Holography of Little Inflation

TL;DR

This paper uses holographic techniques to constrain the early Universe's quark-gluon plasma trajectory, suggesting it passed near the critical point, impacting the Little Inflation model and its phase transition characteristics.

Contribution

It introduces holographic bounds on the cosmic plasma's evolution, linking early Universe conditions to quark matter critical phenomena and refining the Little Inflation scenario.

Findings

Holography constrains the baryonic chemical potential during cosmic cooling.

The plasma likely passed near the quark matter critical point.

Implications for fluctuation phenomena in early Universe phase transitions.

Abstract

For several crucial microseconds of its early history, the Universe consisted of a Quark-Gluon Plasma. As it cooled during this era, it traced out a trajectory in the quark matter phase diagram. The form taken by this trajectory is not known with certainty, but is of great importance: it determines, for example, whether the cosmic plasma passed through a first-order phase change during the transition to the hadron era, as has recently been suggested by advocates of the "Little Inflation" model. Just before this transition, the plasma was strongly coupled and therefore can be studied by holographic techniques. We show that holography imposes a strong constraint (taking the form of a bound on the baryonic chemical potential relative to the temperature) on the domain through which the cosmic plasma could pass as it cooled, with important consequences for Little Inflation. In fact, we find that holography applied to Little Inflation implies that the cosmic plasma must have passed quite close to the quark matter critical point, and might therefore have been affected by the associated fluctuation phenomena.