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Paths of low weight in planar graphs

Igor Fabrici, Jochen Harant, Stanislav Jendrol' (2008)

Discussiones Mathematicae Graph Theory

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 ) d e g G ( u ) ( 3 / 2 ) k ² + ( 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 ) d e g T ( u ) k ² + 13 k 3. Let G be a 3-connected simple planar graph of circumference...

Platonic hypermaps.

Breda d'Azevedo, Antonio J., Jones, Gareth A. (2001)

Beiträge zur Algebra und Geometrie

Rigidity and flexibility of virtual polytopes

G. Panina (2003)

Open Mathematics

All 3-dimensional convex polytopes are known to be rigid. Still their Minkowski differences (virtual polytopes) can be flexible with any finite freedom degree. We derive some sufficient rigidity conditions for virtual polytopes and present some examples of flexible ones. For example, Bricard's first and second flexible octahedra can be supplied by the structure of a virtual polytope.

Self-Assembly of Icosahedral Viral Capsids: the Combinatorial Analysis Approach

R. Kerner (2011)

Mathematical Modelling of Natural Phenomena

An analysis of all possible icosahedral viral capsids is proposed. It takes into account the diversity of coat proteins and their positioning in elementary pentagonal and hexagonal configurations, leading to definite capsid size. We show that the self-organization of observed capsids during their production implies a definite composition and configuration of elementary building blocks. The exact number of different protein dimers is related to the...

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