We make a detailed study of norm retrieval. We give several classification theorems for norm retrieval and give a large number of examples to go with the theory. One consequence is a new result about Parseval frames: If a Parseval frame is divided into two subsets with spans W1,W2 and W1∩W2={0}, then W1⊥W2.
@article{arxiv.1701.08014,
title = {Norm retrieval and phase retrieval by projections},
author = {Peter G. Casazza and Dorsa Ghoreishi and Shani Jose and Janet C. Tremain},
journal= {arXiv preprint arXiv:1701.08014},
year = {2017}
}