{"id":"https://openalex.org/W2100463561","doi":"https://doi.org/10.1088/0004-637x/710/2/1825","title":"A LARGER ESTIMATE OF THE ENTROPY OF THE UNIVERSE","display_name":"A LARGER ESTIMATE OF THE ENTROPY OF THE UNIVERSE","publication_year":2010,"publication_date":"2010-02-03","ids":{"openalex":"https://openalex.org/W2100463561","doi":"https://doi.org/10.1088/0004-637x/710/2/1825","mag":"2100463561"},"language":"en","primary_location":{"id":"doi:10.1088/0004-637x/710/2/1825","doi":"https://doi.org/10.1088/0004-637x/710/2/1825","is_oa":true,"landing_page_url":"https://doi.org/10.1088/0004-637x/710/2/1825","pdf_url":"https://iopscience.iop.org/article/10.1088/0004-637X/710/2/1825/pdf","source":{"id":"https://openalex.org/S1980519","display_name":"The Astrophysical Journal","issn_l":"0004-637X","issn":["0004-637X","1538-4357"],"is_oa":false,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-scientific","cwts-core","doaj","dongbi-a","jufo-1","ki-jl-1","norway-2","oarl","poland-140","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310320083","host_organization_name":"IOP Publishing","host_organization_lineage":["https://openalex.org/P4310320083","https://openalex.org/P4310311669"],"host_organization_lineage_names":["IOP Publishing","Institute of Physics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"The Astrophysical Journal","raw_type":"journal-article"},"volume":null,"type":"article","is_traditional":true,"indexed_in":["arxiv","crossref","datacite","doaj"],"open_access":{"is_oa":true,"oa_status":"bronze","oa_url":"https://iopscience.iop.org/article/10.1088/0004-637X/710/2/1825/pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5015369363","display_name":"Chas A. Egan","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I118347636","display_name":"Australian National University","ror":"https://ror.org/019wvm592","country_code":"AU","type":"education","lineage":["https://openalex.org/I118347636"]},{"id":"https://openalex.org/I31746571","display_name":"UNSW Sydney","ror":"https://ror.org/03r8z3t63","country_code":"AU","type":"education","lineage":["https://openalex.org/I31746571"]}],"countries":["AU"],"is_corresponding":true,"raw_author_name":"Chas A. Egan","raw_affiliation_strings":["Department of Astrophysics, School of Physics, University of New South Wales, Sydney, Australia","Research School of Astronomy and Astrophysics, Australian National University, Canberra, Australia; chas@mso.anu.edu.au","Research School of Astronomy and Astrophysics, Australian National University, Canberra, Australia"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Department of Astrophysics, School of Physics, University of New South Wales, Sydney, Australia","institution_ids":["https://openalex.org/I31746571"]},{"raw_affiliation_string":"Research School of Astronomy and Astrophysics, Australian National University, Canberra, Australia; chas@mso.anu.edu.au","institution_ids":["https://openalex.org/I118347636"]},{"raw_affiliation_string":"Research School of Astronomy and Astrophysics, Australian National University, Canberra, Australia","institution_ids":["https://openalex.org/I118347636"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5011708728","display_name":"Charles H. Lineweaver","orcid":"https://orcid.org/0000-0003-2047-1558","observed_orcids":["https://orcid.org/0000-0003-2047-1558"]},"institutions":[{"id":"https://openalex.org/I118347636","display_name":"Australian National University","ror":"https://ror.org/019wvm592","country_code":"AU","type":"education","lineage":["https://openalex.org/I118347636"]}],"countries":["AU"],"is_corresponding":false,"raw_author_name":"Charles H. Lineweaver","raw_affiliation_strings":["Planetary Science Institute, Research School of Astronomy and Astrophysics and Research School of Earth Sciences, Australian National University, Canberra, Australia"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Planetary Science Institute, Research School of Astronomy and Astrophysics and Research School of Earth Sciences, Australian National