He has continued working on this subject, mainly along the lines of galaxy-absorber identification and study of large-scale structure using QSO absorbers. He has established collaborations with Ken Lanzetta, John Webb, Hsiao-Wen Chen, Jochen Liske, and Amelia Ortiz-Gil, amongst others.

Another path to the study of the high-redshift Universe is through the analysis of very deep images. Alberto has applied photometric redshift techniques to the Hubble Deep Field images, and obtained catalogues of photometry and redshifts that have been widely used for the analysis of the distant Universe. Collaborators in this field include Ken Lanzetta, Hsiao-Wen Chen, and Simon Driver. Similar techniques have also been applied to the selection of distant Gamma Ray Burst afterglows, in collaboration with the Italian Mistici collaboration.

Presently Alberto works at IFCA on applications of photometric redshift techniques to deep imaging surveys. He is involved in two major survey projects: ALHAMBRA and PAU, as well as in the scientific design and exploitation of the OSIRIS camera on GTC, and a possible spectrograph for the E-ELT, the OPTIMOS/EVE design.