Astrophysics

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Princeton University Donald R. Hamilton Colloquium Series

February 12, 2026 | 4:00pm - 5:00pm
Add to calendar 02/12/2026 16:00 02/12/2026 17:00 Princeton University Donald R. Hamilton Colloquium Series use-title Topic: Supernova Explosion Theory: The Emergence of Insight from Complexity Speakers: Adam Burrows, Princeton University More: https://www.ias.edu/sns/events/princeton-university-donald-r-hamilton-colloquium-series-36 ABSTRACT: The theory of compact-object birth and core-collapse supernovae is now entering a new and productive phase of rapid insight into themechanism and systematics of explosion. The panoramic perspective provided by the recent access to tens of state-of-the-art 3D core-collapse simulations taken to late times has revealed potential correlations between supernova observables and physical trends with progenitors. A productive dialogue is slowly emerging between theorists and observers that promises to transform the study of core-collapse supernova explosions and to inaugurate an new era of physical characterization missing from the past. Models now explode without artiface and theory is on the cusp of being able to make quantitative predictions that seemed out of reach only a few years ago. We have discovered correlations between explosion energy, neutron star gravitational birth masses, the yields of the chemical elements, debris morphologies, pulsar kicks, and neutrino and gravitational-wave emissions. However, while I contend the core-collapse supernova problem is in broad outline and qualitatively now solved, there is much yet to do in supernova theory before it can robustly and quantitatively explain the variety of supernova observations. I will close with suggested paths forward to achieve this ultimate goal. Jadwin Hall A-10 a7a99c3d46944b65a08073518d638c23

Abstract: The theory of compact-object birth and core-collapse supernovae is now entering a new and productive phase of rapid insight into themechanism and systematics of explosion. The panoramic perspective provided by the recent access to tens of...

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Institute for Advanced Study Astrophysics Seminar

December 11, 2025 | 11:00am - 12:00pm
Add to calendar 12/11/2025 11:00 12/11/2025 12:00 Institute for Advanced Study Astrophysics Seminar use-title Topic: TBA Speakers: Bart Ripperda, Canadian Institute for Theoretical Astrophysics (CITA), University of Toronto Affiliation: Canadian Institute for Theoretical Astrophysics (CITA), University of Toronto More: https://www.ias.edu/sns/events/institute-advanced-study-astrophysics-seminar-139 Bloomberg Lecture Hall a7a99c3d46944b65a08073518d638c23
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Princeton University Gravity Initiative Seminar

December 08, 2025 | 12:30pm - 1:30pm
Add to calendar 12/08/2025 12:30 12/08/2025 13:30 Princeton University Gravity Initiative Seminar use-title Topic: Cryptographic tests of the python's lunch conjecture Speakers: Michelle Xu, Stanford University More: https://www.ias.edu/sns/events/princeton-university-gravity-initiative-seminar-10 ABSTRACT: In AdS/CFT, a spacetime geometry is said to contain a python's lunch when there exist choices of boundary regions with associated entanglement wedges that contain locally but not globally minimal surfaces. Previously, such geometries have been connected to black hole evaporation and modelled with tensor networks featuring ancillas both added and projected, which has in turn led researchers to conjecture that reconstructing information from past the locally minimal surface is computationally difficult. In this work, we use quantum cryptographic tools related to a primitive known as the Conditional Disclosure of Secrets (CDS) to further develop consequences of the projective tensor network model. We argue from the tensor network picture that the mutual information between appropriate CFT subregions is lower bounded linearly by an area difference associated with the geometry of the lunch, which has bulk geometric consequences we can check. We prove weakened versions of this geometrical statement in asymptotically AdS3 spacetimes satisfying the null energy condition, and confirm it in some example geometries. Jadwin Hall, Princeton Gravity Initiative, 4th Floor a7a99c3d46944b65a08073518d638c23

Abstract: In AdS/CFT, a spacetime geometry is said to contain a python's lunch when there exist choices of boundary regions with associated entanglement wedges that contain locally but not globally minimal surfaces. Previously, such geometries have...

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Princeton University Astroplasmas Seminar

December 05, 2025 | 12:30pm - 1:30pm
Add to calendar 12/05/2025 12:30 12/05/2025 13:30 Princeton University Astroplasmas Seminar use-title Topic: Role of Nonlinear Landau Damping for Cosmic-Ray Transport Speakers: Benedikt Schroer, University of Chicago More: https://www.ias.edu/sns/events/princeton-university-astroplasmas-seminar-96 ABSTRACT: The self-confinement picture of cosmic-ray transport often hinges on the linear theory of growth and damping of magnetic perturbations. Especially the balance between the growth of the resonant streaming instability and non-linear Landau damping plays a crucial role in many astrophysical contexts. Yet, different expressions for the damping rate exist, which lead to widely different physical interpretations. Using hybrid-PIC simulations of the resonant streaming instability, I present a comprehensive assessment of non-linear Landau damping. Our results identify the correct damping rate, scaling with the power in magnetic fields on larger scales. Furthermore, we find an inverse cascade that produces fields on large, non-resonant scales. Applying our findings to self-confinement in the Galaxy, we show that pre-existing turbulence of Alfv\'enic nature at large scales severely affects the damping of waves produced by low-energy cosmic rays; depending on its amplitude, cosmic rays in our Galaxy are either self-confined at all energies or not at all. Dome Room, Peyton Hall or Zoom a7a99c3d46944b65a08073518d638c23

