abstract vertex
51Knot theory — A three dimensional depiction of a thickened trefoil knot, the simplest non trivial knot …
52Van Kampen diagram — In the mathematical area of geometric group theory, a van Kampen diagram is a planar diagram used to represent the fact that a particular word among the generators of a group given by a group presentation represents the identity element in that… …
53Matroid — In combinatorics, a branch of mathematics, a matroid (  /ˈmeɪ …
54Color charge — In particle physics, color charge is a property of quarks and gluons that is related to the particles strong interactions in the theory of quantum chromodynamics (QCD). Color charge has analogies with the notion of electric charge of particles,… …
55Convex regular 4-polytope — The tesseract is one of 6 convex regular 4 polytopes In mathematics, a convex regular 4 polytope is a 4 dimensional polytope that is both regular and convex. These are the four dimensional analogs of the Platonic solids (in three dimensions) and… …
56Schläfli-Hess polychoron — In four dimensional geometry, Schläfli Hess polychora are the complete set of 10 regular self intersecting star polychora (Four dimensional polytopes). They are named in honor of their discoverers: Ludwig Schläfli and Edmund Hess. They are all… …
57Schläfli–Hess polychoron — The great grand 120 cell, one of ten Schläfli–Hess polychora by orthographic projection. In four dimensional geometry, Schläfli–Hess polychora are the complete set of 10 regular self intersecting star polychora (four dimensional polytopes). They… …
58Isomorphism — In abstract algebra, an isomorphism (Greek: ἴσος isos equal , and μορφή morphe shape ) is a bijective map f such that both f and its inverse f −1 are homomorphisms, i.e., structure preserving mappings.In the more general setting of category… …
59Epimorphism — In category theory an epimorphism (also called an epic morphism or an epi) is a morphism f : X rarr; Y which is right cancellative in the following sense: : g 1 o f = g 2 o f implies g 1 = g 2 for all morphisms g 1, g 2 : Y rarr; Z .Epimorphisms… …
60Scale-free network — A scale free network is a network whose degree distribution follows a power law, at least asymptotically. That is, the fraction P ( k ) of nodes in the network having k connections to other nodes goes for large values of k as P ( k ) k − γ where… …
