Dimension of the space of skew-symmetric bilinear functions

In summary, the conversation discusses the dimension of the space of skew-symmetric bilinear functions on a vector space of dimension $n$. The participants determine that the dimension of this space is $n/2$ and consider the case when $n$ is odd. They then discuss the expansion of a skew-symmetric bilinear function using a basis and the number of parameters needed to obtain a concrete number for the function.
  • #1
smile1
19
0
Hello everyone,

I stuck on this problem:
find the dimension of the space of dimension of the space of skew-symmetric bilinear functions on $V$ if $dimV=n$.

I thought in this way, for skew-symmetric bilinear functions, $f(u,v)=-f(v,u)$, then the dimension will be $n/2$

Am I right?

thanks
 
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  • #2
Re: dimension of the space of skew-symmetric bilinear functions

smile said:
I thought in this way, for skew-symmetric bilinear functions, $f(u,v)=-f(v,u)$, then the dimension will be $n/2$
Do you think the space of skew-symmetric functions is a fractal when $s$ is odd? :)
Suppose $(e_1,\dots,e_n)$ is a basis of $V$, $u=\sum_{i=1}^nx_ie_i$ and $v=\sum_{i=1}^ny_ie_i$. Expand $f(u,v)$ using linearity and skew symmetry. If $x_i$ and $y_i$ are fixed, how many parameters do you need to set to get a concrete number for $f(u,v)$?
 

1. What is the dimension of the space of skew-symmetric bilinear functions?

The dimension of the space of skew-symmetric bilinear functions is equal to n(n-1)/2, where n is the number of variables in the function. This is because a skew-symmetric bilinear function has the property that f(x,y) = -f(y,x), which means that the values of the function can be uniquely determined by only considering the upper or lower triangular part of the function. Therefore, the dimension is reduced by half.

2. How is the dimension of the space of skew-symmetric bilinear functions related to the number of variables?

The dimension of the space of skew-symmetric bilinear functions is directly related to the number of variables. As mentioned in the previous answer, the dimension is equal to n(n-1)/2, where n is the number of variables. This means that as the number of variables increases, the dimension of the space also increases.

3. Can you give an example of a skew-symmetric bilinear function?

Yes, an example of a skew-symmetric bilinear function is f(x,y) = 2xy - 3yx. This function satisfies the property of skew-symmetry, as f(x,y) = 2xy - 3yx = -3yx + 2xy = -f(y,x).

4. How can the dimension of the space of skew-symmetric bilinear functions be useful in mathematics?

The dimension of the space of skew-symmetric bilinear functions is useful in many mathematical fields, such as linear algebra, differential geometry, and representation theory. It helps in the study of vector spaces, symmetric and skew-symmetric matrices, and Lie algebras. It also has applications in physics, particularly in mechanics and electromagnetism.

5. How can one determine the basis of the space of skew-symmetric bilinear functions?

To determine the basis of the space of skew-symmetric bilinear functions, one can use the wedge product of two vectors. This product results in a skew-symmetric bilinear function and any skew-symmetric bilinear function can be written as a linear combination of wedge products of vectors. Therefore, the wedge products form a basis for the space of skew-symmetric bilinear functions.

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