Title: Randomly sampling from orthonormal matrices: Coherence and Leverage Scores 
Speaker: Ilse Ipsen (North Carolina State University)
Co-authors: Thomas Wentworth

We consider three strategies for sampling rows from matrices Q with orthonormal columns: Exactly(c) 
without replacement, Exactly(c) with replacement, and Bernoulli sampling.

We present different probabilistic bounds for the condition numbers of the sampled matrices, and express 
them in terms of the coherence or the leverage scores of Q.  We also present lower bounds for the number of 
sampled rows to attain a desired condition number. Numericalexperiments confirm the accuracy of the bounds, even 
for small matrix dimensions.