Get quick answers to your questions about the article from our AI researcher chatbot
{'id': 'https://openalex.org/W3098821480', 'doi': 'https://doi.org/10.1088/0264-9381/32/16/165001', 'title': 'Circular geodesics in the Kerr–Newman–Taub–NUT spacetime', 'display_name': 'Circular geodesics in the Kerr–Newman–Taub–NUT spacetime', 'publication_year': 2015, 'publication_date': '2015-07-23', 'ids': {'openalex': 'https://openalex.org/W3098821480', 'doi': 'https://doi.org/10.1088/0264-9381/32/16/165001', 'mag': '3098821480'}, 'language': 'en', 'primary_location': {'is_oa': False, 'landing_page_url': 'https://doi.org/10.1088/0264-9381/32/16/165001', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S171172751', 'display_name': 'Classical and Quantum Gravity', 'issn_l': '0264-9381', 'issn': ['0264-9381', '1361-6382'], 'is_oa': False, 'is_in_doaj': False, 'is_core': True, 'host_organization': 'https://openalex.org/P4310320083', 'host_organization_name': 'IOP Publishing', 'host_organization_lineage': ['https://openalex.org/P4310311669', 'https://openalex.org/P4310320083'], 'host_organization_lineage_names': ['Institute of Physics', 'IOP Publishing'], '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': 'https://arxiv.org/pdf/1402.0089', 'any_repository_has_fulltext': True}, 'authorships': [{'author_position': 'first', 'author': {'id': 'https://openalex.org/A5026583379', 'display_name': 'Parthapratim Pradhan', 'orcid': 'https://orcid.org/0000-0002-1065-5399'}, 'institutions': [{'id': 'https://openalex.org/I41549804', 'display_name': 'Vidyasagar University', 'ror': 'https://ror.org/027jsza11', 'country_code': 'IN', 'type': 'education', 'lineage': ['https://openalex.org/I41549804']}], 'countries': ['IN'], 'is_corresponding': True, 'raw_author_name': 'Parthapratim Pradhan', 'raw_affiliation_strings': ['Department of Physics, Vivekananda Satabarshiki Mahavidyalaya (Affiliated to Vidyasagar University), Manikpara, Jhargram, West Midnapur, West Bengal 721513, India'], 'affiliations': [{'raw_affiliation_string': 'Department of Physics, Vivekananda Satabarshiki Mahavidyalaya (Affiliated to Vidyasagar University), Manikpara, Jhargram, West Midnapur, West Bengal 721513, India', 'institution_ids': ['https://openalex.org/I41549804']}]}], 'institution_assertions': [], 'countries_distinct_count': 1, 'institutions_distinct_count': 1, 'corresponding_author_ids': ['https://openalex.org/A5026583379'], 'corresponding_institution_ids': ['https://openalex.org/I41549804'], 'apc_list': None, 'apc_paid': None, 'fwci': 2.504, 'has_fulltext': True, 'fulltext_origin': 'pdf', 'cited_by_count': 45, 'citation_normalized_percentile': {'value': 0.999953, 'is_in_top_1_percent': True, 'is_in_top_10_percent': True}, 'cited_by_percentile_year': {'min': 95, 'max': 96}, 'biblio': {'volume': '32', 'issue': '16', 'first_page': '165001', 'last_page': '165001'}, 'is_retracted': False, 'is_paratext': False, 'primary_topic': {'id': 'https://openalex.org/T10744', 'display_name': 'Astrophysical Phenomena and Observations', 'score': 0.9996, 'subfield': {'id': 'https://openalex.org/subfields/3103', 'display_name': 'Astronomy and Astrophysics'}, '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/T10744', 'display_name': 'Astrophysical Phenomena and Observations', 'score': 0.9996, 'subfield': {'id': 'https://openalex.org/subfields/3103', 'display_name': 'Astronomy and Astrophysics'}, '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/T10025', 'display_name': 'Black Holes and Theoretical Physics', 'score': 0.9977, '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/T10463', 