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Quotients of the Hilbert space

Let $G$ be a compact Lie group with a biinvariant metric. Note that $G\times G$ acts isometrically on $G$ from left and right. Consider the quotient $D=G/H$ by a closed subgroup $H\le G\times G$; if $...
Anton Petrunin's user avatar
2 votes
0 answers
120 views

Closure of Laplacian

Let $(M,g)$ be a complete Riemannian manifold and $\Delta$ the (positive) Laplace-Beltrami operator. Now, consider this operator as an operator $$\Delta:\mathcal{D}(\Delta)\to L^{2}(M)$$ There are two ...
B.Hueber's user avatar
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8 votes
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Is there any physics theory which is similar to these analogies?

Since I am doing this little "research" project on my spare time and in my physical neighborhood there are not many people to discuss these ideas, I wanted to share with you a small point of ...
mathoverflowUser's user avatar
2 votes
1 answer
267 views

volume of parallelotope in $L^2(\mathbb R).$ [closed]

Let $L^2(\mathbb R)$ is complex Hilbert space with standard inner product. Does it make sense to talk of volume of parallelotope formed by following vectors in $L^2(\mathbb R):$ say, e.g., $$\{ f(...
Math Learner 's user avatar
2 votes
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210 views

A Riemannian metric on the plane such that the intersection of every two discs is a disc, again

Is there a Riemannian metric on $\mathbb{R}^2$ (or a $2$ dimensional manifold) such that the intersection of every two open discs is an open disc, again? As linear version of this question we ask: ...
Ali Taghavi's user avatar
1 vote
1 answer
94 views

Embedding Riemmanian Manifold Linearly

Given a Hilbert Manifold $M$ does there exist a smooth map into some very large Hilbert space taking geodesics to straight lines?
ABIM's user avatar
  • 5,405
2 votes
0 answers
103 views

Equivariant exponential map on Hilbert manifolds

Let $M$ be a Hilbert Riemannian manifold and $G$ a finite-dimensional Lie group acting on $M$. It is well-known that when $M$, too, is finite-dimensional $$\exp_p: U \subset T_pM \rightarrow \exp_p(U) ...
The-Mick's user avatar