In mathematics, a Listing number of a

topological space In mathematics, a topological space is, roughly speaking, a Geometry, geometrical space in which Closeness (mathematics), closeness is defined but cannot necessarily be measured by a numeric Distance (mathematics), distance. More specifically, a to ...

is one of several topological invariants introduced by the 19th-century mathematician

Johann Benedict Listing Johann Benedict Listing (25 July 1808 – 24 December 1882) was a German mathematician. Early life and education J. B. Listing was born in Frankfurt and died in Göttingen. He finished his studies at the University of Göttingen in 1834, and ...

and later given this name by

Charles Sanders Peirce Charles Sanders Peirce ( ; September 10, 1839 – April 19, 1914) was an American scientist, mathematician, logician, and philosopher who is sometimes known as "the father of pragmatism". According to philosopher Paul Weiss (philosopher), Paul ...

. Unlike the later invariants given by

Bernhard Riemann Georg Friedrich Bernhard Riemann (; ; 17September 182620July 1866) was a German mathematician who made profound contributions to analysis, number theory, and differential geometry. In the field of real analysis, he is mostly known for the f ...

, the Listing numbers do not form a complete set of invariants: two different two-dimensional

manifold In mathematics, a manifold is a topological space that locally resembles Euclidean space near each point. More precisely, an n-dimensional manifold, or ''n-manifold'' for short, is a topological space with the property that each point has a N ...

s may have the same Listing numbers as each other. There are four Listing numbers associated with a space. The smallest Listing number counts the number of connected components of a space, and is thus equivalent to the zeroth Betti number.Peirce, p. 99.

References

Topology Charles Sanders Peirce {{topology-stub