How useful are indefinite state spaces?

[A. Neumaier]

I am continuing here the discussion of side issues from another thread, quoting a number of Careful's promotional posts for indefinite spaces, negative probabilities, and other unconventional ideas for a generalized quantum mechanics. (A Nevanlinna space is a vector space equipped with an indefinite sesquilinear form, and perhaps further properties which Careful can surely point out if they are relevant for the discussion. A Krein space
is a vector space equipped with an indefinite sesquilinear form and extra topological structure described, e.g., in http://en.wikipedia.org/wiki/Krein_space)

if you generalize away to Nevanlinna space, unitary operators also become unbounded (on some subspace of zero norm states) so here, the picture of bounded operators completely evaporates. [...] So, I think C^{*} algebra's (as well as Von Neumann algebra's) are (a) not natural and (b) too limited.

So, in my opinion, bounded operators are dead.

I am afraid you confuse negative energy with negative probability. They are different things. It is very easy to define a Lorentz covariant positive energy Hamiltonian with positive and negative norm particles. The interpretation of course happens on a sub-hilbertspace but (a) this one is dynamical and by no means invariant under the Hamiltonian and (b) observer dependent. [...]

Right, there is no substance behind bounded operators. The best proof is that we never use them.

For example, hermitian operators can have a complex spectrum (on the ''ghost'' states) which is totally unbounded. [...]
What would be interesting from the point of view of ''C* algebra's'' is that you try to extend the GNS construction to non-positive states, so that you will get Nevanlinna space representations. This requires of course a change in the C* norm identities in the first place, but it might be good to define such generalized algebra's.

Hilbert space is not only unsuitable because it has only positive norm

Actually on Nevanlinna space, there is no natural algebraic criterion which gives only operators with a real spectrum.

It is possible of course to define bounded operators on Krein space, but it is not the natural class of operators (since their very definition requires a Hilbert space construction!)

All I am pointing out is that from where I stand and how I know quantum gravity to work out, bounded operators have evaporated.

But what I want to do is pull this discussion away from some silly textbook prejudices people have to situations where it really matters. For example to QFT or quantum gravity: that is where these issues really show their teeth, not in standard QM.

No speculation, operators in Krein space have been rigorously studied as well as spectral decompositions and so on. It is just much less known obviously.

And here a few comments:

(i) All of quantum information theory happens in finite-dimensional Hilbert spaces, in which all observables are bounded.
(ii) Most successes of quanrtum mechanics (with thousands of applications) are on the level of nonrelativistic quantum mechanics.
(iii) All free quantum field theories (in any dimension) and all quantum field theories which are known to exist rigorously (in d<4) - in that the solvability of the dynamics can be rigorously shown, were constructed in the Hilbert space framework.
(iv) Nobody knows about the rigorous status of interacting field theories in 4 or higher dimensions, no matter which techniques are employed.

Indefinite state spaces haven't made the slightest impact in cases (i)-(iii). They have had important heuristic successes in case of (iv), where ghost states are an important feature of gauge theories. But even there, the physics happens in the centralizer of the BRST charge, which is a standard Hilbert space.

Thus your language seems to be far too strong, and your assertions far too speculative.

 

[Careful]

(i) All of quantum information theory happens in finite-dimensional Hilbert spaces, in which all observables are bounded.
(ii) Most successes of quanrtum mechanics (with thousands of applications) are on the level of nonrelativistic quantum mechanics.
(iii) All free quantum field theories (in any dimension) and all quantum field theories which are known to exist rigorously (in d<4) - in that the solvability of the dynamics can be rigorously shown, were constructed in the Hilbert space framework.
(iv) Nobody knows about the rigorous status of interacting field theories in 4 or higher dimensions, no matter which techniques are employed.

Indefinite state spaces haven't made the slightest impact in cases (i)-(iii).

Sure not because all these things you mention do not belong to proper Lorentz covariant physics. So your comment is entirely irrelevant here.

They have had important heuristic successes in case of (iv), where ghost states are an important feature of gauge theories. But even there, the physics happens in the centralizer of the BRST charge, which is a standard Hilbert space.

Sure, because of gauge invariance. But err, we haven't found a rigorous quantization procedure of gauge theories, have we ? What I suggest is to abandon field theory and therefore also gauge invariance, then Nevanlinna spaces will show their true power. Actually, if you want to understand why even complex Nevanlinna spaces are not sufficient, read my book: sections 6-8.

Thus your language seems to be far too strong, and your assertions far too speculative.

They are not, since I actually managed to construct a nonperturbatively defined quantum gravity theory within the language of Clifford-Nevanlinna modules (and constructed some easy solutions). And this matematical language is a minimum minimorum: of course you may utter that I still have to perform computations for the interacting theories. If you can construct a QG theory without it, you have a right to speak. But even the QG aspect is irrelevant: I actually manage to surpass Haag's theorem and Coleman-Mandula in this way which is very relevant for GUT's.

 

[A. Neumaier]

Sure not because all these things you mention do not belong to proper Lorentz covariant physics. So your comment is entirely irrelevant here.

Most uses of QM are not concerned with Lorentz covariant physics.

And _all_ Lorentz covariant QFTs that are known to exist were constructed via Hilbert space methods. Mathematically, the others only have the status of conjectures. The impact of indefinite methods on turning conjectures into theorems has so fare been nil.

Sure, because of gauge invariance. But err, we haven't found a rigorous quantization procedure of gauge theories, have we ?

No, but this is the goal of mathematical (as opposed to heuristic) techniques.
It is worth a million of dollars.

What I suggest is to abandon field theory and therefore also gauge invariance, then Nevanlinna spaces will show their true power. Actually, if you want to understand why even complex Nevanlinna spaces are not sufficient, read my book: sections 6-8.

This will make the rigorous perspective even worse. I very much doubt that indefinite methods (which have much poorer mathematical structure) will be more powerful than Hilbert space methods for proving the existence of gauge theories in 4D.

Show the true power for rigorous results not by easily made promises for the future but by successes in the past!

