Tuesday 10 January 2012

Dark Energy and Expansion 101

BDOA wrote this over at Science 2.0 in reply to an articles on the Einstein plus Higgs expansions paradox. How can space expanded when there's an Aether (except relatisticly invarent) like field of Higgs particle in it. I'll need to dumb this done to the level of the readership.

Space doesn't expand? next you'll be telling me that Hubble was a bungling detective.

Its a good paradox though. Is there an energy cost of free space, as your expand the universe. Especially if that free space has got a 246 GeV Higgs field made out of 126 GeV field particles field in it. Doesn't that Higgs field both cost or gain energy and induce a big cosmological constant. Its like gravity doesn't care about the Higgs field.

Supersymmetry says the energy of the Vacuum is zero. that one of the reasons that physicist like it so much. Add up the vacuum energy from all the fermions and all the bosons and you get zero. of course once you break supersymmetry, and it is broken or they'd be a scalar electron or same mass turning all our molecules into superfluids, all that Vacuum energy comes back, at the breaking scale.

The other pointer, I've seen, is that in a universe with just gravity and photons or massless particles (not sure if this continues with non-abelian or interacting particles), the overall energy is also aways zero. That one of few cases where a definition of global total energy actually works in general relavity, most of the rest of the time they just isn't single definition of energy that works.

The point of the Higg mechanism is a set of massless fields can be redefined as set of massive fields by renaming what you call the particle, then building a Higgs field shouldn't effect the gravity, and the contribution to cosmological constant is zero. What about all the interaction terms though which I question marked above, they need to be proved to not make a difference to the gravity. Begin with a literature search please, and add to a sane distance beyond the current state of the art. Perphaps its already solved, but I tend to look out for that kind of stuff at arXiv and haven't seen it yet.

Now dark energy, that's trickery. Sasha said, the more empty space there is, the more the universe accelerates. That's dark energy with a phantom equation of state, w<-1. If w=-1 is just like a cosmological constant. The observations of dark energy tell us that is w<-.75 and it might even have only switched one recently (six million years, z<2, (z being the redshift factor, used for distance and time in most dark matter literature, which of course get new measurement regularly). Very light particles with very strong self interaction, strong enough to pair create more of themselves would be a good candidate for dark energy for w near to but above minus one. As a model, I gave neutrinos a force like electromagnetism (but not em) between them, expanded the system, and found w to be approximately -17/18 and turned on about z=2.6. There are also good published paper on a QCD ghost dark energy, which only uses standard QCD on a curved background in general relavity (now that really hard math) , but that has w~.75 and turns on around z=2. But it does seem to generate dark energy like expansion from the QCD condensate. The QCD condensate which is another aether like field, that physicist have put in empty space and comes about just breaking the symmetry of the axial color due to the axial anomaly. Can you make a Higgs field from a condensate like the QCD one. Yes, that's called a techicolour Higgs, lots of new physics paper going on there as well. BDOA
Space doesn't expand? next you'll be telling me that Hubble was a bungling detective.

Its a good paradox though. Is there an energy cost of free space, as your expand the universe. Especially if that free space has got a 246 GeV Higgs field made out of 126 GeV field particles field in it. Doesn't that Higgs field both cost or gain energy and induce a big cosmological constant. Its like gravity doesn't care about the Higgs field.

Supersymmetry says the energy of the Vacuum is zero. that one of the reasons that physicist like it so much. Add up the vacuum energy from all the fermions and all the bosons and you get zero. of course once you break supersymmetry, and it is broken or they'd be a scalar electron or same mass turning all our molecules into superfluids, all that Vacuum energy comes back, at the breaking scale.

The other pointer, I've seen, is that in a universe with just gravity and photons or massless particles (not sure if this continues with non-abelian or interacting particles), the overall energy is also aways zero. That one of few cases where a definition of global total energy actually works in general relavity, most of the rest of the time they just isn't single definition of energy that works.

The point of the Higg mechanism is a set of massless fields can be redefined as set of massive fields by renaming what you call the particle, then building a Higgs field shouldn't effect the gravity, and the contribution to cosmological constant is zero. What about all the interaction terms though which I question marked above, they need to be proved to not make a difference to the gravity. Begin with a literature search please, and add to a sane distance beyond the current state of the art. Perphaps its already solved, but I tend to look out for that kind of stuff at arXiv and haven't seen it yet.

Now dark energy, that's tricky. Sasha said, the more empty space there is, the more the universe accelerates. That's dark energy with a phantom equation of state, w<-1. If w=-1 is just like a cosmological constant. The observations of dark energy tell us that is w<-.75 and it might even have only switched one recently (six million years, z<2, (z being the redshift factor, used for distance and time in most dark matter literature, which of course get new measurement regularly). Very light particles with very strong self interaction, strong enough to pair create more of themselves would be a good candidate for dark energy for w near to but above minus one. As a model, I gave neutrinos a force like electromagnetism (but not em) between them, expanded the system, and found w to be approximately -17/18 and turned on about z=2.6. There are also good published paper on a QCD ghost dark energy, which only uses standard QCD on a curved background in general relavity (now that really hard math) , but that has w~.75 and turns on around z=2. But it does seem to generate dark energy like expansion from the QCD condensate. The QCD condensate which is another aether like field, that physicist have put in empty space and comes about just breaking the symmetry of the axial color due to the axial anomaly. Can you make a Higgs field from a condensate like the QCD one. Yes, that's called a techicolour Higgs, lots of new physics paper going on there as well.

4 comments:

Anonymous said...

Hi Dr B D O Adams,

quite a nice site You have here :-)

And it is brave from You to defend Ron Maimon on physics.se
I liked Your answer on Meta ... twice ha ha ;-)

Unfortunately as You can see below dmcke's answer to the same question (had an issue with him then), I`m no longer able to ask or answer questions at physics.se :-/ ... The questions about BSM particle physics have ceased anyway more or less there.

Cheers

Dilaton

Anonymous said...

Oh sorry for the triple posts, thought it does not work and did not notice that You moderate the comments ...

Dilaton again

Dr BDO Adams said...
This comment has been removed by the author.
Dr BDO Adams said...

I'm a bit slow to moderate, but it does get done, just one comment now. Note i'm also posting at science2.0 where I get more readers.