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2 votes
1 answer
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Definition of a Hodge structure

What is a pure Hodge structure of integer weight $n$? Wikipedia defines a pure Hodge structure of integer weight $n$ to be an abelian group $H_\mathbb{Z}$ equipped with a direct sum decomposition (as ...
tcamps's user avatar
  • 6,169
1 vote
0 answers
162 views

Could a differential form be both exact and co-exact?

If my understanding is correct, on a closed manifold, the exact forms and co-exact forms are disjoint, but I'm not sure about the differential forms on manifolds with boundary. Could there be a ...
chaohuang's user avatar
  • 6,459
4 votes
0 answers
192 views

Why is the Hodge Decomposition profound?

The Hodge Decomposition is the following result: Let $X$ be a smooth projective variety over $\mathbf{C}$. For every integer $k \geq 0$, we have a direct sum decomposition $$H^k(X, \mathbf{C}) \cong \...
Adithya Chakravarthy's user avatar
5 votes
2 answers
1k views

What is an example of harmonic form on a compact manifold?

I'm doing some self-study on Hodge theory and elliptic operators right now. I'm trying to come up with an example of a harmonic $p$-form $\omega$ on a compact manifold, i.e. a form such that $d\omega =...
lvxvl's user avatar
  • 167
2 votes
0 answers
45 views

Laplacian on 1-forms on $(\mathbb R^m,\delta)$

I'm trying to show that if $\omega$ is a 1-form on $(\mathbb R^m,\delta)$, the action of the Laplacian is given by $$\Delta\omega=-\sum_{\mu=1}^m\frac{\partial^2\omega_\nu}{\partial x^\mu\partial x^\...
Sanjay Prabhakar's user avatar
4 votes
1 answer
294 views

Let $M$ is compact Riemann surface, if $\omega$ is a 2-form and $\int_{M} \omega =0$ then there exists a smooth function $f$ such that $\omega=d*df$

I want to show that: $(*)$If $\omega \in \Omega^{2}(M)$, which $M$ is compact Riemann surface and $\Omega^{2}(M)$ means 2-form, and $\int_{M} \omega =0$, then there exists a smooth function $f$(i.e....
user avatar
9 votes
1 answer
528 views

What is the meaning and importance of the Hodge codiferential?

In differential geometry given a smooth manifold $M$ we can define the exterior derivative $d$ acting on $k$ forms giving back $k+1$ forms. It is a map $d : \Omega^k(M)\to \Omega^{k+1}(M)$ which is in ...
Gold's user avatar
  • 27.2k
7 votes
1 answer
315 views

Calabi-Yau $3$-fold given as elliptically fibered manifold over $\mathbb{C}P^1 \times \mathbb{C}P^1$

Consider a Calabi-Yau three-fold given as an elliptically fibered manifold over $\mathbb{C}P^1 \times \mathbb{C}P^1$$$y^2 = x^3 + f(z_1, z_2)x + g(z_1, z_2),$$where $z_1$, $z_2$ represent the two $\...
user avatar
9 votes
0 answers
568 views

Could you explain the failure of the Hodge decomposition to exist for non-compact manifolds?

I'm a physicist and the mathematics around the Hodge Decomposition is way formal than I can currently follow (I'm trying to better myself but it'll take a while). Specifically what I'm (pragmatically)...
user223345's user avatar
3 votes
0 answers
195 views

Hodge decomposition on a manifold with a nontrivial connection

I am familiar with the notion of Hodge decomposition of an arbitrary differential form into an exact form, a co-exact form, and a harmonic form. Given a curved space with a connection, could you ...
Alex Eftimiades's user avatar