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Center

Center for Theoretical and Observational Cosmology

Center for Theoretical and Observational Cosmology

The CTOC’s focus is on the field of cosmology, which is the study of the universe as a whole. The Center is interested in understanding the fundamental properties of the universe, such as its matter and energy content, and how structures like galaxies and clusters of galaxies form and evolve over time.

The Center employs a range of observational, theoretical, and computational techniques to achieve these goals. To better understand the universe’s properties, the center members use multi-wavelength surveys and collect data from various parts of the electromagnetic spectrum ranging from sub-mm waves, infrared, and optical to X-rays and gamma rays. They also run computer simulations of galaxy formation and evolution to test different theories and models.

The Center's work is highly collaborative, and its members work with other research institutions and observatories to achieve their goals. For example, the center members are involved in and play central roles in NASA satellites, such as the Chandra X-ray observatory, Swift, and JWST, to study the high-energy phenomena in the universe, such as black holes and supernovae and the properties of the young galaxies in high-redshift Universe.

Another highlight is the HETDEX project, which stands for the Hobby-Eberly Telescope Dark Energy Experiment. This project is designed to study dark energy, a mysterious force that is causing the universe to expand at an accelerating rate. The Center's members are playing a leading role in this project and are working to measure the dark energy properties at early times, distant from all the other observing programs to date. Three out of eight members of the HETDEX Management Team are Center members, as is one of just three Architect-status members of the Survey Steering Committee.

Major collaborations with involvement and leadership from Center members also include the CMB-S4, SDSS-V, and the Subaru Prime Focus Spectrograph.

In addition to observational and theoretical work, the Center's members also use machine learning and other computational techniques to analyze their data. Two members of the Center are formally affiliated with the Institute for Computational and Data Sciences, and many have close ties with Penn State’s Center for Astrostatistics. Computational projects include multi-scale simulations investigating the formation of the earliest galaxies, black holes, and quasars. Center members’ analysis and machine learning expertise are increasingly focused on interpreting data from JWST and the upcoming Rubin LSST. There is increasing overlap between this Center and the CMA, largely driven by the broad impact of current and future gravitational wave detections. The science questions of interest to both centers are traditionally big-picture cosmological questions (e.g., the nature of dark matter and the universe’s expansion rate) and in the understanding of structure in the late universe and the precursor populations for the compact objects seen merging today.

