Approaches to Quantum Gravity (now in Cambridge Press catalog)

[marcus]

I think that is outstanding. It is clear and direct. It is courteous and says exactly what we would like. I am so glad you wrote, Emanuel. Thanks!

We cannot do more than this. If he chooses to answer, he will. If not, we can wait for the appearance of the book.

 

[Emanuel]

Thank you for the kind words. No reply yet, but then it's the holidays so we should probably give it some time. Classes start again in September, but hopefully I'll have received a reply by then.

 

[marcus]

Approaches to Quantum Gravity ( Cambridge Press catalog says Feb 2009)

The publisher's date for availability has been advanced again.

Two months ago, when I started this thread, the target date for publication was May 2009.
... in the past two months, for what it's worth, this book's publication date has ADVANCED and is now earlier.
Now it is listed as March 2009.
...

Now the catalog says available as of February 2009.

It looks like an advance copy of Gerard 't Hooft's essay on the fundamental nature of space and time will NOT be obtainable. I am grateful to Emanuel for trying.
I think the best guess, to give an idea of what it might say, is his piece in the December 2005 Physicsworld:
http://physicsworld.com/cws/article/print/23668

==========================
for me one of the most intriguing features is that after each of the five Parts of the book there is a discussion among all the authors called Questions and Answers.
The five parts (with some paraphrasing by me) are:
Part I Fundamental Ideas
Part II [String]
Part III [Loop and allied approaches]
Part IV Discrete
Part V Effective [and How to Test]

After each part there is a free-for-all where any author, not limited to one featured in that section, can ask questions about stuff in that section. I think that is potentially interesting and constructive.

for ready reference, here is the TOC again, just so you don't have to scroll back.
Keep in mind that we have links to preprint for several of the chapters. I you see one that interests you, you can scroll back and see if there is a preprint link.

Preface;
Part I. Fundamental Ideas and General Formalisms:
1. Unfinished revolution C. Rovelli;
2. The fundamental nature of space and time G. ‘t Hooft;
3. Does locality fail at intermediate length scales R. Sorkin;
4. Prolegomena to any future quantum gravity J. Stachel;
5. Spacetime symmetries in histories canonical gravity N. Savvidou;
6. Categorical geometry and the mathematical foundations of quantum gravity L. Crane;
7. Emergent relativity O. Dreyer;
8. Asymptotic safety R. Percacci;
9. New directions in background independent quantum gravity F. Markopoulou;
Questions and answers;

Part II:
10. Gauge/gravity duality G. Horowitz and J. Polchinski;
11. String theory, holography and quantum gravity T. Banks;
12. String field theory W. Taylor;
Questions and answers;

Part III:
13. Loop Quantum Gravity T. Thiemann;
14. Covariant loop quantum gravity? E. Livine;
15. The spin foam representation of loop quantum gravity A. Perez;
16. 3-dimensional spin foam quantum gravity L. Freidel;
17. The group field theory approach to quantum gravity D. Oriti;
Questions and answers;

Part IV. Discrete Quantum Gravity:
18. Quantum gravity: the art of building spacetime J. Ambjørn, J. Jurkiewicz and R. Loll;
19. Quantum Regge calculations R. Williams;
20. Consistent discretizations as a road to quantum gravity R. Gambini and J. Pullin;
21. The causal set approach to quantum gravity J. Henson;
Questions and answers;

Part V. Effective Models and Quantum Gravity Phenomenology:
22. Quantum gravity phenomenology G. Amelino-Camelia;
23. Quantum gravity and precision tests C. Burgess;
24. Algebraic approach to quantum gravity II: non-commutative spacetime S. Majid;
25. Doubly special relativity J. Kowalski-Glikman;
26. From quantum reference frames to deformed special relativity F. Girelli;
27. Lorentz invariance violation and its role in quantum gravity phenomenology J. Collins, A. Perez and D. Sudarsky;
28. Generic predictions of quantum theories of gravity L. Smolin;
Questions and answers;

Index
=========================
Here is the link to the Cambridge Press page on the book:
http://www.cambridge.org/uk/catalogue/catalogue.asp?isbn=9780521860451

 

[SuperStringboy]

Murcus, nice job! Thanks

 

[Emanuel]

I just finished the preface after receiving my copy from Cambridge Press earlier today. Has anyone else on here received their copy yet? I wanted to bump this topic before I start the book proper to bring it back into the public eye, and because I'll probably get lost in its pages ;) I hope you'll be able to help me out if I do.

 

[marcus]

I just finished the preface after receiving my copy from Cambridge Press earlier today. Has anyone else on here received their copy yet? I wanted to bump this topic before I start the book proper to bring it back into the public eye, and because I'll probably get lost in its pages ;) I hope you'll be able to help me out if I do.

