cosmology

No definitive evidence for cosmic inflation is found, but support remains strong for the theory even as critics highlight its shortcomings as an explanation for how and why the universe began.

Early in cosmic history, our universe may have bumped into another — a primordial clash that could have left traces in the Big Bang’s afterglow.

Testing the multiverse hypothesis requires measuring whether our universe is statistically typical among the infinite variety of universes. But infinity does a number on statistics.

For five years physicists have been tantalized by possible evidence of dark matter in the Milky Way’s center. But new results from small satellite galaxies have complicated the story.

Cosmic dust in the high latitudes of the Milky Way could account for the entire swirl pattern that had been presented as proof of a leading Big Bang theory, according to a new data analysis from the Planck satellite.

The astrophysicist Joshua Frieman seeks to pinpoint the mysterious substance driving the accelerating expansion of the universe.

Katherine Freese, a physicist who will soon lead the Nordic Institute for Theoretical Physics, reflects on the hunt for dark matter and how dark matter heating may have produced the first stars.

The cosmologist David Spergel explains why a widely publicized gravitational-wave discovery could be wrong, and how the “overreaching” study could affect the public’s perception of science.

Chao-Lin Kuo, who helped design the experiment that claimed to have found evidence of gravitational waves from the Big Bang, isn’t bothered by criticism that cosmic dust may account for his results.