Name Role Affiliations Email Phone Office Centers Research topics
Abhay Ashtekar Abhay Ashtekar Faculty ava1@psu.edu +1 814 863 9601 316 Whitmore Laboratory CFT, CMA, CTOC Physical Mathematics
Joshua Black Joshua Black Graduate Student Physics jib38@psu.edu +1 814 865 7533 301D Whitmore Laboratory CTOC Black Holes, Dark Matter
John Blakely John Blakely Undergraduate Student Astronomy, Physics jpb6799@psu.edu +1 814 865 0410 Osmond Laboratory CTOC, IGC Black Holes, Dark Matter
Carlos Blanco Carlos Blanco Faculty ICDS, Physics carlosblanco@psu.edu +1 814 865 7533 303K Osmond Laboratory CFT, CMA, CTOC, IGC Cosmic Rays, Dark Matter, Multimessenger Astrophysics, Neutrinos
W. Niel Brandt W. Niel Brandt Faculty Astronomy, Physics wnbrandt@gmail.com +1 814 865 3509 514A Davey Laboratory CTOC Black Holes, Multimessenger Astrophysics, Quasars, Dynamic Universe
Tommy Chin Tommy Chin Graduate Student Physics wjc5509@psu.edu 6692331822 301D Whitmore Laboratory CFT, CTOC, IGC Quantum Universe, Dynamic Universe
Robin Ciardullo Robin Ciardullo Faculty Astronomy rbc3@psu.edu +1 814 865 6601 525 Davey Laboratory CMA, CTOC Cosmic Surveys
Laura Duffy Laura Duffy Graduate Student Astronomy lrd48@psu.edu +1 814 865 0419 537 Davey Laboratory CTOC Black Holes, Quasars
Michael Eracleous Michael Eracleous Faculty Astronomy mxe17@psu.edu +1 814 863 6041 414 Davey Laboratory CMA, CTOC Black Holes, Multimessenger Astrophysics, Quasars, Dynamic Universe
Derek Fox Derek Fox Faculty Astronomy dbf11@psu.edu +1 814 863 4989 425 Davey Laboratory CMA, CTOC Multimessenger Astrophysics, Neutrinos, Dynamic Universe
Caryl Gronwall Caryl Gronwall Faculty Astronomy cag18@psu.edu +1 814 865 2918 417B Davey Laboratory CMA, CTOC Astrostatistics, Cosmic Surveys
Donghui Jeong Donghui Jeong Faculty Astronomy djeong@psu.edu +1 814 865 1117 518 Davey Laboratory CTOC Gravitational Waves
Rodney Jones Rodney Jones Undergraduate Student Astronomy rjj5488@psu.edu 9412878113 N/A CTOC Dark Matter
Joel Leja Joel Leja Faculty Astronomy, ICDS jql6565@psu.edu +1 814 865 0418 515 Davey Laboratory CTOC Cosmic Surveys
Yuexing Li Yuexing Li Faculty Astronomy yul20@psu.edu +1 814 867 2291 417A Davey Laboratory CMA, CTOC Astroinformatics, Black Holes, Multimessenger Astrophysics
Greg Lukens Greg Lukens Graduate Student Astronomy gmlukens@psu.edu +1 814 865 0419 441 Davey Laboratory CTOC Cosmic Surveys
Niana Mohammed Niana Mohammed Graduate Student Astronomy nnm5189@psu.edu +1 814 865 0419 537 Davey Laboratory Davey Laboratory CMA, CTOC Black Holes, Multimessenger Astrophysics, Quasars
Ella Newhouse Ella Newhouse Undergraduate Student Astronomy ejn5324@psu.edu 412-699-6700 N/A CTOC Cosmic Surveys
Mary Ogborn Mary Ogborn Graduate Student Astronomy mko5309@psu.edu 8148637111 8148637111 Davey Laboratory CMA, CTOC Black Holes, Quasars
Monica Rincon Ramirez Monica Rincon Ramirez Staff Physics mxr463@psu.edu 307 Whitmore Laboratory CFT, CTOC Black Holes, Loop Quantum Gravity, Physical Mathematics, Quantum Universe
B.S. Sathyaprakash B.S. Sathyaprakash Faculty Astronomy, Physics bss25@psu.edu 312 Whitmore Laboratory CMA, CTOC Black Holes, Dark Matter, Gravitational Waves, Multimessenger Astrophysics
Donald Schneider Donald Schneider Faculty Astronomy dps7@psu.edu +1 814 863 9554 508 Davey Laboratory CTOC Black Holes, Cosmic Surveys
Hyungsuk Tak Hyungsuk Tak Faculty hvt5139@psu.edu +1 814 865 1348 326 Osmond Laboratory CTOC Astroinformatics, Astrostatistics
Zhenyuan Wang Zhenyuan Wang Graduate Student zzw173@psu.edu +1 814 865 0419 532 C Davey Laboratory CTOC Cosmic Surveys
Stephanie Wissel Stephanie Wissel Faculty Astronomy, Physics wissel@psu.edu +1 814 863 9598 303B Osmond Laboratory CFT, CMA, CTOC Cosmic Rays, Multimessenger Astrophysics, Neutrinos
Name Role Affiliations Email Phone Office Centers Research topics
Yasaman Homayouni Yasaman Homayouni Postdoc Astronomy ybh5251@psu.edu +1 814 865 0418 525, though working remotely until fall 2022. Davey Laboratory CTOC Black Holes
Sean Prudhoe Sean Prudhoe Faculty Physics stp5134@psu.edu 321 F Whitmore Laboratory CTOC Quantum Universe
Michael Ryan Michael Ryan Graduate Student Physics mzr55@psu.edu 301C Whitmore Laboratory CTOC Black Holes, Dark Matter
V. Ashley Villar V. Ashley Villar Faculty Astronomy, ICDS vav5084@psu.edu 517 Davey Laboratory CTOC Gravitational Waves, Multimessenger Astrophysics
About our wordmark
Monica Rincon Ramirez

The IGC wordmark was created by Monica Rincon Ramirez while she was a graduate student at the Institute. Monica enjoys drawing new connections between fundamental theory and observations. Her graduate work included general relativity, loop quantum gravity, and quantum fields in cosmological backgrounds; her thesis focused on effective quantum corrections to gravitational phenomena from spinfoams and applications to cosmology. She received her PhD in 2024.

The wordmark symbolizes the scope of research at the IGC. The base represents quantum gravity, evoking the quantum geometrical picture from spinfoams and loop quantum gravity — approaches studied at the Center for Fundamental Theory. The middle shows galaxies embedded in a smooth surface characteristic of spacetime in general relativity and the larger physical scales studied at the Center for Theoretical and Observational Cosmology. The top curves to an extreme representing a supermassive black hole accompanied by an energetic jet, with a binary black hole pair nearby — the high-energy phenomena studied at the Center for Multimessenger Astrophysics.