CASSA scientist authors reveal dark energy study at IUB

City Desk :

A new study by Anowar Jaman Shajib, Associate Member of the Center for Astronomy, Space Science and Astrophysics (CASSA) at Independent University Bangladesh (IUB), challenges the longheld belief that dark energy is constant. Published in Physical Review D on September 8, 2025, the paper suggests that dark energy, the mysterious force driving the universe’s accelerated expansion may change over time.

Shajib, also an Einstein Fellow at the University of Chicago, coauthored the paper with Prof. Joshua A. Frieman. Their research indicates that dark energy has possibly decreased by around 10% in recent cosmic history, contradicting the established cosmological constant theory proposed by Einstein. This finding is based on data from major cosmic surveys, including the Dark Energy Survey and the Sloan Digital Sky Survey.

The study outlines different scenarios for the universe’s fate depending on the behavior of dark energy. If dark energy weakens, the universe may gradually cool and fade into a “Big Freeze.” If it strengthens, it could lead to a catastrophic “Big Rip.” Alternatively, if expansion stops, gravity could cause a “Big Crunch,” collapsing the universe. The new model favors a slow evolution of dark energy, suggesting ongoing expansion leading to eventual cosmic death by freezing.

Shajib explained that their model uses the concept of an ultralight particle called the axion, and their results reject the constant dark energy model with 99.6% confidence. He expressed optimism that this research brings cosmologists closer to answering one of the field’s most fundamental questions.

Dr. Khan Muhammad Bin Asad, Assistant Professor and founding director of CASSA, highlighted the centre’s role in promoting astronomy research in Bangladesh and connecting local scientists with the global scientific community. Established in 2024 at IUB, CASSA is currently working on Bangladesh’s first radio telescope project.

Earlier, in December 2024, CASSA Associate Member Dr. Lamiya Mowla made notable contributions to our understanding of galaxy formation using data from NASA’s James Webb Space Telescope, published in the journal Nature.