direct sum

Hello, you have come here looking for the meaning of the word direct sum. In DICTIOUS you will not only get to know all the dictionary meanings for the word direct sum, but we will also tell you about its etymology, its characteristics and you will know how to say direct sum in singular and plural. Everything you need to know about the word direct sum you have here. The definition of the word direct sum will help you to be more precise and correct when speaking or writing your texts. Knowing the definition ofdirect sum, as well as those of other words, enriches your vocabulary and provides you with more and better linguistic resources.

English

English Wikipedia has an article on:
Wikipedia

Noun

direct sum (plural direct sums)

  1. (mathematics) coproduct in some categories, like abelian groups, topological spaces or modules
  2. (linear algebra) A linear sum in which the intersection of the summands has dimension zero. Equivalently, a linear sum of two subspaces, any vector of which can be expressed uniquely as a sum of two vectors: one vector belonging to the first subspace, and the other vector belonging to the second subspace.
  3. (linear algebra) A block diagonal matrix interpreted as having its non-zero blocks (which are square matrices) as summands.[1][2][3]

Translations

References

  1. ^ Garrett Birkhoff with Saunders Mac Lane (©1953) A Survey Of Modern Algebra, Revised edition, U.S.A.: The Macmillan Company, published 1960 (9th printing), §X.8, page 326
  2. ^ David Steven Dummit with Richard M. Foote (©2004) Abstract Algebra, third edition, U.S.A.: John Wiley & Sons, Inc., →ISBN, →OCLC, §12.2, page 475
  3. ^ Kenneth Myron Hoffman with Ray Alden Kunze (©1971) Linear Algebra, second edition, Upper Saddle River, New Jersey: Prentice-Hall, Inc., →ISBN, →OCLC, §6.7, page 214

Further reading