Seesaw mechanism explains light dark energy particles

Dark energy - a mysterious form of matter that is thought to be responsible for the rapid expansion of the universe - could be the result of eight interacting fields through ' seesaw ' mechanisms. This is confirmed by physicists in Finland and Denmark, who say schools will be represented by a single, very light particle. (Phys. Rev. Lett. 99 031301) .

The biggest rival for dark energy is the cosmological constant, which predicts that quantum fluctuations existing in a vacuum can create a constant energy density through space. But another dark energy competitor is a large-scale quintessence - a scalar field with negative pressure - that will overcome gravitational gravity.

Dark energy accounts for nearly half of the universe but physicists are still far from being able to reach consensus. Researchers from the University of Helsinki, Finland and Aarhus University, Denmark think it can be a product of the interaction between eight scalar fields in a kind of ' quintessence ' idea.

Dark energy (Photo: VLVN)

Unlike cosmological constants, quintessence will change over time, so explain why rapid expansion becomes significant in the past nearly 5 billion years ago. Unfortunately, the particle-like mass associated with the quintessence scalar field is 38 times smaller than the electron, and thus easily destroyed by vacuum variations.

However, Kari Enqvist from the University of Helsinki and colleagues from Aarhus University said they could solve this problem by borrowing an idea from particle physics, which explains why neutrinos in the Standard Model are Observation is extremely small but not zero. This idea is called seesaw mechanism, it is assumed that the left-handed neutrinos are observed - the neutrinos whose spins are parallel, opposite in direction to the moment - can have a small mass. if equations are ' balanced ' by right-handed neutrinos, much heavier.

But to explain quintessence with a seesaw mechanism, Enqvist and colleagues say, you will not only need two types of particles, but also eight different scalar fields. Each field will be associated with a large particle of 1 TeV or more, but will interact to form a single ' physical ' quintessence particle with very small mass. Importantly, this particle will be protected from vacuum variations because they will only affect all eight fields as a whole field.

Although 8 schools may cause something exaggerated, they will only have the right properties to explain the early bloat of the universe when exponential expansion. According to Martin Sloth - one of Aarhus University researchers - this means observations of cosmic microwave background futures - radiation begins in the era after bulging. - can form a new probability theory.

Josh Frieman, a pioneering physicist, highlighted the problem of mass of small particles, telling physicsworld.com: 'Explaining dark energy is a challenging issue . One obvious value is research. ideas like this' .

Talking about the possibility of 8-dimensional, he added: 'It may be a correct explanation, but one can hope that in the end nature is not too stingy.'

Damap