Question: What is based on  degrees Celsius that is defining formula is ^{\circ}\text{C} = \text{K} - 273.15 ?
Paraphrase: What is based on degrees Celsius that's characterizing equation is ^{circ}text{C} = text{K} - 273.15 ?
SPARQL (Wikidata): SELECT ?obj WHERE { wd:Q25267 p:P144 ?s . ?s ps:P144 ?obj . ?s pq:P2534 ?x filter(contains(?x , '^{\circ}\text{C} = \text{K} - 273.15')) }