String theory Definition and 782 Threads

Is there any relationship between String Theory and ZPE? I mean, does ST offer anything new, any new reason to ZPE? Thanks!

In the other day's lecture, my professor was going over gravitational potential energy and on a side note he added that there is a theory (though not fully accepted by many people as a theory) out there saying something about another dimension, with tiny strings acting on objects, and that is...

I have come to the conclusion that my ideal area of scientific persuit is the area of theoretical physics in specific string theory. Recently i have been researching on which field of theoretical physics i have the most interest in. My area of interests are most simply put the most fundamental...

Question on Witten's paper: "Perturbative Gauge Theory As A String Theory..." Hi guys, I have a question regarding formula 2.12 of Witten's paper hep-th/0312171 "Perturbative Gauge Theory As A String Theory In Twistor Space". He just states this formula but i don't really understand his...

Ok, i have come to a realisation that my interests revolve not around pure mathematics (as i once thought) and more around theoretical physics, some people would claim that they merge into one at times, and that leads on to my question. If i wanted to be a theoretical physicist (rather than an...

Hi everybody, i'm a phd student in theoretical particle physics... so for my studies I'm learning a lot about qcd and phenomenology, but don't know anything at all about string theory etc... Even though I'm quite skeptical about string theory and the not so many prediction it gave, still i...

Hi In string theory, as I understand it, a frequency between two points creates a particle, different frequencies make different particles. If say the points were arranged in a cube there would be 8 points with twelve strings between them, would this lead to twelve particles or would one...

From what I've read, String Theory is a theory of everything, unlike some of the other quantum gravity theories. That means that String Theory explains other particles and fields including gravitons. So String Theory is a quantum gravity theory because it includes gravitons. But I was...

What is wrong with the following reasoning? String theory has diffeomorphism invariance. Since time reversal is a diffeomorphism, string theory is time-reversal invariant. Therefore T and CP violation can't occur in string theory, and string theory can't describe the standard model in the...

http://www.youtube.com/watch?v=E7FV9aaiwKQ&feature=related" , what mathematical formula are they referring to? (Which is a mathematical formula that describes the strong force and stood at the beginning of string theory research according to this video.) thanks

If I understand Brian Greene’s argument (in The Elegant Universe, and repeated elsewhere) for the Planck length being the minimum measurable length based on T-symmetry in string theory, it goes something like this: There are two ways to measure things, one with vibrational energy v and one...

In another thread: https://www.physicsforums.com/showthread.php?t=436080" a discussion came up relating to the validity of String Theory and the specific thought that, if nothing else, it has helped us to better understand the issues of quantum gravity. I wanted to start a new thread to adress...

FIRST: Please, I don't what this to be a String Theory bashing thread. I've seen and even participated in plenty of those. I think that String Theory is interesting and that if and when we find a Theory of Everything that it is likely that String Theory will at a minimum have pointed us at least...

Hi, guys. I want to do some research on quantum gravity. I know that there are two theories achieving some success in this direction. Do you know something about that? I want to learn something about that. Thank you!

Can some one point out papers that discuss non-perturbative aspects of string theory that have been derived from perturbing gauge theories through the gauge/gravity duality? I can only find papers discussing the other way around - be it in QCD or CMT.

As I understand it, string theory only has one coupling constant, but there is a whole discrete landscape of false vacua, each of which gives different values to the quantities, such as coupling constants, that are taken to be fixed inputs to the standard model. Since the false vacua are...

"Four-qubit entanglement from string theory" This paper Borsten et al., "Four-qubit entanglement from string theory," http://arxiv.org/abs/1005.4915 (published in PRL) is being described http://www.sciencedaily.com/releases/2010/09/100901091938.htm in the popular press as a proposal for an...

This article looks very interesting and shows how there is still experimental hope for String Theory: http://www.physorg.com/news202553083.html

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...

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...