@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix vcard: <http://www.w3.org/2006/vcard/ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00922017v1> a dcat:Dataset ;
    dct:description """
              For a {bounded} non-negative self-adjoint operator acting in a complex, infinite-dimensional, separable Hilbert space H and possessing a dense range R we propose a new approach to characterisation of phenomenon concerning the existence of subspaces M\\subset H such that M\\capR=M^\\perp\\capR=\\{0\\}. We show how the existence of such subspaces leads to various {pathological} properties of {unbounded} self-adjoint operators related to von Neumann theorems \\cite{Neumann}--\\cite{Neumann2}. We revise the von Neumann-Van Daele-Schm\\"udgen assertions \\cite{Neumann}, \\cite{Daele}, \\cite{schmud} to refine them. We also develop {a new systematic approach, which allows to construct for any {unbounded} densely defined symmetric/self-adjoint operator T infinitely many pairs of its closed densely defined restrictions T_k\\subset T such that \\dom(T^* T_{k})=\\{0\\} (\\Rightarrow \\dom T_{k}^2=\\{0\\}$) k=1,2 and \\dom T_1\\cap\\dom T_2=\\{0\\}, \\dom T_1\\dot+\\dom T_2=\\dom T.
            """ ;
    dct:identifier "hal-00922017" ;
    dct:issued "2026-05-07T17:10:10.008844"^^xsd:dateTime ;
    dct:language "en" ;
    dct:modified "2026-05-07T17:10:10.008850"^^xsd:dateTime ;
    dct:publisher <https://rec.harvest-normandie.data4citizen.com/organization/cce9db95-46d9-4dc2-84b6-764215d0a002> ;
    dct:title "Around the Van Daele–Schmüdgen Theorem" ;
    dcat:contactPoint [ a vcard:Organization ;
            vcard:fn "CCSD" ] ;
    dcat:distribution <https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00922017v1/resource/6244d70d-3161-4864-bfc0-e4c82988263a> ;
    dcat:keyword "47a05-47a07-47a20-47a64-47b25",
        "friedrichs-extension",
        "infoeu-reposemanticsarticle",
        "journal-articles",
        "krein-extension",
        "lifting",
        "mathmath-famathematics-mathfunctional-analysis-mathfa",
        "operator-range",
        "parallel-addition",
        "shorted-operator",
        "van-daele--schmudgen-theorem",
        "von-neumann-theorem" ;
    dcat:landingPage <ISSN:%200378-620X> .

<ISSN:%200378-620X> a foaf:Document .

<https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00922017v1/resource/6244d70d-3161-4864-bfc0-e4c82988263a> a dcat:Distribution ;
    dct:format "HTML" ;
    dct:issued "2026-05-07T17:10:10.012501"^^xsd:dateTime ;
    dct:modified "2026-05-07T17:10:09.996303"^^xsd:dateTime ;
    dct:title "Around the Van Daele–Schmüdgen Theorem" ;
    dcat:accessURL <https://hal.science/hal-00922017> .

<https://rec.harvest-normandie.data4citizen.com/organization/cce9db95-46d9-4dc2-84b6-764215d0a002> a foaf:Agent ;
    foaf:name "test_moissonnage_selune" .