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direct sum

direct sum

8.7
A way of joining two sets or spaces so each new item has one part from each
  • noun
  • Specialized
translation icon : suma directa
  • The direct sum of two linear spaces may also be "geometrically" described as the Cartesian product of the two individual linear spaces.

Examples

  • On the other hand, the dimension of the direct sum is d1 + d2.

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  • In linear algebra, the direct sum of two disjoint vector spaces creates a new space formed by adding the corresponding vectors from each space.

  • And here the direct sum refers to the fact that every.

  • And yes, if one talks about one marble, e.g., in the double-slit experiment, it has more possibilities where it can correspond to extending the spaces as a direct sum.

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  • To find the dimension of the entire space, calculate the dimensions of each space and then take their direct sum.

  • The concept of direct sum allows us to combine multiple smaller spaces into a larger one while maintaining their independence.

Synonyms

coproduct
vsdirect sum
  • Specialized
9.9

A way in math to join objects into one while keeping their items separate, like putting two sets together

is a concrete construction making elements from one element taken from each set

Surface Forms

direct sum singular
direct sums plural

Morphology

direct + sum

Although the constituents 'direct' and 'sum' are individually transparent, the precise mathematical meaning — combining disjoint spaces so each element is a tuple/sum of components from each space — is technical and not predictable for an average B1 learner who only knows the common senses of the words. The expression is therefore partially compositional (the words give a general sense of a special kind of sum and many languages calque this term) but its technical constraints and formal interpretation make it not fully transparent.

Etymology

The term direct sum gives a simple picture: take one item from each of two separate boxes and join them side by side; the joining is the sum and it is done in a direct way. So a direct sum in math means 'to add' two separate sets by pairing one item from each so every new item comes from both parts, not from mixing them.