Scientific collaboration
The group works on wave-optics lensing, dark-matter substructure, black-hole binaries and gravitational-wave propagation. My own time is very limited, so if your question falls squarely in one person's area it is usually faster and more productive to write to them directly (see the group page, which lists who works on what). Otherwise, a paragraph on what you have in mind and which of our papers it connects to is the most useful opening.