Cosmology
5. The Universe is expanding (Inflationary perturbations 1)
This is the 3rd post in the series based on my lectures on inflationary perturbations at the University of Helsinki (previous ones can be found here and here).
Today I am going to finally start constructing some theoretical basis for the future posts on inflationary perturbations 
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4. Large scale structure of the Universe. In other wavebands (Inflationary perturbations 1)
In this post, I will briefly describe what astronomers see on the sky in wavebands other than optical as well as what observations in other wavebands are especially good for.
The best instruments to observe the Universe one can have are the space based ones. Currently, the space observatories – the facet eyes of our civilization looking at the sky – include: already mentioned WMAP for observations in 1 mm – 1 cm waveband (microwave radiation), Spitzer space telescope for observations in 1 mkm – 100 mkm waveband (infrared), Solar and Heliospheric Observatory (SOHO) r observations in 50 nm – 500 nm waveband (UV), Hubble Space Telescope for observations in optical band, UV and IR, XMM Newton and Chandra Space Telescope for observations in 0.5 nm – 10 nm waveband (X rays) and INTEGRAL for observations in 100 fm – 100 pm waveband (gamma rays). Finally, we also have eyes in radio waveband (> 1cm) but these are all ground based since radio waves can easily pass through the Earth’s atmosphere.
3. WMAP 5 year – more
I was asked over email how well it is known that the Universe is spatially flat. According to just released WMAP 5 year dataset , the spatial curvature contribution is bounded by 
at the 95% confidence level with prior on the equation of state for the dark energy 
(dark energy = cosmological constant) or 
at the 95% confidence level if the prior above is not set. Therefore, the precision of the statement that the Universe is spatially flat is more than 1 %.
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2. Large scale structure of the Universe. In visible light (Inflationary perturbations 1)
This post is the first one in the series devoted to discussion of the large scale structure of the Universe, inflationary cosmology and inflationary perturbation theory. The series will be essentially based on the lectures I am giving currently at the University of Helsinki for graduate students and advanced undergrads.
1. WMAP 5 year
Clearly, the most important paper(s) in astro-ph today is the release of the 5 year data of WMAP. The references to papers are:
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