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Higgs Data Could Spell Trouble For Leading Big Bang Theory
ananyo writes "Paul Steinhardt, an astrophysicist at Princeton University in New Jersey, and colleagues have posted a controversial paper on ArXiv arguing, based on the latest Higgs data and the cosmic microwave background map from the Planck mission, that the leading theory explaining the first moments of the Big Bang ('inflation') is fatally flawed. In short, Steinhardt says that the models that best fit the Planck data — known as 'plateau models' because their potential-energy profiles level off at relatively low energies — are far less likely to occur naturally than the models that Planck ruled out. Secondly, he says, the news for these plateau models gets dramatically worse when the results are analyzed in conjunction with the latest results about the Higgs field coming from CERN's Large Hadron Collider. Particle physicists working at the LHC have calculated that the Higgs field is likely to have started out in a high-energy, 'metastable' state rather than in a stable, low-energy configuration. Steinhardt likens the odds of the Higgs field initially being perched in the precarious metastable state as to those of dropping out of the sky over the Matterhorn and conveniently landing in a 'dimple near the top,' rather than crashing down to the mountain's base."
That sounds like a cosmic catastrophe in the making. Or has it already happened?
Ezekiel 23:20
....we just don't know.
It wasn't a Big Bang, but a Medium Bang!
gotta get out my papers, nobel prize for fizziks here I come!
A feeling of having made the same mistake before: Deja Foobar
Years ago, this was a significant debate, but in recent years the debate was "settled" - the universe's expansion is actually increasing in rate.
I have always felt that it was wrong to call this settled. The increased rate of expansion of the universe is explained by "Dark Energy", a completely unknown entity with unknown properties. There is no reason why the effects of Dark Energy might change (or even reverse) over time. So, is the universe expanding at an increasing rate? Apparently. Will it continue to do so? I don't think that is even close to answered.
Great warrior...hrmph! Wars not make one great.
Why do you religious people keep saying that atheism is a religion?
Because some atheists act in a religious manner.
We (I am an atheist) cannot prove the non-existance of God. We can use our observations of the world around us and logic to come to a refusal to believe the fairy tales we're taught as children, and this is all in the realm of reason. But those of us who claim to know without doubt that there is no deity have crossed into the realm of faith.
Steinhardt is no novice when it comes to making controversial cosmic claims. For many years, he and some of his colleagues have been developing an alternative 'cyclic model', in which the Universe undergoes a series of Big Bangs and crunches, repeatedly expanding outwards and contracting inwards. Unlike inflation, this framework predicts slight deviations from the smooth Gaussian distribution of temperature fluctuations.
So it's not like he wants to throw out the whole thing, just the "inflation" variation.
Everything is better with chainsaws.
It's not a cosmic catastrophe so much as a physics one, although I'd prefer to call it a physics "opportunity"! Having found the Higgs we already know that there is now an incredible precarious balance even within the Standard Model. The Higgs is a fundamental scalar particle which is a radically different beast from any other fundamental particle we know of. One of the strange properties of the Higgs is that there are corrections to its mass which scale with energy squared.
This might not sound like a big deal but quantum mechanics means that even at low energies these high energy corrections to the Higgs mass are important. The question then becomes "what energy is our current knowledge of physics good to". Well if we look at the Standard Model of particle physics it is missing gravity so, at the scale where gravity becomes important (about a million billion times higher in energy than the LHC) we know the SM breaks down.
The problem is that this means the Higgs mass is corrected by a series of terms each of which is ~32+ orders of magnitude larger than the mass itself. This means that you need a cancellation to better than one part in ~10^32 by chance. This is about the same chance as winning the UK national lottery every week for 4-5 weeks in a row or tossing a coin and having it come up heads over 100 times in a row. If either of these events actually happened nobody would believe they happened by chance - there would be investigations into how someone managed to cheat the lottery or you would want to inspect the coin to make sure it did not have two heads.
There are solutions to this conundrum: Supersymmetry makes all the corrections to the Higgs mass cancel precisely (above some energy scale) and Large Extra Dimensions lowers the scale where gravity becomes important considerably. What would be interesting to know is whether these solutions to the fine tuning problem we have in the Standard Model also solve the fine tuning which this paper suggests that cosmology also has.
If the evolution of a stable universe requires the Higgs field to start out at a metastable point, and if variations in those initial conditions lead to universes which collapse rather than inflating, then "the amplitude" (i.e. the probability that they are the outcome that we turn up in) for those other states is zero. Why? Because those universes all collapse long before we could show up.
On the other hand, if Steinhardt is correct, then his result shows there is a path to here-and-now through the metastable point, and if that's what it takes to get here, then that's enough: that's what it takes. The amplitude of the entire wave function for the Steinhardt path is non-zero, unlike the functions for the ones that collapsed.