Search results

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    Want a group NCG tutorial?

    "An Invitation to NCG" out this month I didn't want to start a new thread for this announcement, so I hope no one objects to I mentioning it here. "An Invitation to Noncommutative Geometry"" (MPI für Mathematik, Bonn) is scheduled to be out this...
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    Smolin Damour

    The audio-visual of the Smolin-Damour debate is up. Go" and click on one of blue icons.
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    #1 physics book in France

    Not related to the thread, but worth pointing out I believe. Connes and Marcolli are currently working on a monograph "Noncommutative Geometry, Quantum Fields and Motives", a preliminary version of which can be downloaded [PLAIN]""[/URL]. Connes' warning...
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    #1 physics book in France

    I managed to get a pdf copy of Connes' preface from the French editors (Dunod, Paris) just after the book came out. Nothing new there...
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    Zwiebach's string theory book

    Whoops! Yes, George is right! I made the mistake of thinking in terms of the 2 identifications x\simx+2\pi R and y\simy+2\pi R, that is (x,y)\sim(x+2\pi R,y), (x,y)\sim(x,y+2\pi R), which, as I came to realise, is discussed on page 31.
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    Zwiebach's string theory book

    No, I think it is T^2.
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    Dantas is missing

    It is very sad to see Christine abandoning the blogosphere after one year of hard work with the blog. I think I understand how she feels to some extent, because I myself could not tolerate all the mess that has been around on blogs. I have been thinking about this whole new blogging phenomenon...
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    Brian Greene's NYT op-ed

    Via". Let me comment to some extent. Greene is very likely referring to the two books (Woit's "Not Even Wrong" and Smolin's "The Trouble with Physics", and ensuing newspaper/magazine articles that appeared recently...
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    As if summoned from the void (nitin's new blog)

    Have a go now r b-j ; )
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    As if summoned from the void (nitin's new blog)

    Hi Marcus Thank you for mentioning my indeed very new blog here! I'm glad you find it good, because I was, and still am, not sure whether it will become something of interest. I am a bit busier than normal these days, but I will make every possible effort to put up what could be interesting...
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    Smolin and Woit #1 and #2 bestsellers

    This bookselling phenomenon at is particularly interesting for a nonfiction book which hasn't yet made it to the stores' bookshelves. I am not sure how the Amazon ranking works, and to what extent this ranking correlates with those of other bookstores (I would guess there would be a...
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    The graviton pisses me off. . . .

    Self-Adjoint: I must say that author is not explicit in the book which theory he is talking about. Anyway, thanks for your effort. I might grab Polchinski (or Zwiebach?) and check. I know that the graviton was already part of the theory before supersymmetry was included in the picture. Anyway...
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    The graviton pisses me off. . . .

    String theory graviton I am currently reading Prof.""). A few pages ago, I read something which still confuses me. I have read, and understood, on several occasions and at several locations on the web that, even if supersymmetry does not show up...
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    Zwiebach's string theory book

    Maverick Have a look at" [Broken]). I believe Cambridge University Press will not start producing a low-price edition of the book unless they start getting a significant number of orders from people in India (or elsewhere in the developing...
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    4 11 26 dimensions?

    Dimitri has got it, nice and simple.:approve: Still, one has to answer "why", which would take one into pages of algebra here. :redface:
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    4 11 26 dimensions?

    I'm pretty sure this is not the way to think about it. J. Baez has a nice" [Broken] on Week 126 as to why the classical bosonic string theory requires a 25+1-dimensional space-time. The Riemann zeta function is for something. As Baez points out, one can...
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    How to prove that d^2/dx^2 is a hermitian operator?

    I have been thinking about putting up something about the (mathematical) requirement in Quantum Mechanics that physical observables be represented in the formalism by Hermitian operators. I understand that Hermiticity guarantees the real-valuedness of the eigenvalues (hence the measured...
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    A Course in Modern Mathematical Physics [Peter Szekeres]

    Hi all I'm currently self-studying a relatively new book, "A Course in Modern Mathematical Physics", by Peter Szekeres, retired fellow at Uni of Adelaide (yes, he's the son of George Szekeres, of "Kruskal-Szekeres coordinates" fame :wink: ). I find it so far to be a totally great book! I...
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    Zwiebach's string theory book

    Hi A quick message to say that I will ignore any request of solutions to exercises in Zwiebach's "A First Course in String Theory" on this thread from now on (because I will no longer read postings here). arivero and about 5 others, as far as I know, are now in possession of the same...
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    Zwiebach's string theory book

    arivero and Mike2 My email bounced back from your account on my 2 attempts. You should have ensured that your accounts have enough free space or can handle ~7Mb emails. Please provide me with another email (and make sure this time it gets to you); I don't have much time and ressource to waste.
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    Zwiebach's string theory book

    Hi yaqh and others I have the solutions to almost all of the end-of-chapter problems. Given that a significant number of people have been seeking solutions, I'm willing to take the risk and supply the solutions to the exercises in Zwiebach's book to whoever is interested. The solutions are...
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    New to the community

    I just finished a course in Quantum Field Theory. There are a few texts I found useful: - Bjorken and Drell (the famous BJ&D) books (1) Relativistic Quantum Mechanics, followed by (2) Relativistic Quantum Fields -Warren Siegel's very comprehensive treatment (3) "Fields", available online. -...
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    Luboš Motl's reference frame down?

    "Luboš Motl's reference frame" down?! Lately, I have tried on several occasions to access Lubos' web log.. the operation timed out every time. Anybody knows what's up? "Not Even Wrong" makes no mention of anything wrong (Peter Woit would normally, I guess, be the first one to voice out any...
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    Zwiebach's string theory book

    Solutions to Zwiebach's exercises Thanks da_willem for the email address ( I sent them an email asking for access, and they kindly replied with the following info, which I provide here for those interested: Go to...
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    Zwiebach's string theory book

    Hello people I have just acquired Zwiebach's "A first course in string theory". I am actually very busy with honours (4th year) coursework and research, so I cannot really get down to reading substantial chunks of it whenever I want to. :mad: Apparently, it covers (and maybe extends) the MIT...
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    What will you be studying this semester?

    Honours Class down at Melbourne Uni: 6 weeks doing: Mathematical Foundations of Quantum Mechanics Relativistic Quantum Mechanics Another 6 weeks doing: Quantum Field Theory Equilibrium Statistical Mechanics Still another 6 weeks doing: General Relativity Extragalactic astrophysics...
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    Biography of Albert Messiah

    Has anybody ever come across a biography of the author Albert Messiah, of "Quantum Mechanics" reknown. His textbook is still being widely used (after half a century of its first appearance), but I wonder how many actually know some interesting thing about him :rolleyes: . I would be grateful if...
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    Source of photon propagation

    Given an infinite time, we can use the uncertainty principle to argue that energy is borrowed from the vacuum, a particle-antiparticle pair for example is created and the particles then annihilate into 2 gamma photons which travel in opposite directions, instead of going back into the vacuum...
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    Theoretical Extinguishing of the Sun with water!

    It would be impossible to extinguish the sun using water. All of it will simply get evaporated long before it reaches the corona. Dumping the sun into a black hole and calculating how much time it takes for the balck hole to devour it is a better, and exceedingly more relevant, problem! :D
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    3 Questions about our universe?

    Attempt at answering your gf's questions: 1) Various theories offer different answers. It is difficult (and some would say irrelevant) to think outside the box, which is the universe. Your response, "that the universe isn't like an object that is expanding into something, more like the universe...