A note on phase (norm) retrievable Real Hilbert space (fusion) frames
arXiv:2107.09606
Abstract
In this manuscript, we present several new results in finite and countable dimensional real Hilbert space phase retrieval and norm retrieval by vectors and projections. We make a detailed study of when hyperplanes do norm retrieval. Also, we show that the families of norm retrievable frames in are not dense in the family of -element sets of vectors in for every finite and the families of vectors which do norm retrieval in are not dense in the infinite families of vectors in . We also show that if a Riesz basis does norm retrieval in , then it is an orthogonal sequence. We provide numerous examples to show that our results are best possible.