# Reheating After Swampland Conjecture

## TL;DR

This paper discusses the constraints on inflationary models from observational data and quantum gravity, focusing on the reheating process and how string theory impacts the traditional reheating scenario.

## Contribution

It explores the implications of string theory on reheating after inflation, contrasting standard cold inflation with warm inflation models and their observational constraints.

## Key findings

- String theory forbids oscillation around the potential minimum during reheating.
- Warm inflation allows thermalization during expansion without a distinct reheating phase.
- Observational data constrains inflationary potentials and models.

## Abstract

The evolution of the universe started from a hot and dense Big Bang point. Temperature fluctuation map of cosmic microwave background (CMB) radiation and initial seeds of large scale structures (LSS) are explained by an inflationary period in a very early time. Inflaton as quanta of inflation field is responsible for the accelerated expansion of the universe. Potentials of the self-interacting single field models are constrained by observational data as well as quantum gravity. Some forms of the potential are rolled out by data of Planck satellite and some of them by quantum gravity constraints. In the standard model of inflation or cold inflation firstly universe expands where the inflaton rolls the nearly flat part of the potential and in the second part, the universe reheats where the inflaton oscillates around the minimum of the potential which leads to thermalized radiation dominated universe. String theory as the best model of quantum gravity forbids the oscillation around the minimum of the potential during the thermalized epoch of the reheating. But in the warm model of inflation thermalization happens during the expansion of the universe where the inflaton rolls nearly steep potential and the universe will be radiation dominated without any separated reheating epoch.