## Sunday, September 30, 2007

### Holomorphy and friends

I'm reading Chapter 8 of Modern Supersymmetry.

To understand the first sentence, I had to review Maldacena's paper, which (not-so) incidentally proposed the AdS/CFT correspondence (hence its numerous citations).

Hmmm. I'll have to read it again. ;-) But moving on ...

Okay, now need to review non-renormalization theorems and Wilsonian effective action.

Wow, lots to catchup!

## Thursday, September 27, 2007

### Quantum Parallel Universes

Professor Andy Albrecht has kindly pointed me to one of a series of papers by David Deutsch that begins the proof of Hugh Everett's Many-World's Hypothesis:

Quantum Theory of Probability and Decisions

This paper removes the requirement to have a probabilistic
interpretation of quantum mechanics, instead casting it into a
non-probabilistic decision theory basis.

The main result is that the usual probabilistic formulation can be
replaced by a rational decision maker using classic decision theory.
Furthermore (and most importantly), quantum processes whose outcomes
look stochastic can be replaced by deterministic evolution of states.

Note that this neatly removes the issues around definitions of probability in the MWI.

I'm now taking, for fun, an advanced Supersymmetry class, taught by Prof. John Terning, which picks up where my last SUSY class left off. Wow, I need to review!

## Saturday, September 22, 2007

### A new direction

After a long hiatus, I'm back ...

Back to what? Well, most of that hiatus was due to work, and I already keep a (boring) work journal. But the main thing is I'm back to doing physics ...

The goal is to start (and finish) a dissertation in Computational Quantum Gravity. What does that mean, exactly? Well, that's the whole point of the journey -- and this blog will help me track my progress. It may not be that interesting to you to read, but it will be useful for me to write, and keep notes, with. And a goal left unstated is left undone -- that's why it's all hanging out here.

So the first order of business is to get really comfortable with LaTeX.

Next, it would be really nice to be able to post equations here. Oh, looks like someone's already hacked that together.

The Einstein equation:

$G_{\alpha \beta} = T_{\alpha \beta}$

Here's a really good intro summary on the state of the art on quantum gravity:

http://plato.stanford.edu/entries/quantum-gravity/

With a reference to the classics:

http://math.ucr.edu/home/baez/einstein/einstein.html

http://math.ucr.edu/home/baez/gr/gr.html