name': 'Nuclear and High Energy Physics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}, {'id': 'https://openalex.org/T11090', 'display_name': 'Dark Matter and Cosmic Phenomena', 'score': 0.9979, 'subfield': {'id': 'https://openalex.org/subfields/3106', 'display_name': 'Nuclear and High Energy Physics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}, {'id': 'https://openalex.org/T10921', 'display_name': 'Neutrino Physics Research', 'score': 0.9965, 'subfield': {'id': 'https://openalex.org/subfields/3106', 'display_name': 'Nuclear and High Energy Physics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}], 'keywords': [], 'concepts': [{'id': 'https://openalex.org/C121332964', 'wikidata': 'https://www.wikidata.org/wiki/Q413', 'display_name': 'Physics', 'level': 0, 'score': 0.97667265}, {'id': 'https://openalex.org/C111309251', 'wikidata': 'https://www.wikidata.org/wiki/Q11547', 'display_name': 'Cosmic ray', 'level': 2, 'score': 0.7761146}, {'id': 'https://openalex.org/C159317903', 'wikidata': 'https://www.wikidata.org/wiki/Q3198', 'display_name': 'Photon', 'level': 2, 'score': 0.7449636}, {'id': 'https://openalex.org/C172695262', 'wikidata': 'https://www.wikidata.org/wiki/Q102165', 'display_name': 'Nucleon', 'level': 2, 'score': 0.66602623}, {'id': 'https://openalex.org/C68709404', 'wikidata': 'https://www.wikidata.org/wiki/Q1134475', 'display_name': 'Flux (metallurgy)', 'level': 2, 'score': 0.6446141}, {'id': 'https://openalex.org/C44870925', 'wikidata': 'https://www.wikidata.org/wiki/Q37547', 'display_name': 'Astrophysics', 'level': 1, 'score': 0.6327718}, {'id': 'https://openalex.org/C206094082', 'wikidata': 'https://www.wikidata.org/wiki/Q4097', 'display_name': 'Pion', 'level': 2, 'score': 0.56390595}, {'id': 'https://openalex.org/C186453547', 'wikidata': 'https://www.wikidata.org/wiki/Q2126', 'display_name': 'Neutrino', 'level': 2, 'score': 0.55420166}, {'id': 'https://openalex.org/C185544564', 'wikidata': 'https://www.wikidata.org/wiki/Q81197', 'display_name': 'Nuclear physics', 'level': 1, 'score': 0.4540991}, {'id': 'https://openalex.org/C204323151', 'wikidata': 'https://www.wikidata.org/wiki/Q905424', 'display_name': 'Range (aeronautics)', 'level': 2, 'score': 0.41861707}, {'id': 'https://openalex.org/C120665830', 'wikidata': 'https://www.wikidata.org/wiki/Q14620', 'display_name': 'Optics', 'level': 1, 'score': 0.06458375}, {'id': 'https://openalex.org/C192562407', 'wikidata': 'https://www.wikidata.org/wiki/Q228736', 'display_name': 'Materials science', 'level': 0, 'score': 0.0}, {'id': 'https://openalex.org/C191897082', 'wikidata': 'https://www.wikidata.org/wiki/Q11467', 'display_name': 'Metallurgy', 'level': 1, 'score': 0.0}, {'id': 'https://openalex.org/C159985019', 'wikidata': 'https://www.wikidata.org/wiki/Q181790', 'display_name': 'Composite material', 'level': 1, 'score': 0.0}], 'mesh': [], 'locations_count': 6, 'locations': [{'is_oa': False, 'landing_page_url': 'https://doi.org/10.1088/1475-7516/2007/11/002', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S120662888', 'display_name': 'Journal of Cosmology and Astroparticle Physics', 'issn_l': '1475-7516', 'issn': ['1475-7508', '1475-7516'], 'is_oa': False, 'is_in_doaj': False, 'is_core': True, 'host_organization': 'https://openalex.org/P4310311669', 'host_organization_name': 'Institute of Physics', 'host_organization_lineage': ['https://openalex.org/P4310311669'], 