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Null vector (vector space)
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Null_vector_(vector_space)" .
In linear algebra , the null vector or zero vector is the vector (0, 0, …, 0) in Euclidean space , all of whose components are zero. It is usually written or 0 or simply 0.
A different kind of vector, also called null vector or zero vector, arises in various generalizations of Euclidean space, as explained below.
Linear algebra
For a general vector space , the zero vector (or null vector) is the uniquely determined vector that is the identity element for vector addition .
The zero vector is unique; if a and b are zero vectors, then a = a + b = b .
The zero vector is a special case of the zero tensor . It is the result of scalar multiplication by the scalar 0.
The preimage of the zero vector under a linear transformation f is called kernel or null space .
A zero space is a linear space whose only element is a zero vector.
The zero vector is, by itself, linearly dependent , and so any set of vectors which includes it is also linearly dependent.
In a normed vector space there is only one vector of norm equal to 0. This is just the zero vector.
Seminormed vector spaces
In a seminormed vector space there might be more than one vector of norm equal to 0. These vectors are often called null vectors.
Examples
The light-like vectors of Minkowski space.
In the Verma module of a Lie algebra there are null vectors.