Recorded 11 October 2022. Albert Fannjiang of the University of California, Davis, presents "From Tomographic Phase Retrieval to Projection Tomography" at IPAM's Diffractive Imaging with Phase Retrieval Workshop. Abstract: We analyze measurement schemes under which 3D unwrapped phase retrieval can be reduced to projection tomography. A key component is the deployment of a coded aperture. Our motivation is to leverage highly successful projection-based techniques in cryo-EM to process diffraction data collected under measurement uncertainties such as sample heterogeneities, unknown orientations and positions. First, with the introduction of a beam splitter, the dataset of diffraction patterns is reducible to that of projections under measurement uncertainties. Second, without a beam splitter, this data reducibility holds true for random conical tilt and orthogonal tilt schemes widely used in cryo-EM. Finally, the resulting phase unwrapping problem for 3D projection tomography can be solved by schemes including as special cases the conical tilting at a conical angle slightly greater than pi/4, the orthogonal dual-axis tilting and a combination of a conical tilting and an orthogonal single-axis tilting. Learn more online at: http://www.ipam.ucla.edu/programs/workshops/workshop-i-diffractive-imaging-with-phase-retrieval/?tab=schedule