Possible Fifth Force Would Make Direct Detection of Dark Matter Unlikely

March 26, 2009 By Lisa Zyga, Phys.org feature

In this image of the Bullet Cluster, the blue area shows what is thought to be dark matter. Physicists are investigating connections between a possible fifth force and the direct detection of dark matter. Image source: NASA / CXC / CIA / STSci / Magellan / Univ. of Ariz. / ESO.
(PhysOrg.com) -- No one knows exactly what a “fifth force” might be, but studies have shown that, if a long-range fifth force does exist, it could have surprising effects on the universe’s structure formation. A fifth force could reduce discrepancies between theory and observation in several areas of cosmology.

Now, as new research has shown, a could also be connected to . In a paper published in , physicists Jo Bovy and Glennys Farrar were surprised to discover that a fifth force in the dark sector could place constraints on dark matter that essentially exclude its through spin-independent interactions. Conversely, if future experiments do detect a spin-independent interaction of dark matter, then any fifth force in the dark sector must be so weak as to be astrophysically irrelevant.

“Our study shows that we can strongly constrain some properties of dark matter, i.e., the combination of its interaction with the visible sector and the strength of a long-range fifth force between , through experiments with ,” Bovy, a Ph.D. student at New York University, told PhysOrg.com. As for which scenario appears to be more likely - a fifth force excluding direct detection of dark matter, or direct detection of dark matter excluding a relevant fifth force - Bovy and Farrar said that it’s impossible to say in advance. “Both would be very interesting both theoretically as well as observationally,” Bovy said.

Previous research has suggested the possibility that a new long-range, attractive fifth force might exist, which arises in several extensions of the standard model. Although most dark matter models predict that the force between dark matter particles is a short-range force, other models such as and string theory allow for the existence of a very light boson which could carry a long-range force in the dark sector.

In the current study, the theorized fifth force - a nongravitational, long-range attractive force - would couple directly to dark matter but not to ordinary visible matter. However, if dark matter particles interacted nongravitationally with ordinary matter, quantum corrections would make the fifth force emerge in the visible sector, as well. This quantum correction occurs when two virtual dark matter particles are coupled to both the fifth force scalar and to two quarks.

“Our study reveals a hitherto unrecognized connection between dark matter interactions with ordinary matter, and dark matter self-interactions,” said Farrar, a physics professor and Director of the Center for and Particle Physics at New York University.

As Bovy and Farrar explain in their study, in order to be astrophysically relevant (i.e., on the order of the gravitational force), the fifth force carrier must have a vacuum expectation value on the order of the Planck mass. In turn, this requires that dark matter be very heavy in most scenarios. In direct detection experiments, scientists look for dark matter by observing ordinary matter particles recoiling due to being scattered by dark matter particles. As the mass of dark matter particles increases, the bounds on the coupling of dark matter and quarks become more stringent, making the direct detection of dark matter more difficult.

Besides its implications on the direct detection of dark matter, a fifth force has also been hypothesized to impact large-scale structure formation. If a fifth force was attractive and had a very long range, it would effectively increase the strength of gravitational interaction, and thus accelerate structure formation. As previous studies have shown, such a force could reduce discrepancies between observations and predictions in several areas, such as by increasing the number of galaxy clusters and superclusters and reducing voids, which would agree better with observations.

As the scientists explain, the impacts of a possible fifth force do not demand its existence, but they do motivate researchers to explore the implications of a fifth force.

“Jo Bovy and I are looking at what the analogous constraints are, between possible dark matter annihilation signals (searched for by Fermi-GLAST and other satellite experiments like PAMELA and ATIC) and a fifth force,” Farrar said. “Also, in collaboration with others, I'm studying the effects of a long-range dark matter force on cosmology and attempting to improve constraints on it from the Bullet cluster.”

Bovy added that he’s also investigating the implications of short-range attractive forces between dark matter particles, which may enable the detection of dark matter annihilation from satellite galaxies of the Milky Way.

More information: Bovy, Jo and Farrar, Glennys R. “Connection between a Possible Fifth Force and the Direct Detection of Dark Matter.” Physical Review Letters 102, 101301 (2009).

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1.1 / 5 (15) Mar 26, 2009
its not a fifth force, but a blind ignorance to a force that is already known... electric forces. The universe is more than 99% plasma, and electric currents flow within it, just as they do in countless laboratory experiments. These currents are in the form of Birkeland currents which form a web throughout our universe.

