What is Superstring: Definition and 47 Discussions
Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings.
'Superstring theory' is a shorthand for supersymmetric string theory because unlike bosonic string theory, it is the version of string theory that accounts for both fermions and bosons and incorporates supersymmetry to model gravity.
Since the second superstring revolution, the five superstring theories are regarded as different limits of a single theory tentatively called M-theory.
A quick question: are there known solutions to superstring theory that reproduce all the properties of the standard model at low energy? I mean: three families, gauge groups, pattern of symmetry breaking, correct quantum number assignments, etc.
It may be that the question is not precise...
Can someone at least gives a summary of the constrains in the E8xE8 heterotic superstring theory? Many sources are mostly outdated that was written decades ago when not much research were done yet in superstring theory. So is E8xE8 already refuted? Or to what degrees and what constrains? I need...
Are the sphaleron & superstring just the epicycles of our era?
I just learned of this thing called a sphaleron, which from my primitive background in physics (i.e., physics for engineers and some self-study of modern physics) just strikes me as "we see stuff that doesn't fit out model &...
I have been trying for a while to read a precise definition of a Vector Multiplet (to whom ##N=2## Supergravity theories couple to in ##4D##) but was not lucky in finding a self-contained one. The best I got was that on https://en.wikipedia.org/wiki/Supermultiplet though it was on...
Is there an existing equation, or set of equations, that directly links the specific vibration of a superstring filament with the resultant particle mass?
A brief explanation of any mathematics would be helpful. Thank you.
I don't know much about gauge/gravity duality but I know that its a conjecture coming from superstring theory and one of its examples is AdS/CFT duality. Now I have two questions:
1) As I said, I know that gauge/gravity duality and superstring theory are related but I don't know how much. Is it...
If superstring theory works, has no infinities, etc. Then what is wrong with it? It must describe some Universe unless there is a contradiction in it somewhere? If it predicts all particles and gravity what is missing from it? Is it not compatible with cosmology for instance?
Is Superstring...
http://arxiv.org/abs/1409.2510
Twistor Origin of the Superstring
Nathan Berkovits (ICTP-SAIFR/IFT-UNESP, Sao Paulo)
(Submitted on 8 Sep 2014)
After introducing a d=10 pure spinor λα, the Virasoro constraint ∂xm∂xm=0 can be replaced by the twistor-like constraint ∂xm(γmλ)α=0. Quantizing this...
I was talking to a friend of a friend who is a physics professor, and I asked him what the best way to learn (the basics of) string theory and he said that this book (Superstring Theory Greene, Schwartz Witten) is the best and the one that everyone seems to use. So I went out and brought it...
So yet we have the Standard Model which tries to explain and unify the 4 fundamental forces or atleast 3 for now since the gravity is not quite well understood in particle physics.So people search for a theory of everything which unifies all forces and yet we didn't found any good theory as...
I'm trying to understand what I have just learned. So some sort of browser based code or binary was discovered in equations for super-string theory. I have a few questions since I am very confused.
If code was created by Claude Shannon in the 1940's, then how could it be in this code? Does...
Homework Statement
Let
\begin{equation}
\delta _{1} \, and \, \delta _{2}
\end{equation}
be two infinitesimal sypersymmetry transformations on xμ compute
\begin{equation}
[\delta _{1}, \delta _{2} ]x^{μ}.
\end{equation}
Homework Equations
The commutator is:
\begin{equation}...
This paper may be intersting:
http://www.springerlink.com/content/d3182t263w74267g/?MUD=MP
On the Foundations of Superstring Theory
Gerard ’t Hooft
Abstract: Superstring theory is an extension of conventional quantum field theory that allows for stringlike and branelike material objects...
Gravity with spin excludes fermionic strings
Abstract:
The existence of intrinsic spin of matter requires the metric-affine formulation of gravity, in which the affine connection is not constrained to be symmetric and its antisymmetric part (torsion tensor) is a dynamical variable. We show...
Tell me if this is a fair characterization of the first superstring revolution or the discovery made by Schwarz-Green in 1984. Schwarz-Green found a theory that allowed for the cancellation of anomalies provided that 10 dimensions existed and the gauge group is (SO(32) and E8 x E8) which...
Homework Statement
The RNS action in flat gauge is given by
S=-\frac{1}{8\pi}\int d\sigma d\tau\,\frac{2}{\alpha'}\partial_\alpha X^{\mu}\partial^\alpha X_\mu+2i\bar{\psi}_A^\mu\gamma_{AB}^\alpha\partial_\alpha\psi_{\mu B}
\mu is a spacetime vector index, \alpha a worldsheet vector intex...
http://arxiv.org/abs/1106.3548
Emergence of Superstring from Pure Spinor
Ichiro Oda
(Submitted on 17 Jun 2011)
Starting with a classical action where a pure spinor $\lambda^\alpha$ is only a fundamental and dynamical variable, the pure spinor formalism for superparticle and superstring is...