'host_organization_lineage_names': ['Institute of Physics'], 'type': 'journal'}, 'license': None, 'license_id': None, 'version': None, 'is_accepted': False, 'is_published': False}, {'is_oa': False, 'landing_page_url': 'https://hal.archives-ouvertes.fr/hal-00713200', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S4306402512', 'display_name': 'HAL (Le Centre pour la Communication Scientifique Directe)', 'issn_l': None, 'issn': None, 'is_oa': True, 'is_in_doaj': False, 'is_core': False, 'host_organization': 'https://openalex.org/I1294671590', 'host_organization_name': 'Centre National de la Recherche Scientifique', 'host_organization_lineage': ['https://openalex.org/I1294671590'], 'host_organization_lineage_names': ['Centre National de la Recherche Scientifique'], 'type': 'repository'}, 'license': None, 'license_id': None, 'version': None, 'is_accepted': False, 'is_published': False}, {'is_oa': False, 'landing_page_url': 'https://hal.science/hal-00713200', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S4306402512', 'display_name': 'HAL (Le Centre pour la Communication Scientifique Directe)', 'issn_l': None, 'issn': None, 'is_oa': True, 'is_in_doaj': False, 'is_core': False, 'host_organization': 'https://openalex.org/I1294671590', 'host_organization_name': 'Centre National de la Recherche Scientifique', 'host_organization_lineage': ['https://openalex.org/I1294671590'], 'host_organization_lineage_names': ['Centre National de la Recherche Scientifique'], 'type': 'repository'}, 'license': None, 'license_id': None, 'version': None, 'is_accepted': False, 'is_published': False}, {'is_oa': True, 'landing_page_url': 'http://arxiv.org/abs/0706.2181', 'pdf_url': 'http://arxiv.org/pdf/0706.2181', 'source': {'id': 'https://openalex.org/S4306400194', 'display_name': 'arXiv (Cornell University)', 'issn_l': None, 'issn': None, 'is_oa': True, 'is_in_doaj': False, 'is_core': False, 'host_organization': 'https://openalex.org/I205783295', 'host_organization_name': 'Cornell University', 'host_organization_lineage': ['https://openalex.org/I205783295'], 'host_organization_lineage_names': ['Cornell University'], 'type': 'repository'}, 'license': None, 'license_id': None, 'version': 'submittedVersion', 'is_accepted': False, 'is_published': False}, {'is_oa': True, 'landing_page_url': 'https://arxiv.org/abs/0706.2181', 'pdf_url': 'https://arxiv.org/pdf/0706.2181', 'source': {'id': 'https://openalex.org/S4306400194', 'display_name': 'arXiv (Cornell University)', 'issn_l': None, 'issn': None, 'is_oa': True, 'is_in_doaj': False, 'is_core': False, 'host_organization': 'https://openalex.org/I205783295', 'host_organization_name': 'Cornell University', 'host_organization_lineage': ['https://openalex.org/I205783295'], 'host_organization_lineage_names': ['Cornell University'], 'type': 'repository'}, 'license': None, 'license_id': None, 'version': 'submittedVersion', 'is_accepted': False, 'is_published': False}, {'is_oa': False, 'landing_page_url': 'https://api.datacite.org/dois/10.48550/arxiv.0706.2181', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S4393179698', 'display_name': 'DataCite API', 'issn_l': None, 'issn': None, 'is_oa': True, 'is_in_doaj': False, 'is_core': False, 'host_organization': 'https://openalex.org/I4210145204', 'host_organization_name': 'DataCite', 'host_organization_lineage': ['https://openalex.org/I4210145204'], 'host_organization_lineage_names': ['DataCite'], 'type': 'metadata'}, 