I actually managed to construct a nonperturbatively defined quantum gravity theory within the language of Clifford-Nevanlinna modules. And this mathematical language is a minimum minimorum. If you can construct a QG theory without it, you have a right to speak. But even the QG aspect is irrelevant: I actually manage to surpass Haag's theorem and Coleman-Mandula in this way which is even relevant for GUT's.

This is not a construction in the mathematical sense, only a plausibility consideration.
A construction would show in particular the existence of a well-defined dynamics -
not only equations of motion, but a proof that these can be satisfied!

Equations of motion for QED were known many years before people found out how to make sense of them perturbatively. The latter was worth a Nobel prize, while writing down the equation of motions was not considered a big achievement.

And your approach lacks the re-derivation of the standard theories in appropriate limits, which is a necessity if you want to claim to do better than tradition.

At least you need to reproduce some of their most conspicuous results, such as a good nonrelativistic limit where the Hilbert space formulation of the standard atomic Hamiltonian approach (on which all of quantum chemistry is based) must reappear, and some relativistic gems such as the color of gold or the numerical value of the Lamb shift.

Before you can do that, your theory is a mere possibility...

 

[Careful]

Most uses of QM are not concerned with Lorentz covariant physics.

And _all_ Lorentz covariant QFTs that are known to exist were constructed via Hilbert space methods. Mathematically, the others only have the status of conjectures. The impact of indefinite methods on turning conjectures into theorems has so fare been nil.

Again, all unphysical ones It is getting quite boring to be honest, you don't care about nature, I do.

No, but this is the goal of mathematical (as opposed to heuristic) techniques.
It is worth a million of dollars.

No, this is not the goal of mathematics. Why don't you try to prove that such construction does not exist? That would be equally mathematical ! The goal of mathematics is to construct natural languages and theories, and gauge theories do not belong to this class since the standard construction is actually the most natural one and it doesn't work ! What you are trying to do is bad mathematics (and physics), you insist upon fitting something where it most likely does not exist. And people give a million dollars for all kinds of silly things, so I am surprised that you are blinded by the silly prize awarded by the Clay institute.

This will make the rigorous perspective even worse. I very much doubt that indefinite methods (which have much poorer mathematical structure) will be more powerful than Hilbert space methods for proving the existence of gauge theories in 4D.

Show the true power for rigorous results not by easily made promises for the future but by successes in the past!

I hope you can read; I said that it is not my aim to recover fied theory on Hilbert space because that does not exist. What I am doing is constructing a theory which behaves like QED to the extend that gravitation is weak and it is not a field theory since causality is violated weakly as is the cluster decompostion principle. So gauge theories in 4 D do NOT exist, period ! The million dollar prize you are running after is a hoax. As concerning the weight of my words: well rationally there is a lot more to say for my position than for yours, at least I do not have 50 years of failure behind me

This is not a construction in the mathematical sense, only a plausibility consideration.
A construction would show in particular the existence of a well-defined dynamics -
not only equations of motion, but a proof that these can be satisfied!

Equations of motion for QED were known many years before people found out how to make sense of them perturbatively. The latter was worth a Nobel prize, while writing down the equation of motions was not considered a big achievement.

Sure not, because the hard work was done before: quantum mechanical equations had to be constructed first and that was worth a few nobels ! Now you tell me that someone who invents a new quantum theory surpassing all difficulties of traditional QFT in one stroke is a ''nobody'' ?? Because he does not only have to do the work of one generation, but of two generations in one book ?

And your approach lacks the re-derivation of the standard theories in appropriate limits, which is a necessity if you want to claim to do better than tradition.

Well at least all free theories are rederived until now... but sure you are right, there is a lot of work to do! Why don't you pull up your sleeves instead of making silly comments like this?

 

[A. Neumaier]

So gauge theories in 4 D do NOT exist, period !

Your proof for this statement shows that what you consider to be rigor is very different from the customary view of rigor.

Proving the nonexistence of gauge theories in 4D would also earn you the Clay prize!

Why don't you pull up your sleeves instead of making silly comments like this?

Because I work on what _I_ find promising, and my standards are very different from yours.

 

[Careful]

Your proof for this statement shows that what you consider to be rigor is very different from the customary view of rigor.

Proving the nonexistence of gauge theories in 4D would also earn you the Clay prize!

Really, did I ever say I had a proof of this ? Please quote me If the Clay institute also rewards money for that, I advise you to change tactics. What you have tremendous problems with are deep plausibility arguments and physical reasoning. You think you have done something worthwile when you can express things Bourbaki style. Well even most mathematicians are not that limited in their understanding; ever heard of the Russian school ? Ever cared to read work of Gromov, Perelman and giants like that ? I guess you would spit on them too !

Because I work on what _I_ find promising, and my standards are very different from yours.

Sure, they are obviously much lower. I actually develop new mathematics because all evidence I know of is pointing into the direction that we need this while you keep on being stuck with tools developed at the beginning of the 20'th century which until now, have proven to be insufficient.

 

[A. Neumaier]

Really, did I ever say I had a proof of this ?

Why do you claim it if you have no proof for it?

 

[Careful]

Why do you claim it if you have no proof for it?

Simple, because you do not understand the dynamics of physics. Your attitude is similar to those professors looking for ad-hc corrections to Newtonian gravity before and after Einstein came along with general relativity. They also needed a proof;well as far as I know, there doesn't even exist something which comes close to that standard. Nevertheless, Newtonian gravity is safely relegated to the trashbin and everybody agrees upon the fact that it is dead. Likewise, it will be so with your quest; you will be frustrated because nobody will prove you wrong but everybody will agree that something else is right. I am sure you would have spit on Einstein too because integrability of his equations was only formally proven 40 years later. It just shows that your attitude is wrong; intelligence consists of more than playing flawlessly logic games, you know. It also consists in knowing which games to play.

 

[dextercioby]

Nevertheless, Newtonian gravity is safely relegated to the trashbin and everybody agrees upon the fact that it is dead. Likewise, it will be so with your quest; you will be frustrated because nobody will prove you wrong but everybody will agree that something else is right. I am sure you would have spit on Einstein too because integrability of his equations was only formally proven 40 years later. It just shows that your attitude is wrong

You haven't justified that gauge theory is dead. You have no mathematical proof for it, your claim is based on the fact that the theory of Newtonian gravity was superseded by the general theory of relativity. But this actually happens (and should normally happen) to any physical theory. Physicsts will have always have to make a living in proving that someone else before them was wrong and didn't see the picture they were seeing.

