Resumen de Dark energy flipped upside down
The universe's relentless march towards cold, empty darkness could be causing its expansion to accelerate, rather than the other way around. The finding could help cosmologists think differently about dark energy, and possibly explain why it has the value it does. In the late 1990s, astronomers observed that the universe's expansion is accelerating. They attributed this to dark energy--an inherent property of the vacuum of space-time. One idea is that dark energy is really the cosmological constant, a quantity arising in Einstein's general relativity. But when calculating its theoretical value, the answer is about 120 orders of magnitude larger than the observed one. The mismatch has vexed cosmologists for decades. Here, Ananthaswamy examines why the cosmological constant has the value it does.
