It is perhaps the biggest mystery of all: What is causing the universe to come unraveled?
A paper, co-authored by Dr. James Dent, an associate professor of physics at the University of ÃÞ»¨ÌÇÖ±²¥ at Lafayette, offers a possible explanation. Dent and Dr. Lawrence Krauss, a well-known theoretical physicist and cosmologist, published their paper, "Higgs Seesaw Mechanism as a Source for Dark Energy," online in Physical Review Letters in early August.
The universe, which may have begun with a big bang, could ultimately fade to black.
For decades, scientists acknowledged that the universe was expanding. But theoretical physics took a new twist in the 1990s, when astronomers discovered that this expansion wasn't happening steadily. Instead, it is accelerating.
Gravity, the force that attracts matter to matter, is being overwhelmed on the cosmic scale by something else, a kind of antigravity that cosmologists have labeled "dark energy."
Dark energy makes up about 70 percent of the universe's "energy budget," explained Dent. Only 5 percent of the universe is made up of visible matter. Dark matter — matter that does not interact with light — makes up the rest.
"What we don't know is, how is this dark energy generated?" said Dent.
Physicists are also puzzled as to why dark energy, which makes up so much of the universe, has such a small value. According to current models, the numbers don’t add up. The observed value of dark energy is 120 orders of magnitude smaller than scientists' calculations suggest.
Krauss and Dent suggest that the Higgs boson might play a role in creating dark energy. It's named after Peter Higgs, one of six physicists who postulated the existence of the elementary particle in 1964. As of March, scientists are almost certain that the Higgs boson has been found. A particle matching its description was observed in the Large Hadron Collider at the CERN laboratory, near Geneva, Switzerland.
"We understand gravity as a field, electromagnetics as a field," Dent said. The Higgs boson arises from the Higgs field, which is believed to give particles mass.
In their paper, the two physicists have devised a new field, in which interactions between the Higgs boson and possible new particles could generate the correct scale to account for dark energy.
The good news: their numbers do add up. This interaction, or mixing of the fields, produces energy of just the right magnitude. A seesaw metaphor describes how the fields relate to one another: if the value of one field goes up, the value of the other goes down.
"We don't know if this model is the right one to account for dark energy," said Dent. "But we may have given physicists another tool to unlock the mystery."