'display_name': 'Pulsars and Gravitational Waves Research', 'score': 0.9952, 'subfield': {'id': 'https://openalex.org/subfields/3103', 'display_name': 'Astronomy and Astrophysics'}, 'field': {'id': 'https://openalex.org/fields/31', 'display_name': 'Physics and Astronomy'}, 'domain': {'id': 'https://openalex.org/domains/3', 'display_name': 'Physical Sciences'}}], 'keywords': [{'id': 'https://openalex.org/keywords/null', 'display_name': 'Null (SQL)', 'score': 0.7242193}, {'id': 'https://openalex.org/keywords/circular-orbit', 'display_name': 'Circular orbit', 'score': 0.5945115}, {'id': 'https://openalex.org/keywords/penrose-process', 'display_name': 'Penrose process', 'score': 0.5905574}, {'id': 'https://openalex.org/keywords/energy-condition', 'display_name': 'Energy condition', 'score': 0.58903134}, {'id': 'https://openalex.org/keywords/negative-energy', 'display_name': 'Negative energy', 'score': 0.55305886}, {'id': 'https://openalex.org/keywords/black-hole', 'display_name': 'Black hole (networking)', 'score': 0.46043792}], 'concepts': [{'id': 'https://openalex.org/C121332964', 'wikidata': 'https://www.wikidata.org/wiki/Q413', 'display_name': 'Physics', 'level': 0, 'score': 0.904213}, {'id': 'https://openalex.org/C203763787', 'wikidata': 'https://www.wikidata.org/wiki/Q371029', 'display_name': 'Null (SQL)', 'level': 2, 'score': 0.7242193}, {'id': 'https://openalex.org/C130187892', 'wikidata': 'https://www.wikidata.org/wiki/Q133327', 'display_name': 'Spacetime', 'level': 2, 'score': 0.63050675}, {'id': 'https://openalex.org/C165818556', 'wikidata': 'https://www.wikidata.org/wiki/Q213488', 'display_name': 'Geodesic', 'level': 2, 'score': 0.61963177}, {'id': 'https://openalex.org/C206391251', 'wikidata': 'https://www.wikidata.org/wiki/Q1186738', 'display_name': 'Nut', 'level': 2, 'score': 0.6041987}, {'id': 'https://openalex.org/C59108619', 'wikidata': 'https://www.wikidata.org/wiki/Q2261398', 'display_name': 'Circular orbit', 'level': 2, 'score': 0.5945115}, {'id': 'https://openalex.org/C45634927', 'wikidata': 'https://www.wikidata.org/wiki/Q616172', 'display_name': 'Penrose process', 'level': 5, 'score': 0.5905574}, {'id': 'https://openalex.org/C149643647', 'wikidata': 'https://www.wikidata.org/wiki/Q986455', 'display_name': 'Energy condition', 'level': 3, 'score': 0.58903134}, {'id': 'https://openalex.org/C63493438', 'wikidata': 'https://www.wikidata.org/wiki/Q5533988', 'display_name': 'Geodesics in general relativity', 'level': 3, 'score': 0.56242317}, {'id': 'https://openalex.org/C2779428274', 'wikidata': 'https://www.wikidata.org/wiki/Q662636', 'display_name': 'Negative energy', 'level': 2, 'score': 0.55305886}, {'id': 'https://openalex.org/C82422596', 'wikidata': 'https://www.wikidata.org/wiki/Q1094364', 'display_name': 'Rotating black hole', 'level': 3, 'score': 0.54256296}, {'id': 'https://openalex.org/C50341732', 'wikidata': 'https://www.wikidata.org/wiki/Q880302', 'display_name': 'Black hole (networking)', 'level': 5, 'score': 0.46043792}, {'id': 'https://openalex.org/C37914503', 'wikidata': 'https://www.wikidata.org/wiki/Q156495', 'display_name': 'Mathematical physics', 'level': 1, 'score': 0.43388847}, {'id': 'https://openalex.org/C72319582', 'wikidata': 'https://www.wikidata.org/wiki/Q584304', 'display_name': 'Degenerate energy levels', 'level': 2, 'score': 0.43068862}, {'id': 'https://openalex.org/C155675718', 'wikidata': 'https://www.wikidata.org/wiki/Q161254', 'display_name': 'Angular momentum', 'level': 2, 'score': 0.3799069}, {'id': 'https://openalex.org/C62520636', 