One of the biggest mysteries in contemporary particle physics and cosmology is why dark energy, which is observed to dominate energy density of the universe, has a remarkably small (but not zero) value, researchers said.
This value is so small, it is perhaps 120 orders of magnitude less than would be expected based on fundamental physics, they said.
Now, physicists — Lawrence Krauss of Arizona State University and James Dent of the University of Louisiana-Lafayette - explore how a possible small coupling between the Higgs particle, and possible new particles likely to be associated with what is conventionally called the Grand Unified Scale could result in the existence of another background field in nature in addition to the Higgs field.
This would contribute an energy density to empty space of precisely the correct scale to correspond to the observed energy density, researchers said.
Current observations of the universe show it is expanding at an accelerated rate. But this acceleration cannot be accounted for on the basis of matter alone, they said.
Putting energy in empty space produces a repulsive gravitational force opposing the attractive force produced by matter, including the dark matter that is inferred to dominate the mass of essentially all galaxies, but which doesn't interact directly with light and, therefore, can only be estimated by its gravitational influence.