University, Canberra, Australia","institution_ids":["https://openalex.org/I118347636"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":["https://openalex.org/A5015369363"],"corresponding_institution_ids":["https://openalex.org/I118347636","https://openalex.org/I31746571"],"apc_list":{"value":4499,"currency":"USD","value_usd":4499},"apc_paid":null,"fwci":5.4576,"has_fulltext":true,"cited_by_count":259,"citation_normalized_percentile":{"value":0.95962712,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":97,"max":100},"biblio":{"volume":"710","issue":"2","first_page":"1825","last_page":"1834"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10095","display_name":"Cosmology and Gravitation Theories","score":0.7817000150680542,"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/T10095","display_name":"Cosmology and Gravitation Theories","score":0.7817000150680542,"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/T10026","display_name":"Galaxies: Formation, Evolution, Phenomena","score":0.1889999955892563,"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/T11090","display_name":"Dark Matter and Cosmic Phenomena","score":0.006500000134110451,"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":[{"id":"https://openalex.org/keywords/supermassive-black-holes","display_name":"supermassive black holes","score":0.9750000238418579},{"id":"https://openalex.org/keywords/cosmic-event-horizon","display_name":"cosmic event horizon","score":0.9049999713897705},{"id":"https://openalex.org/keywords/weakly-interacting-massive-particles","display_name":"WIMPs","score":0.9559999704360962},{"id":"https://openalex.org/keywords/black-hole-entropy","display_name":"black hole entropy","score":0.5260000228881836}],"concepts":[{"id":"https://openalex.org/C121332964","wikidata":"https://www.wikidata.org/wiki/Q413","display_name":"Physics","level":0,"score":0.8352688550949097},{"id":"https://openalex.org/C32848918","wikidata":"https://www.wikidata.org/wiki/Q845789","display_name":"Observable","level":2,"score":0.7362839579582214},{"id":"https://openalex.org/C2778963380","wikidata":"https://www.wikidata.org/wiki/Q221392","display_name":"Observable universe","level":3,"score":0.6920677423477173},{"id":"https://openalex.org/C106301342","wikidata":"https://www.wikidata.org/wiki/Q4117933","display_name":"Entropy (arrow of time)","level":2,"score":0.5804593563079834},{"id":"https://openalex.org/C148292158","wikidata":"https://www.wikidata.org/wiki/Q181741","display_name":"Event horizon","level":3,"score":0.5169962644577026},{"id":"https://openalex.org/C44870925","wikidata":"https://www.wikidata.org/wiki/Q37547","display_name":"Astrophysics","level":1,"score":0.479263037443161},{"id":"https://openalex.org/C59375849","wikidata":"https://www.wikidata.org/wiki/Q5013513","display_name":"COSMIC cancer database","level":2,"score":0.4748694598674774},{"id":"https://openalex.org/C159249277","wikidata":"https://www.wikidata.org/wiki/Q79925","display_name":"Dark matter","level":2,"score":0.4350900948047638},{"id":"https://openalex.org/C84999194","wikidata":"https://www.wikidata.org/wiki/Q1","display_name":"Universe","level":2,"score":0.4304811954498291},{"id":"https://openalex.org/C44752778","wikidata":"https://www.wikidata.org/wiki/Q2482717","display_name":"Particle horizon","level":5,"score":0.42974743247032166},{"id":"https://openalex.org/C26405456","wikidata":"https://www.wikidata.org/wiki/Q338","display_name":"Cosmology","level":2,"score":0.27368074655532837},{"id":"https://openalex.org/C20154449","wikidata":"https://www.wikidata.org/wiki/Q1129469","display_name":"Metric expansion of space","level":4,"score":0.2578777074813843},{"id":"https://openalex.org/C172790937","wikidata":"https://www.wikidata.org/wiki/Q18343","display_name":"Dark energy","level":3,"score":0.2132394015789032},{"id":"https://openalex.org/C62520636","wikidata":"https://www.wikidata.org/wiki/Q944","display_name":"Quantum mechanics","level":1,"score":0.17982211709022522},{"id":"https://openalex.org/C2779662365","wikidata":"https://www.wikidata.org/wiki/Q5416694","display_name":"Event (particle physics)","level":2,"score":0.1492035984992981}],"mesh":[],"locations_count":8,"locations":[{"id":"doi:10.1088/0004-637x/710/2/1825","doi":"https://doi.org/10.1088/0004-637x/710/2/1825","is_oa":true,"landing_page_url":"https://doi.org/10.1088/0004-637x/710/2/1825","pdf_url":"https://iopscience.iop.org/article/10.1088/0004-637X/710/2/1825/pdf","source":{"id":"https://openalex.org/S1980519","display_name":"The