@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

<http://astrothesaurus.org/uat/1288>
  skos:altLabel "pp-wave"@en, "pp-wave spacetimes"@en ;
  skos:broader <http://astrothesaurus.org/uat/678> ;
  skos:prefLabel "pp waves"@en ;
  a skos:Concept .

<http://astrothesaurus.org/uat/678>
  skos:prefLabel "Gravitational waves"@en ;
  a skos:Concept ;
  skos:narrower <http://astrothesaurus.org/uat/1288> .