Accompanying the paper is the release of the software package used to create the results. Pyflation is a Python package which calculates the first and second order perturbation results including the source term required at each time step. It requires Numpy, Scipy and PyTables and a fairly recent version of Python. The full calculation for a large range of Fourier wavemodes takes a long time on a single CPU, but there is support for splitting the calculation into many separate jobs which can be queued on a multi-core or cluster based setup. Alternatively there is also support for calculating the second order results for a single wavemode, which significantly reduces the execution time.

The Pyflation website contains all the details and download links, installation notes and links to the relevant papers. We’ve released the package under a very liberal open source license (modified BSD license) but as citations are increasingly the oil that greases the wheels of academia we ask that anyone who uses results they have obtained with Pyflation to please cite one or more of the related papers.

I think PhD students go through a range of feelings towards their theses, beginning with excitement and some trepidation when they start a blank text file, progressing through despair in the mandatory mid-cycle slough, to eventually being completely fed up and just wanting it out the door. Now that I’ve gone through all that and seen the finished product in lovely blue serge cloth, the only thing left to do was to put it online.

So the final, corrected version of my thesis is now available at the arXiv. I’m not expecting anyone to actually go read the thing but when I have lost or mislaid my copy at least I’ll be able to download it.

The deadline for registering your interest in attending or giving a talk is tomorrow the 16th. Funding is being provided for travel costs and PhD students and postdocs are especially encouraged to apply to speak. More information about the programme and location is on the meeting webpage.

My talk was on Thursday afternoon in the inflation session. The slides are here in pdf format and embedded below by SlideShare. Bear in mind that the talk was only 12 minutes long, and that I have opted for a minimalist approach so there is very little text per slide!

After last week’s Science Online London 2009 conference which I attended, I have been thinking about how to get fellow cosmologists to start interacting online. I am not sure whether anyone else will use it but I have started using the hashtag #cosmo09 on twitter and have created a FriendFeed room for the conference. There might not be much activity, but if people do want to use these tools, at least they will have somewhere to start.

Now that we have finished the preprint version I can concentrate solely on writing up my PhD thesis. It’s going to be a long few months!

The new academic year has brought with it some new tools from one of my favourite web resources Cosmocoffee. As you can read in this forum post, there are three new additions to the service. Firstly new search options are available which allow you to use the search page on Cosmocoffee to search the arXiv, ADS and Google Scholar. I don’t know how useful this might be, as I tend to use the integrated search bar in Firefox to directly search SPIRES and the arXiv.

The main update however is the addition of a bookmarking system to the arXiv listings. While not as fully featured as either Citeulike or Connotea, this is a very intuitive system and can be easily integrated into your workflow if you already use Cosmocoffee to access new arXiv papers.

The final tool is a complimentary function of the bookmarking system, allowing multiple users to share lists of bookmarks in a “Journal Club” system. There is a rudimentary management system, with the ability to add users and other managers, and move papers into “old” and “ignored” categories. There is also an anonymous list of all the papers that have been bookmarked so far, which provides an interesting insight into the reading habits of Cosmocoffee users.

To use the bookmarking system you will need to register at the Cosmocoffee site. Since last year registration has been restricted to people affiliated with academic institutions.

This week there is an international conference taking place in Imperial College. Called PASCOS, it focuses on particles, strings and cosmology, so a little bit of everything really. I headed over there yesterday to see a specific talk by Hiranya Peiris, who recently co-wrote a paper citing us, and doing a numerical simulation which validates the tensor mode bound in our recent paper. It was interesting to actually see someone citing my work, with my name up in lights on the screen!

And next week I might get to meet yet more people involved in the work I have been doing recently, when I go to the ICTP in Trieste for a “workshop” on Strings and Cosmology. I realise now that it is not so much of workshop as a large conference, with around 200 participants registered. But it’s a good reason to get away from the recent dreadful weather and incompetent suicide bombing doctors here in London.

The talk is supposed to be based on our last paper (which will soon appear in JCAP by the way), but with limited time I think I will have to speed through it pretty quickly. As a lot of the paper draws in techniques and results from string theory, I might have to gloss over those to.

The audience is going to be large (at least 50 people), with a mix of postgrads, postdocs and faculty from across the UK. And with a varied mix of theoretical and observational cosmologists, I am finding it difficult to find the right level to pitch the talk at.

To make things a little harder, I have written the talk using Beamer, which is a very impressive presentation class for LaTeX. But I have never used it before, so I am constantly dipping in to the userguide to find out how to do things that in OpenOffice would be simple. That said, I really like being able to incorporate equations into my presentation with no fuss at all, as opposed to the tortuous methods needed in other programs.

With any luck I will be able to overcome these problems before next Tuesday, so here’s hoping the train to Portsmouth gets us there on time!

The conclusion the authors reach is that our knowledge of cosmology and the expansion of the universe would simply be unobtainable in the far future. The acceleration of the expansion of the universe will leave nothing but our own small group of galaxies inside the observable horizon. Evidence of large redshifts at long distances will simply not exist. They reason that pseudo-cosmologists of the future will have to conclude that the universe exists in a steady state, with no reason to expect a big bang initial event.

The New York Times’ Dennis Overbye described the essay as “one of the more depressing scientific papers I have ever read”. While I don’t think I would go that far, there are some worrying aspects. As mentioned in the NY Times article, science in the far future will be hamstrung without enough observational evidence, and will end up trying to explain meaningless coincidences.

[T]hey will puzzle about why the visible universe seems to consist of six galaxies, Dr. Krauss said. “What is the significance of six? Hundreds of papers will be written on that,” he said.

The most troubling aspect of this argument is that it does suggest that we are perhaps even now engaging in the same sort of trivial pondering due to lack of evidence. For example any evidences of multiverses or the like which might once have been observable could now be trapped forever beyond even our future theoretical capabilities.

This isn’t the first time this sort of scenario has been suggested, and in fact dark energy is not even required to fuel the acceleration. George Ellis and Tony Rothman came up with a similar idea back in 1987, in a paper called The epoch of observational cosmology (ADS abstract and link to PDF).