Caltech Relativistic Astrophysics Summer School 2025

High-energy astrophysics has made remarkable progress in describing some of the most extreme phenomena in the universe. Recent discoveries such as compact binary mergers and multi-messenger gravitational wave events, fast radio bursts, ultra-high energy cosmic rays, and advances in our understanding of the transient high energy sky (radio, X-ray, gamma-ray) open up new possibilities for forefront research in these rapidly evolving fields.

This summer school aims to provide beginning and advanced graduate students in astrophysics, physics, and adjacent fields with the knowledge and tools to fully take advantage of these exciting developments.

A particular focus of the school will be the application of emerging computational tools to provide high-fidelity models of high-energy astrophysical phenomena in strong gravity environments, e.g., around black holes or neutron stars.

The one-week long summer school will include lectures on a broad range of topics:

• Black hole astrophysics
• Dynamo and turbulence
• Magnetohydrodynamics
• Multi-messenger gravitational wave events
• Neutrino astrophysics
• Neutron star magnetospheres
• Numerical Relativity
• Plasma kinetics

We will also provide extra-sessions for tutorials, outreach training, as well as social activities. Participants will further have the opportunity to present a poster on their research.

Lecturers include

• Koushik Chatterjee
• Hayk Hakobyan
• Jens Mahlmann
• Elias Most
• Martijn Oei
• Sherwood Richers
• Bart Ripperda
• Nils Vu
• Muni Zhou

Applicants are required to submit their curriculum vitae (CV), which should include all relevant coursework taken and expected to be taken before Summer 2025. Additionally, we ask for a motivation statement and require one (or two) reference letters to be submitted under the registration link by the letter writers.
We have limited funds to offer partial financial support for attendees.

Further information will be announced on a rolling basis.

This school is supported by the National Science Foundation.

Organizing committee

• Samuel Dunham
• Aretaios Lalakos
• Elias Most
• Mike Pajkos
• Sasha Philippov
• Nils Vu
• Yici Zhong

Lodging

​There are a number of motels in Pasadena, several within walking distance of Caltech (e.g., search for "motels" using the Google Map below). Many local motels offer discounted rates to Caltech visitors (usually by phone if you ask, but not via the internet). Various options include:

• Howard Johnson Pasadena
• Pasadena Rose & Crown Hotel
• Pasadena Hotel & Pool
• Hilton Pasadena
• Sheraton Pasadena Hotel
• GreenTree Pasadena Inn
• Hyatt Place Pasadena
• The Langham
• Saga Motor Hotel

Travel

Information for air travelers

If you will be flying into the area there are several options for traveling to Pasadena. Where you will be staying will determine which mode of transportation is best for you. Several options include:

• Ride sharing services
• Fly-Away Bus with Metro Rail
• Rental Car

We highly recommend you read more information about getting to the Pasadena area and moving around Los Angeles in the Caltech Transit Guide. Please also note that when booking flights, be sure to check for flights flying to the Burbank airport in addition to LAX. Often flights into Burbank can be cheaper, and Burbank is closer to Caltech.

Ride sharing services: Both Uber and Lyft serve as options for picking-up and/or dropping-off passengers at LAX. The services can do drop-off directly at your terminal, however, due to construction, the pick-up location has been moved away from the standard location to the "LAX-it" space. In principle one could walk there from the terminal, but there is also a free shuttle which comes every 7 minutes. Please see LAX-itfor more details. The price for a ride from LAX to Caltech is roughly $50, but it depends on surge charges. Both services offer carpool options in LA.

Fly-Away Bus with MetroRail: Go to Ground Transportation Level and look for the "Fly-Away Bus" sign along the curb. Take the bus that goes to Union Station. Once at Union Station you can buy your bus ticket for USD 9.75 (debit and credit cards only, no cash unless booked online in advance) and present it to the driver to retrieve your luggage. Then, enter Union Station and take the Metro Gold Line north to Pasadena. You will need to buy a TAP card at any of the kiosks there and add USD 1.75 value to cover your metro fare to Pasadena. If staying at the Vagabond Inn you will want to exit at the Lake Station. If staying at the Saga Motor Hotel you will want to exit at the Allen Station. Please see the Caltech Transit Guide for more information and for Metro Rail hours of operation.

Rental Car: You can rent a car from most of the airports in the area. We encourage you to look for rates through the company and/or travel websites.

The Caltech campus hosts a few Zipcar vehicles on S. Holliston Ave. and San Pasqual St. (on the east side of campus) that you can rent for the times that you actually need the vehicle. It is sometimes more cost-effective to use the usual rental car venues when needing a car for more than half of a day.

Parking at Caltech

The parking lot closest to Cahill is immediately South of it (highlighted in the above map). Parking costs $9 for all weekdays and is payable at nearby Pay Station vending machines. Park in any unreserved parking space. There is no charge for parking on weekends. More information is available from the Caltech Parking web site.