Indexed metadata
Unknotting number is not additive under connected sum
Mark Brittenham, Susan Hermiller
Source record
Source: Crossref
Published: Sep 1, 2026
DOI: 10.4007/annals.2026.204.2.7
Open original source ↗Source abstract
We give the first examples of a pair of knots , in the -sphere for which their unknotting numbers satisfy $u(K_1 # K_2) < u(K_1)+u(K_2)$. This answers question 1.69(B) from Kirby's problem list, in the negative.
Evidence graph
No public relationships recorded yet.
Integrity note: This page is a factual metadata record created by deterministic ingestion. It is not a claim that the work moves a mathematical frontier or has been independently verified.