Cosmology beyond the Scalar Field model

Scalar fields are widely used in analyzing the cosmological phenomena such as inflation or dark energy. Despite its simplicity the use of scalar fields runs into various theoretical and phenomenological problems. I will demonstrate that going beyond the scalar field paradigm  opens a new direction of model building in cosmology. We consider the thermodynamical behavior of Banks-Zaks theory close to the conformal point in cosmological setting. Due to the anomalous dimension, the energy density and pressure of theory deviate from that of radiation and results various interesting cosmological solutions. The cosmological solutions from unparticles are the result of a collective emergent phenomenon not due modification of gravity or use of scalars. I will address the issue of initial singularity, fine-tuning of cosmological constant and cosmic coincidence problem. Finally, i will also discuss the resolution of cosmic tensions using the unparticles dark energy.

The talk will be based on these works

1.  https://arxiv.org/abs/1912.10532

2. https://arxiv.org/abs/2010.02998

3. https://arxiv.org/abs/2111.09946

4. https://arxiv.org/abs/2302.00067