Plasma cosmology represents a more comprehensive cosmology than the current gravity-dominated cosmology can.
1.3 / 5 (12) Mar 26, 2009
How sure are we about the third force and the fourth force, aka strong and weak interactions? They don't need to exist just because the dominating model demands them. Not all models do:


4.8 / 5 (17) Mar 26, 2009
The forecast calls for an influx of AWT and electric universe comments, with a strong undercurrent of contempt for the "scientific establishment". Hang on to your hats folks.
4.7 / 5 (55) Mar 26, 2009
LOL,... "by AWT this is easily explained,....".

"....the theorized fifth force - a nongravitational, long-range attractive force - would couple directly to dark matter but not to ordinary visible matter. However, if dark matter particles interacted nongravitationally with ordinary matter, quantum corrections would make the fifth force emerge in the visible sector, as well. This quantum correction occurs when two virtual dark matter particles are coupled to both the fifth force scalar and to two quarks."

They're going to end up with ptolemaic epicycles if they don't stop somewhere soon. I mean, how much duck tape can you wrap around a cosmology. If it's convoluted and ad hoc, its less interesting and sublime, even if it saves exiting theories.
1 / 5 (3) Mar 26, 2009
Basics, (from a layman): forces are transferable and convertable. Kinetic can become Potential, and vice-versa. In remote reaches of space, could Gravity convert to Thermo-Electric in the right medium?

Could it even generate the medium if it did not exist?

What happens at the shared boundary of two gravitational fields, when each field does not extend far enough to reach to origin, (generating mass), of the other?

Spontaneous generous of exotic matter, or a simple mechanism for energy conservation and suspension?

( I know. I read too much. ;-)
1.4 / 5 (7) Mar 26, 2009
What happens at the shared boundary of two gravitational fields, when each field does not extend far enough to reach to origin, (generating mass), of the other?

Pluto's gravitational field does not reach the Earth's gravitational field, yet they are both "immersed" in the larger gravitational field of the sun. As such, it's turtles all the way down... As in there is no gravitationally void space.
1.1 / 5 (9) Mar 26, 2009
What happens if gravity diminishes to zero at some cosmological distance instead of continuing to decrease at 1/d squared? The need for these magical dark patches vanishes.
And then again, the coulombic forces are so very much stronger than gravity that the answers probably lie there instead of in ever more epicyclic patches.
Mar 26, 2009
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Mar 26, 2009
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1 / 5 (7) Mar 26, 2009
and then there's always anti-gravity. how many forces are we up to now?

Mar 26, 2009
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3.1 / 5 (8) Mar 26, 2009
This may appear to be an overly simplistic approach, but what happens if conventional theory is based on incorrect assumptions here, so that in reality there is no actual need for dark matter?

Dark matter which does not exist would be... rather difficult to detect. (-:
1.8 / 5 (5) Mar 26, 2009
Right on the invisible nose austux!
1.1 / 5 (7) Mar 27, 2009
Pressure is a better way to understand.
1 / 5 (6) Mar 27, 2009
..Dark matter which does not exist would be... rather difficult to detect...
Dark matter has a two components, so called "hot dark matter", which is supposedly formed by fast particles and the rest, which is elusive and it manifests itself just by gradient of gravity field/density of vacuum. By AWT vacuum appears like nested foam and the cold dark matter is simply area of more dense foam. It's not connected with some special particles, being formed just by "curvature of space time".

For example, underwater gradient is salt concentration cannot be seen, it cannot be fish out - it manifests only by underwater waves, which can sink incautious boats. By AWT dark matter is such gradient of environment density, it's just more blurry.


Every gradient exhibits a refraction phenomena with respect to spreading of energy waves. At the moment, when the refraction results in reflection of energy waves, we are talking about matter. For example event horizon of black holes is density gradient so dense, it reflects all incoming energy back into black holes.

By AWT observable reality is formed just by density gradients, nothing else. We are formed by such gradients, too - so we cannot observe anything else.
1 / 5 (5) Mar 27, 2009
Here are many ways, how to understand dark matter.

By AWT it's a surface tension effect of every gravity field. It behaves like dense blob of vacuum foam refracting the path of light, i.e. like giant but sparse mercury droplet. Surface of every dense object exhibits a surface tension phenomena, because it's curved and it can serve as a surface for spreading of surface energy waves. But energy tends to spread along straight path, so here's additional energy density, not the energy of space-time curvature, which is forming gravity field, but the density of curvature of gravity field curvature. It manifests like additional weak gravity force, which is acting at the surface of gradient field and it has a tendency to compensate it. It's a second order effect, which Einstein field equation doesn't consider explicitly, but it follows just from relativity theory and it makes it nonlinear and infinitely recursive.

