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Institute for Theory and Computation

The mission of the ITC is to advance our knowledge and understanding of the universe through computational and analytical means, to create a forum for exploration and discoveries in theoretical astrophysics, and to train the next generation of astrophysicists.



The ITC uses cutting edge computation and theory to address a wide variety of problems in theoretical astrophysics, including state-of-the-art simulations of galaxy formation in the Universe (led by Lars Hernquist), large scale structure in the universe (led by Daniel Eisenstein), accretion of gas onto black holes (led by Ramesh Narayan), the first stars & black holes and the search for life (led by Avi Loeb), and planet formation (led by Karin Oberg). The computer system is also used to analyze extensive data sets, such as those involving the cosmic microwave background (led by John Kovac), gamma-ray data (led by Doug Finkbeiner) or transients (led by Chris Stubbs). Postdoctoral and Graduate student members of the ITC are actively pursuing an even broader range of topics.

Director's Note

Since its founding in 2004, the Institute for Theory and Computation (ITC) at Harvard University has served as a center of excellence with a primary objective of integrating conceptual theory with computational modeling. It has become the largest center for theoretical astrophysics in North America with over 90 affiliated scientists, including 22 faculty members, 20-30 postdoctoral fellows and about 40 graduate students each year. Over 225 scientists from other institutions visited the ITC in every year to give talks and collaborate with its members.

The ITC fosters interaction between observers and theorists, and its members have provided theoretical foundations for observational projects, including 21-cm cosmology, which led to Harvard's participation in the MWA project; the predicted silhouette structure of black holes, which guided mm-VLBI imaging of SgrA* and M87; the predicted properties of the first stars and galaxies, which provided important motivation for JWST and the GMT; and the modeling of the emission spectrum of accretion disks, which enabled a new census of black hole spins in the local Universe.

The ITC Postdoctoral Fellowship has become one of the most selective fellowships in astrophysics; about 170  candidates apply each year. ITC Fellows have gone on to win faculty positions and Hubble, Einstein, Sagan, NSF, Harvard Society of Fellows, and other prize fellowships at institutions across North America and Europe.

Computational resources at the ITC include its cluster, consisting of 24 nodes each with two water cooled Intel 24-core Platinum 8268 Cascade Lake processors with 4 GB of RAM per core, for a total of 192 GB of RAM per node. This gives a total of 1152 cores available for use and 4.6 TB of RAM. The nodes are interconnected with HDR Infiniband and is part of the larger Cannon Infiniband network.

The ITC organizes multiple weekly talk series, including the ITC Luncheon attended by over 100 scientists, the ITC Colloquium, the ITC Pizza Lunch series in Spring, and various seminars. It also organizes the biennial Sackler Conferences in Theoretical Astrophysics, whose past topics have covered First Generation of Cosmic Structures, Gamma-Ray Bursts, Astrophysics of Planetary Systems, History of Nuclear Black Holes in Galaxies, 21cm Cosmology, Dynamics from the Galactic Center to the Milky Way Halo, the Transient Sky, the Nature of Dark Matter, Gravitational Wave Astrophysics, and Testing General Relativity with Astrophysical Systems.

- Avi Loeb, Director, Institute of Theory and Computation