Post-Planck Cosmology: Day 2

Just finished the last session of the day and it’s only half an hour before the conference dinner begins, so I’ll just do a brief summary.

The weather in Pune continues to be `interesting’:

It’s pouring down at the moment, in fact. The session I chaired started late because we had to postpone the conference photograph because of inclement weather.

Anyway, this morning’s talks were primarily about the difficulties of measuring B-mode polarization in the cosmic microwave background. Carlo Baccigalupi gave a perspective on foregrounds from Planck and Zeeshan Ahmed updated us on Keck/BICEP progress. There are no new results from the latter – we’ll have to wait for data from the extra 220 GHz channel – but Zeeshan also spoke about a proposal for the next generation ground-based experiment, glamorously named CMB-S4 – details of which can be found here.

The afternoon was largely devoted to early universe physics, including inflation. We’re only two days in to the conference but already several speakers have showed this plot (from here), which shows the extent to which current cosmological data disfavours various inflationary models:

Some are disfavoured, but clearly there are still lots of viable models! Too many!

For the final session of the day we were joined by Paul Steinhardt via Skype from the USA. He gave a very cogent and stimulating talk arguing that the prevailing paradigm (i.e. inflation) was about to be overturned. I don’t have time to do a full summary of his contribution, but you can check out a previous post about some of the issues he raised, and here’s a picture of the last slide of his presentation:

Anyway, that will have to do. The conference dinner beckons.

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