eigenvalues of Laplace-Beltrami on half sphere

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Let $ Delta_theta$ denote the Laplace-Beltrami operator on $S^N-1$. The eigenvalues of this are well known. I assume the same is the case of this operator on the upperhalf sphere; say $ S^N-1_+$ with zero Dirichlet boundary conditions. Does anyhow know where I can find a reference for these?

thanks
Craig










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    Let $ Delta_theta$ denote the Laplace-Beltrami operator on $S^N-1$. The eigenvalues of this are well known. I assume the same is the case of this operator on the upperhalf sphere; say $ S^N-1_+$ with zero Dirichlet boundary conditions. Does anyhow know where I can find a reference for these?

    thanks
    Craig










    share|cite|improve this question























      up vote
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      down vote

      favorite









      up vote
      3
      down vote

      favorite











      Let $ Delta_theta$ denote the Laplace-Beltrami operator on $S^N-1$. The eigenvalues of this are well known. I assume the same is the case of this operator on the upperhalf sphere; say $ S^N-1_+$ with zero Dirichlet boundary conditions. Does anyhow know where I can find a reference for these?

      thanks
      Craig










      share|cite|improve this question













      Let $ Delta_theta$ denote the Laplace-Beltrami operator on $S^N-1$. The eigenvalues of this are well known. I assume the same is the case of this operator on the upperhalf sphere; say $ S^N-1_+$ with zero Dirichlet boundary conditions. Does anyhow know where I can find a reference for these?

      thanks
      Craig







      reference-request ap.analysis-of-pdes sp.spectral-theory harmonic-functions






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      asked 1 hour ago









      Math604

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          Using symmetry, you can extend any Dirichlet eigenfunction on the upper half-sphere to the entire sphere $mathbbS^N-1$. Therefore, the spectrum of the upper hemisphere is a subset of the spectrum of the full sphere. You are searching for the spherical harmonics which vanish on the great circle $x_N equiv 0$. The reference that I've seen that explicitly constructs the $N-1$ dimensional spherical harmonics is the following paper of Frye and Efthimiou: https://arxiv.org/pdf/1205.3548.pdf



          In theory, this reduces your question to a combinatorial problem involving Legendre polynomials, though I haven't solved out the combinatorics explicitly. For the 2-sphere, it seems like the eigenfunctions (and their eigenvalues) you are looking for are the $Y_l^m$ where $m+l$ is odd. From this, you can see the that spectrum is $l(l+1)$ but with less degeneracy than with the full sphere.






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            Tools for computing eigenvalues on disks in constant-curvature space forms are worked out in Chapter II, section 5 of Chavel's book Eigenvalues in Riemannian Geometry although skimming it I do not see the spectrum itself explicitly written out. Basic idea is separation of variables in polar coordinates.






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              Using symmetry, you can extend any Dirichlet eigenfunction on the upper half-sphere to the entire sphere $mathbbS^N-1$. Therefore, the spectrum of the upper hemisphere is a subset of the spectrum of the full sphere. You are searching for the spherical harmonics which vanish on the great circle $x_N equiv 0$. The reference that I've seen that explicitly constructs the $N-1$ dimensional spherical harmonics is the following paper of Frye and Efthimiou: https://arxiv.org/pdf/1205.3548.pdf



              In theory, this reduces your question to a combinatorial problem involving Legendre polynomials, though I haven't solved out the combinatorics explicitly. For the 2-sphere, it seems like the eigenfunctions (and their eigenvalues) you are looking for are the $Y_l^m$ where $m+l$ is odd. From this, you can see the that spectrum is $l(l+1)$ but with less degeneracy than with the full sphere.






