SURF @ Cosmic DAWN Center

The summer program will take place at the Cosmic Dawn Center and Dark Cosmology Centre, part of the Niels Bohr Institute in Copenhagen

The Cosmic Dawn Center runs an undergraduate summer research program in conjunction with the Caltech SURF program. Thanks to their generosity, we hope to have approximately 2-5 Caltech students come to Copenhagen and work with us this summer. Formally, these will be SURF projects taking place in Denmark. Thus, students will prepare a SURF application and be asked to write two progress reports and a final report as well as give an on-campus talk or poster in October. It is possible that some students will also be able to come as part of an affiliated NSF IRES REU program

Since travel within Europe can be quite cheap, we plan for this to be an 11 week program (roughly from the official SURF start date in mid-June to September 1), so that students can take a one week vacation to see other parts of Europe. We are still trying to finalize plans to split housing with an affiliated REU program in order to save costs. However, Copenhagen can be expensive for visitors, so although our goal is that students will have about the same take-home pay after travel/housing as they would if they stayed in Caltech housing over the summer, this has not always been the case in past summers.

A couple of projects are already posted on the SURF website. Some of the other research interests of our department can be found here. Only some of the faculty will be around to mentor projects over the summer, with Sune Toft, Charles Steinhardt and Gabe Brammer the most likely. These are all projects in astronomy and astrophysics, but we would be happy to have other majors join us for the summer. We would recommend that you only apply for the program if you're at least potentially interested in this as a future direction of research, since otherwise you can probably find a summer project that's more in line with your interests. However, we're happy to have, e.g., somebody with a biology background who has also been possibly interested in astrophysics and wants to find out more about it before deciding which directions are more interesting going forward.

We hope to finalize who will be coming by mid-January, to make sure that there will be plenty of time to both write a SURF proposal (due February 22) and take care of any necessary visa/housing. We will ask interested students to apply by answering a challenging question (see below), as well as sending a CV, and a reference letter. [For people who haven't done a SURF before, you'll end up needing a few reference letters for the SURF application, so you're just asking for one a little earlier than you'd otherwise need to.

How to apply:

When is the deadline?

  • Full consideration will be given to applications received by January 5. After that, we will begin matching students with mentors but will consider late applications if there are still spots open.

What should I send?

  • The main part of the application is to answer one of the two questions below. There are no clear correct answers to these, like many research problems you will encounter. Rather, you should describe how you came up with your answer, since we are mostly interested in the thought process that you use when attacking an unfamiliar problem.
    • 1. Airlines have found that it is optimal to route most traffic through a series of hubs rather than having nonstop flights. Some operating costs are increased by having longer, non-direct flights (maintenance, salaries for additional staff, etc.), but since many costs do not increase very quickly with more passengers per flight, hubs can also allow routes that would otherwise be unprofitable. How should airlines select the number of hubs and their locations? Currently Africa is poorly connected, with fewer than 10% as many flights per capita as the United States and often overnight connections.

      If you were starting an airline to connect Africa via air as well as North America where would you locate your hubs? If you wanted to start a competing North American airline, where should they be located?

    • 2. In several sports (but no longer basketball), NCAA playoff invitations and seeding are determined through the Ratings Percentage Index (RPI), which is calculated as a combination of a team's win percentage (25%), their opponents' average win percentage (50%), and their opponents' opponents' average win percentage (25%), with no adjustment for score. As a result, losing by a large margin to a team with a good record can be more beneficial than winning by a large margin against a team with a bad record. Most coaches have a little over half their schedule set by conference affiliation, with the remainder free for them to select.

      If every team would agree to play them, how should a coach choose their schedule to maximize their chances of making the playoffs? What would be the result if every team were simultaneously to try to choose a non-conference schedule designed to optimize their ranking? Would there be an equilibrium answer that all teams are satisfied with, or will there always be some team which wants to change its schedule once it knows who everybody has scheduled?

  • Your curriculum vitae
  • Please request that a recommendation letter be sent independently

Where should I send it?

  • Please send all application materials to

When will I hear back?

  • By late January


I'm a freshman. Can I apply anyway?

  • Yes! Some of the projects will be most suitable for researchers with a more formal background, but one of the wonderful things about astronomy is that there are many projects which require relatively little background in order to get to the point that you can make a useful contribution. We would like to have students with a range of backgrounds come to Copenhagen this summer, and we have had freshmen participate every summer.

Is this open to students from all universities?

Should I apply to a specific project?

  • If you have a specific mentor/project in mind, please let us know when you apply, and we will try and match you up with that project.  However, we might also end up suggesting a match with a different mentor, particularly if most people end up requesting the same project.  

I have some more questions.  Who can I ask?

  • Please contact Charles Steinhardt ( with additional questions about the program.