Over the years our group has included about 50 graduate students and postdoctoral researchers. They are now at universities, observatories, research labs, and companies around the world. For each person, a notable paper from their time in the group is listed; for those in academia, a recent paper illustrates what they are working on now.
In academia
- Newlin Weatherford (PhD 2024)
CTAC Postdoctoral Fellow, Carnegie ObservatoriesNotable paper: “A Dynamical Survey of Stellar-mass Black Holes in 50 Milky Way Globular Clusters” (2020, ApJ, 898, 162) [84 citations]Recent paper: “Kinematics of Stellar Streams from Globular Clusters Depend on Black Hole Retention and Star Mass: A Selection Effect for Dark Matter Inference” (2026, ApJ, 997, 90) — Shows that the black holes a globular cluster kept or ejected change the motions of stars in the streams it leaves behind, which matters for using those streams to weigh dark matter. - Rachel Zhang (MS 2024)
Gates Cambridge Scholar, University of Cambridge, UKNotable paper: “On the Likely Dynamical Origin of GW191109 and Binary Black Hole Mergers with Negative Effective Spin” (2023, ApJ, 954, 23) [25 citations]Recent paper: “Predicting Stellar Parameters of Massive Stars from Light Curves with Machine Learning” (2025, ApJ, 995, 136) — Uses machine learning on stellar light curves to predict the parameters of massive stars. - Claire Shi Ye (PhD 2022)
Postdoctoral Fellow, CITA, University of Toronto, CanadaNotable paper: “On the Rate of Neutron Star Binary Mergers from Globular Clusters” (2020, ApJL, 888, L10) [167 citations]Recent paper: “Mass Distribution of Binary Black Hole Mergers from Young and Old Dense Star Clusters” (2026, ApJ, 997, 267) — Compares how the masses of merging black-hole pairs differ depending on whether they formed in young or old dense star clusters. - Mario Spera (Marie Curie Fellow, 2018–2020)
Associate Professor, SISSA, Trieste, ItalyNotable paper: “Populating the Upper Black Hole Mass Gap through Stellar Collisions in Young Star Clusters” (2020, ApJ, 903, 45) [161 citations]Recent paper: “Assembling GW231123 in Star Clusters through the Combination of Stellar Binary Evolution and Hierarchical Mergers” (2025, ApJL, 994, L54) — Explains how the record-breaking gravitational-wave event GW231123 could have been assembled through repeated black-hole mergers inside a dense star cluster. - Kyle Kremer (PhD 2019)
Assistant Professor of Astronomy & Astrophysics, UC San DiegoNotable paper: “Modeling Dense Star Clusters in the Milky Way and Beyond with the CMC Cluster Catalog” (2020, ApJS, 247, 48) [240 citations]Recent paper: “The Diverse Outcomes of Binary White Dwarf Mergers and Connections to Galactic LISA Sources” (2026, ApJ, 1007, 171) — Simulates what happens when two white dwarf stars merge and identifies which outcomes could be detected as gravitational-wave sources by the future LISA observatory. - Sourav Chatterjee (PhD 2010; CIERA Postdoctoral Fellow and Research Assistant Professor, 2014–2018)
Reader, Tata Institute of Fundamental Research, Mumbai, IndiaNotable paper: “Dynamical Outcomes of Planet-Planet Scattering” (2008, ApJ, 686, 580) [855 citations]Recent paper: “The Role of High-mass Stellar Binaries in the Formation of High-mass Black Holes in Dense Star Clusters” (2025, ApJ, 986, 82) — Shows that massive stellar binaries in crowded star clusters are key to growing unusually heavy black holes. - Fabio Antonini (CIERA Postdoctoral Fellow, 2014–2017)
Senior Lecturer, Gravity Exploration Institute, Cardiff University, UKNotable paper: “Merging Black Hole Binaries in Galactic Nuclei: Implications for Advanced-LIGO Detections” (2016, ApJ, 831, 187) [441 citations]Recent paper: “Gravitational-wave constraints on the pair-instability mass gap and nuclear burning in massive stars” (2026, NatAs, 10, 1049) — Uses gravitational-wave observations to pin down the “mass gap” where massive stars blow themselves apart instead of leaving black holes behind. - Carl Rodriguez (PhD 2016)
Associate Professor of Physics & Astronomy, UNC Chapel HillNotable paper: “Binary black hole mergers from globular clusters: Masses, merger rates, and the impact of stellar evolution” (2016, PRD, 93, 084029) [599 citations]Recent paper: “Twin Peaks: Resolving Features in the Binary Black Hole Mass Function with COSMIC-METISSE” (2026, arXiv) — Uses updated stellar-evolution models to explain why the observed masses of merging black holes cluster around two distinct peaks. - Jason Steffen (CIERA Postdoctoral Fellow and Research Assistant Professor, 2012–2015)
