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I just read Wolfram's blog post on the Higgs discovery.

Still, there’s another problem. To get the observed particle masses, the background Higgs field that exists throughout the universe has to have an incredibly high density of energy and mass. Which one might expect would have a huge gravitational effect—in fact, enough of an effect to cause the universe to roll up into a tiny ball. Well, to avoid this, one has to assume that there’s a parameter (a “cosmological constant”) built right into the fundamental equations of gravity that cancels to incredibly high precision the effects of the energy and mass density associated with the background Higgs field.

Then I recalled that one of the great unsolved problems in physics is why the zero-point energy of the vacuum predicts a very large cosmological constant which is not observed.

The language used to describe these two effects confuses me, but as far as I can tell, Higgs->contraction and ZPF->expansion

Any chance these two effects are in balance?

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The effective cosmological constant has potential contributions from several sources: 1) Scalar field potentials like from the Higgs field which does not have to have its minimum at V=0. 2) Quantum vacuum fluctuations. 3) A cosmological constant.

Note that all of these contributions can be positive or negative and are potentially many orders of magnitude larger than the observed cosmological constant. So the cosmological constant problem is why do all these potentially very large terms almost exactly cancel.

One proposed solution is that on very large scales there is a landscape (multiverse) of different potential minima (perhaps from string theory) and galaxies can only form in those pocket-universes where the different contributions in the landscape give a sufficiently small effective cosmological constant. You can see Weinberg's famous paper on it for more details: http://rmp.aps.org/abstract/RMP/v61/i1/p1_1

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