'wikidata': 'https://www.wikidata.org/wiki/Q944', 'display_name': 'Quantum mechanics', 'level': 1, 'score': 0.35564882}, {'id': 'https://openalex.org/C74650414', 'wikidata': 'https://www.wikidata.org/wiki/Q11397', 'display_name': 'Classical mechanics', 'level': 1, 'score': 0.35008544}, {'id': 'https://openalex.org/C147452769', 'wikidata': 'https://www.wikidata.org/wiki/Q11452', 'display_name': 'General relativity', 'level': 2, 'score': 0.23994592}, {'id': 'https://openalex.org/C2524010', 'wikidata': 'https://www.wikidata.org/wiki/Q8087', 'display_name': 'Geometry', 'level': 1, 'score': 0.16915685}, {'id': 'https://openalex.org/C49811471', 'wikidata': 'https://www.wikidata.org/wiki/Q5244744', 'display_name': 'de Sitter–Schwarzschild metric', 'level': 4, 'score': 0.0897727}, {'id': 'https://openalex.org/C31258907', 'wikidata': 'https://www.wikidata.org/wiki/Q1301371', 'display_name': 'Computer network', 'level': 1, 'score': 0.0}, {'id': 'https://openalex.org/C104954878', 'wikidata': 'https://www.wikidata.org/wiki/Q1648707', 'display_name': 'Routing protocol', 'level': 3, 'score': 0.0}, {'id': 'https://openalex.org/C33923547', 'wikidata': 'https://www.wikidata.org/wiki/Q395', 'display_name': 'Mathematics', 'level': 0, 'score': 0.0}, {'id': 'https://openalex.org/C74172769', 'wikidata': 'https://www.wikidata.org/wiki/Q1446839', 'display_name': 'Routing (electronic design automation)', 'level': 2, 'score': 0.0}, {'id': 'https://openalex.org/C77088390', 'wikidata': 'https://www.wikidata.org/wiki/Q8513', 'display_name': 'Database', 'level': 1, 'score': 0.0}, {'id': 'https://openalex.org/C41008148', 'wikidata': 'https://www.wikidata.org/wiki/Q21198', 'display_name': 'Computer science', 'level': 0, 'score': 0.0}, {'id': 'https://openalex.org/C24890656', 'wikidata': 'https://www.wikidata.org/wiki/Q82811', 'display_name': 'Acoustics', 'level': 1, 'score': 0.0}, {'id': 'https://openalex.org/C89305328', 'wikidata': 'https://www.wikidata.org/wiki/Q1755411', 'display_name': 'Link-state routing protocol', 'level': 4, 'score': 0.0}], 'mesh': [], 'locations_count': 3, 'locations': [{'is_oa': False, 'landing_page_url': 'https://doi.org/10.1088/0264-9381/32/16/165001', 'pdf_url': None, 'source': {'id': 'https://openalex.org/S171172751', 'display_name': 'Classical and Quantum Gravity', 'issn_l': '0264-9381', 'issn': ['0264-9381', '1361-6382'], 'is_oa': False, 'is_in_doaj': False, 'is_core': True, 'host_organization': 'https://openalex.org/P4310320083', 'host_organization_name': 'IOP Publishing', 'host_organization_lineage': ['https://openalex.org/P4310311669', 'https://openalex.org/P4310320083'], 'host_organization_lineage_names': ['Institute of Physics', 'IOP Publishing'], 'type': 'journal'}, 'license': None, 'license_id': None, 'version': None, 'is_accepted': False, 'is_published': False}, {'is_oa': True, 'landing_page_url': 'https://arxiv.org/abs/1402.0089', 'pdf_url': 'https://arxiv.org/pdf/1402.0089', '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.1402.0089', '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': 'https://arxiv.org/abs/1402.0089', 'pdf_url': 'https://arxiv.org/pdf/1402.0089', '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', 'display_name': 'Affordable and clean energy', 'score': 0.9}], 'grants': [], 'datasets': [], 'versions': ['https://openalex.org/W1697416122', 'https://openalex.org/W3098821480'], 'referenced_works_count': 22, 'referenced_works': ['https://openalex.org/W1970039196', 'https://openalex.org/W1972339387', 'https://openalex.org/W1976814993', 'https://openalex.org/W1984330431', 