Amr El-Zant, Director

Email: amr.elzant at

Research Interests

Amr El-Zant is an astrophysicist interested in the physics and dynamics of the formation and evolution of galaxies, their clusters , and the putative dark matter in which they are probably imbued. Much of his work has focused on the non-trivial dynamics arising from the coupling of clumpy or non-axisymmetric components (bars, triaxial halos etc); particularly the effect this produces on the evolution of both the luminous and dark galactic and cluster components; on the formation of central mass concentrations and super massive black holes in galaxies, and on the heating of the inter-galactic gas and prevention of cooling catastrophes in clusters.

Also of interest is the origin of the (nearly) universal density and phase space density profiles of gravitationally bound dark matter structures (the halos). This work includes controlled simulations of the formation process coupled with analysis of large scale structure simulations; Fokker-Planck analysis of the effect of substructure; and studying the stability of system trajectories and the nature of the relaxation process. It also involves methods that are of general interest in nonlinear dynamics, which can often prove powerful in describing the relaxation processes, both in the mean field limit and due to discreteness noise.

Selected Publications
  • A. A. El-Zant: Dark Halos and Elliptical Galaxies as Marginally Stable Dynamical Systems, Astrophys. Jour. 779, 64 (2013)
  • A. A. El-Zant: The Persistence of the Universal Halo Profiles, Astrophys. Jour. 681, 1058 (2008)
  • A. A. El-Zant, W.-T. Kim, M. Kamionkowski: “Dynamical-Friction Galaxy-Gas Coupling and Cluster Cooling Flows”, Mon. Not. Roy. Ast. Soc. 354, 169 (2004)
  • A. A. El-Zant, Y. Hoffman, J. Primack, F. Combes, I. Shlosman: “Flat-Cored Dark Matter in Cuspy Clusters of Galaxies”, Astrophys. Jour. 607, L75 (2004)
  • A. A. El-Zant: “Regular and Chaotic Motion in Softened Gravitational Systems”, Mon. Not. Roy. Ast. 331, 23 (2002)
  • A. A. El-Zant, I. Shlosman: “The Shapes of Dark Halos and the Fate of Stellar Bars”,Astrophys. Jour. {f 557}, 626 (2002).