Emanuel, it's good to hear from you. I remember you wrote an excellent email to 't Hooft inquiring about his Nature of Space and Time essay, which we were all wondering about.
Being myself by nature a frugal person, and given that so much of the book (40 or 50 percent?) is available online in draft form, I have not yet taken the plunge and ordered a copy. At the moment, you are the only person I know who owns the book.

What I'm especially curious about are the Q and A sections where the authors of the different chapters can ask questions and respond to each other. Dialog (as Galileo discovered) is a great format for communicating science. So right now it is this Q and A dialog that is primarily tempting me to obtain the book. And also a lot of the chapters have probably been revised, updated, from their original draft versions on arxiv.

BTW at first the book was available directly from Cambridge University Press but not from Amazon. But I just checked the UK amazon and they not only have it in stock, but have almost sold out!

http://www.amazon.com/dp/0521860458/?tag=pfamazon01-20

 

[Emanuel]

Yeah, this is an expensive book! I actually got it as a birthday present; imagine what my parents must think :) If there's anything you'd like to know about the book, let me know.

 

[marcus]

Yeah, this is an expensive book! I actually got it as a birthday present; imagine what my parents must think :) If there's anything you'd like to know about the book, let me know.

Whew! I'm relieved to hear that, Emanuel. HAPPY BIRTHDAY!

Well I am interested in several things actually. One for example is what is your general impression of the Q&A at the end of Part I?

Part I covers a lot of topics and I wonder how many of them get touched on in the Q&A.
For example Part I has Rovelli's perspective piece, which raises among other things some potentially controversial issues by comparing string and background independent approaches. And it also has Percacci's Asymptotic Safety essay. I saw some Q&A regarding that and I wonder if it made it into the final draft. It actually was very helpful, seeing someone else's questions get answered helps me.
And I was not satisfied with the draft I saw of 't Hooft's essay, it left me wondering about a lot of things. 't Hooft is a kind of lighthouse figure that one navigates by, and I was left with a feeling of wanting more clarification about what he was saying.
So I am wondering what was the Part I Q&A like, whose essays got discussed? Rovelli is remarkably adept in dialog, I hope he got asked a few questions.

 

[weburbia]

In case anyone is still looking for 't Hooft's contribution online, there is a version here:
http://www.phys.uu.nl/~thooft/gthpub/QuantumGrav_06.pdf

 

[marcus]

In case anyone is still looking for 't Hooft's contribution online, there is a version here:
http://www.phys.uu.nl/~thooft/gthpub/QuantumGrav_06.pdf

Thanks! I had just seen it once and had been unable to retrieve it. I want to study it more carefully.

 

[Fra]

Thanks weburbia, I was also waiting for this! and I just skimmed it.

Somehow my impression that I expressed in some previous posts in this thread still stands - based on 't Hooft's idea of "deterministic QM", in the sense that there is a yet unknown deterministic model at the Planck scale, in which picture QM is emergent on the large scale. (Since most particle and atomic physics, while beeing the currently smallest explored scale, is still "large scale" as compare to the Planck scale). In this way, he also imagines to escape the usual Bell-type argumentas against hidden variable theories.

I like some of his reasoning, but now it seems to me that what he is leaning towards, is not something I believe in. But it's still possible that his ideas can be developed in a plausible direction.

Somehow the general idea that quantum logic is emergent, is good I think. But I think that I'm moderatley attraced to his idea of his description of this emergent process. At best, I can connect to this idea, if this Planck scale microstructure, rather than beeing classical in the realist sense, is a limit case of where the observer grows and ultimately coverse the universe. I do see how what he says makes sense in that sense, but I fail to see the physical relevance of that picture. Ie. the physical basis and uniquess of this auxiliary structure as he calls it.

One additional way this can make sense, is that one observer (a big observer) can understand the emergence of the "quantum mechanical interactions" WITHIN a smaller system (say particles making up an atom). In THIS sense, I would probably fully agree with his idea that from the point of view of an external large observer, HE can understand the logic of ther emergence of quantum mechanical interactions within the atom.

But, I fail to see how this can make sense if you extend this idea of cosmological scale models, and in general where the approximation of a external observer completely fails. This objection is also as I understnand it the general argument behind Smolins evolving law.

So, in short I think that 't hooft's reasoning could work in an hierachial model where the Planck scal microstructure itself is evolving! Then I think we are close. But as I read 't Hooft this is not quite how he pictures it.

Does anyone have a different impression? Maybe I am missing som depth due to seeing all this from my own perspective.

/Fredrik