- #1
Herbststurm
- 30
- 0
Hi,
I have to find a vector space V with a real sub space U and a bijective linear map.
Here my Ideas and my questions:
If the linear map is bijective, than dim V = dim U
Because U is a real sub space the only way to valid this constraint is if the dimension is infinity. I wrote:
[tex]U \subseteq V ~ f: U \rightarrow V bijective[/tex]
[tex]dim ~ U = dim ~ V = \infty[/tex]
[tex]U = x_{1}e_{1} + x_{2}e_{2} + x_{i}e_{n} = \sum\limits_{i,n=1}^{\infty} x_{i}e_{n} \ x_{i} \in k, ~ e_{n} \in U, ~ i,n \in \mathbb{N}[/tex]
[tex]V = x_{1}e_{1} + x_{2}e_{2} + x_{j}e_{m} = \sum\limits_{j,m=1}^{\infty} x_{j}e_{m} \ x_{j} \in k, ~ e_{m} \in U, ~ j,m \in \mathbb{N}[/tex]
[tex]\sum\limits_{i,n=1}^{\infty} x_{i}e_{n} = \sum\limits_{j,m=1}^{\infty} x_{j}e_{m} ~ \Leftrightarrow ~ f: U \ \rightarrow V ~ isomorphism[/tex]
1.) Are my minds up to now correct?
2.) How to go on? Maybe a complete induction? But I have different indices.
Thank you
all the best
I have to find a vector space V with a real sub space U and a bijective linear map.
Here my Ideas and my questions:
If the linear map is bijective, than dim V = dim U
Because U is a real sub space the only way to valid this constraint is if the dimension is infinity. I wrote:
[tex]U \subseteq V ~ f: U \rightarrow V bijective[/tex]
[tex]dim ~ U = dim ~ V = \infty[/tex]
[tex]U = x_{1}e_{1} + x_{2}e_{2} + x_{i}e_{n} = \sum\limits_{i,n=1}^{\infty} x_{i}e_{n} \ x_{i} \in k, ~ e_{n} \in U, ~ i,n \in \mathbb{N}[/tex]
[tex]V = x_{1}e_{1} + x_{2}e_{2} + x_{j}e_{m} = \sum\limits_{j,m=1}^{\infty} x_{j}e_{m} \ x_{j} \in k, ~ e_{m} \in U, ~ j,m \in \mathbb{N}[/tex]
[tex]\sum\limits_{i,n=1}^{\infty} x_{i}e_{n} = \sum\limits_{j,m=1}^{\infty} x_{j}e_{m} ~ \Leftrightarrow ~ f: U \ \rightarrow V ~ isomorphism[/tex]
1.) Are my minds up to now correct?
2.) How to go on? Maybe a complete induction? But I have different indices.
Thank you
all the best