With this in mind, almost everyone jumped to rearch generalizations for the standard model at the beginning of the 1970', even when this was not only 100% experimentally confirmed (and even today it isn't), nor 100% mathematically accurate (even today it isn't).

You have chosen to work along with the very many. That's ok for you. Others are still interested in laying rigorous foundations for the things we already know.

I think both parties deserve the same credit for their work and should not conflict with one another.

 

[Careful]

You haven't justified that gauge theory is dead.

Oh but I have to Arnold on many occasions. The way Arnold tries to cure gauge theory is actually very mainstream amongst mathematical physicists and can be found in textbooks of Streater and co. Those people lie the blame with Fock space, but Fock space is natural and almost canonical for everyone who understands the issue of Poincare invariance and statistics. Therefore, the perturbative quantization is the natural physical quantization and it fails. The logical conclusion is that something else fails than Fock space but Arnold is not willing to even consider this.

You have no mathematical proof for it, your claim is based on the fact that the theory of Newtonian gravity was superseded by the general theory of relativity. But this actually happens (and should normally happen) to any physical theory. Physicsts will have always have to make a living in proving that someone else before them was wrong and didn't see the picture they were seeing.

Also problems with reading skills I presume ? I said that in phyiscs nothing is proved wrong according to the standards of classical logic employed in mathematics. Physicists actually are far more intelligent and understand the subtle art of accepting better and more plausible theories.

With this in mind, almost everyone jumped to rearch generalizations for the standard model at the beginning of the 1970', even when this was not only 100% experimentally confirmed (and even today it isn't), nor 100% mathematically accurate (even today it isn't).

So what ? It was the natural thing to do and even that fails. It is by no means an argument for your case.

You have chosen to work along with the very many. That's ok for you. Others are still interested in laying rigorous foundations for the things we already know.

This is too silly to even react upon. My ideas are so far those of a singleton; 99,9% doesn't even dare to touch quantum physics.

I think both parties deserve the same credit for their work and should not conflict with one another.

No, they don't because Arnold's approach is very old and the axioms he refers to (the Wightman axioms) also have been relegated to the trashbin already.

Careful

 

[A. Neumaier]

Newtonian gravity is safely relegated to the trashbin and everybody agrees upon the fact that it is dead.

Strange - your community of people whom you call ''everybody'' must be marginally small.

I find it discussed in many physics book.

Also it is still used every day everywhere in the engineering world (and they know best what reality is!) - whether it is kitchen scales, simulations of car behavior on slippery roads, calculating the stability of buildings, whether forecast, computing spacecraft missions, ...

The only major application area where it is a little too inaccurate is the GPS.

 

[A. Neumaier]

The way Arnold tries to cure gauge theory is actually very mainstream amongst mathematical physicists and can be found in textbooks

Indeed, my purpose here on PF is to explain the mainstream views in intelligible terms, with slight corrections in interpretational matters but not in the substance. I wait with explaining more radical attempts to cure the known defects of the main tradition (most of which fail though they are announced with trumpets) until they have become mainstream.

Physicists actually are far more intelligent.

Do you have sociological data to support this, or is it only as well proved as the announced ''fact'' that 4D gauge theories don't exist?

Arnold's approach is very old and the axioms he refers to (the Wightman axioms) also have been relegated to the trashbin already.

Your trashbin seems to contain everything of value except for the speculative theory of Johan Noldus, which is supposed to supersede everything - although no hard conclusion (that could be compared with experiment) has been derived from it so far.

 

[dextercioby]

Your trashbin seems to contain everything of value except for the speculative theory of Johan Noldus, which is supposed to supersede everything - although no hard conclusion (that could be compared with experiment) has been derived from it so far.

My point exactly. The <trashbin> metaphor is what's really bothering in his statements. If the physics community was sharing his drastic view, there would be nothing taught to students in colleges around the world, because everything would be wrong, or inaccurate. We wouldn't be teaching students classical electrodynamics, because this is superseded by the quantum one, which is not even 100% mathematically rigorous, so we wouldn't be teaching that as well. And the examples can continue. If I was mean, I would say to teach only his theory. But the question would be then: Professor, which are the prerequisites for the quantum gravity course you're teaching ?

 

[Careful]

Strange - your community of people whom you call ''everybody'' must be marginally small.

I find it discussed in many physics book.

Also it is still used every day everywhere in the engineering world (and they know best what reality is!) - whether it is kitchen scales, simulations of car behavior on slippery roads, calculating the stability of buildings, whether forecast, computing spacecraft missions, ...

The only major application area where it is a little too inaccurate is the GPS.

There is another major difference between both of us which is that I do not use such cheap diversion tactics. If you want to continue like this, you know, why don't you study the theory of the old Greeks that the universe is inside a platonic solid. You may actually find a lot of friends in the spin foam or LQG community by doing this.

 

[A. Neumaier]

There is another major difference between both of us which is that I do not use such cheap diversion tactics.

I know. Your diversion tactic uses instead a very expensive period:

So gauge theories in 4 D do NOT exist, period !

 

[Careful]

Indeed, my purpose here on PF is to explain the mainstream views in intelligible terms, with slight corrections in interpretational matters but not in the substance. I wait with explaining more radical attempts to cure the known defects of the main tradition (most of which fail though they are announced with trumpets) until they have become mainstream.

A. Your view is not mainstream, it has been largely given up by the theoretical physics community.
B. Your attitude shows you cannot separate something which has potential from something that has not. Conservatism is good as far as it remains plausible. If it is not, then you need to dare something.
C. Nothing is announced here with trumpets, I am merely explaining the virtues of my approach as it has been developed so far. Overadvertising consists in saying things which you did not proof yet. I have never done such thing. So, your psychological problems are elsewhere, perhaps in your own creativity ?

