  One of the most important tasks in understanding the complex spatial
organization of the genome consists in extracting information about this
spatial organization, the function and structure of chromatin topological
domains from existing experimental data, in particular, from genome
colocalization (Hi-C) matrices. Here we present an algorithm allowing to reveal
the underlying hierarchical domain structure of a polymer conformation from
analyzing the modularity of colocalization matrices. We also test this
algorithm on several model polymer structures: equilibrium globules, random
fractal globules and regular fractal (Peano) conformations. We define what we
call a spectrum of cluster borders, and show that these spectra behave
strikingly differently for equilibrium and fractal conformations, allowing us
to suggest an additional criterion to identify fractal polymer conformations.