Are these 'strings' the size of planks constant? Nothing can obtain a size smaller than planks constant...right? What I am trying to figure out is if saying strings were the size of planks constant were a good approximation if the size of them
Hello.
I have a question for the specialists on Superstring Theory:
I am looking for a reference to original research, where the following is proven / shown / evidence is given / made plausible / etc.
- 10D supergravities in their various forms are the low energy limits of superstring...
Hi there,
I 'm currently reading topics relating to type IIB superstring theory. One of the things I am always confused with is Groups. I looked on various websites including Wikipedia but I still haven't quite got it. Could anyone please give me a nice introduction about Groups?
What are...
What is meant when one says that everything we see is the lowest vibrations of the strings (According to String Theory)?
I understand the very fundamental concepts of this theory, like how it only works in 10 dimensions, but the above statement confuses me.
In Szabo's book on string theory he calculates the vacuum to vacuum one loop (genus one)
diagram.
The contributions can be organized according to different spin structures (periodic or antiperiodic along
the two cycles of the torus). The spin structures are (+,+). (-,-) , (-,+) and...
I was wondering if my understanding of string theory was right and if not could someone please correct me.
1.)Is string theory saying that everytrhing in the universe is different vibrating states of one fundamental superstring.
2.) Where is this superstring located?
I just recently started researching and reading about these two theories. I searched the forum and could not find the question I would like to ask, which is: Without getting too difficult is there any obvious differences between the Superstring and M-theory other than that the M-theory...
What's the difference between string theory and superstring theory? Are they two different names for the same thing? Which one came first? Which one is more popular?
Hi all,
The weblink pointed to the school of last year, this one should work:
http://cdsagenda5.ictp.trieste.it/full_display.php?smr=0&ida=a05197#
The deadline is January 10.FlorianOn Thu, 5 Jan 2006, Stefan Fredenhagen wrote:
> Hi all,
>
> as last year somehow we missed to announce the ICTP...
Waddup guys. To my understanding M-Theory is a theory which 'combines' the five superstring theories and supergravity.Also i understand that matematics is not yet advanced enough to make it work(or so I've been told) I am still not sure how this theory is meant to end up as a theory of...
hi, i am new and have a paper due on tuesday about the integration of superstring theory into cosmology for my astro class. I am not very deeply read into either of these topics so if anybody wants to help me out with any information, that would be great. thanks
http://www.scifiscience.co.uk/index.htm
From Astronuc. This gives a very brief introduction to Relativity, Chaos, and Superstring Theories, and a few other Sci-Fi Science concepts.
I want to study superstring theory (and maybe find the theory of everything). Even if I don't end up making that discovery I still want to be able to understand the theory or the closest humanity ever comes to a theory of everything. I've been looking at the math requirements but a lot of...
The spotting of the factor {D-2 \over 24} outside of the scope of string theory should be the trigger for a new revolution in this field. It could mean that a critical dimension is not exclusive of strings, or it could show how to avoid criticality after all.
The term itself is not rare, the...
Instead of superstrings having 10 unitary dimensions (6 of compactified space and 3+1 of ordinary spacetime), imagine these 6 compactified spatial dimensions being of fractal value (3/6=1/2) relative to the 3 apparent dimensions of space.
This corresponds as a dimensional duality to the 6...
In Cumrun Vafa's "Lightning Introduction" to string theory in his http://arxiv.org/hep-th/9702201 , he instroduces supersymmetry to string theory thus:
in addition to the coordinates X^{\mu} we also have anti-commuting fermionic coordinates \psi_{L,R}^{\mu} which are spacetime vectors but...
I posted this thread in the math forum, but no one seems to know what I am talking about... since i heard dr sylvester gates say it and he specializes in superstring theory, maybe someone here can help me out..
im trying to understand the expression, "the more math makes sense, reality...
I was wondering how a string could be a one dimensional vibrationg loop? I am still trying to remove myself from the 3 dimensional ideal of our world, however how can anything have only one dimension, for then it would imply that it has neither of the other two dimensions and therefore wouldn't...
A recent paper details some new insights for the second quantized
string field theory.
This has some implications for future models, it appears to be quite sound, but this is based on a confined early viewpoint of a first once over reading, no doubt there will be more questions to follow...
So far in this past century, the theory of the superstring has held most promising oppertunities for unifying all quantum mechanics. However I noticed some very imediate flaws that eliminate the purpose of the theory. The theory is that everything is made of one-dimensional strings, whose...