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Mar 25, 2019 at 12:45 history edited Ali Taghavi CC BY-SA 4.0
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Mar 24, 2019 at 20:55 history undeleted Ali Taghavi
Carlo Beenakker
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Mar 23, 2019 at 0:01 history deleted CommunityBot Scheduled: RemoveDeadQuestions
Jul 2, 2017 at 10:35 comment added Ali Taghavi @SebastianGoette thanks for this reference. I read your comment just now.
Jun 25, 2017 at 7:24 comment added Sebastian Goette In some cases, there are exotic indices, e.g. the parity of dim ker could be an invariant. Please check the book by Lawson-Michelsohn for details.
Jun 24, 2017 at 9:57 comment added Ali Taghavi @SebastianGoette I think of fredholm index as you mentioned. So according to your comment and comment of Thomas Richard I conclude that the index is zero. But what other type of index on can associate to differential operators?
Jun 24, 2017 at 9:04 comment added Sebastian Goette What kind of index are you thinking of? The operator described by @ThomasRichard has selfadjoint principal symbol, so the classical definition (dim ker - dim coker) does not give anything interesting.
Jun 24, 2017 at 8:29 comment added Ali Taghavi @ThomasRichard What is that deformation?. Moreover do you deform an arbitrary metric a to a metric with constant $g_{ij}$?
Jun 23, 2017 at 11:38 comment added Thomas Richard Also, when $g$ is a flat metric and $X=\partial_x$, $D$ is just the usual laplacian. One can always deform (conformally for instance) a Riemannian metric on $\mathbb{T}^2$ to a flat one. I wonder if the index moves during the deformation. That might help.
Jun 23, 2017 at 11:29 comment added Ali Taghavi @ThomasRichard Thank you for your comment.
Jun 22, 2017 at 8:36 comment added Thomas Richard Computations show that $Df=|X|_g^2\Delta_g f+\dots$ where the terms in the dots depend on $f$ and $df$. So ellipticity is ok since your vector field is non vanishing, as for the index I have no idea.
Jun 22, 2017 at 8:18 comment added Ali Taghavi @ThomasRichard Yes it is a tangent vector.
Jun 22, 2017 at 8:16 comment added Thomas Richard so $h$ is a vector field right ?
Jun 22, 2017 at 7:52 history asked Ali Taghavi CC BY-SA 3.0