Preposterous Universe

 
Hyperspace, Superspace, Theory Space, and Outer Space

Back from sunny, cicada-ridden Baltimore and the conference mentioned previously. It was a small, fun conference; the idea was to keep it simple and informal, so that people could spend time talking to each other and perhaps even get some work done. My talk was scheduled at the very end, so I didn't get any work done, but split my time between socializing and making an electronic version of the talk (which I had given previously, but only on the blackboard at seminars). In the end it was for naught, as I complained about having to make the electronic version and received a chorus of requests to just go ahead and give the blackboard talk, which I did. It went pretty well, so we'll see what kind of reaction the paper gets.

The participants were all theorists working on particle physics, string theory, and cosmology -- overlapping fields with a lot of activity and connections these days. Some of the memorable talks:

• Gia Dvali talked about modified gravity in cosmology (as I blogged about recently).
• Angela Olinto gave a nice review of ultra-high-energy cosmic rays and neutrino experiments.
• Shamit Kachru talked about compactifying extra dimensions in string theory and the string-theory "landscape" of possible vacua.
• Alex Szalay gave an interesting talk on the huge data sets appearing in modern astrophysics -- we're moving from terabytes to petabytes, leading to files that would take years just to search using ordinary methods.
• Ann Nelson and Neil Weiner both gave talks on interactions in the dark sector (undeterred by my skepticism).
• Eva Silverstein talked about inflation from nontrivial kinetic terms for string-theory moduli, including potentially observable signals (!) of non-Gaussianity in the cosmic microwave background.
• Jacob Bekenstein talked about modified gravity as a replacement for dark matter.
• Nima Arkani-Hamed talked about "ghost" fields as dark energy.
• Marc Kamionkowski talked about dark matter that is neutral, but couples to electromagnetism through a dipole moment.
• Hitoshi Murayama talked about the minimal possible model that is consistent with all of our current data.
• Even the summary talk, by Joe Lykken, was fantastic.

You get the idea, I hope: lots of interesting ideas, bumping up against new constraints from experiments, bringing together fields that weren't talking to each other just a little while ago (e.g., when I was in grad school). It's an exciting time.

~ posted by Sean Carroll at 10:53 PM ~ link ~ ~ ~