{"id":"https://openalex.org/W1975323904","doi":"https://doi.org/10.1109/tit.2014.2311434","title":"Mutual Information Matrices Are Not Always Positive Semidefinite","display_name":"Mutual Information Matrices Are Not Always Positive Semidefinite","publication_year":2014,"publication_date":"2014-03-18","ids":{"openalex":"https://openalex.org/W1975323904","doi":"https://doi.org/10.1109/tit.2014.2311434","mag":"1975323904"},"language":"en","primary_location":{"id":"doi:10.1109/tit.2014.2311434","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tit.2014.2311434","pdf_url":null,"source":{"id":"https://openalex.org/S4502562","display_name":"IEEE Transactions on Information Theory","issn_l":"0018-9448","issn":["0018-9448","1557-9654"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Information Theory","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5002224252","display_name":"S. Jakobsen","orcid":"https://orcid.org/0000-0002-6564-040X"},"institutions":[{"id":"https://openalex.org/I166337079","display_name":"Queen Mary University of London","ror":"https://ror.org/026zzn846","country_code":"GB","type":"education","lineage":["https://openalex.org/I124357947","https://openalex.org/I166337079"]}],"countries":["GB"],"is_corresponding":true,"raw_author_name":"Sune K. Jakobsen","raw_affiliation_strings":["School of Mathematical Sciences and School of Electronic Engineering and Computer Science, Queen Mary University of London, London, U.K","Sch. of Math. Sci., Queen Mary, Univ. of London, London, UK"],"affiliations":[{"raw_affiliation_string":"School of Mathematical Sciences and School of Electronic Engineering and Computer Science, Queen Mary University of London, London, U.K","institution_ids":[]},{"raw_affiliation_string":"Sch. of Math. Sci., Queen Mary, Univ. of London, London, UK","institution_ids":["https://openalex.org/I166337079"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5002224252"],"corresponding_institution_ids":["https://openalex.org/I166337079"],"apc_list":null,"apc_paid":null,"fwci":0.8499,"has_fulltext":false,"cited_by_count":15,"citation_normalized_percentile":{"value":0.76427822,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":89,"max":100},"biblio":{"volume":"60","issue":"5","first_page":"2694","last_page":"2696"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10964","display_name":"Wireless Communication Security Techniques","score":0.9980000257492065,"subfield":{"id":"https://openalex.org/subfields/2208","display_name":"Electrical and Electronic Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10964","display_name":"Wireless Communication Security Techniques","score":0.9980000257492065,"subfield":{"id":"https://openalex.org/subfields/2208","display_name":"Electrical and Electronic Engineering"},"field":{"id":"https://openalex.org/fields/22","display_name":"Engineering"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11321","display_name":"Error Correcting Code Techniques","score":0.9965999722480774,"subfield":{"id":"https://openalex.org/subfields/1705","display_name":"Computer Networks and Communications"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11716","display_name":"Random Matrices and Applications","score":0.9965000152587891,"subfield":{"id":"https://openalex.org/subfields/2613","display_name":"Statistics and Probability"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.36215370893478394},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.32537901401519775},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.3244090974330902}],"concepts":[{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.36215370893478394},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.32537901401519775},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.3244090974330902}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1109/tit.2014.2311434","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tit.2014.2311434","pdf_url":null,"source":{"id":"https://openalex.org/S4502562","display_name":"IEEE Transactions on Information Theory","issn_l":"0018-9448","issn":["0018-9448","1557-9654"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Information Theory","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":4,"referenced_works":["https://openalex.org/W1515040589","https://openalex.org/W2112223184","https://openalex.org/W2140678653","https://openalex.org/W4250589301"],"related_works":["https://openalex.org/W2899084033","https://openalex.org/W2748952813","https://openalex.org/W2051487156","https://openalex.org/W2390279801","https://openalex.org/W2358668433","https://openalex.org/W3107474891","https://openalex.org/W303980170","https://openalex.org/W2351491280","https://openalex.org/W2386767533","https://openalex.org/W2371447506"],"abstract_inverted_index":{"For":[0],"discrete":[1],"random":[2,128],"variables":[3],"X":[4,10,35,41,46,72,78,97],"<sub":[5,11,31,36,42,47,62,68,73,79,92,98],"xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"":[6,12,32,37,43,48,63,69,74,80,93,99],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">1</sub>":[7,94],",":[8,95],"...,":[9,96],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">n</sub>":[13,100],"we":[14,25,57,112],"construct":[15],"an":[16],"n":[17,19],"by":[18],"matrix.":[20],"In":[21,51,109],"the":[22,27,54,59,86,116,121],"(i,":[23,55],"j)-entry":[24],"put":[26,58],"mutual":[28,87],"information":[29,88],"I(X":[30,67],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">i</sub>":[33,44,64,70,75,81],";":[34,71],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">j</sub>":[38,49],")":[39,65,76],"between":[40],"and":[45,118],".":[50,82],"particular,":[52],"in":[53],"i)-entry":[56],"entropy":[60],"H(X":[61],"=":[66],"of":[77,90],"This":[83],"matrix,":[84],"called":[85],"matrix":[89],"(X":[91],"),":[101],"has":[102],"been":[103],"conjectured":[104],"to":[105,115,126],"be":[106],"positive":[107],"semidefinite.":[108],"this":[110],"paper,":[111],"give":[113],"counterexamples":[114],"conjecture,":[117],"show":[119],"that":[120],"conjecture":[122],"holds":[123],"for":[124],"up":[125],"three":[127],"variables.":[129]},"counts_by_year":[{"year":2026,"cited_by_count":2},{"year":2024,"cited_by_count":1},{"year":2022,"cited_by_count":2},{"year":2021,"cited_by_count":1},{"year":2020,"cited_by_count":5},{"year":2017,"cited_by_count":2},{"year":2016,"cited_by_count":2}],"updated_date":"2026-03-06T13:50:29.536080","created_date":"2025-10-10T00:00:00"}