1 INTRODUCTION

2 SEMI-ANALYTIC MODELLING AND MOCK CATALOGUES

2.1 Cosmological N-body simulation

2.2 Baryonic prescriptions

2.3 Model calibration and comparison to data

2.4 Emission and radiative transfer of the Ly α line

2.5 Mass resolution of the simulation

2.6 Mock catalogues

3 REVIEW OF THE LITERATURE

4 MODEL PREDICTIONS

4.1 Predicted number counts for typical MUSE surveys

4.2 Number count uncertainties

4.3 Ly α luminosity and Star Formation Rate densities

5 THE ROLE OF LAES IN THE HIERARCHICAL CONTEXT

5.1 The host halos of LAEs at high-redshift

5.2 The descendants of the LAE host halos

5.3 The high-redshift progenitors of $z=0$ halos

5.4 The high-redshift progenitors of MW-like halos

6 DISCUSSION

7 SUMMARY AND CONCLUSIONS