String theory Definition and 833 Threads

someone said they solved Newtonian physics with string theory Is that possible? in a test situation?

LHC thus far has ruled out some of the SUSY parameter space over and above Tev, esp gluinos above a certain mass. So LHC has offered some useful research into SUSY. Were SUSY gluinos detected it would be a huge boost to strings/Supergravity Beyond the Standard Model...

Why are no DIVERGENT quantities (infinities) in String Theory ?? why String theory is FREE of infinities ?? ... why there are no divergent integrals in string theory whereas in normal Quantum Field theory there are infinities ??

Does string theory merge space and time into spacetime? GR combines space and time as spacetime, I've heard that in string theory there is 9+1 or 10+1 spatial dimensions, with 3 large, 6 curled, 1 time dimension. Is there a spacetime in string theory? Are Yau-Calibi manifolds part of this...

Suppose we detect a new force whose gauge group would require a SU(N) rep. What would be the smallest one that could not fit within string theory?

I think it's time to write a short essay why I am really disappointed about string theory. It is not because ST is wrong (we don't know if it is wrong; and we have no proof that other theories such as the SM are right). It is not because it is complicated (the electroweak model is...

Thus far Tevatron and possibly LHC has found no evidence of SUSY, and DM searches thus far null and void. Steinhardt had a paper showing that inflation is incompatible with higher dimensions. There are no experimental evidence for higher dimensions. Thus far proton decay and magnetic monopoles...

regarding the problem of time in QG, Is time absolute or dynamical in LQG? string theory? How does LQG and string theory deal with time in singularities in the center of black holes?

Could the correspondence be proven along the lines suggested by Laurent Freidel---one of the leaders in LQG research? If you haven't heard of Freidel, there are two covariant LQG models currently being studied one being Rovelli et al, the other being Freidel et al's. He gave the invited LQG...

The question I want to ask is pretty much in the title: Why is string theory becoming less of an excitement amongst the scientific community? I don't want to sound picky, but my background in physics is pretty inferior. I understand that the explanation is mainly in the mathematics, so, just...

Has these results been extended to non-extremel BH? Do they work when the cc is +, (deSitter) and where SUSY is strongly broken (like our world) Do they work when the background is strongly varying in time, such as two black holes merging? They work for extremel black holes that are...

I have only taken a few college physics courses, and I have watched some videos about string theory. I would like to get excited about M-theory, but I have always wondered, why there wouldn't be an infinite number of ways to unite the forces, in which case M-theory is just one possibility...

Hi everyone, I'm soon going to be performing a project that looks at quantum turbulence of 3He and 4He, and more specifically how it decays over time depending on the vortex density and temperature. I’ve done much research into the low temperature part of my project however I’ve...

I was reading through Wikipedia under 'String Theory' recently and discovered that within the lest week a Theoretical Physicist by the name of Kremlic Dormac has found evidence of String Theory within Isolated Monopoles. - http://en.wikipedia.org/wiki/String_theory This is extremely interesting...

I have this, probably quite simple, problem. In the RNS superstring, when varying the action, we obtain in general a term \int d\tau [X'_{\mu}\delta X^{\mu}|_{\sigma=\pi}-X'_{\mu}\delta X^{\mu}|_{\sigma=0} + (\psi_+ \delta \psi_+ - \psi_- \delta \psi_-)|_{\sigma=\pi}-(\psi_+ \delta \psi_+ -...

So according to String Theory, the properties of Elementary particles is due to the vibrating properties of strings. Let's pretend that technology was developed that could alter the vibrations of strings, also assuming that string theory is correct. If we change the vibrations of the strings...

I was just wondering, I keep hearing different opinions on this, but how is the reputation of string theory now? I speak to some mathematicians and they completely write it off, while I talk to other people and they say it's still in the works but looks promising. Obviously it's not...

Hello, I am interested in finding out about string theory. I have done reasearch on the internet but that is the basics. I am hoping that I can find someone who works in the field or has a good grasp of M-theory to explain it to me. Thank you

Greetings. My question comes in two parts. Part one - In most "low-level - made for t.v." explanations of the extra dimensional space they describe these extra dimensions as "curled-up". If I were to visualize the extra dimensions of string theory would it be better to think of these extra...

Second attempt here to get an answer, I am really lost on this. Im reading "A first course in String Theory" by Zwiebach and it says that when applying a general \tau gauge parametrization in the form of n_\mu X^\mu = \lambda \tau we can take the vector n_\mu so that for open strings...

Im reading "A first course in String Theory" by Zwiebach and it says that when applying a gauge parametrization in the form of n_\mu X^\mu = \lambda \tau we can take the vector n_\mu so that for open strings connected to branes (fixed end points), n^\mu \mathcal{P}^\tau _\mu is conserved...

Hello everyone, I have been interested by the String Theory and the M-Theory for quite a few years now, I read the Elegant Universe by Brian Greene (and watched the PBS documentary based on his book). This theory sounds really "elegant" indeed, but I was wondering what progress, if any...

How do gravitons interact with the warping of spacetime in string theory? I know gravitons have not been proved to exist. Plus how is it effected by SUSY and what is supergravity?thanks ?

cosmology strings vs loops How well does string cosmology account for inflation, CMB, gravitational waves, evolution classically using FRW metric? does string cosmology offer either qualitative or quantitative predictions? This paper addresses these in the loop framework...