Abstract: The self-confinement picture of cosmic-ray transport often hinges on the linear theory of growth and damping of magnetic perturbations. Especially the balance between the growth of the resonant streaming instability and non-linear Landau...

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Princeton University Gravity Group Lunch Seminar

December 05, 2025 | 12:00pm - 1:00pm
Add to calendar 12/05/2025 12:00 12/05/2025 13:00 Princeton University Gravity Group Lunch Seminar use-title Topic: Searching for New Signals in the Microwave Sky Speakers: Colin Hill, Columbia University More: https://www.ias.edu/sns/events/princeton-university-gravity-group-lunch-seminar-33 Measurements of the small-scale CMB temperature and polarization fields have recently undergone transformative improvements with Data Release 6 (DR6) of the Atacama Cosmology Telescope (ACT) and will soon improve further with the Simons Observatory (SO), which will open new windows into physics beyond the standard models (BSM) of particle physics and cosmology. I will very briefly highlight key findings from our ACT DR6 CMB power spectrum analysis, particularly pertaining to beyond-LCDM models motivated by the "Hubble tension." I will then discuss signals of BSM physics in CMB secondary anisotropies, as could be imprinted by the conversion of CMB photons into massive dark photons (DPs) or axion-like particles. I will show the first results of searches for these signals in CMB data, enabled by our state-of-the-art needlet internal linear combination (NILC) code, yielding leading bounds on DP-photon and axion-photon couplings over two decades in DP/axion mass. I will then present a new NILC-based B-mode inference method, which yields unbiased constraints on the tensor-to-scalar ratio at SO sensitivity and beyond, even for the most complex foreground simulations currently available. Finally, if time permits, I will present robust evidence of a new (standard-model) secondary anisotropy in the microwave sky, arising from the kinematic SZ effect. Jadwin 102 (Joe Henry Room) a7a99c3d46944b65a08073518d638c23

Measurements of the small-scale CMB temperature and polarization fields have recently undergone transformative improvements with Data Release 6 (DR6) of the Atacama Cosmology Telescope (ACT) and will soon improve further with the Simons Observatory...

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Princeton University Galread [Galactic/Extragalactic Reading Group]

December 05, 2025 | 11:00am - 12:00pm
Add to calendar 12/05/2025 11:00 12/05/2025 12:00 Princeton University Galread [Galactic/Extragalactic Reading Group] use-title Topic: TBA Speakers: Hollis Akins, University of Texas at Austin More: https://www.ias.edu/sns/events/princeton-university-galread-galacticextragalactic-reading-group-123 Each week, we hold a relatively informal seminar/discussion series with an emphasis on extra-galactic and large-scale structure astrophysics. During Galread a leader/visitor presents a recent paper to the discussion group. The PDF of the paper is projected onto a large screen, and a guest explains the paper, section by section, in greater detail than may be explained within the text of the article. To aid with discussion, only the article PDF is presented -- no powerpoint-style slides. Galread discussions are very friendly and interactive. Zoom and Peyton Hall, Grand Central a7a99c3d46944b65a08073518d638c23

Each week, we hold a relatively informal seminar/discussion series with an emphasis on extra-galactic and large-scale structure astrophysics.

During Galread a leader/visitor presents a recent paper to the discussion group. The PDF of the paper is...

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Princeton University Thunch Talk

December 04, 2025 | 12:00pm - 1:15pm

Abstract: AGN variability presents a unique way to investigate the motion and structure of accreted material onto supermassive black holes (SMBHs) in active galactic nuclei (AGNs) across cosmic time. Reverberation mapping (RM) is a technique which...

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Institute for Advanced Study Astrophysics Seminar

December 04, 2025 | 11:00am - 12:00pm

I will motivate current work in weak gravitational lensing with cosmic and astrophysical puzzles. The evolution of dark energy, the growth of structure and feedback from supermassive black holes are some of the debated questions. I will describe how...

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Princeton University Dark Cosmos Seminar

December 02, 2025 | 4:00pm - 5:30pm

Abstract: Strong gravitational lenses have provided great insights into the expansion history of the universe and the dark matter distribution from clusters down to sub-galactic scales. Current state-of-the-art measurements involving strong...