#### marcus

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**31 Dimensionless Constants--Wilczek, Tegmark, Aguirre, Rees**

http://arxiv.org/abs/astro-ph/0511774

**Dimensionless constants, cosmology and other dark matters**

Max Tegmark (MIT), Anthony Aguirre (UCSC), Martin Rees (Cambridge), Frank Wilczek (MIT)

29 pages, 12 figs

"We identify

**31 dimensionless physical constants**required by particle physics and cosmology, and emphasize that both microphysical constraints and selection effects might help elucidate their origin. Axion cosmology provides an instructive example, in which these two kinds of arguments must both be taken into account, and work well together. If a Peccei-Quinn phase transition occurred before or during inflation, then the axion dark matter density will vary from place to place with a probability distribution. By calculating the net dark matter halo formation rate as a function of all four relevant cosmological parameters and assessing other constraints, we find that this probability distribution, computed at stable solar systems, is arguably peaked near the observed dark matter density. If cosmologically relevant WIMP dark matter is discovered, then one naturally expects comparable densities of WIMPs and axions, making it important to follow up with precision measurements to determine whether WIMPs account for all of the dark matter or merely part of it."

31 fun numbers that determine the universe

EDIT BTW the first physics blog to flag this paper was Christine Dantas "Background Independence". She's alert.

http://christinedantas.blogspot.com/2005/11/salad-of-dimensionless-constants.html [Broken]

Looks like she posted at 9AM GMT Wednesday 30 November.

Cosmic Variance was nowhere in sight, Peter Woit didnt notice

The new physics blog Aggregate called "Mixed States" posted feed from Christine soon after, maybe a couple of hours.

http://mixedstates.somethingsimilar.com/ [Broken]

also this address

http://somethingsimilar.com/mixedstates/ [Broken]

I think it is going to be a major paper, not for anything new it says but because of being monumentally thorough in laying out the fundamental constants, with current estimates of their values, and going massively into all the interrelation and derived detail. And for temporarily defining the basic goal of physics and cosmology to explain these 31.

or, alternatively, if we decide to give up the quest to explain them, then it shows us just what we are giving up on----so at least we have a clear idea of what we are admitting to be imponderable to us

so this paper can play a kind of landmark or benchmark role

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