EN
The existence of paths of low degree sum of their vertices in planar graphs is investigated. The main results of the paper are:
1. Every 3-connected simple planar graph G that contains a k-path, a path on k vertices, also contains a k-path P such that for its weight (the sum of degrees of its vertices) in G it holds
$w_G(P): = ∑_{u∈ V(P)} deg_G(u) ≤ (3/2)k² + 𝓞(k)$
2. Every plane triangulation T that contains a k-path also contains a k-path P such that for its weight in T it holds
$w_T(P): = ∑_{u∈ V(P)} deg_T(u) ≤ k² +13 k$
3. Let G be a 3-connected simple planar graph of circumference c(G). If c(G) ≥ σ| V(G)| for some constant σ > 0 then for any k, 1 ≤ k ≤ c(G), G contains a k-path P such that
$w_G(P) = ∑_{u∈ V(P)} deg_G(u) ≤ (3/σ + 3)k$.