their surrounding structure in quantitative concordance with TTT predictions and previous observational results. We use a novel approach to study alignments with the large-scale structure using as a reference the galaxy/dark matter halo angular momentum. Using numerical simulations we study alignments predictions in a Cold Dark Matter model with a cosmological constant ($\Lambda$CDM), and compare such predictions with the results obtained from the Sloan Digital Sky Survey, Data Release 6 (SDSS-DR6, Adelman-McCarthy et al., 2007). To this end we use the galaxy two point correlation function applied both, in its three-dimensional definition to the full numerical simulation and in its projected version to mimic the observational limitations. The latter allows us to determine that we should be able to detect the expected low signal alignments, even in small galaxy samples. This allows us to measure the alignment of galaxies and halos over wide ranges in mass and separation, and also to quantify the dependence of this alignment on halo mass, galaxy colour and luminosity.

This paper is organised as follows. Section 2 presents the numerical simulation and the statistical tools we will use in this work; it also presents an analysis of the impact of the observational biases on the 