# Dark energy, gravitation and supernovae

## TL;DR

This paper reviews how supernova observations challenge and inform theories of gravity and dark energy, exploring whether modifications to general relativity or new cosmic components explain the universe's accelerated expansion.

## Contribution

It provides a comprehensive overview of theoretical models tested against supernova data, highlighting potential alternatives to standard cosmology.

## Key findings

- Supernovae support the universe's accelerated expansion.
- Modified gravity theories are viable alternatives to dark energy.
- Observational data constrain different cosmological models.

## Abstract

The discovery of the acceleration of the rate of expansion of the Universe fosters new explorations of the behavior of gravitation theories in the cosmological context. Either the GR framework is valid but a cosmic component with a negative equation of state is dominating the energy--matter contents or the Universe is better described at large by a theory that departs from GR. In this review we address theoretical alternatives that have been explored through supernovae.