Left- and Right- Kernels of Bilinear maps B:VxV->K for V.Spaces

  • Thread starter Bacle
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In summary, the conversation discusses the concept of left and right kernels of a bilinear map in a vector space over k. The question is asked about the relationship between these two kernels, and it is suggested that the answer may involve the tensor product V(x)V. The dimension of VxV and V(x)V are mentioned, and the idea of pulling back the kernel of a bilinear map is brought up. The speaker asks for advice on how to approach this problem.
  • #1
Bacle
662
1
Hi, all:

Let V be a vector space over k, and let B be a bilinear map into k,
i.e.:

B:VxV-->k

Define the left-kernel of B to be the set of A in V with

B (A,v)=0 for all v in V,

and define the right-kernel similarly.

Question: what relation is there between the two kernels , as subspaces
of V?

I am pretty sure the answer has to see with the tensor product V(x)V;

but I am not sure of how to express the dual of VxV in terms of the tensor

product. Any ideas?

Thanks.
 
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  • #2
Unfortunately, the quote function is not working well, so I will
improvise. Let n be the dimension of V, so that Dim(VxV)=2n
and Dim(V(x)V)=n^2

I know that the element B' in V(x)V , corresponding to the
bilinear map B : VxV-->k , is a linear functional in V(x)V, and so
the kernel of B' has codimension 1, or, equivalently, dimension
n^2-1 in B(x)B.

But I don't know any properties of kernels of bilinear maps, and
I don't know if there is a way of somehow pulling back the kernel
of B' back into the kernel of B in VxV.

Anyway, I'll keep trying. Any Advice Appreciated.
 

FAQ: Left- and Right- Kernels of Bilinear maps B:VxV->K for V.Spaces

What is a bilinear map?

A bilinear map is a function that takes two vector inputs and returns a scalar value. It is a type of multilinear map that is linear in each of its inputs separately.

How are bilinear maps related to vector spaces?

Bilinear maps are defined on vector spaces, specifically on the Cartesian product of two vector spaces. They map elements from each input space to a scalar value in the output space.

What are left- and right- kernels of bilinear maps?

The left- and right- kernels of a bilinear map refer to the sets of elements in the input spaces that map to the zero element in the output space. The left kernel consists of all elements in the first input space that map to zero, while the right kernel consists of all elements in the second input space that map to zero.

How are left- and right- kernels related to each other?

The left and right kernels are related by the transpose of the bilinear map. This means that the left kernel of a bilinear map B is the same as the right kernel of the transpose of B, and vice versa.

What is the importance of studying left- and right- kernels of bilinear maps?

Studying the left- and right- kernels of bilinear maps can provide insight into the structure and properties of the bilinear map itself. It can also help in solving systems of linear equations and understanding the relationship between different vector spaces.

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