Talk:Instanton

Very nice, but the article doesn't actually say what an instanton is. Anyone with enough knowledge of theoretical physics want to take a crack at putting some text in this article? Erik Carson

Followup: Ask and ye shall receive. Erik Carson 19:57, 2004 Mar 30 (UTC)

I am a mathematician trying to understand what this article means mathematically, but am limited by the deluge of physics jargon starting from the very beginning of this article. Could at least the introduction be rewritten to be understandable to someone without graduate-level physics knowledge? - Gauge 04:40, 21 August 2005 (UTC)

I've just rewritten the article so that it explains the more general meaning of the term "instanton". The relation to Yang-Mills gauge theory in Minkowski space should be clarified in a subsection. I apologize for leaving the edit in an incomplete state; it will take some time to get everything right.

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U(1) doesn't have instantons. $\pi_3(U(1))=0$. No Abelian gauge theory has instantons. Phys 20:17, 20 October 2005 (UTC)

U(1) gauge theories in two dimensions do have instantons. Spatial infinity here is a circle, and $\pi_1(U(1))=Z$. This is the case the author was discussing.</math>

Put some "m"

Just put the "m" relating to the mass of the particle where needed in the part about Instanton in Quantum Mechanics

Typo

The WKB expression for the probability for the particle to tunnel should be real. The i should be replaced with a 2.

http://upload.wikimedia.org/math/5/c/7/5c719dcaa6e7112fb76f501b5f57a598.png —The preceding unsigned comment was added by 71.136.90.228 (talk) 13:03, 7 December 2006 (UTC).

Noncommutative and SUSY instantons?

Maybe someone could also add at least a note that instantons also exist on noncommutative spacetimes, as well as for supersymmetric gauge theories. And mentioning the ADHM construction would also be good. In particular, its interesting that in the noncommutative case there CAN exist U(1) instantons.

Factor of two mistake corrected

I deleted the factor of two in front of the cosine in the proof of the BPS-bound.

Matrix1329 11:42, 19 April 2007 (UTC)

Nonmathematical explanation?

Is it possible for the introduction to explain the concept in a way that relies on neither mathematics nor physics PhD-level knowledge? This article is as good as gibberish to anyone without that knowledge. Like, it could all be a giant joke, and we wouldn't know. If it's not explainable in terms nonphysicists will understand, it simply isn't, but in that case is it really notable for Wikipedia's purposes? 134.10.18.182 (talk) 08:25, 9 May 2010 (UTC)

I've noticed this about many Wikipedia articles, particularly physics and mathematics articles. An Encyclopedia is supposed to be written in such a way that someone with basically a High School education can understand it. Or at least link to articles designed with such people in mind. Blooddraken (talk) 10:24, 7 May 2011 (UTC)

Not quite. — Preceding unsigned comment added by 81.213.55.37 (talk) 13:06, 30 May 2011 (UTC)

Quantum mechanics

I'm confused by the author mentioning Minkowski in the quantum mechanics setting. Everything looks like nonrelativistic QM for me. I've nobody objects, I will try to rewrite the text, getting rid of Minkovsky completely and taking about real and imaginary time. Fabian Hassler (talk) 07:44, 4 August 2010 (UTC)

I think that the point is that instantons may be considered both in the more physically motivated Minkowskian space-time and in mathematically more familiar Euclidean space-time (these generalize to Lorentzian and Riemannian manifolds, respectively).

A bit of general advice: when making local edits, please, make sure that your sign conventions, etc are consistent with the rest of the article: agreeing with a particular source that you are familiar with is unsufficient, unless you are willing to rewrite everything according to its conventions. In other words, either tread lightly or accept the full burden of correctness for the article as a whole. Good luck! Arcfrk (talk) 07:22, 5 August 2010 (UTC)