# Holographic Principle, Cosmological Constant and Cyclic Cosmology

## TL;DR

This paper explores how the holographic principle informs our understanding of dark energy, the cosmological constant, and cyclic cosmology, proposing models that incorporate holographic dark energy and revisiting the phantom energy scenario.

## Contribution

It introduces a holographic perspective on dark energy and cyclic cosmology, linking UV/IR cutoffs to quantum gravity and discussing the equation of state for dark energy.

## Key findings

- Holographic dark energy relates UV and IR cutoffs in quantum gravity.
- The phantom energy scenario ($\,\omega < -1$) is supported within cyclic models.
- Cyclic cosmology can incorporate a cosmological constant with $\,\omega = -1$.

## Abstract

The holographic principle provides a deep insight into quantum gravity and resolves the fine-tuning crisis concerning the cosmological constant. Holographic dark energy introduces new ultra-violet (UV) and infra-red (IR) cutoffs into quantum gravity which are necessarily strongly related. The equation of state for dark energy $\omega = p/\rho$ is discussed from the holographic point of view. The phantom option of $\omega < -1$ is resurrected, as in an earlier cyclic cosmology. Such a cyclic model can, however, equally use the cosmological constant with $\omega = -1$.