'license': None, 'license_id': None, 'version': None}], 'best_oa_location': {'is_oa': True, 'landing_page_url': 'http://arxiv.org/abs/0706.2181', 'pdf_url': 'http://arxiv.org/pdf/0706.2181', 'source': {'id': 'https://openalex.org/S4306400194', 'display_name': 'arXiv (Cornell University)', 'issn_l': None, 'issn': None, 'is_oa': True, 'is_in_doaj': False, 'is_core': False, 'host_organization': 'https://openalex.org/I205783295', 'host_organization_name': 'Cornell University', 'host_organization_lineage': ['https://openalex.org/I205783295'], 'host_organization_lineage_names': ['Cornell University'], 'type': 'repository'}, 'license': None, 'license_id': None, 'version': 'submittedVersion', 'is_accepted': False, 'is_published': False}, 'sustainable_development_goals': [{'id': 'https://metadata.un.org/sdg/7', 'score': 0.44, 'display_name': 'Affordable and clean energy'}], 'grants': [], 'datasets': [], 'versions': ['https://openalex.org/W2950257145', 'https://openalex.org/W3122995648'], 'referenced_works_count': 90, 'referenced_works': ['https://openalex.org/W13073378', 'https://openalex.org/W1537458170', 'https://openalex.org/W1598802290', 'https://openalex.org/W1623998688', 'https://openalex.org/W1642228177', 'https://openalex.org/W1681283292', 'https://openalex.org/W1771104541', 'https://openalex.org/W1819713413', 'https://openalex.org/W1963984224', 'https://openalex.org/W1965310795', 'https://openalex.org/W1971601450', 'https://openalex.org/W1975041883', 'https://openalex.org/W1976897323', 'https://openalex.org/W1981369239', 'https://openalex.org/W1981860995', 'https://openalex.org/W1983700952', 'https://openalex.org/W1985186992', 'https://openalex.org/W1987473803', 'https://openalex.org/W1989438279', 'https://openalex.org/W1989815304', 'https://openalex.org/W1992596452', 'https://openalex.org/W1994794528', 'https://openalex.org/W1997398153', 'https://openalex.org/W1998174391', 'https://openalex.org/W1999663363', 'https://openalex.org/W2002888699', 'https://openalex.org/W2003688039', 'https://openalex.org/W2006189918', 'https://openalex.org/W2006593537', 'https://openalex.org/W2009643313', 'https://openalex.org/W2013587096', 'https://openalex.org/W2013968399', 'https://openalex.org/W2016034250', 'https://openalex.org/W2019825582', 'https://openalex.org/W2020595089', 'https://openalex.org/W2026069103', 'https://openalex.org/W2030501080', 'https://openalex.org/W2036800616', 'https://openalex.org/W2038180772', 'https://openalex.org/W2038785539', 'https://openalex.org/W2043755933', 'https://openalex.org/W2045603145', 'https://openalex.org/W2047539721', 'https://openalex.org/W2052246495', 'https://openalex.org/W2052276106', 'https://openalex.org/W2054703804', 'https://openalex.org/W2057751156', 'https://openalex.org/W2071152645', 'https://openalex.org/W2072741560', 'https://openalex.org/W2075229374', 'https://openalex.org/W2081869483', 'https://openalex.org/W2085023683', 'https://openalex.org/W2089930139', 'https://openalex.org/W2101888749', 'https://openalex.org/W2115203831', 'https://openalex.org/W2115969817', 'https://openalex.org/W2117392622', 'https://openalex.org/W2121849085', 'https://openalex.org/W2128106770', 'https://openalex.org/W2129806967', 'https://openalex.org/W2130314416', 'https://openalex.org/W2132636807', 'https://openalex.org/W2138310146', 'https://openalex.org/W2140537989', 'https://openalex.org/W2152012149', 'https://openalex.org/W2159526805', 