Proving Existence of Vector Field X for 1-Form w on Smooth Manifold M

In summary, if you have a vector field X on a manifold M and you want to find a point p such that w(p)=f, then there is a vector field X+Y on M such that w(X+Y)=f.
  • #1
daishin
27
0
Let w be a 1-form on smooth manifold M. Then is there a vector field X such that locally w(X)=f where f:M-->R continuous?
How can I prove it?
Thanks.
 
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  • #2
i'm a bit confused, your 1-form acting on the vector field should yield a real number (not f)..
 
  • #3
Sorry what I meant was:
Let w be a 1-form on smooth manifold M. Let f be a continuous function from M to R.
Then is there a vector field X on M such that w(X)=f in some neighborhood of p in M?
 
Last edited:
  • #4
Yes. Take a local chart around p and write the problem. You will see that there are in general infinitely many X satisfying this.
 
  • #5
timur said:
Yes. Take a local chart around p and write the problem. You will see that there are in general infinitely many X satisfying this.

Or none. Let w=0(the 0 1-form). Let f be a non-zero function.
 
  • #6
quetzalcoatl9 said:
i'm a bit confused, your 1-form acting on the vector field should yield a real number (not f)..

a differential 1-form on a manifold acting on a vector field on a manifold yields a function.
 
  • #7
daishin said:
Sorry what I meant was:
Let w be a 1-form on smooth manifold M. Let f be a continuous function from M to R.
Then is there a vector field X on M such that w(X)=f in some neighborhood of p in M?

The operations are linear on each fiber. So, if you solve w(Y)=0 and find one X such that w(X)=f, then X+Y is such that w(X+Y)=f.

The question is not optimally formulated, and it is a little unclear why you are asking this question. Do you have an application in mind? Are you reading a proof in a book or trying to do a problem?
 

1. What is a vector field?

A vector field is a mathematical concept that describes a mapping of vectors onto a space. In other words, it assigns a vector to each point in a given space. This is commonly used in physics and engineering to represent physical quantities such as velocity, force, and electric or magnetic fields.

2. What is a 1-form?

A 1-form is a mathematical object that describes a linear mapping of vectors onto real numbers. It takes in a vector and outputs a real number. In other words, it assigns a number to each vector in a given space. 1-forms are often used in differential geometry to study the behavior of vector fields on smooth manifolds.

3. What is a smooth manifold?

A smooth manifold is a mathematical space that can be locally approximated by Euclidean space. It is a generalization of the concept of a smooth curve or surface in higher dimensions. Examples of smooth manifolds include spheres, tori, and projective spaces. They are used in many areas of mathematics, such as differential geometry, topology, and physics.

4. How do you prove the existence of a vector field on a smooth manifold?

To prove the existence of a vector field on a smooth manifold, you must show that there is a smooth mapping from the manifold to the tangent bundle (the collection of all tangent spaces at each point on the manifold). This mapping assigns a tangent vector at each point on the manifold, thus defining a vector field. This proof often involves using local coordinate systems and showing that the vector field is well-defined and smooth in these coordinates.

5. What is the importance of proving the existence of a vector field on a smooth manifold?

Proving the existence of a vector field on a smooth manifold is important because it allows us to study the behavior of vector fields on these spaces. Vector fields are essential tools in many areas of mathematics and physics, and understanding their existence and properties on smooth manifolds allows us to make important conclusions and predictions about these spaces. Additionally, the proof of existence often involves using sophisticated mathematical techniques, which can lead to new insights and developments in the field.

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