Browse Physics

Detectors buried beneath the Antarctic ice place stringent limits on the presence of dark matter particles, called neutralinos, in the sun.

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.

Two antimatter measurements performed by the PAMELA experiment appear to lead to conflicting results. Now, theorists are exploring the extent to which these measurements can be reconciled.

Interactions between dark matter particles may explain unusual matter-antimatter production rates in the universe.

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.

Mounting evidence seems to rule out weakly interacting massive particles (WIMPs ) as the source of a so-far unexplained signal in the DAMA/LIBRA experiments.

At the current time, we cannot tell if Einstein’s cosmological constant—or some other theory—is the correct description for dark energy in the Universe. A proposed measure based on existing data may help us to better distinguish these ideas.

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.

The cosmic microwave background that fills the Universe provides a test for asymmetries in the laws of physics.

Researchers used a superconducting structure to measure the properties of a rapid phase transition, as may have happened just after the big bang.

The puzzling origins of some isotopes in the solar system are explained by accounting for blasts of antineutrinos in the first seconds of a supernova.

A 1948 paper used general relativity to provide the first quantitative description of the first moments after the big bang.

New astronomical observations contradict the claim that fundamental constants were different in the early universe.

Computer simulations support the controversial theory that the magnetic fields enveloping galaxies are as old as the Universe.

Any object in motion feels a bit of friction as it moves through the sea of radiation that is constantly emitted by its surroundings.

Dark matter arising from extra spatial dimensions could be detected with existing or future experiments.

The 2002 Nobel Prize in Physics went to three experimentalists who opened the window on cosmic neutrinos and x rays.

The mysterious magnetic fields that seem to permeate the cosmos may come from simple physics.

Treating the Universe as a hologram might solve one of the biggest problems bedeviling modern physics.