Continuous-time susbspace flows related to the symmetric eigenvalue problem

The classes of continuous-time flows on Rn×p that induce the same flow
on the set of p-dimensional subspaces of Rn are described. The power
flow is briefly reviewed in this framework, and a subspace generalization
of the Rayleigh quotient flow [Linear Algebra Appl. 368C, 2003,
pp. 343–357] is proposed and analyzed. This new flow displays a property
akin to deflation in finite time.