Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 46290

Elliptic, parabolic and hyperbolic operators. Laplace, Laplace-Beltrami, Schrödinger, Dirac. Exterior derivative and Lie derivative operators.

8 votes
0 answers
474 views

Measuring the non-commutativity of the codifferential and pullbacks

$\newcommand{\id}{\operatorname{Id}}$ $\newcommand{\TM}{\operatorname{TM}}$ $\newcommand{\Hom}{\operatorname{Hom}}$ $\newcommand{\M}{\mathcal{M}}$ $\newcommand{\R}{\mathbb{R}}$ $\newcommand{\N}{\mathc …
Asaf Shachar's user avatar
  • 6,741
7 votes
3 answers
843 views

"Universal" differential identities

(This is a cross-post from MSE). Let $f:\mathbb{R}^d \to \mathbb{R}$ be smooth. The mixed derivatives commute: $f_{xy}=f_{yx}$. This identity is "universal" in the sense that it holds for any smooth …
Asaf Shachar's user avatar
  • 6,741
5 votes
1 answer
221 views

Are all the mappings which satisfy this equation scaled isometries?

Let $M,N$ be smooth oriented $d$-dimensional Riemannian manifolds, $\, f:M \to N$ a smooth map. Let $\Omega^1(M,f^*TN)=\Gamma(T^*M \otimes f^*TN)$ be the space of $f^*TN$-valued one-forms. Let $d$ …
Asaf Shachar's user avatar
  • 6,741
4 votes
2 answers
508 views

Is the kernel of the coderivative infinite-dimensional?

$\newcommand{\al}{\alpha}$ $\newcommand{\euc}{\mathcal{e}}$ $\newcommand{\Cof}{\operatorname{Cof}}$ $\newcommand{\Det}{\operatorname{Det}}$ Let $M,N$ be smooth $n$-dimensional Riemannian manifolds (p …
Asaf Shachar's user avatar
  • 6,741
3 votes
1 answer
175 views

Does the space of harmonic forms change continuously with the metric?

Let $(M,g_0)$ be a closed $n$-dimensional Riemannian manifold. Let $1<k<n$ be fixed, and let $\Delta_{g_0}:\Omega^k(M) \to \Omega^k(M)$ be the $g_0$-Laplacian. Let $H^k_{g_0}=\text{ker} \Delta_{g_0}$. …
Asaf Shachar's user avatar
  • 6,741
2 votes
2 answers
2k views

Commuting of exterior derivative and contraction (vector-valued forms)

$\newcommand{\sig}{\sigma}$ $\newcommand{\tr}{\operatorname{tr}_{\eta}}$ $\newcommand{\al}{\alpha}$ $\newcommand{\be}{\beta}$ $\newcommand{\til}{\tilde}$ Let $E$ be a smooth vector bundle over a mani …
Asaf Shachar's user avatar
  • 6,741
1 vote
Accepted

Does the space of harmonic forms change continuously with the metric?

I think the answer is positive. Let $D$ be the subspace of smooth closed $k$-forms on $M$. Equip $D$ with the supremum- $C^1$ norm: $$ \| \omega \|_{C^1,sup}:=\max\{ \|\omega\|_{sup}, \|T\omega\|_{su …
Asaf Shachar's user avatar
  • 6,741