Astrophysical Journal","issn_l":"0004-637X","issn":["0004-637X","1538-4357"],"is_oa":false,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-scientific","cwts-core","doaj","dongbi-a","jufo-1","ki-jl-1","norway-2","oarl","poland-140","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310320083","host_organization_name":"IOP Publishing","host_organization_lineage":["https://openalex.org/P4310320083","https://openalex.org/P4310311669"],"host_organization_lineage_names":["IOP Publishing","Institute of Physics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"The Astrophysical Journal","raw_type":"journal-article"},{"id":"pmh:oai:arXiv.org:0909.3983","doi":null,"is_oa":true,"landing_page_url":"http://arxiv.org/abs/0909.3983","pdf_url":"https://arxiv.org/pdf/0909.3983","source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"text"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.147.7046","doi":null,"is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.147.7046","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"http://www.mso.anu.edu.au/~charley/papers/0909.3983v1.pdf","raw_type":"text"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.154.7865","doi":null,"is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.154.7865","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"http://www.mso.anu.edu.au/~charley/papers/EganLineweaverApJOnline.pdf","raw_type":"text"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.156.8381","doi":null,"is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.156.8381","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"http://www.mso.anu.edu.au/~charley/papers/EganLineweaverApJAcceptedv2.pdf","raw_type":"text"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.756.4126","doi":null,"is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.756.4126","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"http://arxiv.org/pdf/0909.3983.pdf","raw_type":"text"},{"id":"pmh:oai:openresearch-repository.anu.edu.au:1885/27819","doi":null,"is_oa":false,"landing_page_url":"http://hdl.handle.net/1885/27819","pdf_url":null,"source":{"id":"https://openalex.org/S4306402539","display_name":"ANU Open Research (Australian National University)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I118347636","host_organization_name":"Australian National University","host_organization_lineage":["https://openalex.org/I118347636"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"Astrophysical Journal, The","raw_type":"Journal article"},{"id":"doi:10.48550/arxiv.0909.3983","doi":"https://doi.org/10.48550/arxiv.0909.3983","is_oa":true,"landing_page_url":"https://doi.org/10.48550/arxiv.0909.3983","pdf_url":null,"source":{"id":"https://openalex.org/S4306400194","display_name":"arXiv (Cornell University)","issn_l":"2331-8422","issn":["2331-8422"],"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I205783295","host_organization_name":"Cornell University","host_organization_lineage":["https://openalex.org/I205783295"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":null,"is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"article-journal"}],"best_oa_location":{"id":"doi:10.1088/0004-637x/710/2/1825","doi":"https://doi.org/10.1088/0004-637x/710/2/1825","is_oa":true,"landing_page_url":"https://doi.org/10.1088/0004-637x/710/2/1825","pdf_url":"https://iopscience.iop.org/article/10.1088/0004-637X/710/2/1825/pdf","source":{"id":"https://openalex.org/S1980519","display_name":"The Astrophysical Journal","issn_l":"0004-637X","issn":["0004-637X","1538-4357"],"is_oa":false,"is_in_doaj":true,"is_core":true,"listed_in":["anvur-scientific","cwts-core","doaj","dongbi-a","jufo-1","ki-jl-1","norway-2","oarl","poland-140","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310320083","host_organization_name":"IOP Publishing","host_organization_lineage":["https://openalex.org/P4310320083","https://openalex.org/P4310311669"],"host_organization_lineage_names":["IOP Publishing","Institute of Physics"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"The Astrophysical