A holographic dark energy model for the expansion of the universe

September 27 () –

Theoretical physicists have demonstrated the viability of a holographic model of dark energy alternative to standard cosmology.

In 1998, scientists discovered that our universe is expanding with acceleration, and to explain this effect, the concept of dark matter was introduced. It is a special type of energy that fills all existing space-time, but It is impossible to detect by direct methods.

Its existence and characteristics are described in a standard cosmological model, but scientists have encountered a number of problems (for example, the cosmological constant problem and the fine-tuning problem) that cannot be adequately addressed with this representation.

Scientists from the Kant Baltic Federal University (BFU) have considered an alternative model that they present in an article in the journal Physics Letters B.

“This is a slightly different way of looking at the nature of the accelerated expansion of the universe. It is derived from the holographic principle that follows from quantum gravity and string theory. According to this, all values ​​within a certain amount of volume They can be described by parameters that are observed at their limit.

“In other words, the universe can be represented in the form of some hologram and can be described by the parameters of its boundaries“says Alexander Tepliakov, associate researcher at the BFU Laboratory for Mathematical Modeling of Complex and Nonlinear Systems.

In 2004, a new model of holographic dark energy was proposed within the holographic principle. However, the new model had a limitation. Dark energy is usually represented as a kind of liquid that fills the universe homogeneously and uniformly. To analyze the fluctuations inside this liquid, a special parameter called “square of the speed of sound.”

If it turns out to be negative as a result of the calculations, the model is considered unstable. Previous studies carried out within the framework of a holographic model of dark energy showed a negative square of the speed of sound.

The research team suggests that holographic dark energy should not be considered a liquid, but rather should be considered as perturbations of dark energy, taking into account its metric properties. They concluded that the model is, in fact, stable.

“Now, we need to understand to what extent our model corresponds to the observational data provided by space telescopes. In 2024, precise data will be available for analysis: the relationship between the redshift of type Ia supernovae and the oscillations baryon acoustics. By comparing the proposed cosmological model with these data, we can evaluate whether it describes the real universe.“says Tepliakov.