Do you have sociological data to support this, or is it only as well proved as the announced ''fact'' that 4D gauge theories don't exist?

Sure there exists such data, for example the conversation between me and you is exemplary to prove my assertion.

Your trashbin seems to contain everything of value except for the speculative theory of Johan Noldus, which is supposed to supersede everything - although no hard conclusion (that could be compared with experiment) has been derived from it so far.

First of all, it is not a speculative theory. It appears to be logically consistent framework which has a good gravity limit, gives free QFT and surpasses all traditional no go theorems. Moreover, there are good indications renormalization issues are solved. You say it is speculative because you have never taken the effort to understand it. So, it matches experiment already to a considerable degree. Your golden box however, appears to contain everything theoretical physicists know to be inadequate since 60 years. It appears logical to believe in something which has potential instead of defending those things which have limited application.

 

[Careful]

I know. Your diversion tactic uses instead a very expensive period:

This is not a diversion tactic : it is most likely true; but yes, people who only understand yes or no have trouble with understanding matters of probability.

 

[Careful]

My point exactly. The <trashbin> metaphor is what's really bothering in his statements. If the physics community was sharing his drastic view, there would be nothing taught to students in colleges around the world, because everything would be wrong, or inaccurate. We wouldn't be teaching students classical electrodynamics, because this is superseded by the quantum one, which is not even 100% mathematically rigorous, so we wouldn't be teaching that as well. And the examples can continue. If I was mean, I would say to teach only his theory. But the question would be then: Professor, which are the prerequisites for the quantum gravity course you're teaching ?

You confuse a few important issues here:
A. I see the roll of PF as dual, where people like Arnold can come and explain old undergraduate level stuff. I, on the other hand, am interested in modern physics where the battles are fierce and the arguments heated. This can also be treated here.
B. I have never said students shouldn't learn classical physics or old quantum physics although I suspect that this won't be the case anymore in 100 years. However, once you have gone through the boring obligate stuff you have to do to earn a degree, you have to go to a higher level and see the gaps in what you learned.
C. Considering those points, I think a discussion about C* algebra's as if it were relevant for QM is a bad one. It neither serves the educational purpose, nor is it relevant at the cutting edge of physics. It is only a subject which some dull mathematical physicists talk about because they simply hate infinity (and the mathematical physicists community is very small indeed) and Lorentz covariance. Indeed, those people usually don't even know relativity and Arnold is a clear cut example of that culture (which started 90 years ago, but then for different reasons).

So, you should not try to be unfair to me, while the logical inconsistency is in your line of argumentation. Not mine.

 

[A. Neumaier]

I see the roll of PF as dual, where people like Arnold can come and explain old undergraduate level stuff. I, on the other hand, am interested in modern physics where the battles are fierce and the arguments heated. This can also be treated here.

For this reason, PF has several physics forums.

In particular, the forum ''Quantum Physics'' is for discussing the established QM stuff, while the forum ''Beyond the Standard Model'' is for discussing what goes beyond it.

Your superior intelligence should have no difficulties finding out where your interest should place your postings.

 

[dextercioby]

A. I see the roll of PF as dual, where people like Arnold can come and explain old undergraduate level stuff. I, on the other hand, am interested in modern physics where the battles are fierce and the arguments heated. This can also be treated here.

I see you point. However, in the quantum physics subforum, people discuss issue pertaining to quantum mechanics and QFT of the standard model, even though, according to you, they both are to be <relegated to the trashbin>. For modern theories we've got a subforum which I'm sure you're very familiar with.

I see the purpose of this particular subforum more as a pedagogical one, rather than one focused on research. Most of the discussions here appear because people have problems understanding things you probably consider obsolete.

That being said, I just opened a thread on axioms of quantum mechanics. You are welcome to join it, even though you might think that the quantum mechanics founded 85 years ago is a dead theory, thus it shouldn't have any open interesting points (I think it has).

B. I have never said students shouldn't learn classical physics or old quantum physics although I suspect that this won't be the case anymore in 100 years. However, once you have gone through the boring obligate stuff you have to do to earn a degree, you have to go to a higher level and see the gaps in what you learned.

I agree. That's why I spoke above of two sides: one thinking that what they learn in college must be superseded by a new theory and go searching for it, while other would work only to set what they learn in school on rigorous mathematical foundations. You're part of the first category, Arnord apparently supports the second.

 

[A. Neumaier]

Your trashbin seems to contain everything of value except for the speculative theory of Johan Noldus, which is supposed to supersede everything - although no hard conclusion (that could be compared with experiment) has been derived from it so far.

it is not a speculative theory. It appears to be logically consistent framework

Careful alias Johan Noldus seems to be the only one who rates Noldus' work so highly.
We ordinary mortals apparently don't have enough intelligence to recognize the quality and rigor of his work.

 

[Careful]

In particular, the forum ''Quantum Physics'' is for discussing the established QM stuff, while the forum ''Beyond the Standard Model'' is for discussing what goes beyond it.

Could you actually refer me to this rule? Or is this your personal interpretation ?

 

[Careful]

Careful alias Johan Noldus seems to be the only one who rates Noldus' work so highly.
We ordinary mortals apparently don't have enough intelligence to recognize the quality and rigor of his work.

If you have any specific comment, you might want to discuss it in the appropriate place, I would be happy to do so. All I see now is a pathetic attempt to degrade something you have shown plenty of misunderstandings about. Btw, you repeatedly acknowledged not to have sufficient understanding of, neither to care about quantum gravity. As far as I see, you do not even care about special relativity, so I guess your set of mere mortals at least contains one element

 

[A. Neumaier]

Could you actually refer me to this rule? Or is this your personal interpretation ?

Is your intelligence too advanced to interpret the titles of the forums in the usual, conservative way?

You say that Quantum Mechanics is dead and must be generalized, so discussion based upon this insight is beyond the ''Quantum Mechanics'' forum, and that gauge theories in 4 D do NOT exist, period !, so your insights, comments, and serious work are ''Beyond the Standard Model''.

 

[A. Neumaier]

All I see now is a pathetic attempt to degrade something you have shown plenty of misunderstandings about.