Journal","raw_type":"journal-article"},"sustainable_development_goals":[],"study_designs":[],"awards":[],"funders":[],"has_content":{"grobid_xml":true,"pdf":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2100463561.pdf","grobid_xml":"https://content.openalex.org/works/W2100463561.grobid-xml"},"referenced_works_count":47,"referenced_works":["https://openalex.org/W61065943","https://openalex.org/W229895503","https://openalex.org/W1543790798","https://openalex.org/W1618953413","https://openalex.org/W1631788275","https://openalex.org/W1969412968","https://openalex.org/W1973861971","https://openalex.org/W1976853884","https://openalex.org/W1997271979","https://openalex.org/W2002331838","https://openalex.org/W2005024908","https://openalex.org/W2009628515","https://openalex.org/W2011560927","https://openalex.org/W2013038259","https://openalex.org/W2018451420","https://openalex.org/W2019709661","https://openalex.org/W2020387858","https://openalex.org/W2022487148","https://openalex.org/W2025905724","https://openalex.org/W2032185278","https://openalex.org/W2044117497","https://openalex.org/W2067079032","https://openalex.org/W2072876479","https://openalex.org/W2078140326","https://openalex.org/W2080383482","https://openalex.org/W2082361697","https://openalex.org/W2090747960","https://openalex.org/W2118082065","https://openalex.org/W2120830691","https://openalex.org/W2130491267","https://openalex.org/W2130789130","https://openalex.org/W2134251287","https://openalex.org/W2141586044","https://openalex.org/W2144092614","https://openalex.org/W2146478425","https://openalex.org/W2146877475","https://openalex.org/W2154748230","https://openalex.org/W2313737866","https://openalex.org/W2579930951","https://openalex.org/W2591541672","https://openalex.org/W2989582419","https://openalex.org/W3007754162","https://openalex.org/W3007833553","https://openalex.org/W3016069020","https://openalex.org/W3102854552","https://openalex.org/W3103552626","https://openalex.org/W3104991045"],"related_works":["https://openalex.org/W7100554880","https://openalex.org/W7209474125","https://openalex.org/W7095316562","https://openalex.org/W4414279677","https://openalex.org/W1503112275","https://openalex.org/W4292693864","https://openalex.org/W2054725573","https://openalex.org/W2002331838","https://openalex.org/W2047672762","https://openalex.org/W7097270809"],"abstract_inverted_index":{"Using":[0],"recent":[1],"measurements":[2],"of":[3,22,31,41,65,87,108,111],"the":[4,16,20,23,42,63,66,85,104,109,119],"supermassive":[5],"black":[6],"hole":[7],"(SMBH)":[8],"mass":[9],"function,":[10],"we":[11],"find":[12],"that":[13],"SMBHs":[14],"are":[15],"largest":[17],"contributor":[18],"to":[19,71,136],"entropy":[21,34,40,64,86,110],"observable":[24,43,120],"universe,":[25,121],"contributing":[26],"at":[27],"least":[28],"an":[29],"order":[30],"magnitude":[32],"more":[33],"than":[35],"previously":[36],"estimated.":[37],"The":[38],"total":[39],"universe":[44],"is":[45,49],"correspondingly":[46],"higher,":[47],"and":[48,139],"S":[50,73,90,122],"obs":[51],"=":[52,75,93,124],"3.1":[53],"+3.0":[54],"\u22121.7":[55],"\u00d7":[56,79,97],"10":[57,80,98,125],"104":[58],"k":[59,82,100,129],".":[60,101,130],"We":[61,102,131],"calculate":[62],"current":[67],"cosmic":[68],"event":[69],"horizon":[70],"be":[72],"CEH":[74,91],"2.6":[76],"\u00b1":[77,127],"0.3":[78],"122":[81],",":[83],"dwarfing":[84],"its":[88],"interior,":[89],"int":[92],"1.2":[94],"+1.1":[95],"\u22120.7":[96],"103":[99],"make":[103,140],"first":[105],"tentative":[106],"estimate":[107],"weakly":[112],"interacting":[113],"massive":[114],"particle":[115],"dark":[116],"matter":[117],"within":[118],"dm":[123],"88":[126],"1":[128],"highlight":[132],"several":[133],"caveats":[134],"pertaining":[135],"these":[137],"estimates":[138],"recommendations":[141],"for":[142],"future":[143],"work.":[144]},"counts_by_year":[{"year":2026,"cited_by_count":32},{"year":2025,"cited_by_count":45},{"year":2024,"cited_by_count":8},{"year":2023,"cited_by_count":23},{"year":2022,"cited_by_count":20},{"year":2021,"cited_by_count":15},{"year":2020,"cited_by_count":9},{"year":2019,"cited_by_count":10},{"year":2018,"cited_by_count":4},{"year":2017,"cited_by_count":17},{"year":2016,"cited_by_count":15},{"year":2015,"cited_by_count":9},{"year":2014,"cited_by_count":9},{"year":2013,"cited_by_count":16},{"year":2012,"cited_by_count":10}],"updated_date":"2026-11-07T11:25:07.637180","created_date":"2016-06-24T00:00:00"}