Dark matter: hot and fast?

Can somebody give a comment on the report, though unpublished, that dark
matter may be hot and fast; see for example:
http://news.bbc.co.uk/2/hi/science/nature/4679220.stm
If it has a temperature of 10000 K, would it not radiate, for example, and
be directly observable?

--
Hans Aberg

Thus spake Hans Aberg
Can somebody give a comment on the report, though unpublished, that dark
matter may be hot and fast; see for example:
http://news.bbc.co.uk/2/hi/science/nature/4679220.stm
If it has a temperature of 10000 K, would it not radiate, for example, and
be directly observable?

In historical terms, when there has been a fundamental misconception in
science, the properties of that misconception have a way of becoming
more and more bizarre and less and less tenable as time goes on. I think
this is happening to cold dark matter. I am near to submitting my
teleconnection paper, in which one has to consider the wave function of
photons detected from space. General relativity can't consider that
properly without unification, and that is the problem the teleconnection
is designed to solve. The result is a revision of cosmological
parameters, and reinterpretation of galaxy rotation curves such that
there is no evidence for CDM. Would you like a copy of the pdf?


Regards

--
Charles Francis
Please reply by name

Hans Aberg wrote:
Can somebody give a comment on the report, though unpublished, that dark
matter may be hot and fast; see for example:
http://news.bbc.co.uk/2/hi/science/nature/4679220.stm
If it has a temperature of 10000 K, would it not radiate, for example, and
be directly observable?


Firstly, most of the dark matter in the universe is non-baryonic.
This matter couples very weakly, if at all, to electromagnetic radiation
(else it would not be dark). Therefore it cannot radiate, no matter how
much you heat it, and therefore you will not be able to observe it
directly.

Secondly, you should be careful with interpreting these results. The
results come from fairly small scales, where you study the dynamics
inside individual dwarf galaxies. The observations that give the
strongest support to the current dark matter paradigm come from studies
of phenomena on much larger scales. In my opinion it should not come as
a surprise if we find that dark matter behaves in an unexpected way on
smaller scales. Several years ago it was noticed by people doing
numerical simulations of the formation of galaxies and large scales
structures that the density distributions one obtained from the
simulations had too strong mass concentrations at the centres. Some
researchers then suggested that the dark matter particles had a large
cross section for interacting among themselves. Can that be what Gerry
Gilmores group sees, that locally the dark matter has heated up as it
has collapsed?

Ulf Torkelsson

In article , Ulf Torkelsson
wrote:

Several years ago it was noticed by people doing
numerical simulations of the formation of galaxies and large scales
structures that the density distributions one obtained from the
simulations had too strong mass concentrations at the centres. Some
researchers then suggested that the dark matter particles had a large
cross section for interacting among themselves. Can that be what Gerry
Gilmores group sees, that locally the dark matter has heated up as it
has collapsed?

If the black hole at the center of the galaxy can produce dark matter
through tunneling, perhaps that can account for higher density and higher
temperature of such dark matter towards the galaxy center.

--
Hans Aberg

Hans Aberg wrote:
In article , Ulf Torkelsson
wrote:


Several years ago it was noticed by people doing
numerical simulations of the formation of galaxies and large scales
structures that the density distributions one obtained from the
simulations had too strong mass concentrations at the centres. Some
researchers then suggested that the dark matter particles had a large
cross section for interacting among themselves. Can that be what Gerry
Gilmores group sees, that locally the dark matter has heated up as it
has collapsed?


If the black hole at the center of the galaxy can produce dark matter
through tunneling, perhaps that can account for higher density and higher
temperature of such dark matter towards the galaxy center.

There are several reasons that this is not a likely explanation.
Firstly you need the black hole to be evaporating much faster than is
predicted by the Hawking process, but let us accept this as a
possibility for the moment. The big problem is that the mass of the
black hole in a galaxy is a small fraction of the mass of the galaxy and
consequently is a small fraction of the mass of the dark matter in the
galaxy. Therefore we are forced to the conclusion that if the dark
matter comes from the black hole, then most of the black hole has
already evaporated in most galaxies, and we must expect to find a lot of
galaxies without any black holes at all, but all normal galaxies that we
have studied carefully enough do have black holes in their nuclei.

By the way, most of all we should keep in mind that in this case the
group has been studying some nearby dwarf galaxies. I am not aware of
whether these galaxies are known to have any central black holes at all.

Ulf Torkelsson

In article , Ulf Torkelsson
wrote:

Several years ago it was noticed by people doing
numerical simulations of the formation of galaxies and large scales
structures that the density distributions one obtained from the
simulations had too strong mass concentrations at the centres. Some
researchers then suggested that the dark matter particles had a large
cross section for interacting among themselves. Can that be what Gerry
Gilmores group sees, that locally the dark matter has heated up as it
has collapsed?

If the black hole at the center of the galaxy can produce dark matter
through tunneling, perhaps that can account for higher density and higher
temperature of such dark matter towards the galaxy center.

There are several reasons that this is not a likely explanation.
Firstly you need the black hole to be evaporating much faster than is
predicted by the Hawking process,

Sure, one would have to look for a physical theory that can combine GR &
QM in a unified manner, so as to be able to describe the tunneling
processes that enables dark matter to leave the*black hole. The
Hawking*radiation*does not rely on developing such a theory, and thus just
says that even without such a*theory in hand, some radiation should be
able to leave the black hole. This is a*bare minimum.

...but let us accept this as a
possibility for the moment.* The big problem is that the mass of the
black hole in a galaxy is a small fraction of the mass of the galaxy and
consequently is a small fraction of the mass of the dark matter in the
galaxy.* Therefore we are forced to the conclusion that if the dark
matter comes from the black hole, then most of the black hole has
already evaporated in most galaxies, and we must expect to find a lot of
galaxies without any black holes at all, but all normal galaxies that we
have studied carefully enough do have black holes in their nuclei.

No, this would not be the case, as mainly baryonic matter would constantly
fall into the black hole. Both baryonic and non-baryonic matter might then
leave the*black hole*through tunneling, following the discussions here in
this group before. The baryonic matter,*responsible for the creation of
the infancy matter, would not be able to leave the black hole except at
the poles of the galaxy, as it would react with the baryonic matter
falling into the galaxy from the disc. But if, as you said, the
non-baryonic matter couples weakly with EM, and then perhaps with baryonic
and other non-baryonic matter as well, then it could leave in the disc
direction too.

Thus, there is considerable dynamics required to keep this picture in
place. There, the part of the result that suggests that this dark matter
is fast would play an important role.

* * By the way, most of all we should keep in mind that in this case the
group has been studying some nearby dwarf galaxies.* I am not aware of
whether these galaxies are known to have any central black holes at all.

The fact that this dark matter is fast, suggests one might attempt to
build directional detectors for non-baryonic matter, like one has done in
the case of neutrinos, acting in effect as telescopes in the non-baryonic
spectrum. Then this would lead to method to observe directly if black
holes can produce such dark matter.

--
Hans Aberg

Hans Aberg wrote:
In article , Ulf Torkelsson
wrote:


If the black hole at the center of the galaxy can produce dark matter
through tunneling, perhaps that can account for higher density and higher
temperature of such dark matter towards the galaxy center.


There are several reasons that this is not a likely explanation.
Firstly you need the black hole to be evaporating much faster than is
predicted by the Hawking process,


Sure, one would have to look for a physical theory that can combine GR &
QM in a unified manner, so as to be able to describe the tunneling
processes that enables dark matter to leave the black hole. The
Hawking radiation does not rely on developing such a theory, and thus just
says that even without such a theory in hand, some radiation should be
able to leave the black hole. This is a bare minimum.

Well by postulating new physical effects you can explain anything, so
I do not consider this to be a particularly persuasive argument.