I only try to deflate the conceit of someone who boasts shamelessly about his own superior intelligence that throws everything valuable into the trashbin - mathematical physics, Hilbert space, positive probabilities, quantum mechanics, causality, gauge theories - and expects to be taken seriously with his speculative replacements.

 

[Careful]

Is your intelligence too advanced to interpret the titles of the forums in the usual, conservative way?

It seems yours is not up to the following nuances:

You say that Quantum Mechanics is dead and must be generalized, so discussion based upon this insight is beyond the ''Quantum Mechanics'' forum,

No, I said that OLD quantum mechanics is dead That is QM as it existed up to 1945 which is all what you are discussing. From 1945-2011 a lot of stuff happened you know: QFT was invented (hear hear relativity), the standard model developed and a lot has been done on the foundations too. You have the Brussels-Geneva approach, you have the schools turning around the histories interpretations, you have the work of Durr and others (Durr worked still with Heisenberg) who says already for 40 years that Nevanlinna spaces are vital for the future of quantum physics and so on... So all these people working at legitimate universities are beyond quantum physics because the theory was finished for you in 1945? More recently, people working on Clifford quantum mechanics include David Finkelstein, so this work partially meets mine.

and that gauge theories in 4 D do NOT exist, period !, so your insights, comments, and serious work are ''Beyond the Standard Model''.

You must be emotional because now you even start to make logical mistakes. What I said is that gauge theories in 4 - D do not rigorously exist, which is a very mainstream view. Actually all relevant thinkers have uttered these ideas: gauge theories are an approximation to string theory, 't Hooft has coined that gauge invariance might be emergent and now I do it. There has never been a rigorous QFT of gauge fields and the large majority of theoretical physicists have no such illusion anymore.

 

[Careful]

I only try to deflate the conceit of someone who boasts shamelessly about his own superior intelligence that throws everything valuable into the trashbin - mathematical physics, Hilbert space, positive probabilities, quantum mechanics, causality, gauge theories - and expects to be taken seriously with his speculative replacements.

A. Where did I boast about or even suggested having a superior intelligence ? Please QUOTE ME. I suggested that I was better than you in thinking outside a simple yes/no framework, but that seems clear to me.
B. Second, I never have thrown mathematical physics to the trashbin. I have related those mathematical physicists which are busy with tools which obviously are irrelevant for modern physics to the trashbin indeed, I don't see what is wrong with that. All the rest is emotional crap from your side. Actually, causality and gauge theories are approximations too in most quantum gravity approaches (those people on the forefront of physics must be stupid huh ? ); Hilbert spaces have been outcasted from the generalized quantum mechanics of Sorkin too. Only concerning the generalized probability interpretation, I am somewhat a loner. I always love it when mathematicians are telling how theoretical physicists should run their shop

 

[A. Neumaier]

No, I said that OLD quantum mechanics is dead That is QM as it existed up to 1945 which is all what you are discussing. From 1945-2011 a lot of stuff happened you know: QFT was invented (hear hear relativity), the standard model developed and a lot has been done on the foundations too. You have the Brussels-Geneva approach, you have the schools turning around the histories interpretations, you have the work of Durr and others (Durr worked still with Heisenberg) who says already for 40 years that Nevanlinna spaces are vital for the future of quantum physics and so on... So all these people working at legitimate universities are beyond quantum physics because the theory was finished for you in 1945? More recently, people working on Clifford quantum mechanics include David Finkelstein, so this work partially meets mine.

To support your fantasies, name any modern quantum mechanics textbook that does _not_ teach the stuff you just called dead!

And show the references from before 1945 that discussed the Wightman axioms and proved rigorously the existence of local covariant quantum field theories in dimensions 2 and 3.

And name any modern quantum field theory textbook that teaches the stuff you just cited! The only thing one finds in this direction is the Gupta-Bleuler quantization of QED (no longer fashionable) and - somewhat indirectly only - the ghost story in BRST.

You must be emotional because now you even start to make logical mistakes. What I said is that gauge theories in 4 - D do not rigorously exist, which is a very mainstream view. Actually all relevant thinkers have uttered these ideas: gauge theories are an approximation to string theory, 't Hooft has coined that gauge invariance might be emergent and now I do it. There has never been a rigorous QFT of gauge fields and the large majority of theoretical physicists have no such illusion anymore.

Now you are interpolating words into the sentence that I quoted verbatim!

Independent of that, string theory is also ''Beyond the Standard Model'', and explicitly do not belong to the ''Quantum Mechanics'' forum.

 

[A. Neumaier]

A. Where did I boast about or even suggested having a superior intelligence ? Please QUOTE ME.

I don't dare to quote you anymore for fear that you afterwards insert unwritten words into the quotations...

Anyway, my statement is not a scientifically proven fact. Take it just as the personal, subjective, and fallible impression I got from reading Careful's statements and Noldus' book.

Now that you revoke your superiority, we are again on equal footing. Thus your and my assessment of what is important in physics stand side by side.

You throw all the stuff I value in quantum physics into your thrashbin, and I reciprocate by throwing your book into mine. Nothing is proved by each other's thrashbin, and it is far too early to find out whose view will be more justified by history.

 

[Careful]

To support your fantasies, name any modern quantum mechanics textbook that does _not_ teach the stuff you just called dead!

Didn't I just explicitely explain the meaning of dead before? Didn't I state that it is logical that these things are still fed to students? You have short-term memory lapses?

And show the references from before 1945 that discussed the Wightman axioms and proved rigorously the existence of local covariant quantum field theories in dimensions 2 and 3.

Arnold, do we live in 2 or 3 dimensions ? I am only citing those things which you mention which were once relevant to nature. The Wightman axioms have never been so, they are recently replaced by those of Wald and Hollands which still fall short in my opinion.

And name any modern quantum field theory textbook that teaches the stuff you just cited! The only thing one finds in this direction is the Gupta-Bleuler quantization of QED (no longer fashionable) and - somewhat indirectly only - the ghost story in BRST.

Ah none of course; likewise is there no mainstream QFT book which teaches C* algebraic approaches and the stuff you are interested in. Did I ever make an issue out of that ?

