Cartesian product

noun — 4 senses

Cartesian product

noun

Etymology From Cartesian + product, after French philosopher, mathematician, and scientist René Descartes (1596–1650), whose formulation of analytic geometry gave rise to the concept.

1

Mathematics, Sciences, Set theory The set of all possible ordered pairs of elements, the being first from X, the second from Y, written X×Y. Formally, the set (x,y);|;x∈X;and;y∈Y.

Of two sets X and Y

2

Computing, Databases, Engineering, Mathematics, Natural sciences, Physical sciences, Sciences All possible combinations of rows between all of the tables listed.

3

Geometry, Mathematics, Sciences An (m+n)-dimensional space, formally composed of all possible ordered pairs of points from X and Y, but thought of as an independent (m+n)-dimensional space (in the sense that if, e.g. X and Y are vector spaces, the elements of X×Y are thought of as (m+n)-tuples instead of ordered pairs) and written X×Y.

Of an m-dimensional space X and an n-dimensional space Y

  • On the Cartesian product of two manifolds a differentiable structure can be constructed in the following way.1987, M. Göckeler, T. Schücker, Differential Geometry, Gauge Theories, and Gravity, published 1989, page 98:
4

Mathematics, Sciences Any of several generalizations of the set-theoretic sense, especially one which shares the geometrical intuition outlined above, i.e. one such that the product can be thought of as an object in its own right and not just as a set of pairs.

  • The hypercube is the simplest example of a Cartesian product of graphs; indeed, the m-hypercube is nothing but (K₂)ᵐ.1997, Michel Marie Deza, Monique Laurent, Geometry of Cuts and Metrics, published 2009, page 297:
  • A moment's thought convinces us of the following: The Cartesian product of two Riemannian Einstein metrics with the same constant Ricci scalar ρ is again Ricci-constant, and has Ric2004, David Bao, Colleen Robles, “Ricci and Flag Curvatures in Finsler Geometry”, in David Dai-Wai Bao, Robert L. Bryant, Shiing-Shen Chern, Zhomgmin Shen, editors, A Sampler of Riemann-Finsler Geometry, page 246:
Synonyms
direct product

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.