December 11, 2018

Speaker: Shirley Ho (Flatiron Institute/Center for Computational Astrophysics)

Contact Information: shirleyho@flatironinstitute.org

Title: MACHINE LEARNING FOR THE UNIVERSE: STEPS TOWARDS OPENING THE BLACKBOX

Abstract:

To fully understand the structure formation of the Universe is one of the holy grails of modern astrophysics. Astrophysicists survey large volumes of the Universe and employ a large ensemble of computer simulations to compare with the observed data in order to extract the full information of our own Universe. However, to evolve trillions of galaxies over billions of years even with the simplest physics is a daunting task. In this talk, we discuss our recent work on building a deep neural network to predict the non-linear structure formation of the Universe from simple linear perturbation theory. Our extensive analysis, demonstrates that the deep learning model outperforms the second order perturbation theory, the commonly used fast approximate simulation method, in point-wise comparison, 2-point correlation, and 3-point correlation. We also show that the deep learning model is able to accurately extrapolate far beyond its training data, and predict structutre formation for significantly different cosmological parameters. Our study proves, for the first time, that deep learning is a practical and accurate alternative to approximate simultaions of the gravitational structure formation of the Universe. We will also discuss our efforts in understanding why the deep learning model is able to capture the non-linear structure formation of the Universe.

Visit Schedule:

Monday (10 Dec 2018)

(visitor room: 118)

  • 10:30 a.m.: Astro Coffee

  • 11:00 a.m.: leave empty

  • 11:30 a.m.:

  • 12:00 p.m.:

  • 12:30 p.m.: Wunch (Peyton 140)

  • 2:00 p.m.: Elinor Medezinski (116 Peyton)

  • 2:30 p.m.: Andy Goulding (117 Peyton)

  • 3:00 p.m.: Peter Melchior (036 Peyton)

  • 3:30 p.m.: Miles Cranmer (012 Peyton)

  • 4:00 p.m.: Jenny Greene (001 Peyton)

  • 4:30 p.m.: Renyue Cen (111 Peyton)

  • 5:00 p.m.: Neta Bahcall (137 Peyton)

  • 5:30 p.m.:

  • 6:00 p.m.: DINNER WITH HOST - meet in Grand Central

Dinner Sign-up (students have priority; Joint with IAS) - add your name here:

1. Speaker: Shirley Ho

2. Faculty host: Neta Bahcall

3. Postdoc host: Elinor Medezinski

4. Jordi Miralda-Escude

5. Miles Cranmer

6. Lachlan Lancaster

7. Kris Pardo

8. Christina Kreisch

9. Heather Prince

10. Benjamin Wallisch

11. Alwin Mao

12.

Note: Dinner is on Monday, joint with IAS