Algebraic topology Graph theory 2 Biology and other natural sciences -- Chemistry -- Molecular structure (graph-theoretic methods, methods of differential topology, etc.) 1 Biology and other natural sciences -- Genetics and population dynamics -- Protein sequences, DNA sequences 1 Biology and other natural sciences -- Physiological, cellular and medical topics -- Biochemistry, molecular biology 1 Electric networks 1 Feynman integrals 1 Geometry 1 Information and communication, circuits -- Circuits, networks -- Applications of graph theory 1 Knot theory 1 Manifolds and cell complexes -- Low-dimensional topology -- Knots and links in $S^3$ 1 Manifolds and cell complexes -- Low-dimensional topology -- Relations with graph theory 1 Molecular biology 1 Picard-Lefschetz theory 1 Topology 1