To: Whom it may Concern Subject: Letter of Recommendation for Dr. Eitan Gurewitz Dr. Eitan Gurewitz is an impressive scientist, who I was fortunate enough to host in my group at Caltech. We worked together on new approaches to optimization using powerful physics analogies. I believe that this is some of the very best work that I have done -- innovative, interesting and well regarded. Eitan showed his mastery of both computational science and physics and was a more than equal partner in this endeavor. He not only led the research but effectively supervised my two students Wang and Rose. He clearly meets your requirements for promotion and I would rate him as fully competitive with full professors at major universities. I would be delighted to continue my collaboration with Eitan and I give him my strongest unreserved recommendation