Now you are interpolating words into the sentence that I quoted verbatim!

I assume my readers to be sufficiently intelligent so that they know the meaning of the word to exist in the context I use it.

 

[A. Neumaier]

Didn't I just explicitely explain the meaning of dead before?

If you want to be understood, use the terms with the meaning everyone uses them.

 

[Careful]

Now that you revoke your superiority, we are again on equal footing.

I didn't Where did I write that again ? I asked you for a quotation where I said this, nothing more. I have nothing to hide and nothing to boast about, I only make my point as I know it to be likely. If you have this subjective impression of my book, please adress specific points as I do in your approach (and which you constantly ignore). Your Christian moral severly clashes here with my Nietzschian philosophy.

Furhermore, I do not think that your judgement is equal to mine. You are a mathematician who has until so far displayed little or no knowledge of relativity, quantum gravity, modern approaches to the foundations of quantum mechanics and axiomatic approaches of QFT in curved spacetime. I am not going to tell either that my judgement about Riemannian geometry is as good as that of Misha Gromov because I have studied Petersen, Gromov's own book and Alexandrov on metric geometry, am I ? That would not be very humble of me.

You throw all the stuff I value in quantum physics into your thrashbin, and I reciprocate by throwing your book into mine. Nothing is proved by each other's thrashbin, and it is far too early to find out whose view will be more justified by history.

It is indeed to early to tell wether I will succeed (however likely I think it is). It is however not to early to tell that your chances are extremely slim.

 

[A. Neumaier]

I do not think that your judgement is equal to mine. You are a mathematician who has until so far displayed little or no knowledge of relativity, quantum gravity, modern approaches to the foundations of quantum mechanics and axiomatic approaches of QFT in curved spacetime. I am not going to tell either that my judgement about Riemannian geometry is as good as that of Misha Gromov because I have studied Petersen, Gromov's own book and Alexandrov on metric geometry, am I ? That would not be very humble of me.

But comparing yourself with Gromov is humble!?? Where is your array of prizes??


Anyway, back to the topic of the thread:

Can you explain to us - without requiring us to read your 160 page book - how your indefinite spaces lead to positive probabilities in simple situations?
And how to interpret the negative probabilities if they arise?

 

[Careful]

But comparing yourself with Gromov is humble!?? Where is your array of prizes??

It is not the array of prizes that counts, actually I am pretty sure that would not even come to Gromov's mind; it clearly shows you do not understand how people who have done something of value think. They don't care about prizes, they care about brains. But now I am confused Gromov doesn't write anything down according to your standards of rigor and leaves quite some gaps to the reader; are you saying now that while he does not satisfy your criteria of a proper mathematician, he still is in your high regard because other people have given him ''prizes''?

Anyway, back to the topic of the thread:

Can you explain to us - without requiring us to read your 160 page book - how your indefinite spaces lead to positive probabilities in simple situations?
And how to interpret the negative probabilities if they arise?

As I said, these schemes are being worked out fully at this moment; there are actually inequivalent approaches one can take, one more robust than the other. And no, I cannot explain these things even on one full A4 page since it requires many subtle considerations and additional concepts. But even then you miss the point, it often happened that physicists have developped a mathematical tool they deemed necessary for nature without fully grasping at first the interpretation. The very rule you are questioning now is a prime example of this ! There has been a long debate initially about several competing interpretations going from matter waves to probabilities. But here, even this is not a problem, there however are some real results which need to be developped first before I know which interpretation is preferred.

 

[A. Neumaier]

It is not the array of prizes that counts, actually I am pretty sure that would not even come to Gromov's mind; it clearly shows you do not understand how people who have done something of value think. They don't care about prizes, they care about brains. But now I am confused Gromov doesn't write anything down according to your standards of rigor and leaves quite some gaps to the reader

The work for which Gromov received the prizes is commonly agreed to be rigorous according to the standards of today. (I don't care about prizes, but they reflect the recognition of the community, and hence are useful for comparison. Those who select the prize winners don't care about prizes either, they care about brains.) Gaps do not matter as long as the community agrees that they can be filled. Hardly any mathematician aspires to rigor in the sense of the logicians, where even the smallest gap is filled.

As I said, these schemes are being worked out fully at this moment;

So not even on that you have a definite account, not even at the level of rigor of theoretical physics.

Let me try again:

In which sense is the conventional quantum mechanics in Hilbert spaces an approximation or limiting case of your indefinite theory?

 

[Careful]

The work for which Gromov received the prizes is commonly agreed to be rigorous according to the standards of today. (I don't care about prizes, but they reflect the recognition of the community, and hence are useful for comparison. Those who select the prize winners don't care about prizes either, they care about brains.) Gaps do not matter as long as the community agrees that they can be filled. Hardly any mathematician aspires to rigor in the sense of the logicians, where even the smallest gap is filled.

So perhaps then, it is just a matter of people actually having studied his work and thought about it in great detail for a long while? Note that Gromov often doesn't even care about giving proper definitions. God praise those people who have actually taken the effort for that and not just thrown away the manuscript because not everything was written down in what they conceive as a very precise way. So, what was our discussion again about? Nevanlinna spaces which are not rigorous, unbounded operators which are troublesome or eh new equations whose integrability has not been formally shown yet ? Let me tell you that even in Clifford analysis, similar, but much easier, types of equations than the ones I construct have been investigated and plenty of solutions have been found. But alas, no rigorous integrabilty theorem has been constructed yet even in those simple cases as far as I know.

So not even on that you have a definite account, not even at the level of rigor of theoretical physics.

If you continue to make such idiotic and manifestly false comments, our discussion is over. There is still discussion in our days about the probability interpretation of QM and the equations have been constructed 90 years ago. You constantly show that you do not understand how theoretical physics works; perhaps you should remain with those things you are educated in: mathematics. For example, none of the other quantum gravity programs suggested so far has even attempted to construct a coherent interpretation. So would you also piss on the capacities of say string theorists in that way? You would not even dare so, because you may hide in some dusty corner of your office when Edward Witten comes to you to complain. Moreover, I do have working interpretations, some of which are similar to those proposed in the literature, but you are not aware of those either as far as I understand.