'https://openalex.org/W2164285794', 'https://openalex.org/W2170761360', 'https://openalex.org/W2320961141', 'https://openalex.org/W2594331859', 'https://openalex.org/W2595227860', 'https://openalex.org/W2949089867', 'https://openalex.org/W2986810904', 'https://openalex.org/W3010144461', 'https://openalex.org/W3021676541', 'https://openalex.org/W3098049330', 'https://openalex.org/W3099530034', 'https://openalex.org/W3100744007', 'https://openalex.org/W3101226584', 'https://openalex.org/W3102293548', 'https://openalex.org/W3103273060', 'https://openalex.org/W3103704794', 'https://openalex.org/W3104460937', 'https://openalex.org/W3105027976', 'https://openalex.org/W3123158764', 'https://openalex.org/W3123974054', 'https://openalex.org/W3124873982', 'https://openalex.org/W3125604439', 'https://openalex.org/W3125734777', 'https://openalex.org/W4388395101'], 'related_works': ['https://openalex.org/W942772761', 'https://openalex.org/W2104410223', 'https://openalex.org/W2096794900', 'https://openalex.org/W2093432087', 'https://openalex.org/W2088657486', 'https://openalex.org/W2055625581', 'https://openalex.org/W2015567227', 'https://openalex.org/W1984336294', 'https://openalex.org/W1966824261', 'https://openalex.org/W120556287'], 'abstract_inverted_index': {'We': [0, 84, 106, 164], 'calculate': [1, 77, 85], 'the': [2, 7, 16, 21, 30, 36, 42, 54, 60, 66, 73, 78, 86, 90, 95, 100, 103, 113, 136, 138, 155], 'flux': [3, 8, 27, 98], 'of': [4, 9, 19, 35, 38, 56, 89, 94, 145], '"GZK-photons",': [5], 'namely': [6], 'photons': [10, 80], 'produced': [11, 81, 111, 134], 'by': [12, 47, 82], 'extragalactic': [13], 'nucleons': [14, 39, 110], 'through': [15], 'resonant': [17], 'photoproduction': [18], 'pions,': [20], 'so': [22], 'called': [23], 'GZK': [24, 79, 91], 'effect.': [25], 'This': [26], 'depends': [28], 'on': [29, 33, 53, 59, 167], 'UHECR': [31, 97], 'spectrum': [32, 37], 'Earth,': [34], 'emitted': [40], 'at': [41, 112, 135], 'sources,': [43], 'which': [44], 'we': [45, 76], 'characterize': [46], 'its': [48], 'slope': [49], 'and': [50, 58, 69, 102, 124], 'maximum': [51, 139], 'energy,': [52], 'distribution': [55], 'sources': [57, 114, 137], 'intervening': [61], 'cosmological': [62], 'backgrounds,': [63], 'in': [64], 'particular': [65], 'magnetic': [67], 'field': [68], 'radio': [70], 'backgrounds.': [71], 'For': [72, 132], 'first': [74], 'time': [75], 'nuclei.': [83], 'possible': [87], 'range': [88], 'photon': [92, 140], 'fraction': [93, 141], 'total': [96], 'for': [99, 109, 162], 'AGASA': [101], 'HiRes': [104], 'spectra.': [105], 'find': [107], 'that': [108], 'it': [115], 'could': [116, 157], 'be': [117, 158], 'as': [118, 120, 125, 127], 'large': [119], 'a': [121, 143], 'few': [122], '%': [123], 'low': [126], '10^{-4}': [128], 'above': [129, 151], '10': [130, 152], 'EeV.': [131], 'nuclei': [133], 'is': [142], 'factor': [144], '2': [146], 'to': [147], '3': [148], 'times': [149], 'smaller': [150, 160], 'EeV': [153], 'but': [154], 'minimum': [156], 'much': [159], 'than': [161], 'nucleons.': [163], 'also': [165], 'comment': [166], 'cosmogenic': [168], 'neutrino': [169], 'fluxes.': [170]}, 'cited_by_api_url': 'https://api.openalex.org/works?filter=cites:W2950257145', 'counts_by_year': [{'year': 2021, 'cited_by_count': 1}, {'year': 2020, 'cited_by_count': 1}, {'year': 2013, 'cited_by_count': 1}, {'year': 2012, 'cited_by_count': 2}], 'updated_date': '2024-12-13T23:32:38.349126', 'created_date': '2019-06-27'}