asymptotic set
41Dehn function — In the mathematical subject of geometric group theory, a Dehn function, named after Max Dehn, is an optimal function associated to a finite group presentation which bounds the area of a relation in that group (that is a freely reduced word in the …
42Gauge theory — For a generally accessible and less technical introduction to the topic, see Introduction to gauge theory. In physics, a gauge theory is a type of field theory in which the Lagrangian is invariant under a continuous group of local transformations …
43Perturbation theory (quantum mechanics) — In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a …
44Polynomial and rational function modeling — In statistical modeling (especially process modeling), polynomial functions and rational functions are sometimes used as an empirical technique for curve fitting.Polynomial function modelsA polynomial function is one that has the form:y = a… …
45Bass–Serre theory — is a part of the mathematical subject of group theory that deals with analyzing the algebraic structure of groups acting by automorphisms on simplicial trees. The theory relates group actions on trees with decomposing groups as iterated… …
46subatomic particle — or elementary particle Any of various self contained units of matter or energy. Discovery of the electron in 1897 and of the atomic nucleus in 1911 established that the atom is actually a composite of a cloud of electrons surrounding a tiny but… …
47Combinatorics — is a branch of mathematics concerning the study of finite or countable discrete structures. Aspects of combinatorics include counting the structures of a given kind and size (enumerative combinatorics), deciding when certain criteria can be met,… …
48Fibonacci number — A tiling with squares whose sides are successive Fibonacci numbers in length …
49Systolic geometry — In mathematics, systolic geometry is the study of systolic invariants of manifolds and polyhedra, as initially conceived by Charles Loewner, and developed by Mikhail Gromov and others, in its arithmetic, ergodic, and topological manifestations.… …
50Noisy-channel coding theorem — In information theory, the noisy channel coding theorem (sometimes Shannon s theorem), establishes that for any given degree of noise contamination of a communication channel, it is possible to communicate discrete data (digital information)… …
