This page is intended to give potentially interested students a brief overview of the sort of work I do, less focused on exact projects (which tend to evolve over time) and more focused on the kinds of interests and qualifications that would be a good match. Of course, this page is not meant to replace in-person conversations! If you have questions, please just email me or find me in my office at UMD. Let me try to answer a few common questions.

Q: Are you looking for students?
Yes. I recently joined the University of Maryland, and will be looking for (under?-) graduate students starting in 2020.

Q: What kind of research do you do?
My research focuses on structure formation, the process by which matter in the universe collapses into the objects we observe (such as galaxies) and those that are hidden (such as dark matter halos). This evolution is extremely complex and non-linear, meaning that it cannot easily be understood with pen-and-paper math. Instead, we use supercomputer simulations of two different types: dark matter only “N-body” simulations, where we neglect the normal matter and study dark matter halos and the cosmic web; and hydrodynamical simulations where we include normal matter and study galaxies.

Q: What is your day-to-day work like, and is it for me?
Basically, I run and analyze simulations, and try to connect the results to the galaxies we observe in the real Universe. My particular focus is on analysis that includes the full dynamics of billions of virtual particles. The common theme to virtually all my work is that it is numerical in nature, as in, based on computer programming and large datasets. Some of the skills that you would develop are:

  • Programming in a scripting language (ideally python)
  • Analyzing data sets and creating scientific plots
  • Working with small, medium, and very large computers (shell commands, parallel computing etc)
  • Communicating your research: giving presentations, writing papers etc
  • If you’re really into coding: C/C++ and MPI parallelization
  • Visualizing data

This is not a list of pre-requisites! If you already have some of these skills, great; if not, you will learn them. But as you probably guessed by now, you should be interested in working with computers in some form.

Q: What student projects do you have on offer?
There are way too many possible projects to list here, and choosing a research topic is something that we should do in conversation, not from a website! Nevertheless, here is an incomplete list of some research directions that I intend to pursue:

  • What is the real shape of halos? The splashback radius is a recently proposed definition of the boundary of dark matter halos: how can we measure it in simulations? How does our understanding of structure change when we use it? How can we best observe the edge of halos in the real Universe? What will we be able to achieve with future instruments?
  • Atomic and molecular gas in the IllustrisTNG simulations: how does it compare to observations? How can the simulations become more realistic?
  • Running better N-body simulations: how can we build reliable simulations and understand their limitations?
  • The density structure of dark matter halos and how it is connected to their evolution
  • Understanding the detailed dynamics of billions of dark matter particles with the SPARTA code
  • Applications of machine learning to dark matter simulations
  • Three-dimensional visualization and 3D printing

Again, this is intended as a list of general topics; if any of them pique your interest, let’s talk.