Professor of Physics, University of Nevada, Las VegasNotable paper: “Survival of non-coplanar, closely packed planetary systems after a close encounter” (2018, MNRAS, 481, 2205) [38 citations]Recent paper: “Effect of Galactic Chemical Evolution on Exoplanet Properties” (2025, ApJL, 991, L33) — Models how the Galaxy’s changing chemical makeup over billions of years shapes the planets that form — the earliest planets end up with larger rocky mantles. - Will Farr (CIERA Postdoctoral Fellow, 2011–2013)
Associate Professor, Stony Brook University; group leader, Flatiron Center for Computational AstrophysicsNotable paper: “Secular dynamics in hierarchical three-body systems” (2013, MNRAS, 431, 2155) [420 citations]Recent paper: “Not Just Winds: Why Models Find That Binary Black Hole Formation Is Metallicity-dependent, while Binary Neutron Star Formation Is Not” (2025, ApJ, 979, 209) — Investigates why computer models predict that forming binary black holes depends on the stars’ chemical composition while forming binary neutron stars does not. - Smadar Naoz (IAU Gruber Fellow, 2010–2011)
Professor of Physics & Astronomy and Howard & Astrid Preston Chair in Astrophysics, UCLANotable paper: “Hot Jupiters from secular planet-planet interactions” (2011, Nature, 473, 187) [493 citations]Recent paper: “Triples as Links between Binary Black Hole Mergers, Their Electromagnetic Counterparts, and Galactic Black Holes” (2025, ApJL, 992, L12) — Argues that triple-star systems are the missing link connecting gravitational-wave mergers, the light they may emit, and black holes at the centers of galaxies. - Soko Matsumura (Postdoctoral Fellow, 2006–2009)
Senior Lecturer, University of Dundee, UKRecent paper: “Can the giant planets of the Solar System form via pebble accretion in a smooth protoplanetary disc?” (2024, A&A, 683, A204) — Tests whether the Solar System’s giant planets could have grown by sweeping up small pebbles in a smooth planet-forming disk. - Craig Heinke (Lindheimer Postdoctoral Fellow, 2004–2007)
Professor of Physics, University of Alberta, Edmonton, CanadaNotable paper: “Formation and evolution of compact binaries in globular clusters. I. Binaries with white dwarfs” (2006, MNRAS, 372, 1043) [152 citations]Recent paper: “Catalog of Outbursts of Neutron Star Low-mass X-Ray Binaries” (2025, ApJS, 279, 57) — Compiles a comprehensive catalog of every observed outburst from neutron-star X-ray binaries to understand how these systems flare up over time. - Atakan Gürkan (PhD 2005)
Assistant Professor of Physics, Middle East Technical University (METU), Ankara, TurkeyNotable paper: “Formation of Massive Black Holes in Dense Star Clusters. I. Mass Segregation and Core Collapse” (2004, ApJ, 604, 632) [390 citations]Recent paper: “Irregular longitudinal data analysis with statistical and machine learning methods for hazardous asteroids” (2024, A&C, 47, 100818) — Applies statistical and machine-learning methods to the irregular observational data of hazardous asteroids. - Krzysztof Belczynski (Lindheimer Postdoctoral Fellow, 2002–2005)
Professor, Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Warsaw, Poland (2017–2024)Notable paper: “Compact Object Modeling with the StarTrack Population Synthesis Code” (2008, ApJS, 174, 223) [764 citations] - Natalia Ivanova (Postdoctoral Associate, 2002–2005)
Professor of Physics, University of Alberta, Edmonton, CanadaNotable paper: “Formation and evolution of compact binaries in globular clusters - II. Binaries with neutron stars” (2008, MNRAS, 386, 553) [291 citations]Recent paper: “NATA: A Chemical-picture Equation of State for Stellar Merger Hydrodynamics” (2026, ApJ, 1009, 38) — Introduces a new equation of state for simulating the hot, dense gas physics when two stars collide and merge. - Joshua Faber (MIT PhD, 2001; Postdoctoral Associate, 2001–2004)
Head of the School of Mathematics and Statistics, Rochester Institute of TechnologyRecent paper: “Addition of tabulated equation of state and neutrino leakage support to IllinoisGRMHD” (2023, PhRvD, 107, 044037) — Adds realistic equations of state and neutrino physics to the IllinoisGRMHD code for simulating neutron star mergers. - Simon Portegies Zwart (NASA Hubble Fellow, 1998–2001)
Professor, Leiden Observatory, The NetherlandsNotable paper: “Monte Carlo Simulations of Globular Cluster Evolution. I. Method and Test Calculations” (2000, ApJ, 540, 969) [189 citations]Recent paper: “The formation of periodic three-body orbits for Newtonian systems” (2026, A&A, 707, A215) — Discovers new families of repeating three-body orbits governed by Newton’s gravity. - Eric Ford (MIT BS, 1999)
Distinguished Professor of Astronomy and Astrophysics, Penn State UniversityNotable paper: “Origins of Eccentric Extrasolar Planets: Testing the Planet-Planet Scattering Model” (2008, ApJ, 686, 621) [445 citations]Recent paper: “Enhancing Exoplanet Surveys via Physics-informed Machine Learning” (2025, IAUS, 368, 1) — Describes how machine learning guided by physical models can make exoplanet surveys more efficient.