When the density gradient becomes very strong and curved (usually at presence of black holes), the energy density of curvature of this field becomes more significant, then density of space-time curvature, event horizon tends to drown beneath the event horizon and it becomes undulate like quantum wave.

We can see, dark matter can be interpreted like quantum gravity phenomena, too.
1 / 5 (5) Mar 27, 2009
Another way, how to understand dark matter is concept of omnidirectional Universe expansion. It's usually used for explanation of Hubble's red shift, but this is not a complete view. When some galaxy is shinning in omnidirectionally expanding space-time, it's light spreads more and more slowly with compare to expanding space-time. At certain distance from source of light photons effectively freeze in expanding space, which may be observed like dark matter phenomena from outside. By this approach dark matter manifests like weak deceleration force, proportional to product of speed of light and Hubble constant. This deceleration can explain quite well Pioneer spacecraft anomaly, for example. When such galaxy is rotating, the deceleration field creates a solid ring around it, which was observed too.
We can observe similar phenomena near rotating black holes, just in more pronounced way (so called Kerr's solution of black holes).

1 / 5 (2) Mar 27, 2009
By AWT, I'm glad you came out.
2.5 / 5 (4) Mar 27, 2009
It sounds similar to entanglement of particles by the way of how the article seems to describe it. If it is then we might have found it already. If not that doesn't make things any less curious.
1.3 / 5 (7) Mar 27, 2009
we just like to think outside the box

1 / 5 (5) Mar 27, 2009
it's outside the modern box
I've no problem to interpret dark matter both by quantum mechanics, both relativity, both Aether or MOND theory. The future is in plurality of thinking - just at the case, you can explain some phenomena by more than single theory at the same moment, you can say, you understood both theory both subject well.

Personally I consider Aether concept more intuitive and general, then formal theories based on ad-hoced postulates - but's it's the matter of personal preferences. Here exists many people, who are experimenced in formal thinking as well. The only problem is, they cannot explain their understanding to other layman people.

We shouldn't forget, concept of paralelized multiparticle environment doesn't play well with formal rigor, based on consecutive logic. The same problem we can met during modeling of real life phenomena, like flame or turbulence by formal math. Despite piles of theories, both engineering simulations, both movie effects are mostly based on particle models due the speed, reliability and flexibility.

Reality around us is based on multicomponent systems - the fact, some local connections can be expressed in math more effectivelly doesn't change the chaotic character of reality. And at the very end, every chaotic system can be modeled by particle gas or compressible fluid.
1.3 / 5 (7) Mar 27, 2009

ether no; outmoded yes; Newtonian yes; sans maths no; gravity symmetric who knows; supported by evidence yes; not what you are expecting as the next step forward who cares; correct yes.

check it out.

1 / 5 (5) Mar 27, 2009
..if you can't put math to the test of theory, then theory becomes hypothesis without merit...
Even without math you can propose testable hypothesis, like those above presented. Galilo was able to predict order of Venus phases without math. And vice versa - even pile of math will not help you in testable predictions, if you have no clue, what such math can describe. As we can see on example of forty years old string theory.

This is because logic is the base of every formal model, even math itself. In math every conjecture must be proven by predicate logic first, before they can be used in another rigorous derivations.

But somehow, contemporary physicists started to believe, they can manage their theories without predicate logics on background. So we can say: no less - but more math based rigor is required for physics by now! We should build a robust logical model of reality first, before we should try to derive something more specific about it.

AWT can be modeled and tested by particle gas simulations on computer with unlimited precision. It may be possible, chaotic gas cannot be modeled by math in their entirety, but this is a limitation of formal math, not the AWT.

For example, even system of five gravitating bodies cannot be solved by formal math - by such way, the formal math is virtually unusable for modeling of nearly every real life phenomena.

Whereas by computer simulation we can model turbulent phenomena, which are highly divergent and which cannot be solved in formal way. This is because particle is zero dimensional object - as such is singular by its very nature and formal math cannot handle it.
1.3 / 5 (4) Mar 27, 2009
velanarris yes i have. take a look at Investigation

Mar 27, 2009
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Mar 27, 2009
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Mar 27, 2009
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Mar 27, 2009
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1 / 5 (3) Mar 28, 2009
Dudes energy doesnt even exist...
1.2 / 5 (5) Mar 28, 2009
The fifth force has been found!
TION Unified Field Time.
Even The Univrse Begins in the Particle State.

c. Liberte
Ed Britt/cpu//
386 Charlotte Street
Apt. 10, Third Floor,
Sydney, Nova Scotia,
Canada, B1P 1E2.
not rated yet Mar 30, 2009
It's always fun to read how one unknown could constrain the detection of second unknown.
5 / 5 (2) Mar 30, 2009
Why does anything remotely connected to cosmology devolve into spam threads about plasma cosmology and AWT?

