Staff Directory

Zoltan Haiman received his Ph.D. in Astronomy from Harvard University in 1998, and a B.S. in Physics and Electrical Engineering from MIT. He held postdoctoral positions at Fermilab and at Princeton University. His research interests are in topics in theoretical astrophysics and cosmology, including the formation of the first stars and black holes, the subsequent growth of black holes, mergers between black holes and corresponding electromagnetic and gravitational wave signatures, and determining the nature of dark energy and dark matter using large Astronomical surveys, especially through weak gravitational lensing.  

Prof. Haiman is a recipient of NASA’s Hubble Fellowship, a Gyorgy Bekesy Fellowship from the Hungarian Ministry of Education, a NYAS Blavatnik Award for Young Scientists (2010) and a Simons Fellowship in Theoretical Physics (2016). He was named in 2002 as one of the Brilliant 10 young scientists by Popular Science magazine. He is currently serving on the Science and Technology Definition Team (STDT) for NASA’s concept study for the X-ray satellite Lynx; he is an ESA-appointed member of the LISA Science Group, where he co-leads multi-messenger astrophysics efforts, and a NASA-appointed member of the NASA LISA Study Team.  He has published over 250 peer-reviewed publications, and while on on the Columbia faculty, he has mentored 16 Astronomy and Physics PhD students, of whom 6 have gone on to faculty positions to date.

Yuri Levin got his PhD at Caltech, working on the theory of Thermal and Quantum Noise in LIGO interferometers, and on r-mode oscillations of neutron stars. His scientific style was influenced by his two very different PhD advisors,  Kip Thorne and Vladmir Braginsky, and also by the free-wheeling, open discussions with Peter Goldreich, Sterl Phinney and others. 

After leaving Caltech, Levin travelled the world, with postdoc and faculty gigs in Berkeley, Toronto, Leiden, and Melbourne, before coming to Columbia in 2017.    He works on a variety of topics in theoretical astrophysics.  His current interests include: 1. Stellar and gas dynamics of galactic nuclei. 2. Motion of superfluid vortices inside neutron stars, and their connection to pulsar glitches. 3.  Magneto-dynamics of neutron star quakes and oscillations. 4. Gravitational waves from cosmic strings and  other topological defects.

Levin is always interested in learning from his colleagues. Please stop by and tell him something interesting.

Xin Sheng is a Physics PhD student whose research focuses on compact objects and numerical simulations. He is currently studying neutron star glitches using large-scale molecular dynamics simulations. Xin earned his bachelor’s degree in physics from the University of California, Santa Barbara.

Vishal is a NASA Hubble Fellow at Columbia University who studies gravitational wave astrophysics. His research focuses on understanding the origins of gravitational wave sources, particularly how compact-object binaries, such as pairs of black holes and neutron stars, form and evolve. Although mergers of these objects have been detected by observatories like LIGO, Virgo, and Kagra, their exact origins and formation processes remain unclear. Vishal's work aims to address key questions about how, when, and where these binaries form, as well as the stellar environments that shape them. With future gravitational wave detections, he aims to explore how these objects acquire their spins and further understand the life cycles of merging compact objects.

I received my PhD in Astrophysics from Princeton University in 2022, BS in Physics from Caltech in 2016. My interests are in hydrodynamic and MHD turbulence in the interiors of stars and compact objects. My focus is often on understanding dynamos---how magnetic fields can be generated in realistic astrophysical parameter regimes. Feel free to reach out if you are an undergrad or grad student interested in projects on astro/geophysical fluid dynamics.

B.Tech in Engineering Physics and Electrical Engineering (second major), Indian Institute of Technology Hyderabad

M.S. in Physics, The Ohio State University

PhD in Physics, The Ohio State University

Research Interests: Supernovae, neutron stars and magnetars, gamma-ray bursts, heavy element nucleosynthesis

Stan DeLaurentiis is a 1st year Astro PhD

Sean is a physics PhD candidate broadly interested in compact objects and luminous transients. He grew up in Massachusetts and completed his undergraduate studies at Bowdoin College in Brunswick, Maine. Besides physics, Sean enjoys tennis, hiking, and live music.

