{"id":"https://openalex.org/W2101458911","doi":"https://doi.org/10.1016/s0893-9659(00)00164-6","title":"Perturbed S1-symmetric hamiltonian systems","display_name":"Perturbed S1-symmetric hamiltonian systems","publication_year":2001,"publication_date":"2001-04-01","ids":{"openalex":"https://openalex.org/W2101458911","doi":"https://doi.org/10.1016/s0893-9659(00)00164-6","mag":"2101458911"},"language":"en","primary_location":{"id":"doi:10.1016/s0893-9659(00)00164-6","is_oa":false,"landing_page_url":"https://doi.org/10.1016/s0893-9659(00)00164-6","pdf_url":null,"source":{"id":"https://openalex.org/S7571225","display_name":"Applied Mathematics Letters","issn_l":"0893-9659","issn":["0893-9659","1873-5452"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Applied Mathematics Letters","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/A5018250642","display_name":"Marco Squassina","orcid":"https://orcid.org/0000-0003-0858-4648"},"institutions":[{"id":"https://openalex.org/I189158943","display_name":"University of Milan","ror":"https://ror.org/00wjc7c48","country_code":"IT","type":"education","lineage":["https://openalex.org/I189158943"]}],"countries":["IT"],"is_corresponding":true,"raw_author_name":"M. Squassina","raw_affiliation_strings":["Dipartimento di Matematica, Universit\u00e0 di Milano Via C. Saldini 50, I-20133 Milano, Italy","Dipartimento di Matematica, Universit\u00e0 di Milano, Via C. Saldini 50, I-20133 Milano, Italy"],"affiliations":[{"raw_affiliation_string":"Dipartimento di Matematica, Universit\u00e0 di Milano Via C. Saldini 50, I-20133 Milano, Italy","institution_ids":["https://openalex.org/I189158943"]},{"raw_affiliation_string":"Dipartimento di Matematica, Universit\u00e0 di Milano, Via C. Saldini 50, I-20133 Milano, Italy","institution_ids":["https://openalex.org/I189158943"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":1,"corresponding_author_ids":["https://openalex.org/A5018250642"],"corresponding_institution_ids":["https://openalex.org/I189158943"],"apc_list":{"value":3540,"currency":"USD","value_usd":3540},"apc_paid":null,"fwci":0.4958,"has_fulltext":false,"cited_by_count":2,"citation_normalized_percentile":{"value":0.63244939,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":null,"biblio":{"volume":"14","issue":"3","first_page":"375","last_page":"380"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11022","display_name":"Spectral Theory in Mathematical Physics","score":0.9986000061035156,"subfield":{"id":"https://openalex.org/subfields/2610","display_name":"Mathematical Physics"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11022","display_name":"Spectral Theory in Mathematical Physics","score":0.9986000061035156,"subfield":{"id":"https://openalex.org/subfields/2610","display_name":"Mathematical Physics"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10248","display_name":"Nonlinear Waves and Solitons","score":0.9973999857902527,"subfield":{"id":"https://openalex.org/subfields/3109","display_name":"Statistical and Nonlinear 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/T10194","display_name":"Nonlinear Partial Differential Equations","score":0.9936000108718872,"subfield":{"id":"https://openalex.org/subfields/2604","display_name":"Applied Mathematics"},"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/mathematics","display_name":"Mathematics","score":0.7943313717842102},{"id":"https://openalex.org/keywords/hamiltonian-system","display_name":"Hamiltonian system","score":0.6156437993049622},{"id":"https://openalex.org/keywords/hamiltonian","display_name":"Hamiltonian (control theory)","score":0.5751613974571228},{"id":"https://openalex.org/keywords/mathematical-physics","display_name":"Mathematical physics","score":0.5006430149078369},{"id":"https://openalex.org/keywords/pure-mathematics","display_name":"Pure mathematics","score":0.34108465909957886},{"id":"https://openalex.org/keywords/applied-mathematics","display_name":"Applied mathematics","score":0.3264777660369873},{"id":"https://openalex.org/keywords/mathematical-optimization","display_name":"Mathematical optimization","score":0.18372946977615356}],"concepts":[{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.7943313717842102},{"id":"https://openalex.org/C121770821","wikidata":"https://www.wikidata.org/wiki/Q2072471","display_name":"Hamiltonian system","level":2,"score":0.6156437993049622},{"id":"https://openalex.org/C130787639","wikidata":"https://www.wikidata.org/wiki/Q5645293","display_name":"Hamiltonian (control theory)","level":2,"score":0.5751613974571228},{"id":"https://openalex.org/C37914503","wikidata":"https://www.wikidata.org/wiki/Q156495","display_name":"Mathematical physics","level":1,"score":0.5006430149078369},{"id":"https://openalex.org/C202444582","wikidata":"https://www.wikidata.org/wiki/Q837863","display_name":"Pure mathematics","level":1,"score":0.34108465909957886},{"id":"https://openalex.org/C28826006","wikidata":"https://www.wikidata.org/wiki/Q33521","display_name":"Applied mathematics","level":1,"score":0.3264777660369873},{"id":"https://openalex.org/C126255220","wikidata":"https://www.wikidata.org/wiki/Q141495","display_name":"Mathematical optimization","level":1,"score":0.18372946977615356}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1016/s0893-9659(00)00164-6","is_oa":false,"landing_page_url":"https://doi.org/10.1016/s0893-9659(00)00164-6","pdf_url":null,"source":{"id":"https://openalex.org/S7571225","display_name":"Applied Mathematics Letters","issn_l":"0893-9659","issn":["0893-9659","1873-5452"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320990","host_organization_name":"Elsevier BV","host_organization_lineage":["https://openalex.org/P4310320990"],"host_organization_lineage_names":["Elsevier BV"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Applied Mathematics Letters","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[{"display_name":"Climate action","score":0.75,"id":"https://metadata.un.org/sdg/13"}],"awards":[],"funders":[],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":9,"referenced_works":["https://openalex.org/W1571927898","https://openalex.org/W1981288703","https://openalex.org/W2058270372","https://openalex.org/W2077813952","https://openalex.org/W2086611760","https://openalex.org/W2147530742","https://openalex.org/W2269549044","https://openalex.org/W6664990416","https://openalex.org/W6681816409"],"related_works":["https://openalex.org/W2075972694","https://openalex.org/W1983586807","https://openalex.org/W4238581249","https://openalex.org/W1640151394","https://openalex.org/W2027510160","https://openalex.org/W2037624026","https://openalex.org/W2044047017","https://openalex.org/W2068754437","https://openalex.org/W1608333910","https://openalex.org/W3101093746"],"abstract_inverted_index":null,"counts_by_year":[],"updated_date":"2026-03-10T14:07:55.174380","created_date":"2025-10-10T00:00:00"}