Sampling Theorem
In order for a band-limited (i.e., one with a zero Power Spectrum for frequencies 
) baseband (
) signal to bereconstructed fully, it must be sampled at a rate 
. A signal sampled at 
is said to be NyquistSampled, and is called the Nyquist Frequency. No information is lost if a signal is sampledat the Nyquist Frequency, and no additional information is gained by sampling faster than this rate.
- Kirkman's Schoolgirl Problem
- Kirkman Triple System
- Kissing Circles Problem
- Kissing Number
- Kiss Surface
- Kite
- Klarner-Rado Sequence
- Klarner's Theorem
- Klein-Beltrami Model
- Klein Bottle
- Klein Four-Group
- Klein-Gordon Equation
- Kleinian Group
- Klein Quartic
- Klein's Absolute Invariant
- Klein's Equation
- Klein's Theorem
- Kloosterman's Sum
- k-Matrix
- Knapsack Problem
- Kneser-Sommerfeld Formula
- Knights of the Round Table
- Knights Problem
- Knight's Tour
- Knot