...but let us accept this as a
possibility for the moment. The big problem is that the mass of the
black hole in a galaxy is a small fraction of the mass of the galaxy and
consequently is a small fraction of the mass of the dark matter in the
galaxy. Therefore we are forced to the conclusion that if the dark
matter comes from the black hole, then most of the black hole has
already evaporated in most galaxies, and we must expect to find a lot of
galaxies without any black holes at all, but all normal galaxies that we
have studied carefully enough do have black holes in their nuclei.


No, this would not be the case, as mainly baryonic matter would constantly
fall into the black hole. Both baryonic and non-baryonic matter might then
leave the black hole through tunneling, following the discussions here in
this group before. The baryonic matter, responsible for the creation of
the infancy matter, would not be able to leave the black hole except at
the poles of the galaxy, as it would react with the baryonic matter
falling into the galaxy from the disc.

It appears here that you claim that the no-hair theorem for black
holes is not true, since the no-hair theorem tells us that there is no
difference between a black hole of baryonic matter versus one of dark
non-baryonic matter. That means that you are postulating new physics again.

But if, as you said, the
non-baryonic matter couples weakly with EM, and then perhaps with baryonic
and other non-baryonic matter as well, then it could leave in the disc
direction too.

Thus, there is considerable dynamics required to keep this picture in
place. There, the part of the result that suggests that this dark matter
is fast would play an important role.

Are you suggesting that in the past the galaxies had enormous black
holes consisting of the dark matter that we see in the galaxies today,
while nowadays they have black holes consisting of baryonic matter only?
Let us think about the numbers here. A typical mass of a sizable
galaxy is something like 1e11 solar masses, though you can find some
considerably heavier and quite a number of much smaller galaxies. The
dark matter that we find in the galaxies must be a considerable fraction
of this mass, let us say 50%. The masses of the black holes that we
find at the centres of the galaxies today are about 1e7 to 1e8 solar
masses (in particular for the ellipticals there is even a strong
correlation between the mass of the black hole and the mass of the
galaxy, so we can be sure that the mass of the black hole is small
compared to that of the galaxy), but assuming that the dark matter was
in the beginning concentrated in a black hole at the centre of the
galaxy, we would from the start have had a black hole of 5e10 solar
masses, which has then been spread out over the entire galaxy. Such an
event would have been a catastrophe for the galaxy and would have
completely destroyed the inner part of the galaxy simply because it
suffered a monumental loss of gravitating mass. As a matter of fact, we
must ask ourselves whether the galaxy could have survived at all, and in
particular whether it could have managed to keep the dark matter that
was thrown out from a distance of less than 1 pc from the centre to a
distance of several tens of kpc.

Ulf Torkelsson

In article , Ulf Torkelsson
wrote:

If the black hole at the center of the galaxy can produce dark matter
through tunneling, perhaps that can account for higher density and higher
temperature of such dark matter towards the galaxy center.

There are several reasons that this is not a likely explanation.
Firstly you need the black hole to be evaporating much faster than is
predicted by the Hawking process,

Sure, one would have to look for a physical theory that can combine GR &
QM in a unified manner, so as to be able to describe the tunneling
processes that enables dark matter to leave the black hole. The
Hawking radiation does not rely on developing such a theory, and thus just
says that even without such a theory in hand, some radiation should be
able to leave the black hole. This is a bare minimum.

Well by postulating new physical effects you can explain anything, so
I do not consider this to be a particularly persuasive argument.

It's only that one needs a*theory that can describe tunneling. Of course,
any theory must eventually become adjusted against physical observations.
This includes the Hawking radiation model, incidentally.

I do have some ideas about how to create such a model mathematically (see
below). But it is hard to produce a proper set of equations in such
models.

...but let us accept this as a
possibility for the moment.* The big problem is that the mass of the
black hole in a galaxy is a small fraction of the mass of the galaxy and
consequently is a small fraction of the mass of the dark matter in the
galaxy.* Therefore we are forced to the conclusion that if the dark
matter comes from the black hole, then most of the black hole has
already evaporated in most galaxies, and we must expect to find a lot of
galaxies without any black holes at all, but all normal galaxies that we
have studied carefully enough do have black holes in their nuclei.


