Ishak-Boushaki Mustapha

ISHAK-BOUSHAKI Mustapha

Professor of Physics and Astrophysics University of Texas at Dallas, United States

Origins & Education

Mustapha Ishak-Boushaki was born in Algeria, where he grew up and completed his pre-university studies in the city of Bouira. His academic journey demonstrates a solid multidisciplinary foundation and a constant pursuit of excellence.

In 1987, he moved to Montreal, Canada, to pursue his higher education. He first obtained an undergraduate degree in computer science at the University of Quebec at Montreal in 1994, followed by an additional undergraduate degree in physics from the University of Montreal in 1998. This dual training provided him with valuable expertise at the intersection of computer science and physics, a considerable asset for his future research in theoretical cosmology.

He then attended Queen's University at Kingston, where he completed his PhD in general relativity and theoretical cosmology with distinction in 2002. His graduate work focused on advanced topics such as inhomogeneous cosmologies, wormholes, exact solutions in general relativity of compact objects (such as neutron stars), and an inverse approach to the Einstein field equations. The excellence of his doctoral work earned him the prestigious fellowship of the Research Council of Canada.

Scientific Career

After completing his PhD, Mustapha Ishak-Boushaki began his professional career as a research associate at Princeton University, a world-renowned institution in theoretical physics. This experience allowed him to collaborate with leading researchers and deepen his work in the field of cosmology.

In 2005, he joined the University of Texas at Dallas as a professor, where he formed an active group of cosmologists and astrophysicists. His career at UT Dallas has been marked not only by the excellence of his research but also by his exceptional commitment to teaching and mentoring, as evidenced by the numerous awards he has received in these areas.

His research work focuses on several fundamental areas of modern cosmology:

• The origin and cause of cosmic acceleration and dark energy: 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. The idea was based on the fact that cosmic acceleration affects both the expansion rate and the growth rate of large-scale structures in the universe. This publication was one of the first to contrast dark energy versus modified gravity as cause of cosmic acceleration, and use inconsistencies between Lambda-CDM model cosmological parameters to test gravitational theory at cosmological scales.
• Testing general relativity at cosmological scales: His contributions in this field have been so significant that he was invited to write a review article in 2018 on the current state of research in the field of testing general relativity in the journal Living Reviews in Relativity.
• The application of gravitational lensing to cosmology: Ishak-Boushaki and collaborators made a first detection of the large-scale intrinsic alignment of galaxies of type "intrinsic shear – gravitational shear" using a spectroscopic galaxy sample from the Sloan Digital Sky Survey. They also made a first detection of these intrinsic alignments using a self-calibration method in the photometric galaxy sample in Kilo-Degree Survey.
• Intrinsic alignment of galaxies: With his collaborators, he wrote a review article on the intrinsic alignment of galaxies and its impact on weak gravitational lensing.
• Large-scale structure of the Universe: His research contributes to our understanding of the formation and evolution of large-scale structures in the universe, a key element for testing cosmological models.

Mustapha Ishak-Boushaki is an active member and leader in the Legacy Survey of Space and Time - Dark Energy Science Collaboration (LSST-DESC) and the Dark Energy Spectroscopic Instrument (DESI) survey collaboration. These two international collaborations aim to revolutionize our understanding of the universe, gravity, and cosmic acceleration. He is co-lead of the DESI Working Group that led the cosmological analysis that provided the most remarkable results about Dark Energy and Cosmic Acceleration.

His scientific output is impressive, with over 100 publications with nearly 8,000 citations, testifying to the significant impact of his work on the scientific community. On April 4th, 2024, he delivered a memorable invited talk at the American Physical Society Meeting on behalf of the entire DESI collaboration to announce the famous result that Dark Energy is evolving in time, a discovery that echoed around the world.

Distinctions & Recognition

Mustapha Ishak-Boushaki's exceptional career has been recognized by numerous prestigious distinctions, both for his scientific contributions and for his excellence in teaching:

Scientific Distinctions:

• Elected Fellow of the American Physical Society (APS) in 2022, 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."
• Elected Fellow of the American Association for the Advancement of Science (AAAS) in 2021.
• Department of Energy Excellence Award for DESI (Dark Energy Spectroscopic Instrument) Collaboration in 2021.
• Granted Builder Status Recognition for the Legacy Survey of Space and Time (LSST) – Dark Energy Science Collaboration (DESC) in 2020 (26 recognized members over 1005 members in July 2020).
• Robert S. Hyer Research Award from the Texas Section of the American Physics Society in 2013.

Teaching Excellence Recognitions:

• Provost's Award for Faculty Excellence in Graduate Research Mentoring at the University of Texas at Dallas in 2023.
• University of Texas System Regents' Outstanding Teaching Award in 2022.
• President's Teaching Excellence Award at University of Texas at Dallas in 2021.
• Award for Outstanding Teacher of the Year from the School of Natural Sciences and Mathematics, University of Texas at Dallas in 2007 and 2018.
• Texas Statewide Piper Outstanding Teaching Award in 2025.

His publications have also received specific recognitions. In 2002, one of his publications was voted by the Editorial Board of Classical and Quantum Gravity as one of the journal's highlights of the year. In 2008, one of his publications was selected by Nobel Laureate Gerardus't Hooft to be on the Chief Editor List of the Foundation of Physics Journal. In 2013, his publication in Physical Review Letters was selected by the editors to be highlighted in the Spotlighting Exceptional Research in Physics website of the American Physical Society.

Impact & Influence

Mustapha Ishak-Boushaki's impact on the field of theoretical cosmology and astrophysics is considerable and multidimensional.

On the scientific level, his pioneering work on testing general relativity at cosmological scales has opened new perspectives for understanding the origin of cosmic acceleration, one of the greatest mysteries of modern physics. His proposal of methods to distinguish between dark energy and modifications to general relativity has helped structure an entire branch of research in observational and theoretical cosmology.

His 2018 review article on testing general relativity in cosmology, published in Living Reviews in Relativity, constitutes an essential reference for researchers in the field. With its 204 pages, this comprehensive document summarizes the current state of knowledge and guides future developments in this crucial area of research.

His contributions to the study of the intrinsic alignment of galaxies also have a significant impact on our ability to correctly interpret observations of weak gravitational lensing, an essential technique for mapping the distribution of matter in the universe and testing cosmological models.

As co-lead of the DESI Working Group that led the cosmological analysis, he played a central role in the recent discovery of the time evolution of dark energy, a result that could transform our understanding of the nature of this mysterious component that dominates the energy of the universe.

Beyond his direct scientific contributions, Mustapha Ishak-Boushaki also has a significant impact as an educator and mentor. The numerous awards he has received for excellence in teaching testify to his exceptional ability to transmit complex knowledge and inspire the next generation of physicists and astrophysicists. His dedication to mentoring research students contributes to training qualified scientists who will continue the exploration of cosmic mysteries.

As an invited speaker at numerous international events, including the 2019 Opening Plenary Talk of the International Conference of the 100th anniversary of the 1919 Solar Eclipse expedition and experiment that confirmed Einstein's Theory of General Relativity, he contributes to the dissemination of cosmological knowledge and the inspiration of a wider audience.

Finally, as a scientist of Algerian origin who has reached the highest levels of excellence in the field of theoretical physics in the United States, he represents an inspiring model for young researchers around the world, particularly those from developing countries. His journey illustrates how talent, determination, and dedication can lead to significant contributions to our understanding of the universe, regardless of geographical origins.

Learn More

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