  If $f:\mathbb{N}\rightarrow \mathbb{N}$ is a function, then let us say that
$f$ is sublinear if \[\lim_{n\rightarrow +\infty}\frac{f(n)}{n}=0.\] If
$G=(V,E)$ is a cubic graph and $c:E\rightarrow \{1,...,k\}$ is a proper
$k$-edge-coloring of $G$, then an edge $e=uv$ of $G$ is poor (rich) in $c$, if
the edges incident to $u$ and $v$ are colored with three (five) colors. An edge
is abnormal if it is neither rich nor poor. The Petersen coloring conjecture of
Jaeger states that any bridgeless cubic graph admits a proper 5-edge-coloring
$c$, such that there is no an abnormal edge of $G$ with respect to $c$. For a
proper 5-edge-coloring $c$ of $G$, let $N_G(c)$ be the set of abnormal edges of
$G$ with respect to $c$. In this paper we show that (a) The Petersen coloring
conjecture is equivalent to the statement that there is a sublinear function
$f:\mathbb{N}\rightarrow \mathbb{N}$, such that all bridgeless cubic graphs
admit a proper 5-edge-coloring $c$ with $|N_G(c)|\leq f(|V|)$; (b) for
$k=2,3,4$, the statement that there is a sublinear function
$f:\mathbb{N}\rightarrow \mathbb{N}$, such that all (cyclically)
$k$-edge-connected cubic graphs admit a proper 5-edge-coloring $c$ with
$|N_G(c)|\leq f(|V|)$ is equivalent to the statement that all (cyclically)
$k$-edge-connected cubic graphs admit a proper 5-edge-coloring $c$ with
$|N_G(c)|\leq 2k+1$.