Ryan Golant is a fifth-year Ph.D. candidate and a NASA FINESST Future Investigator in the Department of Astronomy at Columbia University. He attended Princeton University for undergrad, majoring in Astrophysical Sciences and minoring in Computer Science. Ryan is broadly interested in computational astrophysics and plasma astrophysics, with a particular focus on the interplay between turbulence and magnetic fields. For his thesis, Ryan is combining small-scale particle-in-cell (PIC) simulations with large-scale cosmological MHD simulations to probe the origins of the magnetic fields in cosmic voids. Ryan has also done work on the growth of magnetic fields around gamma-ray burst afterglow shocks, the impact of stellar feedback on the ISM, the growth of instabilities in the solar wind, and the application of machine learning to galaxy cluster identification. Outside of astronomy, Ryan enjoys playing violin and video games, learning about art history, and spending time with his cat, Alfvie.

Professor Mukherjee's research interests are in high-energy astrophysics and astroparticle physics. She uses ground-based atmospheric Cherenkov telescopes to study galactic and extragalactic high-energy gamma-ray sources. One of her current projects is VERITAS (Very Energetic Radiation Imaging Telescope Array System), a major ground-based gamma-ray observatory, located in southern Arizona, that enables the study of extragalactic and galactic high energy gamma-ray sources. Mukherjee is also involved with the study of active galaxies, thought to be powered by supermassive black holes at their centers, and unidentified high-energy gamma-ray sources, with no known counterparts at other wavelengths. She is involved in the study of Galactic Pevatrons and Galactic TeV halo candidates and in multimessenger studies of IceCube high-energy neutrinos events. Her current research projects include VERITAS, Cherenkov Telescope Array Observatory (CTAO) (https://www.ctao.org/), the Schwarzschild Couder Telescope (SCT) (https://cta-psct.physics.ucla.edu/) and the Gamma-Ray and AntiMatter Survey (GRAMS) experiment (https://grams.sites.northeastern.edu/). 

Rebecca Diesing is a joint postdoctoral fellow at the Institute for Advanced Study in Princeton and at Columbia University in New York City. She earned her PhD from the University of Chicago in 2023, where she was a Harper Fellow. 

Rebecca is interested in the acceleration and astrophysical impact of cosmic rays. She is currently using a detailed model of cosmic ray acceleration to better understand the evolutions and environments of extreme astrophysical phenomena, including supernova remnants, novae, and winds launched by active galactic nuclei.

My research focuses on the (magneto)hydrodynamics of neutron star interiors, with specific topics of interest including stellar oscillations, the observational implications of quantum mechanical effects associated with super-strong magnetic fields, and neutron superfluidity and proton superconductivity in neutron star cores. My overall research goal is to understand how microscopic phenomena that occur within the extreme environment of neutron stars can have macroscopic effects on neutron star dynamics, and how we can observe these effects. My research combines semi-analytic calculations (pen and paper calculations aided by numeric computation) and numerical simulations.

Ore is a Flatiron and THEA research fellow who’s working on theoretical high-energy astrophysics by combining GRMHD simulations with analytic calculations to predict and interpret multi-messenger signals.

Noah is a Data Science Major with a Mathematics concentration in Columbia College. His passions are Machine Learning, AI, and the interface of these fields with cutting-edge research in academically-rich fields like theoretical physics, math, computer science, statistics, etc. Under the guidance of Professor Zoltan Haiman, he has been working on a computational astrophysics project evaluating the validity of quasar PG1302 as a supermassive binary black hole system through analysis of false periodicities in time-domain surveys. He hopes to publish soon. Noah has plans to attend graduate school for a PhD in the near future.

I am Nilay Mancini, an Italian student from Rome.

I am interested in compact objects, with specific focus on their gravitational and electromagnetic emission.

Marguerite Epstein-Martin is a graduate student in the Astronomy department at Columbia University and received a BS in physics from Yale University and an MS in Planetary Science from the California Institute of Technology. She is interested in using analytical techniques to understand astrophysical disks, including protoplanetary disks and active galactic nuclei. Her research currently focuses on the relationship between active galactic nuclei and the stellar and stellar mass black hole populations they interact with. Outside of astronomy, Marguerite likes running, reading science fiction, and swing dancing. 

Luca Orusa has postdoctoral position at Princeton University and at Columbia University in New York City. Luca received his Ph.D. in Physics in 2023 from the University of Torino in Italy where he obtained also his B.S. and M.S. Cum Laude.

