Dark matter in higher dimensional space.

[Sorcerer]

This relates to my other thread on "Flatland" and Hilbert space. But is a seperate question.

 

Are there any theories or models which attempt to account for dark matters gravitational influence, yet its seemingly non interactional presence otherwise, by describing dark matter as a higher dimensional particle which does not intersect with our 3 dimensions but however is so close to doing so it's gravitational effects still pass to our 3 dimensions?

 

Or perhaps explaining it as all particles/fields having a higher dimensional form, the common matter and energy we observe intersect as to be observed by us in 3D. Some particles and fields however don't intersect with 3D, they still interact with the particle's that do however on the other dimensions. So when we observe their effect, but cannot show their existence otherwise, that is accounted for by the higher dimensional interaction, yet none in 3D.

 

If this is correct, would it mean experimental physics/particle accelerators can never observe directly the truth of reality?

Edited October 17, 2015 by Sorcerer

[Sorcerer]

http://www.nature.com/news/2005/050829/full/news050829-18.html

 

So, Google is my friend, seems like I'm about 10 years late with my idea.

[MigL]

Didn't read the link , but yes, strings and branes could affect gravity.

In string theory the graviton is the only boson that is a closed loop and therefore not confined to a brane, while brane bound gauge bosons and fermions are open ended strings where the ends are attached to a brane.

That means that gravity could 'leak' into other dimensions. This was originally postulated in relation to compactified, Planck scale dimensions.

Since gravity strength falls off as r^(n-1), where n is the number of available dimensions, gravity would then have increased as measurements approach Planck scale.

I don't think any measurements have proved conclusive ( or sensitive enough ) yet.

 

The effect is always an increase in gravitational strength as more dimensions come together. So if branes were close enough due to galactic presence for this effect to be significant, we, being part of the galaxy would note nothing out of the ordinary, and so cannot account for dark matter affecting galactic rotation.

What we would note is decreased gravity in the voids between galaxies, compared to in, or about, the galaxy.

[hoola]

what if the idea of the other dimensions ( presumably within our universe) possibly interacting with our 3Ds were instead not interactions between dimensions, but between universes? Since our universe has virtual particles, and this proposed "partner" universe possibly has similar structures, and if the warpage of space, hence gravity, is tied to the changed orbital distortions in their emergence and recombination paths, then perhaps there is some interaction between another universe's VPs and ours, causing the dark matter effect. Perhaps a series of some sort of modified casimir effect tests could separate an anomaly that could be attributed to the partner's particles distorting ours, thus making the results uneven as the test drifts through various densities of partner particles? I would think the test would have to be conducted in space to avoid interference from the earth's gravitational noise. Perhaps the "closed loop" gravity inducing string is analogous the closed loop of a VP's creation / destruction process?..

[MigL]

You want to speculate about speculations ???

 

I'll stick with Occam's razor.

What's affecting gravity at galactic scales ( but not al lesser scales a not even at greater scales AFAIK ) interacts gravitationally, but not electromagnetically.

Anything beyond that is pure conjecture.

[Bill Angel]

Didn't read the link , but yes, strings and branes could affect gravity.

In string theory the graviton is the only boson that is a closed loop and therefore not confined to a brane, while brane bound gauge bosons and fermions are open ended strings where the ends are attached to a brane.

That means that gravity could 'leak' into other dimensions. This was originally postulated in relation to compactified, Planck scale dimensions.

what if the idea of the other dimensions ( presumably within our universe) possibly interacting with our 3Ds were instead not interactions between dimensions, but between universes? ..?

Here is a speculative idea on the dark matter problem that relates to the issues mentioned in the above two posts.:

Dark matter would only interact with visible matter gravitationally, i.e. only through the exchange of gravitons, if it existed IN ANOTHER UNIVERSE. The idea that matter in our universe could be interacting with matter in another universe is an idea taken seriously by string theorists. For example, the idea is discussed in the book "The Hidden Reality, Parallel Universes and the Deep Laws of the Cosmos" by Brian Greene

[hoola]

yes, and to further elaborate, virtual particles at minimum energy, or symmetrically simple orbits could provide the basic accelerative force of expansion, and when orbits distort and held past normal time signatures when proximate to matter, increase output of their local harmonic oscillator property and provide increased repulsive force, or gravity. If that is true, then gravity should be re-callibrated, based in units of the minimum energy level of space, or lamda. I have read about the shawyer EMG engine and have seen little about it lately, and am becoming afraid it may end up being another "cold fusion" type deal. But, for a while the microwaves "doing something" to space seemed pretty cool. I was thinking at the time that if microwaves actually distort virtual particle decay paths, that might constitute creating an artificial gravity within the EMG engine, which approximated thrust. So, if we could distort local gravity, perhaps with a modulation of signal amplitude, might that not allow a possible mode of communication to a partner universe, like early AM radio via the shared gravitational effect?

[Sorcerer]

 

Here is a speculative idea on the dark matter problem that relates to the issues mentioned in the above two posts.:

Dark matter would only interact with visible matter gravitationally, i.e. only through the exchange of gravitons, if it existed IN ANOTHER UNIVERSE. The idea that matter in our universe could be interacting with matter in another universe is an idea taken seriously by string theorists. For example, the idea is discussed in the book "The Hidden Reality, Parallel Universes and the Deep Laws of the Cosmos" by Brian Greene

It's not another universe the universe would then simply be extended to include the higher dimensional space. You cannot have effects occurring over non existent boundaries, there must be some connection which the gravitons pass through. In this case our spacetime would simply be a subset of a larger universe.

 

Universe by definition literally means the entirety of everything that exists.

Edited October 18, 2015 by Sorcerer

[Bill Angel]

It's not another universe the universe would then simply be extended to include the higher dimensional space. You cannot have effects occurring over non existent boundaries, there must be some connection which the gravitons pass through. In this case our spacetime would simply be a subset of a larger universe.

Universe by definition literally means the entirety of everything that exists.

I grasp your point. There is however a tie in between what I was suggesting and the so called Ekpyrotic Universe, which is based on the idea that our hot big bang universe was created from the collision of two three-dimensional worlds moving along a hidden, extra dimension. The tie in is that the Ekpyrotic model posits as I do the gravitational interaction between two branes that are situated close to each other. See http://wwwphy.princeton.edu/~steinh/npr/

 

Here is an animation by Neil Turok showing the interaction between two branes which illustrate his Ekpyrotic Universe model. His animation could also serve to illustrate the gravitational interaction between two branes corresponding to two separate worlds. From the perspective of our world, the matter in the other world would be dark matter whose presence is felt only via gravitational attraction i. e. the exchange of gravitons.

 

[MigL]

First time I read about gravity possibly 'leaking' into other dimensions was over ten yrs ago in a paper by Lisa Randall and Raman Sundrum.

Lisa Randall is somewhat of a celebrity for her intelligence ( tenure at Harvard working on theoretical Particle Physics and Cosmology ) and good looks ( best looking Physics PhD I've ever seen, certainly better looking than Swansont judging by the few pictures pointed out in a recent thread ).

 

I think there has been some work done at the LHC on this subject, but to no conclusion.

 

edit: Don't mean to pick on you Swansont but I don't know who else is a PhD on here ( and can take a joke )

Edited October 19, 2015 by MigL

[Sorcerer]

I grasp your point. There is however a tie in between what I was suggesting and the so called Ekpyrotic Universe, which is based on the idea that our hot big bang universe was created from the collision of two three-dimensional worlds moving along a hidden, extra dimension. The tie in is that the Ekpyrotic model posits as I do the gravitational interaction between two branes that are situated close to each other. See http://wwwphy.princeton.edu/~steinh/npr/

 

Here is an animation by Neil Turok showing the interaction between two branes which illustrate his Ekpyrotic Universe model. His animation could also serve to illustrate the gravitational interaction between two branes corresponding to two separate worlds. From the perspective of our world, the matter in the other world would be dark matter whose presence is felt only via gravitational attraction i. e. the exchange of gravitons.

 

 

Interesting, but where did the branes come from before that?

 

Are the two branes currently overlapping or did they pass right through each other?

How does time work with another dimension and branes that move and able to collide at some point, is the movement of the branes through the extra dimension relative to our spacetime?

How long would it take for them to pass through each other?

Does the universe exist at the intersection of two branes (I picture that like a ven diagram), or was that just where the orgin in 4d is?

 

Are the branes thought to be identical?

What does a brane consist of before the collision?

Does the extra dimension contain more branes, why would only 2 exist if not, why not 1 or none?

Is there a possibility of our universe colliding with another brane?

What are the probabilites of a collison in extra dimensional space?

I speculated on a type of mirror universe recently, where one side fails and collides with the other side. It's a similar idea, but I was explaining it as one moves back in time (it's time) towards the origin http://www.scienceforums.net/topic/91649-the-chimrea-twin-universe/#entry888566

 

What if the branes are produced as a pair, extra dimensional space contains a probability of producing a pair of branes, like our universes virtual particles, which exactly balance and so don't violate conservation of energy. The branes, which are opposite but equal, are able to move in this extra dimension and collide.

Regarding a mirror universe.

http://www.pbs.org/w...runs-backwards/

Edited October 19, 2015 by Sorcerer

[Bill Angel]

Interesting, but where did the branes come from before that?

 

Are the two branes currently overlapping or did they pass right through each other?

How does time work with another dimension and branes that move and able to collide at some point, is the movement of the branes through the extra dimension relative to our spacetime?

How long would it take for them to pass through each other?

Does the universe exist at the intersection of two branes (I picture that like a ven diagram), or was that just where the orgin in 4d is?

 

Are the branes thought to be identical?

What does a brane consist of before the collision?

Does the extra dimension contain more branes, why would only 2 exist if not, why not 1 or none?

Is there a possibility of our universe colliding with another brane?

What are the probabilites of a collison in extra dimensional space?

 

I speculated on a type of mirror universe recently, where one side fails and collides with the other side. It's a similar idea, but I was explaining it as one moves back in time (it's time) towards the origin http://www.scienceforums.net/topic/91649-the-chimrea-twin-universe/#entry888566

 

What if the branes are produced as a pair, extra dimensional space contains a probability of producing a pair of branes, like our universes virtual particles, which exactly balance and so don't violate conservation of energy. The branes, which are opposite but equal, are able to move in this extra dimension and collide.

 

Regarding a mirror universe.

http://www.pbs.org/w...runs-backwards/

 

Those a certainly good questions.

Here are some conjectures that relate to some of them.

 

 

The latest version of braneworld cosmology is the giant brane collision model, also known as the Ekpyrotic Universe, or the Big Splat.

The Ekpyrotic Universe starts out as a cold, flat, static five-dimensional spacetime that is close to being a supersymmetric BPS state, meaning a state invariant under some special subalgebra of the supersymmetry algebra. The four space dimensions of the bulk are bounded by two three-dimensional walls or three-branes, and one of those three-branes makes up the space that we live on.

But how does the Universe evolve to give the Big Bang cosmology for which there is so much observational evidence? The Ekpyrotic theory postulates that there is a third three-brane loose between the two bounding branes of the four dimensional bulk world, and when this brane collides with the brane on which we live, the energy from the collision heats up our brane and the Big Bang occurs in our visible Universe as described elsewhere in this site.

This proposal is quite new, and it remains to be seen whether it will survive careful scrutiny.

See Inflation vs. the giant brane collision