Comment Re:Good news for inflation, but... (Score 1) 161
(First, a disclaimer: I'm only a physics student, so feel free to correct me if I'm getting this wrong.)
As far as I can remember (and I'm too lazy to find my cosmology lecture notes), inflation was originally proposed by Alan Guth, then Linde sorted out some of the maths to make it work properly . . .
More importantly, inflation theory *does* predict a flat universe, but this isn't necessarily the same as one with zero cosmological constant. The cosmological constant is a term proposed by Einstein in order for his equations of general relativity to hold for a universe that wasn't expanding. When it was discovered that the universe *was*, the term was neglected and assumed to be zero. Whether or not the universe is flat is to do with the value of omega-nought, the density parameter, which is something different.
However there are various problems with inflationary theory and cold dark matter models (for example models predict much higher velocities of galaxies than are observed), and one way of solving these is to use a non-zero cosmological constant, whcih helps with the problem of there not being enough density. Although a non-zero cosmological constant is still a fairly unlikely possibility, this study does not say that the cosmological constant is zero. In fact if you read the Nature article, they used values of the constant between 0 and 1.
-Judith
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More is happening out there than we are aware of.
As far as I can remember (and I'm too lazy to find my cosmology lecture notes), inflation was originally proposed by Alan Guth, then Linde sorted out some of the maths to make it work properly . . .
More importantly, inflation theory *does* predict a flat universe, but this isn't necessarily the same as one with zero cosmological constant. The cosmological constant is a term proposed by Einstein in order for his equations of general relativity to hold for a universe that wasn't expanding. When it was discovered that the universe *was*, the term was neglected and assumed to be zero. Whether or not the universe is flat is to do with the value of omega-nought, the density parameter, which is something different.
However there are various problems with inflationary theory and cold dark matter models (for example models predict much higher velocities of galaxies than are observed), and one way of solving these is to use a non-zero cosmological constant, whcih helps with the problem of there not being enough density. Although a non-zero cosmological constant is still a fairly unlikely possibility, this study does not say that the cosmological constant is zero. In fact if you read the Nature article, they used values of the constant between 0 and 1.
-Judith
-----------
More is happening out there than we are aware of.
