Word.ws English Dictionary

direct sums

direct sums is the plural of direct sum.

Meaning of direct sum

Noun

direct sum (plural direct sums)

  1. coproduct in some categories, like abelian groups, topological spaces or modules
  2. 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. A block diagonal matrix interpreted as having its non-zero blocks (which are square matrices) as summands.

Questions about direct sums

What is direct sums the plural of?
Direct sums is the plural of direct sum.

Words near direct sums in the dictionary

  1. direct selling
  2. direct sequel
  3. direct sequels
  4. direct speech
  5. direct sum
  6. direct sums
  7. direct system
  8. direct systems
  9. direct tax
  10. direct taxes
  11. direct verb

Source and license

Adapted from Wiktionary: direct sums (page history and authors); direct sum (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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Cite this entry: “direct sums.” Word.ws, https://word.ws/direct_sums. Based on Wiktionary, CC BY-SA 4.0.