Browse Physics

The first results from the space-borne Alpha Magnetic Spectrometer confirm an unexplained excess of high-energy positrons in Earth-bound cosmic rays.

A new cosmological theory tackles the description of the earliest era of the Universe, a period inaccessible by current models.

Observations of the way light scatters from large astrophysical bodies provides independent confirmation of the standard model of cosmology.

Gravitational lensing distorts maps of the cosmic microwave background, providing yet another way of probing the matter and energy content of the universe.

On the largest distance scales, the distribution of galaxies appears to be clumpier than the standard cosmological model predicts.

A modification of the theory of gravity can explain the dynamics of gas-rich galaxies without the need for dark matter.

A set of proposed relations among observable quantities may allow strong tests of whether a rapid expansion of the very early universe produced the seeds of the large-scale structure we see today.

Results from the first three weeks of running the XENON100 experiment show its promise as a sensitive detector of particle dark matter in the form of WIMPs.

Defects—in the form of vortices in superconductors or “strings” in the fabric of the universe—can reveal the state of a system at the time it was cooled.

New results from the Fermi Gamma-Ray Space Telescope, the most precise to date in the energy range $20\text{GeV}$ to $1\text{TeV}$, should help resolve whether cosmic rays composed of the lightest charged particles, i.e., electrons and positrons, come from dark matter or some other astrophysical source.

Many cosmologists believe that antiprotons in cosmic rays come from the annihilation of dark matter. Data from the PAMELA experiment on board a Russian satellite provide an important test of this possibility.

New upper limits on the spin-independent interaction of WIMPs and nucleons marks the latest volley in the worldwide effort to detect and identify particle dark matter.

The universe we see today is the result of mass-energy fluctuations during the rapid inflationary expansion that followed the big bang. A new approach to analyzing those fluctuations brings theory into better alignment with observational data.