Formulas
- James's theorem
- Kuramoto–Sivashinsky equation
- Kuratowski's free set theorem
- Kuratowski's intersection theorem
- Kuratowski convergence
- Kuratowski embedding
- Kuratowski–Ulam theorem
- Kurosh subgroup theorem
- Ky Fan inequality
- Ky Fan inequality (game theory)
- Ky Fan lemma
- Kähler differential
- Kähler quotient
- Künneth theorem
- Kōmura's theorem