'https://openalex.org/W2006008518', 'https://openalex.org/W2014841181', 'https://openalex.org/W2031153828', 'https://openalex.org/W2033001310', 'https://openalex.org/W2036726718', 'https://openalex.org/W2039326276', 'https://openalex.org/W2042561523', 'https://openalex.org/W2042650304', 'https://openalex.org/W2043407636', 'https://openalex.org/W2052881510', 'https://openalex.org/W2063806773', 'https://openalex.org/W2066530641', 'https://openalex.org/W2069976267', 'https://openalex.org/W2142414487', 'https://openalex.org/W3092596371', 'https://openalex.org/W3102583462', 'https://openalex.org/W3104880264', 'https://openalex.org/W3123973633'], 'related_works': ['https://openalex.org/W4253148939', 'https://openalex.org/W3123326721', 'https://openalex.org/W3098821480', 'https://openalex.org/W2317140342', 'https://openalex.org/W2168233238', 'https://openalex.org/W2126067753', 'https://openalex.org/W2073489576', 'https://openalex.org/W1994171500', 'https://openalex.org/W1993103214', 'https://openalex.org/W1828214186'], 'abstract_inverted_index': {'In': [0], 'this': [1, 27, 122, 131], 'paper': [2], 'we': [3], 'investigate': [4, 113], 'the': [5, 14, 38, 49, 52, 55, 69, 91, 94, 98, 101, 107, 114, 118, 128, 137, 146, 152, 161, 166, 169, 174], 'equatorial': [6], 'causal': [7], '(time-like': [8], 'and': [9, 37, 64, 81, 139, 159], 'null)': [10], 'circular': [11, 58, 62, 65], 'geodesics': [12], 'of': [13, 26, 34, 54, 71, 93, 100, 130, 168], 'Kerr–Newman–Taub–NUT': [15, 72], '(Newman–Unti–Tamburino)': [16], 'black': [17, 28, 132], 'hole': [18, 29, 133], 'in': [19, 68, 104], 'four-dimensional': [20], 'Lorentzian': [21], 'geometry.': [22], 'The': [23, 75], 'special': [24], 'characteristics': [25], 'are': [30, 41], 'that': [31, 90, 127, 145], 'it': [32], 'is': [33, 88, 125, 143, 149, 172, 177], 'Petrov–Pirani': [35], 'type-D': [36], 'photon': [39, 66], 'trajectories': [40], 'doubly': [42], 'degenerate': [43], 'principal': [44], 'null': [45, 82], 'congruence.': [46], 'We': [47, 111], 'derive': [48], 'conditions': [50], 'for': [51, 78, 121, 160], 'existence': [53], 'innermost': [56], 'stable': [57], 'orbit,': [59], 'marginally': [60], 'bound': [61], 'orbit': [63, 67], 'background': [70], '(KNTN)': [73], 'spacetime.': [74, 123], 'effective': [76, 102], 'potential': [77, 103], 'both': [79, 136], 'time-like': [80], 'cases': [83], 'have': [84], 'been': [85], 'studied.': [86], 'It': [87, 124, 142], 'shown': [89, 126], 'presence': [92], 'NUT': [95, 109, 140, 153, 170], 'parameter': [96, 154, 171], 'deforms': [97], 'shape': [99], 'contrast': [105], 'with': [106], 'zero': [108, 157], 'parameter.': [110, 141], 'further': [112], 'energy': [115, 147, 175], 'extraction': [116], 'by': [117], 'Penrose': [119], 'process': [120], 'efficiency': [129], 'depends': [134], 'on': [135], 'charge': [138], 'observed': [144], 'gain': [148, 176], 'maximum': [150, 162], 'when': [151], 'goes': [155], 'to': [156], 'value': [158, 167], 'spin': [163], 'value.': [164], 'When': [165], 'increasing,': [173], 'decreasing.': [178]}, 'cited_by_api_url': 'https://api.openalex.org/works?filter=cites:W3098821480', 'counts_by_year': [{'year': 2024, 'cited_by_count': 5}, {'year': 2023, 'cited_by_count': 6}, {'year': 2022, 'cited_by_count': 4}, {'year': 2021, 'cited_by_count': 4}, {'year': 2020, 'cited_by_count': 3}, {'year': 2019, 'cited_by_count': 6}, {'year': 2018, 'cited_by_count': 4}, {'year': 2017, 'cited_by_count': 6}, {'year': 2016, 'cited_by_count': 5}, {'year': 2015, 'cited_by_count': 2}], 'updated_date': '2025-01-11T11:04:28.944573', 'created_date': '2020-11-23'}