Beyond academia
- Dany Atallah (PhD 2026)
Senior Member of Technical Staff, The Aerospace CorporationNotable paper: “Growing black holes through successive mergers in galactic nuclei - I. Methods and first results” (2023, MNRAS, 523, 4227) [38 citations] - Giacomo Fragione (CIERA Postdoctoral Fellow and Research Assistant Professor, 2019–2024)
Engineer, OptumNotable paper: “On the Origin of GW190521-like Events from Repeated Black Hole Mergers in Star Clusters” (2020, ApJL, 902, L26) [119 citations] - Ben Nelson (Data Science Scholar, 2015–2018)
Senior Data Engineer, Altos Labs - Jason Hwang (PhD 2017)
Staff Data Scientist, StripeNotable paper: “Stability and Coalescence of Massive Twin Binaries” (2015, ApJ, 806, 135) [23 citations] - Maggie Morscher (PhD 2015)
Systems & Performance StrategistNotable paper: “The Dynamical Evolution of Stellar Black Holes in Globular Clusters” (2015, ApJ, 800, 9) [287 citations] - Francesca Valsecchi (CIERA Postdoctoral Fellow, 2012–2015)
Data Scientist, IDEONotable paper: “Tidally-driven Roche-lobe Overflow of Hot Jupiters with MESA” (2015, ApJ, 813, 101) [77 citations] - Bharath Pattabiraman (PhD 2014)
Senior Staff Software Engineer, GoogleNotable paper: “A Parallel Monte Carlo Code for Simulating Collisional N-body Systems” (2013, ApJS, 204, 15) [96 citations] - Sanghamitra Goswami (PhD 2013)
Senior Director, Machine Learning and AI, PagerDutyNotable paper: “Formation of Massive Black Holes in Dense Star Clusters. II. Initial Mass Function and Primordial Mass Segregation” (2012, ApJ, 752, 43) [37 citations] - Stefan Umbreit (Postdoctoral Associate, 2006–2013)
Senior Principal Software Engineer, MediaoceanNotable paper: “Monte Carlo Simulations of Globular Cluster Evolution. VI. The Influence of an Intermediate-mass Black Hole” (2012, ApJ, 750, 31) [55 citations] - Evghenii Gaburov (NASA Hubble Fellow, 2011–2012)
Software Engineer, NvidiaNotable paper: “Astrophysical weighted particle magnetohydrodynamics” (2011, MNRAS, 414, 129) [100 citations] - John Fregeau (MIT PhD, 2004; Chandra Fellow, 2006–2009)
Research Staff, Institute for Defense Analyses (IDA)Notable paper: “Stellar collisions during binary-binary and binary-single star interactions” (2004, MNRAS, 352, 1) [351 citations] - Emmanouela Rantsiou (PhD 2009)
Scientist, Neutron Optics and Scientific Computing, Paul Scherrer Institute, SwitzerlandNotable paper: “Mergers of Black Hole-Neutron Star Binaries. I. Methods and First Results” (2008, ApJ, 680, 1326) [60 citations] - Genya Takeda (PhD 2008)
President & COO, Sanoh Industrial Co., Tokyo, JapanNotable paper: “Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog” (2007, ApJS, 168, 297) [291 citations] - Kris Joshi (MIT PhD, 2000)
Board member, Axuall; former CEO for Software, Network & Data, OptumNotable paper: “Monte Carlo Simulations of Globular Cluster Evolution. I. Method and Test Calculations” (2000, ApJ, 540, 969) [189 citations]