Sidebars

Dark matter distribution in the galaxy cluster CL0152-1357 detected by gravitational weak-lensing from the Hubble Advanced Camera for Surveys (ACS) observations. The intensity of the purplish color is proportional to the density of dark matter.

The Cosmological Cousins of the Higgs

The discovery of the Higgs particle would open a new chapter in particle physics, because it would be the first of new breed of particle. Every elementary particle discovered so far spins like an eternal top. The Higgs particle would be the first elementary particle without spin.

Moreover, theorists predict that other Higgslike particles without spin as essential elements of cosmology. The Higgs particle will be the first step toward understanding such spinless particles and how they might give the universe the shape it has today.

Why is the universe so big? Theory suggests that the universe underwent a cosmic inflation from its microscopic beginnings to its current vast size. To power inflation, physicists postulate one or more Higgs-like particles called inflatons.

Why is the universe speeding up? Cosmological observations confirm that the expansion of the universe is accelerating. Dark energy, which makes up a staggering 70 percent of the universe today, is thought to be responsible for cosmic acceleration. Because dark energy is very similar to cosmic inflation, many physicists believe that dark energy may also involve Higgs-like particles.

Why are there particles that don’t spin? One possible explanation is supersymmetry, which says that particles that do spin have partners that don’t. Or, if there are extra spatial dimensions, particles spinning in the extra dimensions may appear not to spin in our dimensions. Once physicists discover the Higgs, they plan to find out why and how the Higgs exists and thus gain insights into the mechanisms for inflation and dark energy.