Luca's research focuses on the lifecycle of cosmic rays, from their creation in astrophysical sources to their journey through the Galaxy. He uses kinetic plasma simulations to model particle acceleration at astrophysical shocks, like those of supernova remnants, and examines how cosmic rays affect transport in the vicinity of their sources. By combining these insights with phenomenological models of cosmic ray transport in the Galaxy, he generates observables that can be directly compared with cosmic ray data, with a particular focus on the positron flux. He is also interested in input from laboratory experiments, such as the study of collisionless shocks produced in laser plasma experiments and the analysis of production cross sections from accelerator experiments, which can improve the understanding of the origin of cosmic rays.

Luca is a plasma astrophysicist with research interests bridging high-energy astrophysics, plasma physics, and astroparticle physics. He combines analytical calculations with large-scale numerical simulations on supercomputers to investigate the emission processes and messengers—such as electromagnetic radiation, cosmic rays, and neutrinos—from a range of astrophysical sources. These include accretion flows around black holes, jets from active galactic nuclei (AGNs), gamma-ray bursts (GRBs), pulsar wind nebulae (PWNe), tidal disruption events (TDEs), and other potential sources of ultra-high-energy cosmic rays (UHECRs). His research is supported by NASA, the National Science Foundation, and the Department of Energy. 

Prior to moving to Columbia University, Luca was a postdoctoral researcher in the Department of Astrophysical Sciences of Princeton University and a long-term visitor in the Theory Department of the Princeton Plasma Physics Laboratory. He received his Ph.D. in plasma physics from the Polytechnic University of Turin. Before pursuing his passion for physics, he obtained a bachelor’s degree in aerospace engineering and a master’s degree in space engineering from the Polytechnic University of Milan.

Lorenzo Sironi is an associate professor in the Department of Astronomy. His research group investigates how fundamental plasma processes, shocks, magnetic reconnection and turbulence can power the non-thermal signatures of a wide variety of astrophysical objects, especially the most powerful and compact sources in our universe: neutron stars and black holes. Most recently, Sironi has become fascinated with the rich and puzzling phenomenology of fast radio bursts and with the hard X-ray “coronal” emission of X-ray binaries and active galactic nuclei. He has a decade-long interest in magnetic dissipation and particle acceleration in relativistic black hole jets, focusing both on their multi-wavelength emission as well as on their potential role as multi-messenger sources (ultra-high-energy cosmic rays and high-energy neutrinos).

By modeling the plasma physics of high-energy astrophysical sources from first principles, Sironi and his group aim to build self-consistent, falsifiable models of their observables. By creating a diverse and inclusive environment that benefits everyone’s scientific efforts, he strives to foster the growth of the next cohort of plasma astrophysicists.

Sironi became passionate about astronomy and plasmas at the University of Pisa before moving to the Department of Astrophysical Sciences at Princeton University for his Ph.D. After working as a NASA Einstein Fellow at Harvard University, he moved to Columbia in 2016. He has been awarded the 2019 Sloan Fellowship in Physics, the 2020 Cottrell Scholar Award, the 2023 Department of Energy Early Career Award, and the 2025 Presidential Early Career Award for Scientists and Engineers (PECASE).

Joonas Nattila is a joint Flatiron Research Fellow in the Computational Center for Astrophysics and Columbia University in New York. Before coming to New York, he was a Nordita Fellow in the Nordic Institute for Theoretical Physics. He received his Ph.D. from the University of Turku, Finland, in 2017. His research is focused on understanding high-energy astrophysical phenomena around neutron stars and black holes.

Currently, I am a THEA fellow collaborating closely with Professors Sironi and Beloborodov. In January, I will begin my position as an assistant professor at Dartmouth College. I specialize in high-energy astrophysics, focusing on plasma processes in magnetized environments such as magnetars, black holes, stars, and accretion flows. My work integrates theoretical frameworks with advanced simulations conducted on high-performance computing systems. Specifically, my primary research investigates the origins of plasma near neutron stars and the mechanisms behind the generation of radio and X-ray bursts during magnetospheric instabilities. Guided by the detailed observations and advanced theories of planetary magnetospheres, including those of Earth and Jupiter, I explore fundamental plasma processes in extreme astrophysical environments. I build trustworthy non-linear models of how electromagnetic energy within stellar magnetospheres transforms into signals observable through telescopes. With expertise in scientific code development, I customize simulations to capture the intricacies of diverse astrophysical environments ensuring the highest accuracy in modeling complex plasma dynamics. Beyond my research, I am deeply committed to fostering effective communication and conflict resolution within scientific teams. I actively incorporate these communication skills into my work environment, contributing to a collaborative and inclusive scientific community.

