[1][2][3][4][5] He was elected as a fellow of the American Association for the Advancement of Science (AAAS) in 2021 and as a fellow of the American Physical Society (APS) with the quote: "For distinguished contributions to the field of theoretical cosmology, particularly for testing modifications to general relativity at cosmological scales, and for sustained excellence in teaching and mentoring of students.
[8] His graduate work[8] included studies on inhomogeneous cosmologies, wormholes, exact solutions in general relativity of compact objects (such as neutron stars), and an inverse approach to the Einstein field equations.
[16] In 2005, Ishak-Boushaki and collaborators proposed a procedure to distinguish between dark energy and modification to general relativity at cosmological scales as a cause of cosmic acceleration.
He and collaborators also made a first detection of these intrinsic alignments using a self-calibration method in the photometric galaxy sample in Kilo-Degree Survey.
[19] Ishak-Boushaki and collaborator wrote a review article on the intrinsic alignment of galaxies and its impact on weak gravitational lensing.