No, this would not be the case, as mainly baryonic matter would constantly
fall into the black hole. Both baryonic and non-baryonic matter might then
leave the black hole through tunneling, following the discussions here in
this group before. The baryonic matter, responsible for the creation of
the infancy matter, would not be able to leave the black hole except at
the poles of the galaxy, as it would react with the baryonic matter
falling into the galaxy from the disc.

* * It appears here that you claim that the no-hair theorem for black
holes is not true, since the no-hair theorem tells us that there is no
difference between a black hole of baryonic matter versus one of dark
non-baryonic matter.* That means that you are postulating new physics again.

I do not know the exact details of this theorem, which mathematical models
it relies on, and what the exact conclusions are.

If, however,*constructs spin using the Clifford bundle, then the
Levi-Civita connection, which in GR communicates gravity, becomes trivial,
which suggests that spin survives the transitions into the black hole. As
far as I can see, one can construct a physical model that preserves the
other QM invariants this way, essentially by building a Fock space using
the*cotangent bundle. The*particles have a common timespace, represented
by the Lorentz manifold, and each particle has its own energy-momentum,
represented by a copy of the*cotangent tensor bundle. In such model, the
cotangent tensor part is flat, viewed as a manifold, which means that if
gravity is again communicated by the Levi-Civita connection, it acts
trivially on this component, which means that QM invariants will become
preserved under the influence of gravity.

So if ordinary matter, molecules made up of neutrons, protons, and
electrons, fall into a black hole, their QM invariants should be
preserved, in this model. The neutrons should fall apart into protons,
electrons, and neutrinos. If these particles then can tunnel
out,*disregarding any nucleosynthesis, one should get these
particles,*protons, electrons, and neutrinos, back.

In particular, the black whole ought to emit neutrinos. Is that the case?
Is it possible with todays neutrino-detectors to see if the hub of our
galaxy emits a large amount of neutrinos?

If one adds, in the tunneling process, nucleosynthesis into the picture to
produce infancy matter, then that will suck up neutrinos when creating a
certain amount of neutrons again. So that would lower the rate
of*neutrinos expected from a black hole.

But if, as you said, the
non-baryonic matter couples weakly with EM, and then perhaps with baryonic
and other non-baryonic matter as well, then it could leave in the disc
direction too.

Thus, there is considerable dynamics required to keep this picture in
place. There, the part of the result that suggests that this dark matter
is fast would play an important role.

* * Are you suggesting that in the past the galaxies had enormous black
holes consisting of the dark matter that we see in the galaxies today,
while nowadays they have black holes consisting of baryonic matter only?

I am a mathematician, so I have no feeling for these quantifications.

If these QM invariants are preserved when matter is falling in and
tunneling out, it the what happens with the structure of the black hole
depends on how easy it for the different QM invariants to tunnel out. Say
for example that it is easier for neutrinos to tunnel out than baryons,
then indeed the black hole would accumulate baryon invariants.

The second question is how the matter that falls in and the matter that
tunnels out balance. So when I think of it, a black hole could grow with
the galaxy, as well as its age. The question is really how to get physical
data to adjust such a model.

** Let us think about the numbers here.* A typical mass of a sizable
galaxy is something like 1e11 solar masses, though you can find some
considerably heavier and quite a number of much smaller galaxies.* The
dark matter that we find in the galaxies must be a considerable fraction
of this mass, let us say 50%.* The masses of the black holes that we
find at the centres of the galaxies today are about 1e7 to 1e8 solar
masses (in particular for the ellipticals there is even a strong
correlation between the mass of the black hole and the mass of the
galaxy, so we can be sure that the mass of the black hole is small
compared to that of the galaxy), but assuming that the dark matter was
in the beginning concentrated in a black hole at the centre of the
galaxy, we would from the start have had a black hole of 5e10 solar
masses, which has then been spread out over the entire galaxy.*

I do not think of a galaxy forming with a lot of dark matter in the
centre, but rather a more even distribution of dark matter*already
produced in by other back holes in the galaxy. Then, when a galaxy is
forming and gets its relatively small black hole, it becomes responsible
for uppering the amount of dark matter closer to the centre, just as the
remarks you made, of galaxies having too much dark matter towards the hub.

