Happy to learn Maldacena’s thoughts on the relationship between vacuum fluctuations and spacetime stretching

Natalie Wolchover wrote another excellent article. This one is titled “Why Gravity Is Not Like the Other Forces“. She talked to 4 well-known physicists about gravity. This is what Juan Maldacena communicated to her.

“Furthermore, from the perspective of particle physics, the vacuum of space is a complex object. We can picture many entities called fields superimposed on top of one another and extending throughout space. The value of each field is constantly fluctuating at short distances. Out of these fluctuating fields and their interactions, the vacuum state emerges. Particles are disturbances in this vacuum state. We can picture them as small defects in the structure of the vacuum.”

“When we consider gravity, we find that the expansion of the universe appears to produce more of this vacuum stuff out of nothing. When space-time is created, it just happens to be in the state that corresponds to the vacuum without any defects. How the vacuum appears in precisely the right arrangement is one of the main questions we need to answer to obtain a consistent quantum description of black holes and cosmology. In both of these cases there is a kind of stretching of space-time that results in the creation of more of the vacuum substance.”

Compare Juan Maldacena’s thoughts to what I have been writing in various articles and most recently in this post titled “Recent discussions on dark energy“. I was very happy to see the similarity.

There is an action/reaction relationship between the external space and the internal space (quantum vacuum). In my view “dark energy” is a measure of the activity level in the internal space. Vacuum (internal space) activity develops as a reaction to the expansion of the external space. Vacuum fluctuations start as soon as the external space emerges. Particle fields and their quanta are created out of the vacuum fluctuations. 

If there is an action/reaction relationship between the external space and the internal space then we expect the activity level of the internal space to increase as the external space expands faster and faster. This means that the energy density of space will increase over time. This is a feedback loop that causes amplification of both the expansion and the level of quantum fluctuations in empty space. This is a fundamental instability.