Do proponents of this crap think that trying to win the support of fellow idiots will somehow be helpful to their side in the debate?
1 / 5 (2) Mar 30, 2009
What did you think of my Investigation Velanarris?
3 / 5 (2) Mar 30, 2009
"However the objects that contribute most of the mass of the galaxy, stars and molecular clouds, are electrically neutral..."

Absolutely, positively, patently false.
2.3 / 5 (3) Mar 30, 2009
evidence earls? why would they be charged if conductive plasma is between them?
Mar 30, 2009
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1 / 5 (1) Mar 31, 2009
Thanks. I work in a Newtonian universe. This doesn't mean I disagree with Relativity or Quantum Mechanics etc. Its just that my scales are big and my speeds are small so Newton gives a good enough approximation. As such there is no medium. I just treat AGM as particles bouncing around in three dimensional space. The sentence you quote describes the assumptions that a particular set of maths is based on. These assumptions are not general. AGM particles do have kinetic energy. Later on you see that the assumption that we can ignore AGM Pressure can be valid at very large scales because it is overwealmed by anti-gravity. However I'll re-word that sentence to make it clearer.
3 / 5 (2) Apr 03, 2009
*sigh* I keep hearing theories about dark matter and now this - a fifth force? Of course I suppose anything is possible, but with some theories (made just to justify certain equations) I can't help picturing them coming from a bunch of drunk theorists at the local bar - and then ending up in published papers. lol.

Sorry... don't mean to be cynical.
1 / 5 (1) Apr 03, 2009
Velanarris. Don't suppose you could do me an enormous favour and email something a bit more specific? Maybe I just need to explain why I'm assuming what when.
1 / 5 (3) Apr 04, 2009
Energetic Origin Of Mass and Gravity, Commonsensible Conception

A. A note about "new Theory of Everything Breakthrough"

"We are a group that is challenging the current paradigm in physics which is Quantum Mechanics and String Theory. There is a new Theory of Everything Breakthrough. It exposes the flaws in both Quantum Theory and String Theory. Please Help us set the physics community back on the right course and prove that Einstein was right! Visit our site The Theory of Super Relativity:
Super Relativity

Mark Fiorentino Mar. 18, 2009"

B. My note, of a commonsensible primitive mind, about the above note

I think you'll find this link of "complementary interest" to you, even if without math, and not that you need complementary ideas...


However, "my ether" is being laid by the expanding galactic-clusters...

C. Commonsensible conception of gravity

1. According to the standard model, which describes all the forces in nature except gravity, all elementary particles were born massless. Interactions with the proposed Higgs field would slow down some of the particles and endow them with mass. Finding the Higgs %u2014 or proving it does not exist %u2014 has therefore become one of the most important quests in particle physics.

However, for a commonsensible primitive mind with a commonsensible universe represented by
E=Total[m(1 D)], this conceptual equation describes gravity. It does not explain gravity. It describes it. It applies to the whole universe and to every and all specific cases, regardless of size.

2. Thus gravity is simply another face of the total cosmic energy. Thus gravity is THE cosmic parent of phenomena such as black holes and life. It is the display of THE all-pervasive-embracive strained space texture, laid down by the expanding galactic clusters, also noticed in the expanding energy backlashes into various constructs of temporary constrained energy packages.

D. Commonsensible conception of the forces other than gravity

The forces other than gravity are, commonsensibly, forces involved in conjunction with evolution:

The farthest we go in reductionism in Everything, including in Life, we shall still end up with wholism, until we arrive at energy. Energy is the base element of everything and of all in the universe. At the beginning was the energy singularity, at the end will be near zero mass and an infinite dispersion of the beginning energy, and in-between, the universe undergoes continuous evolution consisting of myriad energy-to-energy and energy-to-mass-to-energy transformations.

The universe, and everything in it, are continuously evolving, and all the evolutions are intertwined.

Dov Henis
(Comments From The 22nd Century)
Life's Manifest
EVOLUTION Beyond Darwin 200

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