Such an
event would have been a catastrophe for the galaxy and would have
completely destroyed the inner part of the galaxy simply because it
suffered a monumental loss of gravitating mass.* As a matter of fact, we
must ask ourselves whether the galaxy could have survived at all, and in
particular whether it could have managed to keep the dark matter that
was thrown out from a distance of less than 1 pc from the centre to a
distance of several tens of kpc.

So this picture would never come into play.

--
Hans Aberg

Hans Aberg wrote:
In article , Ulf Torkelsson
wrote:

If the black hole at the center of the galaxy can produce dark matter
through tunneling, perhaps that can account for higher density and higher
temperature of such dark matter towards the galaxy center.

Since you are both discussing the pros and cons of a fairly speculative
hypothesis, I thought I'd throw in my two cents.

For what it's worth, it is possible to argue that when a black hole
forms,
it mediates the creation of a baby universe. This was a pet idea of
Stephen Hawking's and some others. Though Hawking recently de-
cided that black holes cannot create such baby universes, based
on very abstract topological arguments, I think it is still worth
consi-
dering until the evidence is all in... as follows:

Hypothesis...
When a black hole of mass Mbh forms in our universe, it forms a
daughter universe of total mass Md, whose own velocity of light,
Cd obeys

1) Mbh*Co = Md*Cd ,

where Co is our own vel. of light in field free space. Also, the black
hole and the daughter universe follow a Klein-Gordon style relation
for total conserved energy E_t

2) (E_t)^2 = (Md*Co^2)^2 = (Mbh*Co^2)^2 + (Pd*Co)^2 ,

where Mbh is BH mass, and Pd = Md*V, the analogous relativistic
momentum of the baby universe. Here the BH mass Mbh plays the
role normally played by a particle's rest mass in the K-G formalism.
A working hypothesis is that V (see eq. 4) is the velocity of the n-
dimensional surface of the daughter's hypersphere as its space-time
expands balloonlike on the 'other side' of the black hole's event hori-
zon. It is now in effect a white hole universe operating 'outside' of
our universe.

1) and 2) allow conservation of energy, linear momentum and
angular momentum for the entire system including BH and baby
universe.

Analysis shows that Md, the daughter's total mass, obeys

3) Md = Mbh / [ 1 - V^2/Co^2 ]^1/2

and Cd and V are always orthogonal to one another, so that

4) Co^2 = Cd^2 + V^2 .

Cd is the baby universe's proper velocity of light, which in general is
Co. This can be intuited by considering the daughter as analogous
to a relativistic spaceship with velocity V. Its 'onboard' velocity of
light
as deduced, say, from the 'ticking' of an onboard light-clock, by a lab
_at rest_ will be

5) Cd = Co [ 1 - V^2/Co^2 ]^1/2 .

Space prohibits showing how Rd, the daughter's radius-of-curvature
has an analogous relationship with Ru, the radius of curvature of
our universe, which is ~ 13.7 billion light years.

I want to keep this short, so I am omitting crucial material. Suffice
it
to say...while actual matter cannot travel back from a baby universe
into our universe, its gravitational potential can do so. These extra
grav-potentials from all of the baby universes, formed by all of the
BHs
inside the solar circle in the Milky Way Galaxy, are cumulative. That
is, they 'leak' back out into the galaxy and create a net single extra
gravitational potential, laid on top of the normal luminous g-potential
known to be created by stars, gas and dust. This would be interpreted
as the mysterious dark matter potential, currently ascribed to WIMPs,
etc.

A rough calculation yields a flat velocity curve quite similar to that
actually observed for our galaxy. If this model is roughly correct,
one
does not need to posit exotic dark matter particles, except insofar as
they might constitute the quanta for the extra g-potential from
daughter
universes.

Cheers
Gene Partlow