I don't think Hal is even reading your e-mails about the Susskind
article. He was on a week long trip to NC last week and came back with
a bad chest cold. He is not in the office. I know he is behind in
reading his e-mails for these two reasons. But he still stands firm
that ZPE does not gravitate because of its Lorentz invariance and
isotropicity (uniformity) in space.
But that is a completely wrong inference as Lenny Susskind very clearly
unambiguously writes. The argument you cite is inconsistent. No one of
influence in the field believes that. Lenny Susskind is very clear about
that. So, according to Hal the universe cannot accelerate and the
uniform cosmological constant does not exert a vacuum force on ordinary
matter etc. This is obviously wrong and disagrees with observation in a
very serious way. So Hal would have to say Lenny Susskind's book is
wrong in Ch 2 for example. Hal cites John Peacock's book, which
contradicts what you wrote.
Also Lorentz invariance and equivalence principle give directly in weak
field case for simplicity
In Einstein's theory of gravity
Guv = kTuv
k = 8piG/c^4 = 1/(string tension)
has the weak field slow-speed Newtonian static limit for an isotropic source
Grad^2V = 4pi(G/c^2)(Energy Density)(1 + 3w)
w = pressure/(energy density)
For all isotropic ZPF fields w = -1.
Therefore,
Grad^2V(ZPF) = -8pic^2/\zpf
Note here the sign convention is F = -GradV so that a positive source
term in the Poisson equation is an attractive force. A negative source
term is a repulsive force.
where from Lorentz invariance and the equivalence principle
Tuv(ZPF) = (c^4/8piG)/\zpfguv
Anisotropies from Casimir-type boundaries in confined spaces will shift
w on a case-by-case basis. The critical value of w for our purpose of
metric engineering is
w < - 1/3
Note that
w < -1
is dangerous on the cosmic scale causing the "Big Rip" in our local
Level I Hubble universe.
Note starting from the spherically symmetric quadratic interior
potential for the Higgs Ocean for example
V(ZPF) = - (1/2)c^2/\zpf r^2
GradV(ZPF) = -c^2/\zpfr = -F
/\zpf > 0 is repulsive exotic vacuum force F(Dark Energy)
/\zpf < 0 is attractive exotic vacuum force F(Dark Matter)
Grad^2V(ZPF) = - c^2/\zpf
I'm doing a study from supersymmetric theory on the negative energy
content of fermionic ZPE. The contribution from this is alleged by
cosmologists to cancel out the EM ZPE above some cut-off frequency, thus
yielding the tiny cosmological constant.
No, this does not work. Lenny Susskind explicitly talks about this.
Indeed if you read my messages carefully you will see I quote Lenny on
precisely this point.
However, no one has properly modeled the weak and strong force ZPEs, and
their contributions to the EM ZPE need to be considered before we can
properly address fermionic ZPE cancellation and the reason why the
cosmological constant is so tiny.
Reading Lenny's book gave me the idea of spontaneous broken vacuum
supersymmetry. The dynamics is still supersymmetric but the vacuum is
not. It's simply "More is different" P.W. Anderson again - this is a
different variation on what I previously proposed.
Here the vacuum order parameter is simply proportional to the difference
in the fermion and boson field species which may vary from place to
place and on different scales inside the same Level 1 Hubble universe.
This would be consistent with Cosmic Landscape i.e. tunneling from
parallel "branes" into our local universe perhaps. However, I only got
this idea yesterday from reading Lenny's book.
Dominance of the fermions is attractive virtual dark matter no real
particles to be detected. Dominance of the bosons is repulsive virtual
dark energy. 96% of all the stuff of the world is, therefore, exotic
vacuum and only ~ 4% is on-mass-shell particles whizzing through space
that causes counters to click.
Eric
Eric W. Davis, Ph.D., FBIS
Inst. for Advanced Studies at Austin
4030 W. Braker Lane, Suite 300
Austin, TX 78759