Hi, I have no knowledge of ST but have a probably simple question. I saw a program about how the extra dimensions of space in string theory are curled in on them selves. What I want to know is if they really are the same dimensions. Say for example if there are 11 dimensions and I would pick...

What do you make of the following interview: http://www.npr.org/templates/story/story.php?storyId=6172247 To me, the whole premise of the interview seems to be a bit loaded. I love NPR, but I would have expected a more objective approach. Take notice of the following quote: Does this...

Hey all I hope to do an undergraduate degree in physics.I was just wondering if anyone could please tell me the best pathway to learn string theory,M theory, General relativity and those stuff from following degrees.I mean that course modules that really help to learn above areas...

Notes on string theory. Gerard ’t Hooft Institute for Theoretical Physics Utrecht University, Leuvenlaan 4 3584 CC Utrecht, the Netherlands and Spinoza Institute Postbox 80.195 3508 TD Utrecht, the Netherlands e-mail: g.thooft@phys.uu.nl internet: http://www.phys.uu.nl/~thooft/

I saw a show about string theory on TV, and I don't understand why this hasn't already been ruled out. My thought is this: If there is a dimension that is curled up, wouldn't this violate relativity because moving would cause it to length contract? This seems to violate relativity since there...

Until recently the twistor theory of Roger Penrose on one hand and string theory on another, epitomized by Ed Witten and many others, have been inconsistent. Twistor space uses 3+1 dimensions and is a complex space in additional dimensions with imaginary components, analogous to the complex...

if gravity is a a sheet of space and time how is it also a graviton particle as in string theory

in string theory is it that each quark of an atom has one string or is it made up of millions? i know this is a kinda silly question

I am very bored and looking for entertainment such as a book or lecture having to do with string theory. Any suggestions are greatly appreciated. Thank you.

String theory posits spacetime that is infinitely continuous. Earlier at PF there was a discussion of lorentz invariance and Fermi Gamma-ray Space Telescope showing that very high energy photons travel at c, which makes discrete theories of QG less favored and string theory more favored, as...

I've heard that that origin of String Theory was in Gabriele Veneziano's analysis of the Euler beta function in relation to the strong force. I was wondering if anyone could refer me to a paper or derivation describing how this function ended up describing particles as strings.

String theory requires 9 spatial dimensions, M-theory 10. One followup to Verlinde's paper is this: http://arxiv.org/abs/1002.0488 Hidden symmetries for thermodynamics and emergence of relativity Liu Zhao (Submitted on 2 Feb 2010) Verlinde recently proposed an idea about the thermodynamic...

I'm taking an introductory string theory course which focuses on bosonic string theory. The lecturer says to include fermions supersymmetry must be included (aka. superstrings). If we face the event that the LHC fails to find any supersymmetry at TeV scale and the physics community lose faith in...

It seems to me that string theory is a highly complex way of dealing with the need to avoid zero distances in our mathematical description of the physical world. Wouldn't it be much easier to just say let's use 10^-25cm as a limit and not allow anything to get closer than that in our...

I know the main points of string theory, but can someone tell me where the evidence is that it could be true?

In string theory, what are the fundamental properties of a string? Is the tension in the string a constant at all points on the string and the same in all strings? Is the string "labelled" with fields/spin/etc along its length? How about "velocity"? Is each 'bit' of the string labelled with...

Hi there, I 've recently looked at how the Nambu-Goto action of an open string can be derived from the proper area of the parameterised world-sheet, in the form of either the derivatives of space-time coordinates or the determinant of the induced metric. However, may I ask what are the...

In string theory, a solution involving flat 10D space seems like a valid solution. The Universe could be described by a solution that is 10D space, all large and flat. Of course for string theory to describe our universe, 3D remain large and flat, and 6D or 7D are curled up in a Yau Calibi...

What role does "torsion'' play in string theory? In general relativity we assume that connection is torsion free. However from a purely geometrical viewpoint, the concept of torsion can not be ignored (theoretically) and in string theory, it is said that "torsion" does play its role. Can...

This might be a noob question, so excuse me if I'm beating a dead horse. I'm trying to wrap my head around string theory. If it is how the universe operates, is there such a thing as matter? It seems that everything at its most basic form is just energy. Is this true? Or am I missing a...

http://www.infocobuild.com/education/audio-video-courses/physics/string-theory-cern.html This brings some video lectures on string theory from http://cdsweb.cern.ch/" - introduction to string theory, string theory, string theory for pedestrians etc.

Iv'e scene the documentary about string theory and i just have a few questions about it.(laymen terms) : 1.How does string theory contribute to a unified field theory? 2.Is matter really made of "vibrationg strings"? 3.What does string theory actually mean or what has been the impact...

Is Asymptotic Darkness explicitly known to be realized in string theory?

What makes the strings in string theory "vibrate"? Does string theory include or say what is responsible for making strings vibrate? Also, why do the strings not all vibrate in the same pattern; what makes a string "choose" one pattern over another?

Could the higher dimensional spaces of string theory be used by point particles? Take the idea of extra dimensions of string theory and use point particles instead of strings. Point particles need some type of internal degrees of freedom? Thank you for any help.

Assuming string theory is on the right track, would the electromagnetic field of some radio station antenna be given by some collective motion of string theory strings in their curled-up dimensions and the dimensions of space? If a string moves at the speed of light doesn't it have to be mass...