Hodge duality and some properties

In summary, Hodge duality is a mathematical operation that has different forms depending on the signature of the manifold. In Euclidean signature, it is represented by the formula $$⋆(dx^i_1 \wedge ... \wedge dx^i_p)= \frac{1}{(n-p)!} \epsilon^{i_1..i_p}_{i_{p+1}..i_n} dx^{i_{p+1} } \wedge dx^{i_n}$$ where p represents the p in p-form and n is the dimensional number. This formula can also be applied to complex functions on a complex manifold. However, on a complex manifold, one is usually more interested in taking the H
  • #1
PhyAmateur
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So we know that [Hodge duality](http://en.wikipedia.org/wiki/Hodge_dual) works this way

$$⋆(dx^i_1 \wedge ... \wedge dx^i_p)= \frac{1}{(n-p)!} \epsilon^{i_1..i_p}_{i_{p+1}..i_n} dx^{i_{p+1} } \wedge dx^{i_n}$$

where p represents the p in p-form and n is the dimensional number.

My question is: How does hodge duality work on the imaginary number "i" on one hand and on partial derivative like $$\partial_x\alpha$$ let us say on the other where $$\alpha$$ is a complex function.
 
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  • #2
Why is this in GR rather than in the differential geometry forum? The formula you've written is not correct on Lorentzian-signature manifolds.

However, in Euclidean signature, this is correct:

PhyAmateur said:
$$⋆(dx^i_1 \wedge ... \wedge dx^i_p)= \frac{1}{(n-p)!} \epsilon^{i_1..i_p}_{i_{p+1}..i_n} dx^{i_{p+1} } \wedge dx^{i_n}$$

where p represents the p in p-form and n is the dimensional number.

And it means exactly the same thing if you make all of your variables complex.

The catch is that on a complex manifold, one is usually more interested in taking the Hodge dual and the complex conjugate simultaneously.
 
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  • #3
Thanks. I would appreciate if we could move this to the other section or if you could guide me so that I can move it. On the other hand, I want to ask you to please elaborate on your answer, because this answer doesn't make it clear to me if we have for example $$\star{(i\partial _x \alpha)}$$ it is also the partial differential that is worrying me. @Ben Niehoff
 
  • #4
What is ##\alpha##?
 
  • #5
Any complex function, I mentioned that in the given. @Ben Niehoff
 
  • #6
So, a function is a 0-form. What's the Hodge dual of a 0-form?
 
  • #7
$$-1/3 (i \partial _x \alpha) dx \wedge dy \wedge dz?$$ @Ben Niehoff
 

Related to Hodge duality and some properties

1. What is Hodge duality?

Hodge duality is a mathematical concept in differential geometry and algebraic topology that relates the cohomology and homology groups of a smooth manifold. It is based on the idea that certain geometric objects, such as vectors, forms, and submanifolds, can be paired together in a way that allows for the computation of topological invariants.

2. How is Hodge duality related to de Rham cohomology?

Hodge duality is closely related to de Rham cohomology, which is a tool for studying the topological properties of smooth manifolds using differential forms. In particular, Hodge duality is used to define the inner product on the space of differential forms, which is a key ingredient in the de Rham cohomology theory.

3. What are some important properties of Hodge duality?

Hodge duality has several important properties, including linearity, symmetry, and compatibility with the exterior derivative. It also allows for the computation of topological invariants, such as the Euler characteristic and Betti numbers, and is closely related to the Poincaré duality theorem.

4. How is Hodge duality used in physics?

In physics, Hodge duality is used to study the topological properties of spacetime in theories such as general relativity and string theory. It also plays a crucial role in gauge theories, where it is used to define the dual of a gauge field and to construct topological field theories.

5. Are there any open questions or ongoing research related to Hodge duality?

Yes, there are many open questions and ongoing research related to Hodge duality. Some of these include extending Hodge duality to non-compact manifolds, understanding its role in the Langlands program, and exploring its connections to other areas of mathematics, such as mirror symmetry and mathematical physics.

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