Let me try again:

In which sense is the conventional quantum mechanics in Hilbert spaces an approximation or limiting case of your indefinite theory?

That is a different question which I do have a definite answer for (and which is also provided in the book); it is not the same one you asked before. The negative norm originates from the indefinite character of the Clifford numbers which are only turned on when there is a nonzero gravitational field. So, in case gravity vanishes, the dynamical sector leaves a Hilbert space invariant and you have the standard interpretation.

 

[A. Neumaier]

new equations whose integrability has not been formally shown yet ?

Has it been shown at least perturbatively to second order in the gravitational constant?
If not, the status of your theory is like that of QED in 1930, maybe with all the problems ahead that QED had to face. Or like that of string theory around 1980, where the problems still aren't overcome.

There is still discussion in our days about the probability interpretation of QM and the equations have been constructed 90 years ago.

But this discussion is irrelevant for the practice of quantum mechanics. The probabilistic aspect of QM is very well understood; only its origin is somewhat in the clouds.

The negative norm originates from the indefinite character of the Clifford numbers which are only turned on when there is a nonzero gravitational field. So, in case gravity vanishes, the dynamical sector leaves a Hilbert space invariant and you have the standard interpretation.

What happens when the gravitational field is small, bulk matter is far away, and energies are far below the Planck scale? Do you get a Hilbert space and an external gravitational field?

 

[Careful]

Has it been shown at least perturbatively to second order in the gravitational constant?
If not, the status of your theory is like that of QED in 1930, maybe with all the problems ahead that QED had to face. Or like that of string theory around 1980, where the problems still aren't overcome.

My computations (which are not in the draft yet) so far reveal no problems on the perturbative level, the hard question is whether it closes nonpertubatively. Moreover, again, you are extremely unreasonable. Your contributions to this discussion are nihil because you put me in the situation where I would have to present a fully closed theory as a single person in a single effort. Either you comment upon the proposal as it stands now (and which is much more precisely formulated than other approaches going on for many years), or you shut up. What you do not want to see is that my comments regarding your work are embedded in a historical series of failed attempts while my approach is fully fresh and has no evidence against it at this moment in time. If you refuse to understand this dynamics and important difference in your next post, I will report it as obstructive. My patience with your nonsensical comments is over.

But this discussion is irrelevant for the practice of quantum mechanics. The probabilistic aspect of QM is very well understood; only its origin is somewhat in the clouds.

Again, you do not understand the point here. It is alas like that with professors who think that God likes them in all aspects. In a theory of quantum gravity, the probability aspect becomes different because you do not dispose anymore of the classical observer. Hence, what you calculate is an ''absolute'' probability which has nothing to do with observation which requires relative probabilities. This aspect is just an example of the very many things which are alive still. You may also wish to study the work of Sorkin who tries to construct dynamical probability interpretations starting from the quantum measure. Here you actually have to prove some decoherence for ''macroscopic'' bodies in order for the Born rule to emerge.

What happens when the gravitational field is small, bulk matter is far away, and energies are far below the Planck scale? Do you get a Hilbert space and an external gravitational field?

Probably not, the dynamics will go slightly outside any fixed sub-Hilbert space, but that is not a problem is it ? Point is, that the pure Hilbert space picture does not exist because G is nonzero.

 

[Careful]

To summarize, you are only pleased with Noldus when he performs the work of Heisenberg, Von Neumann, Wigner (regarding a fully complete and rigorous foundation of a new quantum theory) and Feynman, 't Hooft (showing that the theory makes sense - although there is no renormalization issue in my approach) in one book. And then, I did not even speak about the gravitational theory. Otherwise, you deem it unworthy of theoretical physics. Please, go back to your mathematical desk and fill in epsilon's and delta's in proofs of people who have real ideas and don't bother people who do work hard to get a genuine new insight.

You constantly refuse to see or understand or acknowledge the point I am making to you. The level of irrationality (and this is a very mild word) which you display here (in many ways) is beyond comprehension for someone who has an actual responsability towards the intellectual capital he teaches to every year.

Careful

 

[A. Neumaier]

you put me in the situation where I would have to present a fully closed theory as a single person in a single effort.

Great and radical claims are measured by much higher standards than minor main stream contributions.

And asking for a finite second order perturbation theory is far from asking for a closed theory.

If [...] I will report it as obstructive. My patience with your nonsensical comments is over.

Your derisive comments would be worthy of reporting, too. I'd never challenge a humble mind like I challenge you!

It is alas like that with professors who think that God likes them in all aspects.

Well, why shouldn't he like his children? He gives them freedom of thought and power to think independently.

In a theory of quantum gravity, the probability aspect becomes different because you do not dispose anymore of the classical observer.

Even in flat space quantum field theory, one doesn't have (or need) a classical observer.
As is well-known, all known observers are quantum objects, though macroscopic ones.

Hence, what you calculate is an ''absolute'' probability which has nothing to do with observation which requires relative probabilities.

What should an absolute probability mean, if it cannot be observed and hence tested?

Probably not, the dynamics will go slightly outside any fixed sub-Hilbert space, but that is not a problem is it ? Point is, that the pure Hilbert space picture does not exist because G is nonzero.

One needs to be able to recover to first order in G the standard Hilbert space quantum mechanics in an external gravitational field, under the assumption that an observer inside the system observes another subsystem - since this is what we observe as real observers.

I hope you are at least able to do first order perturbation theory...

I am looking for _some_ things that you can explain without a 160 page overhead...

 

[A. Neumaier]

The level of irrationality (and this is a very mild word) which you display here (in many ways) is beyond comprehension for someone who has an actual responsibility towards the intellectual capital he teaches to every year.

Well, it seems that you are the only one who perceives me as being irrational.
Others here appreciate a lot my way of imparting understanding:

BTW it'd be really nice to have a teacher like you : )

^ That was a surprisingly good (and concise) explanation.

 

[Hurkyl]

If you think a post deserves to be reported, you should report it, rather than responding to it...

