Tensor Vector scaler theories.

[toph]

Hello

I have recently read an article about tensor vector scaler theories (Te VeS), including John Moffats STVG and Philip Mannheim's "conformal gravity", available at

http://physicsweb.org/articles/world/19/6/5/1

I understand that Newtonian-Einstein gravity works very well across a broad range of scales and that it should not be written off just yet. And that these ideas are still very theoretical and may prove to be just that, ideas! However i find the idea of 'doing without' (my term) dark matter and dark energy as appealing if not simple solutions to cosmolical problems such as expansion rates.

I have four questions,

1) Please can someone explain to me (layman) what a 'phion field' is?

2) How in nature would such a field be formed? and what action would drive it?

3) What is a fourth order "Weyl tensor"?

4) How much experimental evidence is there for the existence of DM and DE.

4) I would also be interested in hearing your thoughts on these theories, are they worthy of pursut? and do you think they will yield any fruitful results?

Thank you for your input, i may have more questions as the thread evolves.

toph.

 

[marcus]

Hello

I have recently read an article about tensor vector scaler theories (Te VeS), including John Moffats STVG and Philip Mannheim's "conformal gravity", available at

http://physicsweb.org/articles/world/19/6/5/1

I understand that Newtonian-Einstein gravity works very well across a broad range of scales and that it should not be written off just yet. And that these ideas are still very theoretical and may prove to be just that, ideas! However i find the idea of 'doing without' (my term) dark matter and dark energy as appealing if not simple solutions to cosmolical problems such as expansion rates.

I have four questions,

1) Please can someone explain to me (layman) what a 'phion field' is?

2) How in nature would such a field be formed? and what action would drive it?

3) What is a fourth order "Weyl tensor"?

4) How much experimental evidence is there for the existence of DM and DE.

4) I would also be interested in hearing your thoughts on these theories, are they worthy of pursut? and do you think they will yield any fruitful results?

Thank you for your input, i may have more questions as the thread evolves.

toph.

that is a good find! the physicsweb article you gave us a link to is really careful and thorough

http://physicsweb.org/articles/world/19/6/5/1

I hope someone can reply to your questions and explain what John Moffat means by "phion field" Phi is just a scalar-valued function that occurs in his theory. Till now I didnt hear him talk about it as if it is the field of a particle. So this article is telling me something new---actually quite a lot new.

the modified general relativity business really seems to be taking off.

 

[marcus]

I see that none of the others checked in.
There has been a lot of discussion of this very topic (TVS theories) recently in this subforum, but it is somewhat scattered.

for example see yanniru's question here
https://www.physicsforums.com/showthread.php?t=112820&page=3
it is post #31 on the current "dark matter dark energy" thread

https://www.physicsforums.com/showpost.php?p=929306&postcount=31
and yanniru asks a question about Bekenstein TeVeS theory along same lines as you ask. He asks

"Could someone comment on Jakob Bekenstein's last few papers which attribute Dark Matter to theoretical artifact; http://arxiv.org/abs/astro-ph/0412652, http://arxiv.org/abs/astro-ph/0509519, http://arxiv.org/abs/astro-ph/0602266 ?"

there is a lot of interest in MOND, especially relativistic MOND, these days.

If nobody else comes in, I will make a few more comments

 

[marcus]

BTW toph, I think the reason we are seeing a rush to get on the MOND-waggon
is that different MOND theories are TESTABLE by probes within the solar system

You understand that you asked about TeVeS which is a PARTICULAR CASE of a relativistic MOND. the keyword here, for better or for worse, is "MOND" which really does not give an adequate description of the topic----but for historical accident reasons that has become the keyword. (the first modified gravity of this type was Moti Milgrom 1981 "MOdified Newton Dynamics" and Bekenstein called his TeVeS a TYPE of MOND, so it became the generic word that people use)

a good way to find out about what's happening is just go to arxiv.org
and do an author search for these two authors: Bekenstein
and also J Moffat

In both cases you will find recent papers having to do with TESTING WITHIN SOLAR SYSTEM.

JUST GO HERE
http://arxiv.org/find
AND TYPE BEKENSTEIN IN THE AUTHOR BOX

you will get this
http://arxiv.org/find/grp_physics/1/au:+bekenstein/0/1/0/all/0/1

and the top of the list of 39 papers will be about testing

and do the same for J MOFFAT
you will get a list of 100 papers by John Moffat and the second one in the list
will be about testing (by time delays) in the solar system
http://arxiv.org/find/grp_physics/1/au:+MOFFAT_J/0/1/0/all/0/1

Just for thoroughness, I typed MOND into the "abstract" box and got
http://arxiv.org/find/grp_physics/1/abs:+MOND/0/1/0/all/0/1

this is a list of 154 articles about MOND.

the most recent 56 papers were posted SINCE JAN 2005. this means the topic heated up lately.

 

[toph]

Marcus

Thanks for your input, i certainly have plenty to read about now. should keep me busy for a long time! cheers.

 

[marcus]

Marcus

Thanks for your input, i certainly have plenty to read about now. should keep me busy for a long time! cheers.

don't necessarily think of it as having a lot to read, the nice thing is you only have time to read a sampling and then POOF the situation will get simpler by someone figuring something out

and gradually the wrong ideas will get pruned away and the simpler clear idea will emerge from the thicket, and it will get easier.

this is kind of a faith---you can't be sure it will get easier, but I think it will.