Planck 2014 Overview

It's been a week, but I still think it's close enough to look back on Planck 2014 as a whole.



One thing I did notice was that there seemed to be a lot of inflation talks this year, at least compared to what I remember from the last two times.  This might just be my mind playing tricks on me, but then it would make sense in view of the (now somewhat contested) BICEP2 results.  Of course, I'm not really an inflation expert so I can't say too much on them.

What I can comment on is the greater scepticism shown towards SUSY this year than before.  Indeed, this was not just apparent in the talks but in the discussions around the conference as well.  It's kind of odd, given that we don't really have any new results compared to last year, and now is the time to push any remaining SUSY stuff out the door before it is decisively tested at the LHC next year.

A kind of corollary to the more pessimistic view on SUSY was a rise in more simple models, attempting to solve non-hierarchy problems (neutrino masses, dark matter) or looking at the whole hierarchy question in a different way.  Strumia's talk on the first morning of the conference heralded this.  Though on that subject, apparently the particular model of gravity he considered is an old idea, and the ghost problem dissuaded many serious people from taking it seriously.  To remind you, Strumia does not really address this problem: he just assumes it can be solved and considers if the phenomenology does what he wants.

Anthropic (landscape) arguments also showed up, though not in great numbers.  The basic problem is that it's hard to make any kind of predictions.  Still, Lawrence Hall's concluding talk was inspiring in this direction.  The message I took from it was that we might not be able to answer everything just now, but we can still make progress working on smaller problems (just like everywhere else in physics); and we have barely scratched the surface here.

Apart from all this, there was one more thing I took from Planck.  This was my first time in Paris, and before arriving I had doubts the city could live up to its reputation.  I was wrong.  It is fabulous.  If you've never been, go.