An inequality for rational functions with applications to some statistical estimation problems

The well-known Baum-Eagon inequality I31 provides an effective iterative scheme for finding a local maximum for homogeneous polynomials with positive coefticients over a domain of probability values. However, in many applications we are interested in maximizing a general rational function. We extend the Baum-Eagon inequality to rational functions. We briefly describe some of the applications of this inequality to statistical estimation problems. Index Terms -Nonlinear optimization, statistical estimation, hidden Markov models, speech recognition.