Thursday, October 11, 2007

And Now for Something Completely Different...

A man with string theory up his nose.

As our gracious host has already pointed out, I'm actually a physics student, so it's an honor to be able to write for this fine astronomy blog. In any case I'm beginning to understand the AdS/CFT correspondence, which as you may already know, deals with the apparent duality that exist between some string theories and quantum field theories.
What we can aspire to do with this approach is to investigate quantum field theories without relying on perturbation theory, which limit our understanding of nature. For example, Quantum Cromodynamics (QCD) enjoys asymptotic freedom at high energies, this means that since interactions are weak at those energy scales it's sane to use perturvative methods. However in cases where energy scales are small, we simply do not know how to perform calculations. As always numerical methods are useful to some extent, but even they have a hard time dealing with some situations (they involve dealing with some dynamical quarks, as far as I know). Other option is to study the AdS/CFT correspondence and gather bits of information about gauge theories in general. It all boils down to this: either, A) Find a string theory dual to QCD to be able to make calculations or B) Understand properties about gauge theories in general so you can make predictions about QCD. The second option is more viable and has had success in the past. But I'll explain that some other time.

Since I'm just starting studies on this subject I hope I'm not making some false statements, (I'm not, as far as I know). Feel free to comment on the subject should you feel otherwise.

On a side note, Toots Thielemans is playing tomorrow at Netzahualcoyotl Concert Hall, one of Mexico's most beautiful concert halls in my own opinion. This will be interesting...

1 comment:

Luis Sanchez said...

A great first post. One thing that has really amazed me is the paper of Hartnoll et al, where they claim to use an ADS-High T_c corresponence to study the Nernst Effect.

Another really exciting result of the AdS/CFT correspondence regards the RHIC observations. It esentially says that when the quantum physics scale is invariant, the viscosity of the system takes it's minimun value. This was unexpected and it's far from beeing clear in QCD.

Enjoy the Toots Thielemans concert, I wish I could attend it.