Dark energy: investigation and modeling

TL;DR

This paper reviews observational constraints and theoretical models of dark energy, discussing their viability based on current cosmological data and exploring various explanations for the universe's accelerated expansion.

Contribution

It provides a comprehensive overview of recent observational bounds and compares multiple theoretical approaches to explain dark energy's origin and nature.

Findings

Type Ia supernovae, CMB, and BAO data constrain dark energy models.

Some models are favored or ruled out by current observations.

The review highlights the most promising theoretical explanations.

Abstract

Constantly accumulating observational data continue to confirm that about 70% of the energy density today consists of dark energy responsible for the accelerated expansion of the Universe. We present recent observational bounds on dark energy constrained by the type Ia supernovae, cosmic microwave background, and baryon acoustic oscillations. We review a number of theoretical approaches that have been adopted so far to explain the origin of dark energy. This includes the cosmological constant, modified matter models (such as quintessence, k-essence, coupled dark energy, unified models of dark energy and dark matter), modified gravity models (such as f(R) gravity, scalar-tensor theories, braneworlds), and inhomogeneous models. We also discuss observational and experimental constraints on those models and clarify which models are favored or ruled out in current observations.