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                up vote
                5
                down vote













                Using symmetry, you can extend any Dirichlet eigenfunction on the upper half-sphere to the entire sphere $mathbbS^N-1$. Therefore, the spectrum of the upper hemisphere is a subset of the spectrum of the full sphere. You are searching for the spherical harmonics which vanish on the great circle $x_N equiv 0$. The reference that I've seen that explicitly constructs the $N-1$ dimensional spherical harmonics is the following paper of Frye and Efthimiou: https://arxiv.org/pdf/1205.3548.pdf



                In theory, this reduces your question to a combinatorial problem involving Legendre polynomials, though I haven't solved out the combinatorics explicitly. For the 2-sphere, it seems like the eigenfunctions (and their eigenvalues) you are looking for are the $Y_l^m$ where $m+l$ is odd. From this, you can see the that spectrum is $l(l+1)$ but with less degeneracy than with the full sphere.






                share|cite|improve this answer






















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                  up vote
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                  Using symmetry, you can extend any Dirichlet eigenfunction on the upper half-sphere to the entire sphere $mathbbS^N-1$. Therefore, the spectrum of the upper hemisphere is a subset of the spectrum of the full sphere. You are searching for the spherical harmonics which vanish on the great circle $x_N equiv 0$. The reference that I've seen that explicitly constructs the $N-1$ dimensional spherical harmonics is the following paper of Frye and Efthimiou: https://arxiv.org/pdf/1205.3548.pdf



                  In theory, this reduces your question to a combinatorial problem involving Legendre polynomials, though I haven't solved out the combinatorics explicitly. For the 2-sphere, it seems like the eigenfunctions (and their eigenvalues) you are looking for are the $Y_l^m$ where $m+l$ is odd. From this, you can see the that spectrum is $l(l+1)$ but with less degeneracy than with the full sphere.






                  share|cite|improve this answer












                  Using symmetry, you can extend any Dirichlet eigenfunction on the upper half-sphere to the entire sphere $mathbbS^N-1$. Therefore, the spectrum of the upper hemisphere is a subset of the spectrum of the full sphere. You are searching for the spherical harmonics which vanish on the great circle $x_N equiv 0$. The reference that I've seen that explicitly constructs the $N-1$ dimensional spherical harmonics is the following paper of Frye and Efthimiou: https://arxiv.org/pdf/1205.3548.pdf



                  In theory, this reduces your question to a combinatorial problem involving Legendre polynomials, though I haven't solved out the combinatorics explicitly. For the 2-sphere, it seems like the eigenfunctions (and their eigenvalues) you are looking for are the $Y_l^m$ where $m+l$ is odd. From this, you can see the that spectrum is $l(l+1)$ but with less degeneracy than with the full sphere.







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                  answered 42 mins ago









                  Gabe K

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                      up vote
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                      Tools for computing eigenvalues on disks in constant-curvature space forms are worked out in Chapter II, section 5 of Chavel's book Eigenvalues in Riemannian Geometry although skimming it I do not see the spectrum itself explicitly written out. Basic idea is separation of variables in polar coordinates.






                      share|cite|improve this answer
























                        up vote
                        1
                        down vote













                        Tools for computing eigenvalues on disks in constant-curvature space forms are worked out in Chapter II, section 5 of Chavel's book Eigenvalues in Riemannian Geometry although skimming it I do not see the spectrum itself explicitly written out. Basic idea is separation of variables in polar coordinates.






                        share|cite|improve this answer






















                          up vote
                          1
                          down vote










                          up vote
                          1
                          down vote









                          Tools for computing eigenvalues on disks in constant-curvature space forms are worked out in Chapter II, section 5 of Chavel's book Eigenvalues in Riemannian Geometry although skimming it I do not see the spectrum itself explicitly written out. Basic idea is separation of variables in polar coordinates.






                          share|cite|improve this answer












                          Tools for computing eigenvalues on disks in constant-curvature space forms are worked out in Chapter II, section 5 of Chavel's book Eigenvalues in Riemannian Geometry although skimming it I do not see the spectrum itself explicitly written out. Basic idea is separation of variables in polar coordinates.







                          share|cite|improve this answer












                          share|cite|improve this answer



                          share|cite|improve this answer










                          answered 46 mins ago









                          Neal

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