Semi-analytic Modelling of Galaxy Formation
The semi-analytic modelling approach combines dark matter halo merger trees from N-body or Monte-Carlo simulations with analytic models for baryonic processes that lead to the formation of galaxies within dark halos. We use SIMURGH a highly modular and adaptable SAM code.  
  1.  The High Redshift Universe
We are interested in questions related to the star formation and mass assembly of galaxies at early times in the hierarchical universe. Cold accretion flows dominate the formation of massive galaxies at high redshifts and have significant impact on their dynamical state. Such accretion flows can provide the necessary energy to drive turbulence in z=2 galaxies and the fuel needed to sustain high star formation rates. We try to understand how this mode of galaxy formation is regulated and reflected in the general properties of the galaxy population.  
Khochfar et al. 2007
  1.  Properties of Early-type galaxies
We use SIMURGH to model in detail the properties of early-type galaxies. Based on the merging history of an early-type galaxy it is possible to predict its properties in terms of e.g. sizes, isophotal shapes or mean stellar ages, just to name a few. Of particular importance are so-called dry mergers, mergers between galaxies with not much involvement of gas. In a series of papers we could show that this is the dominant growth mechanism for massive early-type galaxies. Furthermore, we try to model the properties of fast and slow rotating early-type galaxies as observed with integral field spectroscopy in the ATLAS3D survey.      
Khochfar & Silk 2006
Evolution of the faint-end slope of the galaxy luminosity function with cosmic time
Size-evolution of early-type galaxies