Janna Levin is the Tow Professor of physics and astronomy at Barnard College of Columbia University. She has contributed to an understanding of black holes, the cosmology of extra dimensions, and gravitational waves in the shape of spacetime. Among other prizes she has been named a Guggenheim Fellow. She is also director of sciences at the cultural center Pioneer Works and the editor-in-chief of The Broadcast. Her previous books include How the Universe Got Its Spots and a novel, A Madman Dreams of Turing Machines, which won the PEN/Bingham Prize. Her book, Black Hole Blues and Other Songs from Outer Space, is the inside story on the discovery of the century: the sound of spacetime ringing from the collision of two black holes over a billion years ago. Her most recent book is Black Hole Survival Guide.

Itai Linial received his PhD from the Hebrew University of Jerusalem in Israel in 2022, where he was an Adams Fellow. He is currently a postdoctoral fellow at the THEA group in Columbia University and at the Institute for Advanced Study in Princeton. He received The Gruber Foundation postdoctoral prize (2022) and the Rothschild Fellowship (2022-2023).

Itai's research spans a variety of topics in theoretical astrophysics, including high-energy astrophysical phenomena, dynamical processes in galactic nuclei and hydrodynamics.

I am mainly working on searching for gravitational waves using the pulsar timing array data. I am also interested in early universe physics such as primordial black holes and cosmic strings.

Hayk has a joint position in Princeton Plasma Physics Laboratory and Columbia University. He is interested in fundamental plasma physical processes that govern energy dissipation and particle acceleration in the magnetospheres surrounding compact objects, such as neutron stars and black holes. The dynamics of these extreme plasmas are largely governed by quantum electrodynamic processes that couple charged particles with the emitted light. To study these phenomena Hayk uses novel numerical algorithms for QED processes incorporated in first-principles plasma simulations using particle-in-cell approach.
 

Brian Metzger received his B.S. at the University of Iowa and his Ph.D. at UC Berkeley in 2009. He held a NASA Einstein Postdoctoral Fellowship at Princeton, before joining the Columbia Department of Physics in 2013, where he is currently a Professor.  Metzger also holds the position of Senior Research Scientist at the Center for Computational Astrophysics within the Flatiron Institute.

Metzger’s research is in theoretical high energy astrophysics, on topics including gamma-ray bursts; supernovae; fast radio bursts; accretion processes; compact objects; nucleosynthesis (astrophysical origin of the elements); and the electromagnetic counterparts of gravitational wave sources. His recognitions include the New Horizons Breakthrough Prize in Physics; the Bruno Rossi Prize of the American Astronomical Society; and the Blavatnik Awards for Young Scientists.  His research is supported by the National Science Foundation and NASA.  He is currently a Simons Investigator.   

Aristo Liu is an undergrad from Copley, Ohio studying Astrophysics and Mathematics. He is working with Dr. Jordy Davelaar and Prof. Lorenzo Sironi to study the spin evolution of black holes. Outside of the lab, he is the president of the Columbia chess club.

Anthony is a PhD student in Astrophysics from Columbia University. He's broadly interested in computational astrophysics and high energy astrophysics. Before joining the PhD program, he received his B.A. in Astrophysics from Columbia University. 

Anirudh (Ani) Patel is broadly interested in the microphysics of extreme phenomena and their connection to multi-messenger observables. His work has focused on understanding rapid neutron capture nucleosynthesis and its thermal and non-thermal signatures in magnetar flares and supernovae. He investigates these systems with a combination of analytical and numerical tools.

Ani began his graduate studies in the Physics Department at Columbia in 2022 where he is currently a Julian Schwinger Fellow.

Andrea is a Flatiron Research Fellow at CCA. Her work explores the transients arising from red and yellow supergiants near the ends of their lives.  As a computational theorist, she uses magneto- and radiation-hydrodynamic simulations to determine the observational signatures of mass-loss events, explosions, and implosions of these hydrogen-rich progenitors in an effort to understand the underlying populations of stellar-mass black holes and the circumstellar environments in which the stars die. Prior to joining CCA, Andrea earned her Ph.D. in Astrophysics at UC Berkeley.