The topic of Lattice QCD or Lattice gauge theory or even Lattice field theory is quite old now. And the main reason for the interest in the topic is the ability to calculate nonperturbative stuff on a computer.

It seems that to do research with lattice you need an access to some supercomputer. But now everyone can afford something that is as powerful as supercomputers 20 years ago. Maybe it possible to redo some of the results of that time?

Is there any project that is:

1. Relatively simple.
2. Allows to calculate some real-world quantity (like mass of the proton).
3. Can be done with an average home computer.
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 Do you want to program something yourself, and if so, what is your skill level? – Gerben May 23 '11 at 11:52 @Gerben , yes I want to program myself. Preferably from scratch. Assume that I have all the experience needed in numerics, computing, CS, low-level or parallel programming e.t.c. – Kostya May 23 '11 at 12:18

While not strictly lattice QCD, Michael Creutz' 30 year old lattice gauge papers have very simple C implementations (!).

For example, look at this paper, which gives a very readable explanation of lattice gauge simulations, with source code:

http://latticeguy.net/mypubs/pub165.pdf

The source code is also available here:

http://thy.phy.bnl.gov/~creutz/z2/

This compiles and runs out of the box and reproduces the results in the paper. Current papers like the portugese GPU groups' mentioned by Lubos all build on Creutz's 30 year old stuff.

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 Now that is the answer I was waiting for. Thanks a lot for the links. – Kostya Feb 15 '12 at 17:40

You don't need a really big computer.

Peter LePage used to do talks where he'd ask the audience fro a "random" number as the beginning of the talk (but not 7, 17, 42, or 69 'cause he'd already done those) and start a simulation on one screen with that number as a seed. Then he'd give a talk on how to speed up LQCD calculations on the other screen while his PII 200 MHz laptop crunched a $b\bar{b}$ state during the talk.

First, heavy flavor is easier to do than anything involving light quarks. Especially $u$ or $d$ quarks. You certainly want to learn this business with a faster problem than the proton mass.

Second, "relatively simple" in LQCD is still pretty complicated. Peter's 45 minute talk was intended to give people who knew roughly what a naive LQCD calculation looked like an idea of how his very clever trick for optimizing the business worked. I also sat through four hours of the same thing at a graduate summer school where he was teaching the technique and I only sort of got it (because it was targeted at students who were doing LQCD).

This is a big project.

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 In the same vein, I'd suggest something more modest than true QCD, like finding the phase diagram of the Higgs sector. Even setting that up properly will take quite some time, and I know for a fact that (when done efficiently) it's not a very expensive calculation. For ideas on how it's done, check out Montvay/Münster (Quantum fields on a lattice), or one of the countless other canonical references of the field. – Gerben May 23 '11 at 18:23

You may try to download QCD software for CUDA - using GPU etc. - at

http://nemea.ist.utl.pt/~ptqcd/