Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rigorous results for a population model with selection I: evolution of
  the fitness distribution   We consider a model of a population of fixed size $N$ undergoing selection.
Each individual acquires beneficial mutations at rate $\mu_N$, and each
beneficial mutation increases the individual's fitness by $s_N$. Each
individual dies at rate one, and when a death occurs, an individual is chosen
with probability proportional to the individual's fitness to give birth. Under
certain conditions on the parameters $\mu_N$ and $s_N$, we obtain rigorous
results for the rate at which mutations accumulate in the population and the
distribution of the fitnesses of individuals in the population at a given time.
Our results confirm predictions of Desai and Fisher (2007).

14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas