Higgs Boson and M-Theory

[LiquidMentality]

Theorisations over the Higgs Boson, and M-Theory, both have an ultimate aim in helping reach a 'Theory of Everything'.

 

However, if one day soon scientists were able to prove that one of these 2 theories is correct, would that necessarily disprove the other?

 

i.e. Could a Higgs-field manifest itself in a string-based Universe? Or would it be even needed? (and vice versa..)

 

 

[Zarnaxus]

To my understanding, the Higgs Boson is just part of the standard model (a collection of the elementary particles in the universe), but it's theoretical.

 

M-theory attempts to combine the five string theories.

 

Each string theory is an attempt to combine the standard model with general relativity.

 

Although this is all currently theoretical, the discovery of the Higgs Boson would not disprove string theory or M-theory.

[timo]

I'd expect that most string and string-like models actually aim to implement at least one Higgs Boson.

[LiquidMentality]

"To my understanding, the Higgs Boson is just part of the standard model (a collection of the elementary particles in the universe), but it's theoretical."

Yes, i believe that the Higgs is a (theoretical) component of the now Standard Model..however M-Theory (what i understand as essentially a 'collation' of all the String Theories..? ) is not; i thought M-Theory was an attempt at an alternate structure to the Standard Model.

 

But i agree with you both, the proof of a Higgs' existence wouldn't directly disprove it - it could probably be incorporated into M-Theory as a macro-manifestation of string vibrations of some kind..

[ajb]

... i thought M-Theory was an attempt at an alternate structure to the Standard Model.

 

If M-theory does provide the framework for understanding our Universe then the standard model will appear in some limit. The way to the low energy physics of the standard model would be through a string theory, which is understood as a limit within M-theory itself.

 

String theory does seem to have the right ingredients to include the phenomenology of the standard model.

[LiquidMentality]

"String theory does seem to have the right ingredients to include the phenomenology of the standard model."

 

This is true, and as is the converse; The Standard Model can't explain some phenomena, which String Theory can...and so this may probably mean that over time, it is found a kind of hybrid between the models is found to more closely fit with observed occurances, and not simply a conclusion such as 'String Theory is correct'

 

And perhaps the Higgs Boson would find its place more suitable within this hybrid model, compared to manifestations in merely one or the other..

[ajb]

"String theory does seem to have the right ingredients to include the phenomenology of the standard model."

 

This is true, and as is the converse; The Standard Model can't explain some phenomena, which String Theory can...

 

Can you be more specific? Dealing with phenomenology with string theory is difficult, or at least the details are. This is in part due to the huge number of possible vacua in the theory. One of these may describe the Universe we live in and then the challenge is to explain what that one.

[LiquidMentality]

I mean that, for some currently 'unexplainable' phenomena observed in nature, the mathematical framework behind String Theory predictions provides a more suitable fit than similar predictions based on the current Standard Model. And the converse is true in other instances.

This may lead to the conclusion that neither system is technically correct as they are conceived today. Adjustments or alterations to either of these models may be made in the future, or possibly other, more suitable models may be hypothesised that are able to explain and account for todays unexplained phenomena that no current model is able to achieve.

[ajb]

I mean that, for some currently 'unexplainable' phenomena observed in nature...

 

Just so we are all on the same page, what "unexplainable phenomena" are you referring to?

[LiquidMentality]

I guess the major one would be gravity; as it is able to be incorporated quite well into the mathematical construct that String Theory assumptions provide. Whereas to date, there has been no proper success in acheiving this with the current model.

Though of course this may well change, with experiments currently searching for postulated gravity waves in far stretches of the cosmos. This may provide a more tangible understanding to the phenomena of gravity, and may allow for it be be incorporated in the current model at last.

[ajb]

Right, ok.

 

Indeed the standard model does not include the gravitational interaction as where string theory necessarily does. That by itself warrants that string theory should be investigated.

[Zarnaxus]

General relativity explains gravity. The standard model explains electromagnetism and the weak and strong nuclear force (a GUT). They were united into a bosonic string theory, but this later turned into five superstring theories (using a supersymmetric standard model). Why have five theories? Because they are all sides of the same theory, M-theory. This is a theory uniting all forces of the universe (TOE) explaining events that are have large gravity and are very small (like a singularity).

[LiquidMentality]

"General relativity explains gravity"

 

It does, to some degree, but not to the extent that M-Theory provides. An attempt at a GUT would be able to incorporate and fully explain all of the Fundamental forces, including gravity. This is one of the hopefully outcomes of M-Theory.

[ajb]

"General relativity explains gravity"

 

It does, to some degree, but not to the extent that M-Theory provides.

 

Really? To my mind M-theory is really in its infancy. Most people that claim to be doing M-theory are really doing 11 dimensional supergravity, which is one of the limits of M-theory. Full "M-theory proper" is not known. Effective theories for multiple M2 branes exists, look up BLG-theory and the related ABJM-theory. These both add to our understanding of M2 branes, which are one half of the story...

 

Multiple M5 branes appear to be a bit harder to model. A breakthrough could happen at any time.

 

Anyway, I would like you to justify your statement.

 

General relativity explains gravity.

 

Yes, so classical gravity is very well understood in terms of general relativity. Quantum aspects not so much. Perturbative quantum general relativity is sick.

 

The standard model explains electromagnetism and the weak and strong nuclear force (a GUT). They were united into a bosonic string theory...

 

This cannot be right. The bosonic string does not allow for any fermionic states. It simply cannot have the correct particle states to contain the standard model.

 

but this later turned into five superstring theories (using a supersymmetric standard model). Why have five theories? Because they are all sides of the same theory, M-theory.

 

Right, the 5 perturbative string theories are linked together and are understood as expansions about different vacua of some larger theory we call M-theory. 11 dimensional supergravity is also a limit of M-theory.

 

The interesting thing about the bosonic string is, as far as I know, it is not understood as a limit of M-theory. One nieve question is "how does the bosonic string fit into M-theory?".

[Dr. Tom Snyder]

What's the actual evidence or proof for M-theory? Or is it just theoretical speculation? No one seems to say.

[ajb]

What's the actual evidence or proof for M-theory? Or is it just theoretical speculation? No one seems to say.

The 'proof' as such is that it provides a non-perturbaive framework in which to understand the different string theories. In that sense it is all theoretical and builds on string theory, which itself has lots of good motivation to be studied.

 

I don't think my comments from 2011 have changes much. That said, I am not an expert in string theory or M-theory.

[MigL]

String ( or M ) theory is a very elegant theory ( so they say, myself, I don't understand the math ) in search of a universe to describe.

It provides an infinitude of models. Picking the one which describes our particular universe is a challenge.

That doesn't mean it shouldn't be investigated further, as it could provide a 'framework' for a final theory, although I have a particular fascination with the competing LQG.

 

Investigating these theories experimentally is way beyond current technology, even if they did make testable predictions.

 

The evidence for the Higgs mechanism, the Higgs boson ( and the final proof of the Electroweak symmetry break ), has been found. It turns out it was hiding in Switzerland all along.

It will keep the standard model viable, even if only a 'limit' for years to come.

[IM Egdall]

As of today, there is no compelling evidence for string theory (or M theory) or any quantum gravity theory. They are all speculation.