deletions | additions       diff --git a/Clustering.tex b/Clustering.tex  index 3eb8e2d..18bbcf2 100644  --- a/Clustering.tex  +++ b/Clustering.tex 
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{\bf Thoughts:}  {\it Question 1:} A 1:}A  first step is to solve the (coupled) diffusion equations of the medium and (mean field?). This gives coarse, deterministic behaviour. (Then need a way into the statistics.) Can we use RG flow (see e.g. Bertin (2009), Matthieu)? Make a very simple Hamiltonian which captures some of the features of the swimmer clusters, then group them together in an increasingly course way. What happens to critical exponents, to couplings, etc? Will this actually be useful (given the Hamiltonian is necessarily very crude)? Could Instead of keeping track of all the particle positions $\vec x_i$, I could  try putting all particles them  on a regular square  lattice and just modifying the interactions interaction strengths  between them. them:   \begin{equation}   \sum_{\rm particles} J x_i \rightarrow \sum_{\rm grid} J_{ij}.   \end{equation}     {\it Question 3:} Random energy wells with some distribution of depths: what clustering statistics would this lead to? What distribution of wells gives a fractal distribution of clusters?