Astro Seminar Series - VIA ZOOM

Wednesday, November 10, 2021 11:30 am - 11:30 am EST (GMT -05:00)

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Dr. Andrew Pontzen is a Royal Society University Research Fellow and Professor of Cosmology at the University College London (UCL). He obtained his PhD from the Institute of Astronomy, Cambridge in 2009.  His work focuses on understanding dark matter – a mysterious component of the universe that is hypothesised to drive the formation of galaxies and other structures. While little is known about the nature of dark matter, the basic idea of an invisible sector interacting through gravity with what we can see has been highly predictive. Over the last 20 years, the dark matter hypothesis has generated a huge number of correct predictions about both the present day universe and the ancient "cosmic microwave background" light.

Talk Title and Abstract:

A new approach to cosmological simulations

The next generation of astronomical observatories bring a realistic prospect of paradigm-shifting constraints on the nature of dark matter and dark energy, both through deeper observations of large scale structure and by pushing to fainter surface brightness galaxies. I will discuss the unique computational challenges that producing simulations for this era pose. On the one hand we wish to simulate large volumes to gain representative samples of galaxies and to understand the cosmological implications of forthcoming survey data from e.g. LSST. On the other, we also want to maintain very high resolution to resolve highly non-linear astrophysical processes and internal kinematics for Gaia, MaNGA and the like. These two requirements result in a tension on how to best spend limited computer time. I will argue that a new approach to simulations, in which we use statistical models to tailor cosmological initial conditions for different questions, can help relieve this tension. I will mainly focus on recent applications to understanding the diversity of dwarf galaxies, and will also give a quicker overview of results for higher mass galaxies and large scale structure.

Would you like to join this Zoom seminar?  Please e-mail WCA.