Exploring Bosonic Decays After Inflation

[Shahrokh]

Inflation , as proposed, leaves the universe cold and empty. The compensating theory of reheating or preheating then needed to operate after inflationary era. Such theories prefer three legs bosonic decays φ→χχ, which doesn't have any analogy with standard model processes as much as I know. How and on which foundation one could handle the properties of these decays, like decay rate, running of the coupling constant and so on. I just know that such interactions could appear in the Lagrangian by assuming g φ^2χ^2 term and spontaneous symmetry-breaking for the inflaton φ afterward. Of course, the Higg's decay into two photons or two W's have to be considered as close realistic counterparts, though they are gouge particles. I'll appreciate any comment as well as introducing linked references. Thanks.

 

[AndyW]

Thank you for bringing up this interesting topic. I would like to offer some insights on the compensating theory of reheating or preheating after the inflationary era.

Firstly, it is important to note that the inflationary era is a hypothetical period of rapid expansion of the universe in its early stages. While it is a widely accepted theory, it is still an area of ongoing research and there are still many unanswered questions about its mechanisms and consequences.

One of these consequences is the cold and empty state of the universe after inflation. This is where the compensating theory of reheating or preheating comes in. It suggests that after the inflationary era, the universe underwent a period of rapid heating and energy transfer, leading to the formation of particles and the eventual creation of the hot, dense universe we observe today.

One proposed mechanism for this reheating process is through the decay of the inflaton field, which is the field responsible for driving inflation. This is where the three legs bosonic decays φ→χχ come into play. These decays involve the inflaton field decaying into two other particles, χ and χ, which then go on to interact and create the particles that make up our universe.

However, as you mentioned, these decays do not have an analogy with standard model processes. This is because the inflaton field is a hypothetical field, and its interactions and properties are still not fully understood. Therefore, the properties of these decays, such as the decay rate and running of the coupling constant, are also not well understood and require further research.

To handle these properties, scientists often use theoretical models and simulations to study the behavior of the inflaton field and its interactions. These models are based on the assumption of a g φ^2χ^2 term in the Lagrangian and spontaneous symmetry-breaking for the inflaton field. By studying the behavior of these models, we can gain insights into the properties of the decays and make predictions that can be tested through experiments.

In terms of references, there are many articles and papers published on the topic of reheating and preheating after inflation. Some key references include "Reheating after Inflation" by David H. Lyth and Andrew R. Liddle, and "Preheating after Inflation" by Lev Kofman, Andrei Linde, and Alexei A. Starobinsky.

I hope this helps to answer