In geometric topology, a branch of mathematics, a '''crumpled cube''' is any space in '''R'''<sup>3</sup> homeomorphic to a 2-sphere together with its interior.<ref name="Martin65">{{cite journal | last1 = Martin | first1 = Joseph | year = 1966 | title = The sum of two crumpled cubes | url = http://projecteuclid.org/euclid.mmj/1028999538 | journal = Michigan Mathematical Journal | volume = 13 | issue = 2| pages = 147–151 | doi=10.1307/mmj/1028999538| doi-access = free }} {{open access}}</ref> Lininger showed in 1965 that the union of a crumpled cube and an open 3-ball glued along their boundaries is a 3-sphere.<ref name="Lininger1965">{{cite journal | last1=Lininger | first1=Lloyd L. | title=Some results on crumpled cubes | jstor=1993977 | mr=0178460 | year=1965 | journal=Transactions of the American Mathematical Society | issn=0002-9947 | volume=118 | pages=534–549 | doi=10.2307/1993977| doi-access=free }} {{open access}}</ref>
==References== <references/>
Category:Geometric topology
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