 

[Careful]

Great and radical claims are measured by much higher standards than minor main stream contributions.

Yes, it requires 5 nobels in one book

Your derisive comments would be worthy of reporting, too. I'd never challenge a humble mind like I challenge you!

There are two points:
A. I am actually more humble than you are it seems to me.
B. You did not challenge me at any instant: all you did was mentioning projects which I did not finish yet for very understandable reasons. This is fun in the beginning, but gets very annoying in the end.

Even in flat space quantum field theory, one doesn't have (or need) a classical observer.
As is well-known, all known observers are quantum objects, though macroscopic ones.

Nonsense, in that case you need a super observer and the state of the system is not directly discribing the probabilities of measurements you make. Actually, this superobserver would first have to measure you and then the system under study and apply the Bayesian rule.

One needs to be able to recover to first order in G the standard Hilbert space quantum mechanics in an external gravitational field, under the assumption that an observer inside the system observes another subsystem - since this is what we observe as real observers.

Sure, this is the standard analytical perturbative argument no? If you shut off G, you get standard QFT with all it's limitations, if G is turned on, then first order corrections arise.

I am looking for _some_ things that you can explain without a 160 page overhead...

It is difficult, of similar order than explaining general relativity to Newtonian physicists. You must accept that some ideas are not trivial and that 160 pages is sometimes not too much. For example, I once send you a summary and you found it full of buzzwords, while for QG physicists it was very clear what I wrote. You think you can decouple gravity from QM and what I have learned is that both need each other for a consistent formulation.

 

[Careful]

Well, it seems that you are the only one who perceives me as being irrational.
Others here appreciate a lot my way of imparting understanding:

Well, I thought the same when I got to know you. And indeed, you explain standard stuff impartial and in a good way - we had never a dispute about that (we are both intelligent enough for this). However, you get irrational when some bold, new ideas are launched; you understand very well the process of repetition, but alas not of innovation.

Let us quit here with our little fight. I guess we both understand that battles can be fought without any need for casualties ... an art which is not too well understood.

 

[A. Neumaier]

You did not challenge me at any instant: all you did was mentioning projects which I did not finish yet for very understandable reasons. This is fun in the beginning, but gets very annoying in the end.

I challenged your patience to the point where you threatened to report me.

Nonsense, in that case you need a super observer and the state of the system is not directly describing the probabilities of measurements you make. Actually, this superobserver would first have to measure you and then the system under study and apply the Bayesian rule.

Nonsense. There are no such superobservers.

But we routinely observe as quantum systems other quantum systems at energies where quantum corrections to gravity are completely negligible.

Sure, this is the standard analytical perturbative argument no? If you shut off G, you get standard QFT with all it's limitations, if G is turned on, then first order corrections arise.

Of course. But since you start with indefinite space, the question is whether or not you end up in a Hilbert space - as it must be in this case, since it is very well known how to describe this situation.[/QUOTE]

I once send you a summary and you found it full of buzzwords, while for QG physicists it was very clear what I wrote.

It is very easy to claim clarity. It is much more difficult to make it believable.

Please have some QG physicist comment here in PF on your book, to confirm your claim that for QG physicists it was very clear what you wrote.

 

[Careful]

I challenged your patience to the point where you threatened to report me.

Yes that is true, you managed to raise my bloodpressure !

Nonsense. There are no such superobservers.

Sure there are, if you have only quantum systems and the observers are quantum themselves, you need something which breaks the superpostion of this observer. You may call this a second classical observer, but it will only lead to the conclusion of a superobserver.

But we routinely observe as quantum systems other quantum systems at energies where quantum corrections to gravity are completely negligible.
Of course. But since you start with indefinite space, the question is whether or not you end up in a Hilbert space - as it must be in this case, since it is very well known how to describe this situation.

Didn't we have this whole discussion that you should not end up in Hilbert spaces in the first place because gauge theories in 4-D strongly appear to resist such formulation ? You are right in the sense that the dynamics should approximately leave some Hilbert space invariant, but not exactly.

It is very easy to claim clarity. It is much more difficult to make it believable.

Please have some QG physicist comment here in PF on your book, to confirm your claim that for QG physicists it was very clear what I wrote.

I know this due to personal communication. Why would I say this if this were not the case ? Have I ever tried to conceal a fact from you? I think all my responses were fair... what content is concerned. You may actually check the forum and you will see that tom.stoer found an almost complete copy of this document helpful and actually requested for me to put it on te web (but this is not the communication I was talking about).

 

[A. Neumaier]

Sure there are, if you have only quantum systems and the observers are quantum themselves, you need something which breaks the superposition of this observer.

Only if one subscribes to von Neumann's very idealized description of the measurement process. I don't, because it is very inadequate to account for the practice of measurement. It applies only to certain idealized model measurements capable of treatment in the 1930's.

Didn't we have this whole discussion that you should not end up in Hilbert spaces in the first place because gauge theories in 4-D strongly appear to resist such formulation ?

This doesn't relieve you from the need to recover the traditional framework (which adequately expresses almost everything we can measure at ordinary distances and energies) in some very good approximation. If you can't, your predictions will be inconsistent with experiment.

 

[Careful]

Only if one subscribes to von Neumann's very idealized description of the measurement process. I don't, because it is very inadequate to account for the practice of measurement. It applies only to certain idealized model measurements capable of treatment in the 1930's.

Von Neumann's is the only sensible one. Moreover, there exists no interpretation which can do what you want it to do. If you think there is, please provide all details; I will be happy to shoot them down.

 

[A. Neumaier]

Von Neumann's is the only sensible one.

Von Neumann's cannot be sensible since for consistency it requires a hierarchy of bigger and bigger superobservers, which is nonsense.

Moreover, there exists no interpretation which can do what you want it to do. If you think there is, please provide all details; I will be happy to shoot them down.

See Sections 7.3 - 7.5 of http://lanl.arxiv.org/abs/0810.1019

 

[Maui]

Von Neumann's cannot be sensible since for consistency it requires a hierarchy of bigger and bigger superobservers, which is nonsense.

You have a viable second option that doesn't resort to miracles?