Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An evolution equation of the population genetics: relation to the
  density-matrix theory of quasiparticles with general dispersion laws   The Waxman-Peck theory of the population genetics is discussed in regard of
soil bacteria. Each bacterium is understood as a carrier of a phenotypic
parameter p. The central aim is the calculation of the probability density with
respect to p of the carriers living at time t>0. The theory involves two small
parameters: the mutation probability $\mu$ and a parameter $\gamma$ involved in
a function w(p) defining the fitness of the bacteria to survive the generation
time $\tau$ and give birth to offspring. The mutation from a state p to a state
q is defined by a Gaussian. The author focuses attention on an equation
generalizing Waxman's equation. The author solves this equation in the standard
style of a perturbation theory and discusses how the solution depends on the
choice of the fitness function w(p). In a sense, the function
$c(p)=1-w(p)/w(0)$ is analogous to the dispersion function E(p) of fictitious
quasiparticles. With a general function c(p), the distribution function
${\mathit\Phi}(p,t;0)$ is composed of a delta-function component,
$N(t)\delta(p)$, and a blurred component. The author shows that asymptotically
N(t) may tend to a positive value, in contrast with zero resulting from
Waxman's approximation where $c(p)\sim p^2$.

17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat