# Probing the spacetime evolution of heavy ion collisions with photons and dileptons

## TL;DR

This paper reviews how photons and dileptons emitted during heavy ion collisions reveal information about the medium's evolution across different phases, complementing other measurements and enhancing understanding of the quark-gluon plasma.

## Contribution

It synthesizes recent developments in electromagnetic emission modeling throughout the collision timeline within a hydrodynamic framework.

## Key findings

- Electromagnetic probes provide insights into early, crossover, and late stages of the medium.
- Recent advances improve understanding of photon and dilepton emission mechanisms.
- Hydrodynamic models help interpret electromagnetic signals in heavy ion collisions.

## Abstract

Photons and dileptons are emitted throughout the evolution of the deconfined nuclear medium produced in heavy ion collisions. As such they can provide valuable information about the different phases of the medium, and complement hadronic measurements and other observables. In this work, recent developments related to electromagnetic emissions at early time, in the cross-over region, and at late times are reviewed. The spacetime description of the nuclear medium from a hydrodynamic model of heavy ion collisions is used to provide context and guide the discussion.