 Dekel was awarded a Visiting Miller Professorship at UC Berkeley, a Blaise Pascal International Chair of Research by the École Normale Supérieure in Paris (2004–06), and a Lagrange fellowship in IAP Paris (2015–16).Dekel is known for his contributions to research in cosmology, especially the study of the formation of galaxies and large-scale structure in the Universe, which is dominated by dark energy and dark matter.His expertise is dwarf galaxies and supernova feedback (1986, 2003), large-scale cosmic flows and early estimates of fundamental cosmological parameters (1989-2001),

the structure of dark-matter galactic halos (2000–2003), and the theory of galaxy formation (2003–2012).