Xin Zhang

Scientists have long debated: is dark energy constant or does it change? Fresh measurements point to a third path — it is conversing with dark matter. This turns a lone cosmic force into a duet of invisible interlocutors.

The Hubble constant — the expansion rate of the universe — has become a bone of contention: data from the cosmic microwave background and the distance ladder diverge by 6 sigma. Astrophysicists have proposed a new arbitration by cross-breeding 142 gravitational-wave events from the GWTC-4 catalog wi

Astronomers added a short-lived dark energy to the standard model, which appeared right after the Big Bang. This idea reconciled two methods of measuring cosmic expansion that previously gave different speeds—like two different thermometers. This approach strengthens the model without a major overha