Speaker
Description
The advent of X-ray polarimetry has opened a new observational window into the accretion physics of compact objects. Observations with the Imaging X-ray Polarimetry Explorer (IXPE) provide unique constraints on the geometry and physical conditions of emission regions in black hole X-ray binaries. However, the first polarimetric results have raised new challenges for existing accretion models. In particular, the detection of unexpectedly high polarization fractions in both the hard and soft spectral states places strong constraints on the mechanisms responsible for X-ray emission and the structure of the accretion flow. In this talk, I will describe possible solutions to these emerging puzzles and discuss implications of IXPE observations for our understanding of black hole accretion models.