Holography of Little Inflation

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.Comment: Expanded explanation of the way holography can be applied to FRW spacetimes; 19 pages, one figure; version to appear in Nuclear Physics

Field theories without a holographic dual

“…Thus, it is not clear that the inequality (1) must always hold in these cases. It will hold for small deviations away from the Einstein condition, but, as was shown in [25], not always under more extreme conditions; not, in particular, when the magnetic field is very strong.…”

“…Similarly, there has recently been intense interest in the extreme magnetic fields associated with the QGP produced in peripheral collisions [18][19][20][21] at heavy-ion facilities. The holographic treatment of this system, which will be our main focus in this work, requires a magnetic field in the bulk [22][23][24][25][26][27][28]. The bulk metric again ceases to be Einstein when the back-reaction from the magnetic field is taken into account.…”

“…In the usual way, the Lorentzian versions of the black hole parameters have "holographic" physical interpretations as quantities describing the dual field theory: its temperature T , baryonic chemical potential µ B , and its associated magnetic field B. The relations (see [25]) are…”

Inflationary universe in the presence of a minimal measurable length

“…We will also study the effect of GUP deformed thermodynamics on the inflationary cosmology It is possible to study the inflationary cosmology by using a potential to derive the properties of the inflationary cosmology. Thus, a specific form of the potential is chosen, and the model of the inflationary cosmology depends on the details of the potential chosen [31,32,33,34]. However, in addition to all of other possible ways of considering inflation [35,36], it is also possible to use the Hamilton-Jacobi formalism to model the inflationary universe [37,38,39,40,41].…”

Galileons, phantom fields, and the fate of the Universe

“…Thus, a number of the phantom models have been discussed in the literature [32][33][34][35][36][37][38][39][40][41][42][43][44][45], for instance, brane world and non-minimally coupled scalar field models can give phantom energy [46][47][48][49]. The simplest way to introduce the phantom effect is provided by a scalar field with a negative kinetic energy term which could be motivated from S-brane constructs in string theory [50][51][52][53][54][55][56][57][58]. The concept of the phantom field was first used in the steady state theory of Hoyle and subsequently incorporated in the Hoyle and Narlikar theory of gravitation [59][60][61].…”