Cosmology is a research area in astrophysics that investigates the large-scale properties, origin, composition, and dynamical evolution of the Universe as a whole. It integrates general relativity, quantum field theory, and observational astronomy to construct and test models such as the ΛCDM paradigm, characterized by dark energy, cold dark matter, and baryonic matter. Cosmology addresses the expansion history, cosmic microwave background anisotropies, structure formation, and primordial nucleosynthesis, using data from galaxy surveys, gravitational lensing, supernovae, and cosmic background experiments to constrain fundamental parameters and probe physics at energy scales inaccessible to terrestrial laboratories.
One of the most stubborn issues in cosmology today concerns the universe's rate of expansion. Scientists know it's expanding, but defining the rate of that expansion is challenging. The rate of expansion is called the Hubble ...
Astronomy
Jan 19, 2026
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Scientists are a step closer to solving one of the universe's biggest mysteries as new research finds evidence that two of its least understood components may be interacting, offering a rare window into the darkest recesses ...
Astronomy
Jan 7, 2026
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An international team of astronomers led by Canadian researchers has found something the universe wasn't supposed to have: a galaxy cluster blazing with hot gas just 1.4 billion years after the Big Bang, far earlier and hotter ...
Astronomy
Jan 5, 2026
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The shape of the universe is not something we often think about. My colleagues and I have published a new study that suggests it could be asymmetric or lopsided, meaning not the same in every direction.
Astronomy
Dec 23, 2025
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Scientists search for "decaying" dark matter (DDM) because it offers unique signatures like specific X-ray or gamma-ray lines or neutrino signals not seen in normal matter, potentially revealing dark matter's particle nature, ...
Astronomy
Dec 17, 2025
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Galaxy clusters are the most massive objects in the universe held together by gravity, containing up to several thousand individual galaxies and huge reservoirs of superheated, X-ray-emitting gas. The mass of this hot gas ...
Astronomy
Dec 10, 2025
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There is an important and unresolved tension in cosmology regarding the rate at which the universe is expanding, and resolving this could reveal new physics. Astronomers constantly seek new ways to measure this expansion ...
Astronomy
Dec 5, 2025
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In the leading model of cosmology, most of the universe is invisible: a combined 95% is made of dark matter and dark energy. Exactly what these dark components are remains a mystery, but they have a tremendous impact on our ...
Astronomy
Dec 4, 2025
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A new theory for the origins of dark matter suggests that fast-moving, neutrino-like dark particles could have decoupled from Standard Model particles far earlier than previous theories had suggested.
Dark matter and its impact on cosmology have puzzled physicists for nearly a century. At Perimeter Institute, two researchers are trying to better understand how one potential dark matter candidate, self-interacting dark ...
Astronomy
Dec 1, 2025
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