Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: How to Measure the Fractal Geometry of the Relativistic Fermion
  Propagator   We study the geometry of propagation of relativistic fermions. We propose how
to measure its quantum mechanical length. Numerical lattice results for the
free propagator of Dirac-Wilson fermions yield Hausdorff dimension d_H=2 for
the unit-matrix component and d_H=1 for any gamma-matrix component. A possible
generalization when matter interacts with radiation is discussed.

8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph